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From: John Hubbard <[email protected]>
This combines the common elements of these routines:
page_cache_get_speculative()
page_cache_add_speculative()
This was anticipated by the original author, as shown by the comment in
commit ce0ad7f095258 ("powerpc/mm: Lockless get_user_pages_fast() for
64-bit (v3)"):
"Same as above, but add instead of inc (could just be merged)"
There is no intention to introduce any behavioral change, but there is a
small risk of that, due to slightly differing ways of expressing the
TINY_RCU and related configurations.
This also removes the VM_BUG_ON(in_interrupt()) that was in
page_cache_add_speculative(), but not in page_cache_get_speculative().
This provides slightly less detection of such bugs, but it given that it
was only there on the "add" path anyway, we can likely do without it
just fine.
And it removes the
VM_BUG_ON_PAGE(PageCompound(page) && page != compound_head(page), page);
that page_cache_add_speculative() had.
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: John Hubbard <[email protected]>
Reviewed-by: Andrew Morton <[email protected]>
Cc: Benjamin Herrenschmidt <[email protected]>
Cc: Dave Kleikamp <[email protected]>
Cc: Hugh Dickins <[email protected]>
Cc: Jeff Layton <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Cc: Nicholas Piggin <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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mm/debug-pagealloc.c is no more, so of course header now needs to be
updated. This seems like something checkpatch should be able to catch -
worth looking into?
Link: http://lkml.kernel.org/r/[email protected]
Fixes: 8823b1dbc05f ("mm/page_poison.c: enable PAGE_POISONING as a separate option")
Signed-off-by: Michael S. Tsirkin <[email protected]>
Reviewed-by: Andrew Morton <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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Number of online NUMA nodes can't be negative as well. This doesn't
save space as the variable is used only in 32-bit context, but do it
anyway for consistency.
Link: http://lkml.kernel.org/r/20190201223151.GB15820@avx2
Signed-off-by: Alexey Dobriyan <[email protected]>
Reviewed-by: Andrew Morton <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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Number of NUMA nodes can't be negative.
This saves a few bytes on x86_64:
add/remove: 0/0 grow/shrink: 4/21 up/down: 27/-265 (-238)
Function old new delta
hv_synic_alloc.cold 88 110 +22
prealloc_shrinker 260 262 +2
bootstrap 249 251 +2
sched_init_numa 1566 1567 +1
show_slab_objects 778 777 -1
s_show 1201 1200 -1
kmem_cache_init 346 345 -1
__alloc_workqueue_key 1146 1145 -1
mem_cgroup_css_alloc 1614 1612 -2
__do_sys_swapon 4702 4699 -3
__list_lru_init 655 651 -4
nic_probe 2379 2374 -5
store_user_store 118 111 -7
red_zone_store 106 99 -7
poison_store 106 99 -7
wq_numa_init 348 338 -10
__kmem_cache_empty 75 65 -10
task_numa_free 186 173 -13
merge_across_nodes_store 351 336 -15
irq_create_affinity_masks 1261 1246 -15
do_numa_crng_init 343 321 -22
task_numa_fault 4760 4737 -23
swapfile_init 179 156 -23
hv_synic_alloc 536 492 -44
apply_wqattrs_prepare 746 695 -51
Link: http://lkml.kernel.org/r/20190201223029.GA15820@avx2
Signed-off-by: Alexey Dobriyan <[email protected]>
Reviewed-by: Andrew Morton <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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mem_cgroup_is_root() is the preferred API to check if memcg is root or
not. Use it instead of deferencing css->parent.
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Yang Shi <[email protected]>
Acked-by: Michal Hocko <[email protected]>
Cc: Huang Ying <[email protected]>
Cc: Tim Chen <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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Android uses ashmem for sharing memory regions. We are looking forward
to migrating all usecases of ashmem to memfd so that we can possibly
remove the ashmem driver in the future from staging while also
benefiting from using memfd and contributing to it. Note staging
drivers are also not ABI and generally can be removed at anytime.
One of the main usecases Android has is the ability to create a region
and mmap it as writeable, then add protection against making any
"future" writes while keeping the existing already mmap'ed
writeable-region active. This allows us to implement a usecase where
receivers of the shared memory buffer can get a read-only view, while
the sender continues to write to the buffer. See CursorWindow
documentation in Android for more details:
https://developer.android.com/reference/android/database/CursorWindow
This usecase cannot be implemented with the existing F_SEAL_WRITE seal.
To support the usecase, this patch adds a new F_SEAL_FUTURE_WRITE seal
which prevents any future mmap and write syscalls from succeeding while
keeping the existing mmap active.
A better way to do F_SEAL_FUTURE_WRITE seal was discussed [1] last week
where we don't need to modify core VFS structures to get the same
behavior of the seal. This solves several side-effects pointed by Andy.
self-tests are provided in later patch to verify the expected semantics.
[1] https://lore.kernel.org/lkml/[email protected]/
Thanks a lot to Andy for suggestions to improve code.
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Joel Fernandes (Google) <[email protected]>
Acked-by: John Stultz <[email protected]>
Cc: Andy Lutomirski <[email protected]>
Cc: Minchan Kim <[email protected]>
Cc: Jann Horn <[email protected]>
Cc: Al Viro <[email protected]>
Cc: Andy Lutomirski <[email protected]>
Cc: Hugh Dickins <[email protected]>
Cc: J. Bruce Fields <[email protected]>
Cc: Jeff Layton <[email protected]>
Cc: Marc-Andr Lureau <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Cc: Mike Kravetz <[email protected]>
Cc: Shuah Khan <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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This patch updates get_user_pages_longterm to migrate pages allocated
out of CMA region. This makes sure that we don't keep non-movable pages
(due to page reference count) in the CMA area.
This will be used by ppc64 in a later patch to avoid pinning pages in
the CMA region. ppc64 uses CMA region for allocation of the hardware
page table (hash page table) and not able to migrate pages out of CMA
region results in page table allocation failures.
One case where we hit this easy is when a guest using a VFIO passthrough
device. VFIO locks all the guest's memory and if the guest memory is
backed by CMA region, it becomes unmovable resulting in fragmenting the
CMA and possibly preventing other guests from allocation a large enough
hash page table.
NOTE: We allocate the new page without using __GFP_THISNODE
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Aneesh Kumar K.V <[email protected]>
Cc: Alexey Kardashevskiy <[email protected]>
Cc: Andrea Arcangeli <[email protected]>
Cc: David Gibson <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Mel Gorman <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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Patch series "mm/kvm/vfio/ppc64: Migrate compound pages out of CMA
region", v8.
ppc64 uses the CMA area for the allocation of guest page table (hash
page table). We won't be able to start guest if we fail to allocate
hash page table. We have observed hash table allocation failure because
we failed to migrate pages out of CMA region because they were pinned.
This happen when we are using VFIO. VFIO on ppc64 pins the entire guest
RAM. If the guest RAM pages get allocated out of CMA region, we won't
be able to migrate those pages. The pages are also pinned for the
lifetime of the guest.
Currently we support migration of non-compound pages. With THP and with
the addition of hugetlb migration we can end up allocating compound
pages from CMA region. This patch series add support for migrating
compound pages.
This patch (of 4):
Add PF_MEMALLOC_NOCMA which make sure any allocation in that context is
marked non-movable and hence cannot be satisfied by CMA region.
This is useful with get_user_pages_longterm where we want to take a page
pin by migrating pages from CMA region. Marking the section
PF_MEMALLOC_NOCMA ensures that we avoid unnecessary page migration
later.
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Aneesh Kumar K.V <[email protected]>
Suggested-by: Andrea Arcangeli <[email protected]>
Reviewed-by: Andrea Arcangeli <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Alexey Kardashevskiy <[email protected]>
Cc: David Gibson <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: Mel Gorman <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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The usage of PG_reserved and how PG_reserved pages are to be treated is
buried deep down in different parts of the kernel. Let's shine some
light onto these details by documenting current users and expected
behavior.
Especially, clarify on the "Some of them might not even exist" case.
These are physical memory gaps that will never be dumped as they are not
marked as IORESOURCE_SYSRAM. PG_reserved does in general not hinder
anybody from dumping or swapping. In some cases, these pages will not
be stored in the hibernation image.
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: David Hildenbrand <[email protected]>
Reviewed-by: Andrew Morton <[email protected]>
Cc: Stephen Rothwell <[email protected]>
Cc: Pavel Tatashin <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Alexander Duyck <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Cc: Anthony Yznaga <[email protected]>
Cc: Miles Chen <[email protected]>
Cc: <[email protected]>
Cc: Dan Williams <[email protected]>
Cc: Randy Dunlap <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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This patch was initially posted by Kelley Nielsen. Reposting the patch
with all review comments addressed and with minor modifications and
optimizations. Also, folding in the fixes offered by Hugh Dickins and
Huang Ying. Tests were rerun and commit message updated with new
results.
try_to_unuse() is of quadratic complexity, with a lot of wasted effort.
It unuses swap entries one by one, potentially iterating over all the
page tables for all the processes in the system for each one.
This new proposed implementation of try_to_unuse simplifies its
complexity to linear. It iterates over the system's mms once, unusing
all the affected entries as it walks each set of page tables. It also
makes similar changes to shmem_unuse.
Improvement
swapoff was called on a swap partition containing about 6G of data, in a
VM(8cpu, 16G RAM), and calls to unuse_pte_range() were counted.
Present implementation....about 1200M calls(8min, avg 80% cpu util).
Prototype.................about 9.0K calls(3min, avg 5% cpu util).
Details
In shmem_unuse(), iterate over the shmem_swaplist and, for each
shmem_inode_info that contains a swap entry, pass it to
shmem_unuse_inode(), along with the swap type. In shmem_unuse_inode(),
iterate over its associated xarray, and store the index and value of
each swap entry in an array for passing to shmem_swapin_page() outside
of the RCU critical section.
In try_to_unuse(), instead of iterating over the entries in the type and
unusing them one by one, perhaps walking all the page tables for all the
processes for each one, iterate over the mmlist, making one pass. Pass
each mm to unuse_mm() to begin its page table walk, and during the walk,
unuse all the ptes that have backing store in the swap type received by
try_to_unuse(). After the walk, check the type for orphaned swap
entries with find_next_to_unuse(), and remove them from the swap cache.
If find_next_to_unuse() starts over at the beginning of the type, repeat
the check of the shmem_swaplist and the walk a maximum of three times.
Change unuse_mm() and the intervening walk functions down to
unuse_pte_range() to take the type as a parameter, and to iterate over
their entire range, calling the next function down on every iteration.
In unuse_pte_range(), make a swap entry from each pte in the range using
the passed in type. If it has backing store in the type, call
swapin_readahead() to retrieve the page and pass it to unuse_pte().
Pass the count of pages_to_unuse down the page table walks in
try_to_unuse(), and return from the walk when the desired number of
pages has been swapped back in.
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Vineeth Remanan Pillai <[email protected]>
Signed-off-by: Kelley Nielsen <[email protected]>
Signed-off-by: Huang Ying <[email protected]>
Acked-by: Hugh Dickins <[email protected]>
Cc: Rik van Riel <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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Architectures like ppc64 require to do a conditional tlb flush based on
the old and new value of pte. Follow the regular pte change protection
sequence for hugetlb too. This allows the architectures to override the
update sequence.
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Aneesh Kumar K.V <[email protected]>
Reviewed-by: Michael Ellerman <[email protected]>
Cc: Benjamin Herrenschmidt <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: "H. Peter Anvin" <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Martin Schwidefsky <[email protected]>
Cc: Nicholas Piggin <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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Architectures like ppc64 require to do a conditional tlb flush based on
the old and new value of pte. Enable that by passing old pte value as
the arg.
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Aneesh Kumar K.V <[email protected]>
Cc: Benjamin Herrenschmidt <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: "H. Peter Anvin" <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Martin Schwidefsky <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: Nicholas Piggin <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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Patch series "NestMMU pte upgrade workaround for mprotect", v5.
We can upgrade pte access (R -> RW transition) via mprotect. We need to
make sure we follow the recommended pte update sequence as outlined in
commit bd5050e38aec ("powerpc/mm/radix: Change pte relax sequence to
handle nest MMU hang") for such updates. This patch series does that.
This patch (of 5):
Some architectures may want to call flush_tlb_range from these helpers.
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Aneesh Kumar K.V <[email protected]>
Cc: Nicholas Piggin <[email protected]>
Cc: Benjamin Herrenschmidt <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Martin Schwidefsky <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: "H. Peter Anvin" <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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No functional change.
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Wei Yang <[email protected]>
Reviewed-by: Pekka Enberg <[email protected]>
Acked-by: Mike Rapoport <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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This is the start of a series of patches similar to my earlier
DEFINE_MEMCG_MAX_OR_VAL work, but with less Macro Magic(tm).
There are a bunch of places we go from seq_file to mem_cgroup, which
currently requires manually getting the css, then getting the mem_cgroup
from the css. It's in enough places now that having mem_cgroup_from_seq
makes sense (and also makes the next patch a bit nicer).
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Chris Down <[email protected]>
Acked-by: Johannes Weiner <[email protected]>
Acked-by: Michal Hocko <[email protected]>
Cc: Tejun Heo <[email protected]>
Cc: Roman Gushchin <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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Cgroup has a standardized poll/notification mechanism for waking all
pollers on all fds when a filesystem node changes. To allow polling for
custom events, add a .poll callback that can override the default.
This is in preparation for pollable cgroup pressure files which have
per-fd trigger configurations.
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Johannes Weiner <[email protected]>
Signed-off-by: Suren Baghdasaryan <[email protected]>
Cc: Dennis Zhou <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Jens Axboe <[email protected]>
Cc: Li Zefan <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Tejun Heo <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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Patch series "psi: pressure stall monitors", v3.
Android is adopting psi to detect and remedy memory pressure that
results in stuttering and decreased responsiveness on mobile devices.
Psi gives us the stall information, but because we're dealing with
latencies in the millisecond range, periodically reading the pressure
files to detect stalls in a timely fashion is not feasible. Psi also
doesn't aggregate its averages at a high enough frequency right now.
This patch series extends the psi interface such that users can
configure sensitive latency thresholds and use poll() and friends to be
notified when these are breached.
As high-frequency aggregation is costly, it implements an aggregation
method that is optimized for fast, short-interval averaging, and makes
the aggregation frequency adaptive, such that high-frequency updates
only happen while monitored stall events are actively occurring.
With these patches applied, Android can monitor for, and ward off,
mounting memory shortages before they cause problems for the user. For
example, using memory stall monitors in userspace low memory killer
daemon (lmkd) we can detect mounting pressure and kill less important
processes before device becomes visibly sluggish.
In our memory stress testing psi memory monitors produce roughly 10x
less false positives compared to vmpressure signals. Having ability to
specify multiple triggers for the same psi metric allows other parts of
Android framework to monitor memory state of the device and act
accordingly.
The new interface is straightforward. The user opens one of the
pressure files for writing and writes a trigger description into the
file descriptor that defines the stall state - some or full, and the
maximum stall time over a given window of time. E.g.:
/* Signal when stall time exceeds 100ms of a 1s window */
char trigger[] = "full 100000 1000000";
fd = open("/proc/pressure/memory");
write(fd, trigger, sizeof(trigger));
while (poll() >= 0) {
...
}
close(fd);
When the monitored stall state is entered, psi adapts its aggregation
frequency according to what the configured time window requires in order
to emit event signals in a timely fashion. Once the stalling subsides,
aggregation reverts back to normal.
The trigger is associated with the open file descriptor. To stop
monitoring, the user only needs to close the file descriptor and the
trigger is discarded.
Patches 1-4 prepare the psi code for polling support. Patch 5
implements the adaptive polling logic, the pressure growth detection
optimized for short intervals, and hooks up write() and poll() on the
pressure files.
The patches were developed in collaboration with Johannes Weiner.
This patch (of 5):
Kernfs has a standardized poll/notification mechanism for waking all
pollers on all fds when a filesystem node changes. To allow polling for
custom events, add a .poll callback that can override the default.
This is in preparation for pollable cgroup pressure files which have
per-fd trigger configurations.
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Johannes Weiner <[email protected]>
Signed-off-by: Suren Baghdasaryan <[email protected]>
Cc: Dennis Zhou <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Jens Axboe <[email protected]>
Cc: Li Zefan <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Tejun Heo <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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Compaction is inherently race-prone as a suitable page freed during
compaction can be allocated by any parallel task. This patch uses a
capture_control structure to isolate a page immediately when it is freed
by a direct compactor in the slow path of the page allocator. The
intent is to avoid redundant scanning.
5.0.0-rc1 5.0.0-rc1
selective-v3r17 capture-v3r19
Amean fault-both-1 0.00 ( 0.00%) 0.00 * 0.00%*
Amean fault-both-3 2582.11 ( 0.00%) 2563.68 ( 0.71%)
Amean fault-both-5 4500.26 ( 0.00%) 4233.52 ( 5.93%)
Amean fault-both-7 5819.53 ( 0.00%) 6333.65 ( -8.83%)
Amean fault-both-12 9321.18 ( 0.00%) 9759.38 ( -4.70%)
Amean fault-both-18 9782.76 ( 0.00%) 10338.76 ( -5.68%)
Amean fault-both-24 15272.81 ( 0.00%) 13379.55 * 12.40%*
Amean fault-both-30 15121.34 ( 0.00%) 16158.25 ( -6.86%)
Amean fault-both-32 18466.67 ( 0.00%) 18971.21 ( -2.73%)
Latency is only moderately affected but the devil is in the details. A
closer examination indicates that base page fault latency is reduced but
latency of huge pages is increased as it takes creater care to succeed.
Part of the "problem" is that allocation success rates are close to 100%
even when under pressure and compaction gets harder
5.0.0-rc1 5.0.0-rc1
selective-v3r17 capture-v3r19
Percentage huge-3 96.70 ( 0.00%) 98.23 ( 1.58%)
Percentage huge-5 96.99 ( 0.00%) 95.30 ( -1.75%)
Percentage huge-7 94.19 ( 0.00%) 97.24 ( 3.24%)
Percentage huge-12 94.95 ( 0.00%) 97.35 ( 2.53%)
Percentage huge-18 96.74 ( 0.00%) 97.30 ( 0.58%)
Percentage huge-24 97.07 ( 0.00%) 97.55 ( 0.50%)
Percentage huge-30 95.69 ( 0.00%) 98.50 ( 2.95%)
Percentage huge-32 96.70 ( 0.00%) 99.27 ( 2.65%)
And scan rates are reduced as expected by 6% for the migration scanner
and 29% for the free scanner indicating that there is less redundant
work.
Compaction migrate scanned 20815362 19573286
Compaction free scanned 16352612 11510663
[[email protected]: remove redundant check]
Link: http://lkml.kernel.org/r/[email protected]
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Mel Gorman <[email protected]>
Acked-by: Vlastimil Babka <[email protected]>
Cc: Andrea Arcangeli <[email protected]>
Cc: Dan Carpenter <[email protected]>
Cc: David Rientjes <[email protected]>
Cc: YueHaibing <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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Pageblock hints are cleared when compaction restarts or kswapd makes
enough progress that it can sleep but it's over-eager in that the bit is
cleared for migration sources with no LRU pages and migration targets
with no free pages. As pageblock skip hint flushes are relatively rare
and out-of-band with respect to kswapd, this patch makes a few more
expensive checks to see if it's appropriate to even clear the bit.
Every pageblock that is not cleared will avoid 512 pages being scanned
unnecessarily on x86-64.
The impact is variable with different workloads showing small
differences in latency, success rates and scan rates. This is expected
as clearing the hints is not that common but doing a small amount of
work out-of-band to avoid a large amount of work in-band later is
generally a good thing.
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Mel Gorman <[email protected]>
Signed-off-by: Qian Cai <[email protected]>
Acked-by: Vlastimil Babka <[email protected]>
Cc: Andrea Arcangeli <[email protected]>
Cc: Dan Carpenter <[email protected]>
Cc: David Rientjes <[email protected]>
Cc: YueHaibing <[email protected]>
[[email protected]: no stuck in __reset_isolation_pfn()]
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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The migration scanner is a linear scan of a zone with a potentiall large
search space. Furthermore, many pageblocks are unusable such as those
filled with reserved pages or partially filled with pages that cannot
migrate. These still get scanned in the common case of allocating a THP
and the cost accumulates.
The patch uses a partial search of the free lists to locate a migration
source candidate that is marked as MOVABLE when allocating a THP. It
prefers picking a block with a larger number of free pages already on
the basis that there are fewer pages to migrate to free the entire
block. The lowest PFN found during searches is tracked as the basis of
the start for the linear search after the first search of the free list
fails. After the search, the free list is shuffled so that the next
search will not encounter the same page. If the search fails then the
subsequent searches will be shorter and the linear scanner is used.
If this search fails, or if the request is for a small or
unmovable/reclaimable allocation then the linear scanner is still used.
It is somewhat pointless to use the list search in those cases. Small
free pages must be used for the search and there is no guarantee that
movable pages are located within that block that are contiguous.
5.0.0-rc1 5.0.0-rc1
noboost-v3r10 findmig-v3r15
Amean fault-both-3 3771.41 ( 0.00%) 3390.40 ( 10.10%)
Amean fault-both-5 5409.05 ( 0.00%) 5082.28 ( 6.04%)
Amean fault-both-7 7040.74 ( 0.00%) 7012.51 ( 0.40%)
Amean fault-both-12 11887.35 ( 0.00%) 11346.63 ( 4.55%)
Amean fault-both-18 16718.19 ( 0.00%) 15324.19 ( 8.34%)
Amean fault-both-24 21157.19 ( 0.00%) 16088.50 * 23.96%*
Amean fault-both-30 21175.92 ( 0.00%) 18723.42 * 11.58%*
Amean fault-both-32 21339.03 ( 0.00%) 18612.01 * 12.78%*
5.0.0-rc1 5.0.0-rc1
noboost-v3r10 findmig-v3r15
Percentage huge-3 86.50 ( 0.00%) 89.83 ( 3.85%)
Percentage huge-5 92.52 ( 0.00%) 91.96 ( -0.61%)
Percentage huge-7 92.44 ( 0.00%) 92.85 ( 0.44%)
Percentage huge-12 92.98 ( 0.00%) 92.74 ( -0.25%)
Percentage huge-18 91.70 ( 0.00%) 91.71 ( 0.02%)
Percentage huge-24 91.59 ( 0.00%) 92.13 ( 0.60%)
Percentage huge-30 90.14 ( 0.00%) 93.79 ( 4.04%)
Percentage huge-32 90.03 ( 0.00%) 91.27 ( 1.37%)
This shows an improvement in allocation latencies with similar
allocation success rates. While not presented, there was a 31%
reduction in migration scanning and a 8% reduction on system CPU usage.
A 2-socket machine showed similar benefits.
[[email protected]: several fixes]
Link: http://lkml.kernel.org/r/[email protected]
[[email protected]: migrate block that was found-fast, some optimisations]
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Mel Gorman <[email protected]>
Acked-by: Vlastimil Babka <[email protected]>
Cc: Andrea Arcangeli <[email protected]>
Cc: Dan Carpenter <[email protected]>
Cc: David Rientjes <[email protected]>
Cc: YueHaibing <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
|
|
GFP_KERNEL is one of the most used constant but on archs like arm with
fixed length instruction some constants are more equal than the others.
Constants with tightly packed bits can be injected directly into
instruction stream:
0: e3a00d33 mov r0, #3264 ; 0xcc0
Others require multiple instructions or even loading out of instruction
stream:
0: e3a000c0 mov r0, #192 ; 0xc0
4: e3400060 movt r0, #96 ; 0x60
Shuffle GFP_* flags so that GFP_KERNEL/GFP_ATOMIC + __GFP_ZERO bits are
close to each other.
Savings on arm configs are ~0.1%.
Link: http://lkml.kernel.org/r/20190109201838.GA9140@avx2
Signed-off-by: Alexey Dobriyan <[email protected]>
Reviewed-by: Andrew Morton <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
|
|
Architectures like arm64 have HugeTLB page sizes which are different
than generic sizes at PMD, PUD, PGD level and implemented via contiguous
bits. At present these special size HugeTLB pages cannot be identified
through macros like (PMD|PUD|PGDIR)_SHIFT and hence chosen not be
migrated.
Enabling migration support for these special HugeTLB page sizes along
with the generic ones (PMD|PUD|PGD) would require identifying all of
them on a given platform. A platform specific hook can precisely
enumerate all huge page sizes supported for migration. Instead of
comparing against standard huge page orders let
hugetlb_migration_support() function call a platform hook
arch_hugetlb_migration_support(). Default definition for the platform
hook maintains existing semantics which checks standard huge page order.
But an architecture can choose to override the default and provide
support for a comprehensive set of huge page sizes.
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Anshuman Khandual <[email protected]>
Reviewed-by: Naoya Horiguchi <[email protected]>
Reviewed-by: Steve Capper <[email protected]>
Acked-by: Michal Hocko <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Michal Hocko <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
|
|
Architectures like arm64 have PUD level HugeTLB pages for certain configs
(1GB huge page is PUD based on ARM64_4K_PAGES base page size) that can
be enabled for migration. It can be achieved through checking for
PUD_SHIFT order based HugeTLB pages during migration.
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Anshuman Khandual <[email protected]>
Reviewed-by: Naoya Horiguchi <[email protected]>
Reviewed-by: Steve Capper <[email protected]>
Acked-by: Michal Hocko <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Michal Hocko <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
|
|
Patch series "arm64/mm: Enable HugeTLB migration", v4.
This patch series enables HugeTLB migration support for all supported
huge page sizes at all levels including contiguous bit implementation.
Following HugeTLB migration support matrix has been enabled with this
patch series. All permutations have been tested except for the 16GB.
CONT PTE PMD CONT PMD PUD
-------- --- -------- ---
4K: 64K 2M 32M 1G
16K: 2M 32M 1G
64K: 2M 512M 16G
First the series adds migration support for PUD based huge pages. It
then adds a platform specific hook to query an architecture if a given
huge page size is supported for migration while also providing a default
fallback option preserving the existing semantics which just checks for
(PMD|PUD|PGDIR)_SHIFT macros. The last two patches enables HugeTLB
migration on arm64 and subscribe to this new platform specific hook by
defining an override.
The second patch differentiates between movability and migratability
aspects of huge pages and implements hugepage_movable_supported() which
can then be used during allocation to decide whether to place the huge
page in movable zone or not.
This patch (of 5):
During huge page allocation it's migratability is checked to determine
if it should be placed under movable zones with GFP_HIGHUSER_MOVABLE.
But the movability aspect of the huge page could depend on other factors
than just migratability. Movability in itself is a distinct property
which should not be tied with migratability alone.
This differentiates these two and implements an enhanced movability check
which also considers huge page size to determine if it is feasible to be
placed under a movable zone. At present it just checks for gigantic pages
but going forward it can incorporate other enhanced checks.
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Anshuman Khandual <[email protected]>
Reviewed-by: Steve Capper <[email protected]>
Reviewed-by: Naoya Horiguchi <[email protected]>
Suggested-by: Michal Hocko <[email protected]>
Acked-by: Michal Hocko <[email protected]>
Cc: Catalin Marinas <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
|
|
sysctl_extfrag_handler() neglects to propagate the return value from
proc_dointvec_minmax() to its caller. It's a wrapper that doesn't need
to exist, so just use proc_dointvec_minmax() directly.
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Matthew Wilcox <[email protected]>
Reported-by: Aditya Pakki <[email protected]>
Acked-by: Mel Gorman <[email protected]>
Acked-by: Randy Dunlap <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
|
|
Move the memcg_kmem_enabled() checks into memcg kmem charge/uncharge
functions, so, the users don't have to explicitly check that condition.
This is purely code cleanup patch without any functional change. Only
the order of checks in memcg_charge_slab() can potentially be changed
but the functionally it will be same. This should not matter as
memcg_charge_slab() is not in the hot path.
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Shakeel Butt <[email protected]>
Acked-by: Michal Hocko <[email protected]>
Cc: Johannes Weiner <[email protected]>
Cc: Vladimir Davydov <[email protected]>
Cc: Roman Gushchin <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
|
|
Add an optimization for KSM pages almost in the same way that we have
for ordinary anonymous pages. If there is a write fault in a page,
which is mapped to an only pte, and it is not related to swap cache; the
page may be reused without copying its content.
[ Note that we do not consider PageSwapCache() pages at least for now,
since we don't want to complicate __get_ksm_page(), which has nice
optimization based on this (for the migration case). Currenly it is
spinning on PageSwapCache() pages, waiting for when they have
unfreezed counters (i.e., for the migration finish). But we don't want
to make it also spinning on swap cache pages, which we try to reuse,
since there is not a very high probability to reuse them. So, for now
we do not consider PageSwapCache() pages at all. ]
So in reuse_ksm_page() we check for 1) PageSwapCache() and 2)
page_stable_node(), to skip a page, which KSM is currently trying to
link to stable tree. Then we do page_ref_freeze() to prohibit KSM to
merge one more page into the page, we are reusing. After that, nobody
can refer to the reusing page: KSM skips !PageSwapCache() pages with
zero refcount; and the protection against of all other participants is
the same as for reused ordinary anon pages pte lock, page lock and
mmap_sem.
[[email protected]: replace BUG_ON()s with WARN_ON()s]
Link: http://lkml.kernel.org/r/154471491016.31352.1168978849911555609.stgit@localhost.localdomain
Signed-off-by: Kirill Tkhai <[email protected]>
Reviewed-by: Yang Shi <[email protected]>
Cc: "Kirill A. Shutemov" <[email protected]>
Cc: Hugh Dickins <[email protected]>
Cc: Andrea Arcangeli <[email protected]>
Cc: Christian Koenig <[email protected]>
Cc: Claudio Imbrenda <[email protected]>
Cc: Rik van Riel <[email protected]>
Cc: Huang Ying <[email protected]>
Cc: Minchan Kim <[email protected]>
Cc: Kirill Tkhai <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
|
|
Patch series "Replace all open encodings for NUMA_NO_NODE", v3.
All these places for replacement were found by running the following
grep patterns on the entire kernel code. Please let me know if this
might have missed some instances. This might also have replaced some
false positives. I will appreciate suggestions, inputs and review.
1. git grep "nid == -1"
2. git grep "node == -1"
3. git grep "nid = -1"
4. git grep "node = -1"
This patch (of 2):
At present there are multiple places where invalid node number is
encoded as -1. Even though implicitly understood it is always better to
have macros in there. Replace these open encodings for an invalid node
number with the global macro NUMA_NO_NODE. This helps remove NUMA
related assumptions like 'invalid node' from various places redirecting
them to a common definition.
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Anshuman Khandual <[email protected]>
Reviewed-by: David Hildenbrand <[email protected]>
Acked-by: Jeff Kirsher <[email protected]> [ixgbe]
Acked-by: Jens Axboe <[email protected]> [mtip32xx]
Acked-by: Vinod Koul <[email protected]> [dmaengine.c]
Acked-by: Michael Ellerman <[email protected]> [powerpc]
Acked-by: Doug Ledford <[email protected]> [drivers/infiniband]
Cc: Joseph Qi <[email protected]>
Cc: Hans Verkuil <[email protected]>
Cc: Stephen Rothwell <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
|
|
PG_balloon was introduced to implement page migration/compaction for
pages inflated in virtio-balloon. Nowadays, it is only a marker that a
page is part of virtio-balloon and therefore logically offline.
We also want to make use of this flag in other balloon drivers - for
inflated pages or when onlining a section but keeping some pages offline
(e.g. used right now by XEN and Hyper-V via set_online_page_callback()).
We are going to expose this flag to dump tools like makedumpfile. But
instead of exposing PG_balloon, let's generalize the concept of marking
pages as logically offline, so it can be reused for other purposes later
on.
Rename PG_balloon to PG_offline. This is an indicator that the page is
logically offline, the content stale and that it should not be touched
(e.g. a hypervisor would have to allocate backing storage in order for
the guest to dump an unused page). We can then e.g. exclude such pages
from dumps.
We replace and reuse KPF_BALLOON (23), as this shouldn't really harm
(and for now the semantics stay the same). In following patches, we
will make use of this bit also in other balloon drivers. While at it,
document PGTABLE.
[[email protected]: fix comment text, per David]
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: David Hildenbrand <[email protected]>
Acked-by: Konstantin Khlebnikov <[email protected]>
Acked-by: Michael S. Tsirkin <[email protected]>
Acked-by: Pankaj gupta <[email protected]>
Cc: Jonathan Corbet <[email protected]>
Cc: Alexey Dobriyan <[email protected]>
Cc: Mike Rapoport <[email protected]>
Cc: Christian Hansen <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Cc: "Kirill A. Shutemov" <[email protected]>
Cc: Stephen Rothwell <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Pavel Tatashin <[email protected]>
Cc: Alexander Duyck <[email protected]>
Cc: Naoya Horiguchi <[email protected]>
Cc: Miles Chen <[email protected]>
Cc: David Rientjes <[email protected]>
Cc: Kazuhito Hagio <[email protected]>
Cc: Arnd Bergmann <[email protected]>
Cc: Baoquan He <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Boris Ostrovsky <[email protected]>
Cc: Dave Young <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: Haiyang Zhang <[email protected]>
Cc: Juergen Gross <[email protected]>
Cc: Julien Freche <[email protected]>
Cc: Kairui Song <[email protected]>
Cc: "K. Y. Srinivasan" <[email protected]>
Cc: Len Brown <[email protected]>
Cc: Lianbo Jiang <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Nadav Amit <[email protected]>
Cc: Omar Sandoval <[email protected]>
Cc: Pavel Machek <[email protected]>
Cc: Rafael J. Wysocki <[email protected]>
Cc: "Rafael J. Wysocki" <[email protected]>
Cc: Stefano Stabellini <[email protected]>
Cc: Stephen Hemminger <[email protected]>
Cc: Vitaly Kuznetsov <[email protected]>
Cc: Xavier Deguillard <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
|
|
Patch series "mm/kdump: allow to exclude pages that are logically
offline"
Right now, pages inflated as part of a balloon driver will be dumped by
dump tools like makedumpfile. While XEN is able to check in the crash
kernel whether a certain pfn is actuall backed by memory in the
hypervisor (see xen_oldmem_pfn_is_ram) and optimize this case, dumps of
virtio-balloon, hv-balloon and VMWare balloon inflated memory will
essentially result in zero pages getting allocated by the hypervisor and
the dump getting filled with this data.
The allocation and reading of zero pages can directly be avoided if a
dumping tool could know which pages only contain stale information not
to be dumped.
Also for XEN, calling into the kernel and asking the hypervisor if a pfn
is backed can be avoided if the duming tool would skip such pages right
from the beginning.
Dumping tools have no idea whether a given page is part of a balloon
driver and shall not be dumped. Esp. PG_reserved cannot be used for
that purpose as all memory allocated during early boot is also
PG_reserved, see discussion at [1]. So some other way of indication is
required and a new page flag is frowned upon.
We have PG_balloon (MAPCOUNT value), which is essentially unused now. I
suggest renaming it to something more generic (PG_offline) to mark pages
as logically offline. This flag can than e.g. also be used by
virtio-mem in the future to mark subsections as offline. Or by other
code that wants to put pages logically offline (e.g. later maybe
poisoned pages that shall no longer be used).
This series converts PG_balloon to PG_offline, allows dumping tools to
query the value to detect such pages and marks pages in the hv-balloon
and XEN balloon properly as PG_offline. Note that virtio-balloon
already set pages to PG_balloon (and now PG_offline).
Please note that this is also helpful for a problem we were seeing under
Hyper-V: Dumping logically offline memory (pages kept fake offline while
onlining a section via online_page_callback) would under some condicions
result in a kernel panic when dumping them.
As I don't have access to neither XEN nor Hyper-V nor VMWare
installations, this was only tested with the virtio-balloon and pages
were properly skipped when dumping. I'll also attach the makedumpfile
patch to this series.
[1] https://lkml.org/lkml/2018/7/20/566
This patch (of 8):
Commit b1123ea6d3b3 ("mm: balloon: use general non-lru movable page
feature") reworked balloon handling to make use of the general non-lru
movable page feature. The big comment block in balloon_compaction.h
contains quite some outdated information. Let's fix this.
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: David Hildenbrand <[email protected]>
Acked-by: Michael S. Tsirkin <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Alexander Duyck <[email protected]>
Cc: Alexey Dobriyan <[email protected]>
Cc: Arnd Bergmann <[email protected]>
Cc: Baoquan He <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Boris Ostrovsky <[email protected]>
Cc: Christian Hansen <[email protected]>
Cc: Dave Young <[email protected]>
Cc: David Rientjes <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: Haiyang Zhang <[email protected]>
Cc: Jonathan Corbet <[email protected]>
Cc: Juergen Gross <[email protected]>
Cc: Julien Freche <[email protected]>
Cc: Kairui Song <[email protected]>
Cc: Kazuhito Hagio <[email protected]>
Cc: "Kirill A. Shutemov" <[email protected]>
Cc: Konstantin Khlebnikov <[email protected]>
Cc: "K. Y. Srinivasan" <[email protected]>
Cc: Len Brown <[email protected]>
Cc: Lianbo Jiang <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Mike Rapoport <[email protected]>
Cc: Miles Chen <[email protected]>
Cc: Nadav Amit <[email protected]>
Cc: Naoya Horiguchi <[email protected]>
Cc: Omar Sandoval <[email protected]>
Cc: Pankaj gupta <[email protected]>
Cc: Pavel Machek <[email protected]>
Cc: Pavel Tatashin <[email protected]>
Cc: Rafael J. Wysocki <[email protected]>
Cc: "Rafael J. Wysocki" <[email protected]>
Cc: Stefano Stabellini <[email protected]>
Cc: Stephen Hemminger <[email protected]>
Cc: Stephen Rothwell <[email protected]>
Cc: Vitaly Kuznetsov <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Cc: Xavier Deguillard <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
|
|
When freeing pages are done with higher order, time spent on coalescing
pages by buddy allocator can be reduced. With section size of 256MB,
hot add latency of a single section shows improvement from 50-60 ms to
less than 1 ms, hence improving the hot add latency by 60 times. Modify
external providers of online callback to align with the change.
[[email protected]: v11]
Link: http://lkml.kernel.org/r/[email protected]
[[email protected]: remove unused local, per Arun]
[[email protected]: avoid return of void-returning __free_pages_core(), per Oscar]
[[email protected]: fix it for mm-convert-totalram_pages-and-totalhigh_pages-variables-to-atomic.patch]
[[email protected]: v8]
Link: http://lkml.kernel.org/r/[email protected]
[[email protected]: v9]
Link: http://lkml.kernel.org/r/[email protected]
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arun KS <[email protected]>
Reviewed-by: Andrew Morton <[email protected]>
Acked-by: Michal Hocko <[email protected]>
Reviewed-by: Oscar Salvador <[email protected]>
Reviewed-by: Alexander Duyck <[email protected]>
Cc: K. Y. Srinivasan <[email protected]>
Cc: Haiyang Zhang <[email protected]>
Cc: Stephen Hemminger <[email protected]>
Cc: Boris Ostrovsky <[email protected]>
Cc: Juergen Gross <[email protected]>
Cc: Dan Williams <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Cc: Joonsoo Kim <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: Mathieu Malaterre <[email protected]>
Cc: "Kirill A. Shutemov" <[email protected]>
Cc: Souptick Joarder <[email protected]>
Cc: Mel Gorman <[email protected]>
Cc: Aaron Lu <[email protected]>
Cc: Srivatsa Vaddagiri <[email protected]>
Cc: Vinayak Menon <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
|
|
Capitialize comment string, use C89 comment style, correct
grammar/punctuation in comments.
Link: http://lkml.kernel.org/r/[email protected]
Link: http://lkml.kernel.org/r/[email protected]
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Tobin C. Harding <[email protected]>
Reviewed-by: Andrew Morton <[email protected]>
Reviewed-by: William Kucharski <[email protected]>
Cc: Christoph Lameter <[email protected]>
Cc: Pekka Enberg <[email protected]>
Cc: David Rientjes <[email protected]>
Cc: Joonsoo Kim <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
|
|
Building little-endian allmodconfig kernels on arm64 started failing
with the generated atomic.h implementation, since we now try to call
kasan helpers from the EFI stub:
aarch64-linux-gnu-ld: drivers/firmware/efi/libstub/arm-stub.stub.o: in function `atomic_set':
include/generated/atomic-instrumented.h:44: undefined reference to `__efistub_kasan_check_write'
I suspect that we get similar problems in other files that explicitly
disable KASAN for some reason but call atomic_t based helper functions.
We can fix this by checking the predefined __SANITIZE_ADDRESS__ macro
that the compiler sets instead of checking CONFIG_KASAN, but this in
turn requires a small hack in mm/kasan/common.c so we do see the extern
declaration there instead of the inline function.
Link: http://lkml.kernel.org/r/[email protected]
Fixes: b1864b828644 ("locking/atomics: build atomic headers as required")
Signed-off-by: Arnd Bergmann <[email protected]>
Reported-by: Anders Roxell <[email protected]>
Acked-by: Andrey Ryabinin <[email protected]>
Cc: Ard Biesheuvel <[email protected]>
Cc: Will Deacon <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Alexander Potapenko <[email protected]>
Cc: Dmitry Vyukov <[email protected]>
Cc: Andrey Konovalov <[email protected]>
Cc: Stephen Rothwell <[email protected]>,
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
|
|
We use below condition to check inline_xattr_size boundary:
if (!F2FS_OPTION(sbi).inline_xattr_size ||
F2FS_OPTION(sbi).inline_xattr_size >=
DEF_ADDRS_PER_INODE -
F2FS_TOTAL_EXTRA_ATTR_SIZE -
DEF_INLINE_RESERVED_SIZE -
DEF_MIN_INLINE_SIZE)
There is there problems in that check:
- we should allow inline_xattr_size equaling to min size of inline
{data,dentry} area.
- F2FS_TOTAL_EXTRA_ATTR_SIZE and inline_xattr_size are based on
different size unit, previous one is 4 bytes, latter one is 1 bytes.
- DEF_MIN_INLINE_SIZE only indicate min size of inline data area,
however, we need to consider min size of inline dentry area as well,
minimal inline dentry should at least contain two entries: '.' and
'..', so that min inline_dentry size is 40 bytes.
.bitmap 1 * 1 = 1
.reserved 1 * 1 = 1
.dentry 11 * 2 = 22
.filename 8 * 2 = 16
total 40
Signed-off-by: Chao Yu <[email protected]>
Signed-off-by: Jaegeuk Kim <[email protected]>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull RCU updates from Ingo Molnar:
"The main RCU related changes in this cycle were:
- Additional cleanups after RCU flavor consolidation
- Grace-period forward-progress cleanups and improvements
- Documentation updates
- Miscellaneous fixes
- spin_is_locked() conversions to lockdep
- SPDX changes to RCU source and header files
- SRCU updates
- Torture-test updates, including nolibc updates and moving nolibc to
tools/include"
* 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (71 commits)
locking/locktorture: Convert to SPDX license identifier
linux/torture: Convert to SPDX license identifier
torture: Convert to SPDX license identifier
linux/srcu: Convert to SPDX license identifier
linux/rcutree: Convert to SPDX license identifier
linux/rcutiny: Convert to SPDX license identifier
linux/rcu_sync: Convert to SPDX license identifier
linux/rcu_segcblist: Convert to SPDX license identifier
linux/rcupdate: Convert to SPDX license identifier
linux/rcu_node_tree: Convert to SPDX license identifier
rcu/update: Convert to SPDX license identifier
rcu/tree: Convert to SPDX license identifier
rcu/tiny: Convert to SPDX license identifier
rcu/sync: Convert to SPDX license identifier
rcu/srcu: Convert to SPDX license identifier
rcu/rcutorture: Convert to SPDX license identifier
rcu/rcu_segcblist: Convert to SPDX license identifier
rcu/rcuperf: Convert to SPDX license identifier
rcu/rcu.h: Convert to SPDX license identifier
RCU/torture.txt: Remove section MODULE PARAMETERS
...
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull year 2038 updates from Thomas Gleixner:
"Another round of changes to make the kernel ready for 2038. After lots
of preparatory work this is the first set of syscalls which are 2038
safe:
403 clock_gettime64
404 clock_settime64
405 clock_adjtime64
406 clock_getres_time64
407 clock_nanosleep_time64
408 timer_gettime64
409 timer_settime64
410 timerfd_gettime64
411 timerfd_settime64
412 utimensat_time64
413 pselect6_time64
414 ppoll_time64
416 io_pgetevents_time64
417 recvmmsg_time64
418 mq_timedsend_time64
419 mq_timedreceiv_time64
420 semtimedop_time64
421 rt_sigtimedwait_time64
422 futex_time64
423 sched_rr_get_interval_time64
The syscall numbers are identical all over the architectures"
* 'timers-2038-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (36 commits)
riscv: Use latest system call ABI
checksyscalls: fix up mq_timedreceive and stat exceptions
unicore32: Fix __ARCH_WANT_STAT64 definition
asm-generic: Make time32 syscall numbers optional
asm-generic: Drop getrlimit and setrlimit syscalls from default list
32-bit userspace ABI: introduce ARCH_32BIT_OFF_T config option
compat ABI: use non-compat openat and open_by_handle_at variants
y2038: add 64-bit time_t syscalls to all 32-bit architectures
y2038: rename old time and utime syscalls
y2038: remove struct definition redirects
y2038: use time32 syscall names on 32-bit
syscalls: remove obsolete __IGNORE_ macros
y2038: syscalls: rename y2038 compat syscalls
x86/x32: use time64 versions of sigtimedwait and recvmmsg
timex: change syscalls to use struct __kernel_timex
timex: use __kernel_timex internally
sparc64: add custom adjtimex/clock_adjtime functions
time: fix sys_timer_settime prototype
time: Add struct __kernel_timex
time: make adjtime compat handling available for 32 bit
...
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86/pti update from Thomas Gleixner:
"Just a single change from the anti-performance departement:
- Add a new PR_SPEC_DISABLE_NOEXEC option which allows to apply the
speculation protections on a process without inheriting the state
on exec.
This remedies a situation where a Java-launcher has speculation
protections enabled because that's the default for JVMs which
causes the launched regular harmless processes to inherit the
protection state which results in unintended performance
degradation"
* 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/speculation: Add PR_SPEC_DISABLE_NOEXEC
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull irq updates from Thomas Gleixner:
"The interrupt departement delivers this time:
- New infrastructure to manage NMIs on platforms which have a sane
NMI delivery, i.e. identifiable NMI vectors instead of a single
lump.
- Simplification of the interrupt affinity management so drivers
don't have to implement ugly loops around the PCI/MSI enablement.
- Speedup for interrupt statistics in /proc/stat
- Provide a function to retrieve the default irq domain
- A new interrupt controller for the Loongson LS1X platform
- Affinity support for the SiFive PLIC
- Better support for the iMX irqsteer driver
- NUMA aware memory allocations for GICv3
- The usual small fixes, improvements and cleanups all over the
place"
* 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (36 commits)
irqchip/imx-irqsteer: Add multi output interrupts support
irqchip/imx-irqsteer: Change to use reg_num instead of irq_group
dt-bindings: irq: imx-irqsteer: Add multi output interrupts support
dt-binding: irq: imx-irqsteer: Use irq number instead of group number
irqchip/brcmstb-l2: Use _irqsave locking variants in non-interrupt code
irqchip/gicv3-its: Use NUMA aware memory allocation for ITS tables
irqdomain: Allow the default irq domain to be retrieved
irqchip/sifive-plic: Implement irq_set_affinity() for SMP host
irqchip/sifive-plic: Differentiate between PLIC handler and context
irqchip/sifive-plic: Add warning in plic_init() if handler already present
irqchip/sifive-plic: Pre-compute context hart base and enable base
PCI/MSI: Remove obsolete sanity checks for multiple interrupt sets
genirq/affinity: Remove the leftovers of the original set support
nvme-pci: Simplify interrupt allocation
genirq/affinity: Add new callback for (re)calculating interrupt sets
genirq/affinity: Store interrupt sets size in struct irq_affinity
genirq/affinity: Code consolidation
irqchip/irq-sifive-plic: Check and continue in case of an invalid cpuid.
irqchip/i8259: Fix shutdown order by moving syscore_ops registration
dt-bindings: interrupt-controller: loongson ls1x intc
...
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer and clockevent updates from Thomas Gleixner:
"The time(r) core and clockevent updates are mostly boring this time:
- A new driver for the Tegra210 timer
- Small fixes and improvements alll over the place
- Documentation updates and cleanups"
* 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (22 commits)
soc/tegra: default select TEGRA_TIMER for Tegra210
clocksource/drivers/tegra: Add Tegra210 timer support
dt-bindings: timer: add Tegra210 timer
clocksource/drivers/timer-cs5535: Rename the file for consistency
clocksource/drivers/timer-pxa: Rename the file for consistency
clocksource/drivers/tango-xtal: Rename the file for consistency
dt-bindings: timer: gpt: update binding doc
clocksource/drivers/exynos_mct: Remove unused header includes
dt-bindings: timer: mediatek: update bindings for MT7629 SoC
clocksource/drivers/exynos_mct: Fix error path in timer resources initialization
clocksource/drivers/exynos_mct: Remove dead code
clocksource/drivers/riscv: Add required checks during clock source init
dt-bindings: timer: renesas: tmu: Document r8a774c0 bindings
dt-bindings: timer: renesas, cmt: Document r8a774c0 CMT support
clocksource/drivers/exynos_mct: Clear timer interrupt when shutdown
clocksource/drivers/exynos_mct: Move one-shot check from tick clear to ISR
clocksource/drivers/arch_timer: Workaround for Allwinner A64 timer instability
clocksource/drivers/sun5i: Fail gracefully when clock rate is unavailable
timers: Mark expected switch fall-throughs
timekeeping/debug: No need to check return value of debugfs_create functions
...
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Add a "create" module parameter, which allows device-mapper targets to
be configured at boot time. This enables early use of DM targets in the
boot process (as the root device or otherwise) without the need of an
initramfs.
The syntax used in the boot param is based on the concise format from
the dmsetup tool to follow the rule of least surprise:
dmsetup table --concise /dev/mapper/lroot
Which is:
dm-mod.create=<name>,<uuid>,<minor>,<flags>,<table>[,<table>+][;<name>,<uuid>,<minor>,<flags>,<table>[,<table>+]+]
Where,
<name> ::= The device name.
<uuid> ::= xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx | ""
<minor> ::= The device minor number | ""
<flags> ::= "ro" | "rw"
<table> ::= <start_sector> <num_sectors> <target_type> <target_args>
<target_type> ::= "verity" | "linear" | ...
For example, the following could be added in the boot parameters:
dm-mod.create="lroot,,,rw, 0 4096 linear 98:16 0, 4096 4096 linear 98:32 0" root=/dev/dm-0
Only the targets that were tested are allowed and the ones that don't
change any block device when the device is create as read-only. For
example, mirror and cache targets are not allowed. The rationale behind
this is that if the user makes a mistake, choosing the wrong device to
be the mirror or the cache can corrupt data.
The only targets initially allowed are:
* crypt
* delay
* linear
* snapshot-origin
* striped
* verity
Co-developed-by: Will Drewry <[email protected]>
Co-developed-by: Kees Cook <[email protected]>
Co-developed-by: Enric Balletbo i Serra <[email protected]>
Signed-off-by: Helen Koike <[email protected]>
Reviewed-by: Kees Cook <[email protected]>
Signed-off-by: Mike Snitzer <[email protected]>
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A dm-raid array with devices larger than 4GB won't assemble on
a 32 bit host since _check_data_dev_sectors() was added in 4.16.
This is because to_sector() treats its argument as an "unsigned long"
which is 32bits (4GB) on a 32bit host. Using "unsigned long long"
is more correct.
Kernels as early as 4.2 can have other problems due to to_sector()
being used on the size of a device.
Fixes: 0cf4503174c1 ("dm raid: add support for the MD RAID0 personality")
cc: [email protected] (v4.2+)
Reported-and-tested-by: Guillaume Perréal <[email protected]>
Signed-off-by: NeilBrown <[email protected]>
Signed-off-by: Mike Snitzer <[email protected]>
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Pull MIPS updates from Paul Burton:
- Support for the MIPSr6 MemoryMapID register & Global INValidate TLB
(GINVT) instructions, allowing for more efficient TLB maintenance
when running on a CPU such as the I6500 that supports these.
- Enable huge page support for MIPS64r6.
- Optimize post-DMA cache sync by removing that code entirely for
kernel configurations in which we know it won't be needed.
- The number of pages allocated for interrupt stacks is now calculated
correctly, where before we would wastefully allocate too much memory
in some configurations.
- The ath79 platform migrates to devicetree.
- The bcm47xx platform sees fixes for the Buffalo WHR-G54S board.
- The ingenic/jz4740 platform gains support for appended devicetrees.
- The cavium_octeon, lantiq, loongson32 & sgi-ip27 platforms all see
cleanups as do various pieces of core architecture code.
* tag 'mips_5.1' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux: (66 commits)
MIPS: lantiq: Remove separate GPHY Firmware loader
MIPS: ingenic: Add support for appended devicetree
MIPS: SGI-IP27: rework HUB interrupts
MIPS: SGI-IP27: do boot CPU init later
MIPS: SGI-IP27: do xtalk scanning later
MIPS: SGI-IP27: use pr_info/pr_emerg and pr_cont to fix output
MIPS: SGI-IP27: clean up bridge access and header files
MIPS: SGI-IP27: get rid of volatile and hubreg_t
MIPS: irq: Allocate accurate order pages for irq stack
MIPS: dma-noncoherent: Remove bogus condition in dma_sync_phys()
MIPS: eBPF: Remove REG_32BIT_ZERO_EX
MIPS: eBPF: Always return sign extended 32b values
MIPS: CM: Fix indentation
MIPS: BCM47XX: Fix/improve Buffalo WHR-G54S support
MIPS: OCTEON: program rx/tx-delay always from DT
MIPS: OCTEON: delete board-specific link status
MIPS: OCTEON: don't lie about interface type of CN3005 board
MIPS: OCTEON: warn if deprecated link status is being used
MIPS: OCTEON: add fixed-link nodes to in-kernel device tree
MIPS: Delete unused flush_cache_sigtramp()
...
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git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux
Pull s390 updates from Martin Schwidefsky:
- A copy of Arnds compat wrapper generation series
- Pass information about the KVM guest to the host in form the control
program code and the control program version code
- Map IOV resources to support PCI physical functions on s390
- Add vector load and store alignment hints to improve performance
- Use the "jdd" constraint with gcc 9 to make jump labels working again
- Remove amode workaround for old z/VM releases from the DCSS code
- Add support for in-kernel performance measurements using the CPU
measurement counter facility
- Introduce a new PMU device cpum_cf_diag to capture counters and store
thenn as event raw data.
- Bug fixes and cleanups
* tag 's390-5.1-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (54 commits)
Revert "s390/cpum_cf: Add kernel message exaplanations"
s390/dasd: fix read device characteristic with CONFIG_VMAP_STACK=y
s390/suspend: fix prefix register reset in swsusp_arch_resume
s390: warn about clearing als implied facilities
s390: allow overriding facilities via command line
s390: clean up redundant facilities list setup
s390/als: remove duplicated in-place implementation of stfle
s390/cio: Use cpa range elsewhere within vfio-ccw
s390/cio: Fix vfio-ccw handling of recursive TICs
s390: vfio_ap: link the vfio_ap devices to the vfio_ap bus subsystem
s390/cpum_cf: Handle EBUSY return code from CPU counter facility reservation
s390/cpum_cf: Add kernel message exaplanations
s390/cpum_cf_diag: Add support for s390 counter facility diagnostic trace
s390/cpum_cf: add ctr_stcctm() function
s390/cpum_cf: move common functions into a separate file
s390/cpum_cf: introduce kernel_cpumcf_avail() function
s390/cpu_mf: replace stcctm5() with the stcctm() function
s390/cpu_mf: add store cpu counter multiple instruction support
s390/cpum_cf: Add minimal in-kernel interface for counter measurements
s390/cpum_cf: introduce kernel_cpumcf_alert() to obtain measurement alerts
...
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If number of caps exceed the limit, ceph_trim_dentires() also trim
dentries with valid leases. Trimming dentry releases references to
associated inode, which may evict inode and release caps.
By default, there is no limit for caps count.
Signed-off-by: "Yan, Zheng" <[email protected]>
Reviewed-by: Jeff Layton <[email protected]>
Signed-off-by: Ilya Dryomov <[email protected]>
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git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6
Pull crypto update from Herbert Xu:
"API:
- Add helper for simple skcipher modes.
- Add helper to register multiple templates.
- Set CRYPTO_TFM_NEED_KEY when setkey fails.
- Require neither or both of export/import in shash.
- AEAD decryption test vectors are now generated from encryption
ones.
- New option CONFIG_CRYPTO_MANAGER_EXTRA_TESTS that includes random
fuzzing.
Algorithms:
- Conversions to skcipher and helper for many templates.
- Add more test vectors for nhpoly1305 and adiantum.
Drivers:
- Add crypto4xx prng support.
- Add xcbc/cmac/ecb support in caam.
- Add AES support for Exynos5433 in s5p.
- Remove sha384/sha512 from artpec7 as hardware cannot do partial
hash"
[ There is a merge of the Freescale SoC tree in order to pull in changes
required by patches to the caam/qi2 driver. ]
* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: (174 commits)
crypto: s5p - add AES support for Exynos5433
dt-bindings: crypto: document Exynos5433 SlimSSS
crypto: crypto4xx - add missing of_node_put after of_device_is_available
crypto: cavium/zip - fix collision with generic cra_driver_name
crypto: af_alg - use struct_size() in sock_kfree_s()
crypto: caam - remove redundant likely/unlikely annotation
crypto: s5p - update iv after AES-CBC op end
crypto: x86/poly1305 - Clear key material from stack in SSE2 variant
crypto: caam - generate hash keys in-place
crypto: caam - fix DMA mapping xcbc key twice
crypto: caam - fix hash context DMA unmap size
hwrng: bcm2835 - fix probe as platform device
crypto: s5p-sss - Use AES_BLOCK_SIZE define instead of number
crypto: stm32 - drop pointless static qualifier in stm32_hash_remove()
crypto: chelsio - Fixed Traffic Stall
crypto: marvell - Remove set but not used variable 'ivsize'
crypto: ccp - Update driver messages to remove some confusion
crypto: adiantum - add 1536 and 4096-byte test vectors
crypto: nhpoly1305 - add a test vector with len % 16 != 0
crypto: arm/aes-ce - update IV after partial final CTR block
...
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Pull networking updates from David Miller:
"Here we go, another merge window full of networking and #ebpf changes:
1) Snoop DHCPACKS in batman-adv to learn MAC/IP pairs in the DHCP
range without dealing with floods of ARP traffic, from Linus
Lüssing.
2) Throttle buffered multicast packet transmission in mt76, from
Felix Fietkau.
3) Support adaptive interrupt moderation in ice, from Brett Creeley.
4) A lot of struct_size conversions, from Gustavo A. R. Silva.
5) Add peek/push/pop commands to bpftool, as well as bash completion,
from Stanislav Fomichev.
6) Optimize sk_msg_clone(), from Vakul Garg.
7) Add SO_BINDTOIFINDEX, from David Herrmann.
8) Be more conservative with local resends due to local congestion,
from Yuchung Cheng.
9) Allow vetoing of unsupported VXLAN FDBs, from Petr Machata.
10) Add health buffer support to devlink, from Eran Ben Elisha.
11) Add TXQ scheduling API to mac80211, from Toke Høiland-Jørgensen.
12) Add statistics to basic packet scheduler filter, from Cong Wang.
13) Add GRE tunnel support for mlxsw Spectrum-2, from Nir Dotan.
14) Lots of new IP tunneling forwarding tests, also from Nir Dotan.
15) Add 3ad stats to bonding, from Nikolay Aleksandrov.
16) Lots of probing improvements for bpftool, from Quentin Monnet.
17) Various nfp drive #ebpf JIT improvements from Jakub Kicinski.
18) Allow #ebpf programs to access gso_segs from skb shared info, from
Eric Dumazet.
19) Add sock_diag support for AF_XDP sockets, from Björn Töpel.
20) Support 22260 iwlwifi devices, from Luca Coelho.
21) Use rbtree for ipv6 defragmentation, from Peter Oskolkov.
22) Add JMP32 instruction class support to #ebpf, from Jiong Wang.
23) Add spinlock support to #ebpf, from Alexei Starovoitov.
24) Support 256-bit keys and TLS 1.3 in ktls, from Dave Watson.
25) Add device infomation API to devlink, from Jakub Kicinski.
26) Add new timestamping socket options which are y2038 safe, from
Deepa Dinamani.
27) Add RX checksum offloading for various sh_eth chips, from Sergei
Shtylyov.
28) Flow offload infrastructure, from Pablo Neira Ayuso.
29) Numerous cleanups, improvements, and bug fixes to the PHY layer
and many drivers from Heiner Kallweit.
30) Lots of changes to try and make packet scheduler classifiers run
lockless as much as possible, from Vlad Buslov.
31) Support BCM957504 chip in bnxt_en driver, from Erik Burrows.
32) Add concurrency tests to tc-tests infrastructure, from Vlad
Buslov.
33) Add hwmon support to aquantia, from Heiner Kallweit.
34) Allow 64-bit values for SO_MAX_PACING_RATE, from Eric Dumazet.
And I would be remiss if I didn't thank the various major networking
subsystem maintainers for integrating much of this work before I even
saw it. Alexei Starovoitov, Daniel Borkmann, Pablo Neira Ayuso,
Johannes Berg, Kalle Valo, and many others. Thank you!"
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (2207 commits)
net/sched: avoid unused-label warning
net: ignore sysctl_devconf_inherit_init_net without SYSCTL
phy: mdio-mux: fix Kconfig dependencies
net: phy: use phy_modify_mmd_changed in genphy_c45_an_config_aneg
net: dsa: mv88e6xxx: add call to mv88e6xxx_ports_cmode_init to probe for new DSA framework
selftest/net: Remove duplicate header
sky2: Disable MSI on Dell Inspiron 1545 and Gateway P-79
net/mlx5e: Update tx reporter status in case channels were successfully opened
devlink: Add support for direct reporter health state update
devlink: Update reporter state to error even if recover aborted
sctp: call iov_iter_revert() after sending ABORT
team: Free BPF filter when unregistering netdev
ip6mr: Do not call __IP6_INC_STATS() from preemptible context
isdn: mISDN: Fix potential NULL pointer dereference of kzalloc
net: dsa: mv88e6xxx: support in-band signalling on SGMII ports with external PHYs
cxgb4/chtls: Prefix adapter flags with CXGB4
net-sysfs: Switch to bitmap_zalloc()
mellanox: Switch to bitmap_zalloc()
bpf: add test cases for non-pointer sanitiation logic
mlxsw: i2c: Extend initialization by querying resources data
...
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The kill() syscall operates on process identifiers (pid). After a process
has exited its pid can be reused by another process. If a caller sends a
signal to a reused pid it will end up signaling the wrong process. This
issue has often surfaced and there has been a push to address this problem [1].
This patch uses file descriptors (fd) from proc/<pid> as stable handles on
struct pid. Even if a pid is recycled the handle will not change. The fd
can be used to send signals to the process it refers to.
Thus, the new syscall pidfd_send_signal() is introduced to solve this
problem. Instead of pids it operates on process fds (pidfd).
/* prototype and argument /*
long pidfd_send_signal(int pidfd, int sig, siginfo_t *info, unsigned int flags);
/* syscall number 424 */
The syscall number was chosen to be 424 to align with Arnd's rework in his
y2038 to minimize merge conflicts (cf. [25]).
In addition to the pidfd and signal argument it takes an additional
siginfo_t and flags argument. If the siginfo_t argument is NULL then
pidfd_send_signal() is equivalent to kill(<positive-pid>, <signal>). If it
is not NULL pidfd_send_signal() is equivalent to rt_sigqueueinfo().
The flags argument is added to allow for future extensions of this syscall.
It currently needs to be passed as 0. Failing to do so will cause EINVAL.
/* pidfd_send_signal() replaces multiple pid-based syscalls */
The pidfd_send_signal() syscall currently takes on the job of
rt_sigqueueinfo(2) and parts of the functionality of kill(2), Namely, when a
positive pid is passed to kill(2). It will however be possible to also
replace tgkill(2) and rt_tgsigqueueinfo(2) if this syscall is extended.
/* sending signals to threads (tid) and process groups (pgid) */
Specifically, the pidfd_send_signal() syscall does currently not operate on
process groups or threads. This is left for future extensions.
In order to extend the syscall to allow sending signal to threads and
process groups appropriately named flags (e.g. PIDFD_TYPE_PGID, and
PIDFD_TYPE_TID) should be added. This implies that the flags argument will
determine what is signaled and not the file descriptor itself. Put in other
words, grouping in this api is a property of the flags argument not a
property of the file descriptor (cf. [13]). Clarification for this has been
requested by Eric (cf. [19]).
When appropriate extensions through the flags argument are added then
pidfd_send_signal() can additionally replace the part of kill(2) which
operates on process groups as well as the tgkill(2) and
rt_tgsigqueueinfo(2) syscalls.
How such an extension could be implemented has been very roughly sketched
in [14], [15], and [16]. However, this should not be taken as a commitment
to a particular implementation. There might be better ways to do it.
Right now this is intentionally left out to keep this patchset as simple as
possible (cf. [4]).
/* naming */
The syscall had various names throughout iterations of this patchset:
- procfd_signal()
- procfd_send_signal()
- taskfd_send_signal()
In the last round of reviews it was pointed out that given that if the
flags argument decides the scope of the signal instead of different types
of fds it might make sense to either settle for "procfd_" or "pidfd_" as
prefix. The community was willing to accept either (cf. [17] and [18]).
Given that one developer expressed strong preference for the "pidfd_"
prefix (cf. [13]) and with other developers less opinionated about the name
we should settle for "pidfd_" to avoid further bikeshedding.
The "_send_signal" suffix was chosen to reflect the fact that the syscall
takes on the job of multiple syscalls. It is therefore intentional that the
name is not reminiscent of neither kill(2) nor rt_sigqueueinfo(2). Not the
fomer because it might imply that pidfd_send_signal() is a replacement for
kill(2), and not the latter because it is a hassle to remember the correct
spelling - especially for non-native speakers - and because it is not
descriptive enough of what the syscall actually does. The name
"pidfd_send_signal" makes it very clear that its job is to send signals.
/* zombies */
Zombies can be signaled just as any other process. No special error will be
reported since a zombie state is an unreliable state (cf. [3]). However,
this can be added as an extension through the @flags argument if the need
ever arises.
/* cross-namespace signals */
The patch currently enforces that the signaler and signalee either are in
the same pid namespace or that the signaler's pid namespace is an ancestor
of the signalee's pid namespace. This is done for the sake of simplicity
and because it is unclear to what values certain members of struct
siginfo_t would need to be set to (cf. [5], [6]).
/* compat syscalls */
It became clear that we would like to avoid adding compat syscalls
(cf. [7]). The compat syscall handling is now done in kernel/signal.c
itself by adding __copy_siginfo_from_user_generic() which lets us avoid
compat syscalls (cf. [8]). It should be noted that the addition of
__copy_siginfo_from_user_any() is caused by a bug in the original
implementation of rt_sigqueueinfo(2) (cf. 12).
With upcoming rework for syscall handling things might improve
significantly (cf. [11]) and __copy_siginfo_from_user_any() will not gain
any additional callers.
/* testing */
This patch was tested on x64 and x86.
/* userspace usage */
An asciinema recording for the basic functionality can be found under [9].
With this patch a process can be killed via:
#define _GNU_SOURCE
#include <errno.h>
#include <fcntl.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#include <sys/syscall.h>
#include <sys/types.h>
#include <unistd.h>
static inline int do_pidfd_send_signal(int pidfd, int sig, siginfo_t *info,
unsigned int flags)
{
#ifdef __NR_pidfd_send_signal
return syscall(__NR_pidfd_send_signal, pidfd, sig, info, flags);
#else
return -ENOSYS;
#endif
}
int main(int argc, char *argv[])
{
int fd, ret, saved_errno, sig;
if (argc < 3)
exit(EXIT_FAILURE);
fd = open(argv[1], O_DIRECTORY | O_CLOEXEC);
if (fd < 0) {
printf("%s - Failed to open \"%s\"\n", strerror(errno), argv[1]);
exit(EXIT_FAILURE);
}
sig = atoi(argv[2]);
printf("Sending signal %d to process %s\n", sig, argv[1]);
ret = do_pidfd_send_signal(fd, sig, NULL, 0);
saved_errno = errno;
close(fd);
errno = saved_errno;
if (ret < 0) {
printf("%s - Failed to send signal %d to process %s\n",
strerror(errno), sig, argv[1]);
exit(EXIT_FAILURE);
}
exit(EXIT_SUCCESS);
}
/* Q&A
* Given that it seems the same questions get asked again by people who are
* late to the party it makes sense to add a Q&A section to the commit
* message so it's hopefully easier to avoid duplicate threads.
*
* For the sake of progress please consider these arguments settled unless
* there is a new point that desperately needs to be addressed. Please make
* sure to check the links to the threads in this commit message whether
* this has not already been covered.
*/
Q-01: (Florian Weimer [20], Andrew Morton [21])
What happens when the target process has exited?
A-01: Sending the signal will fail with ESRCH (cf. [22]).
Q-02: (Andrew Morton [21])
Is the task_struct pinned by the fd?
A-02: No. A reference to struct pid is kept. struct pid - as far as I
understand - was created exactly for the reason to not require to
pin struct task_struct (cf. [22]).
Q-03: (Andrew Morton [21])
Does the entire procfs directory remain visible? Just one entry
within it?
A-03: The same thing that happens right now when you hold a file descriptor
to /proc/<pid> open (cf. [22]).
Q-04: (Andrew Morton [21])
Does the pid remain reserved?
A-04: No. This patchset guarantees a stable handle not that pids are not
recycled (cf. [22]).
Q-05: (Andrew Morton [21])
Do attempts to signal that fd return errors?
A-05: See {Q,A}-01.
Q-06: (Andrew Morton [22])
Is there a cleaner way of obtaining the fd? Another syscall perhaps.
A-06: Userspace can already trivially retrieve file descriptors from procfs
so this is something that we will need to support anyway. Hence,
there's no immediate need to add another syscalls just to make
pidfd_send_signal() not dependent on the presence of procfs. However,
adding a syscalls to get such file descriptors is planned for a
future patchset (cf. [22]).
Q-07: (Andrew Morton [21] and others)
This fd-for-a-process sounds like a handy thing and people may well
think up other uses for it in the future, probably unrelated to
signals. Are the code and the interface designed to permit such
future applications?
A-07: Yes (cf. [22]).
Q-08: (Andrew Morton [21] and others)
Now I think about it, why a new syscall? This thing is looking
rather like an ioctl?
A-08: This has been extensively discussed. It was agreed that a syscall is
preferred for a variety or reasons. Here are just a few taken from
prior threads. Syscalls are safer than ioctl()s especially when
signaling to fds. Processes are a core kernel concept so a syscall
seems more appropriate. The layout of the syscall with its four
arguments would require the addition of a custom struct for the
ioctl() thereby causing at least the same amount or even more
complexity for userspace than a simple syscall. The new syscall will
replace multiple other pid-based syscalls (see description above).
The file-descriptors-for-processes concept introduced with this
syscall will be extended with other syscalls in the future. See also
[22], [23] and various other threads already linked in here.
Q-09: (Florian Weimer [24])
What happens if you use the new interface with an O_PATH descriptor?
A-09:
pidfds opened as O_PATH fds cannot be used to send signals to a
process (cf. [2]). Signaling processes through pidfds is the
equivalent of writing to a file. Thus, this is not an operation that
operates "purely at the file descriptor level" as required by the
open(2) manpage. See also [4].
/* References */
[1]: https://lore.kernel.org/lkml/[email protected]/
[2]: https://lore.kernel.org/lkml/[email protected]/
[3]: https://lore.kernel.org/lkml/[email protected]/
[4]: https://lore.kernel.org/lkml/[email protected]/
[5]: https://lore.kernel.org/lkml/[email protected]/
[6]: https://lore.kernel.org/lkml/[email protected]/
[7]: https://lore.kernel.org/lkml/[email protected]/
[8]: https://lore.kernel.org/lkml/[email protected]/
[9]: https://asciinema.org/a/IQjuCHew6bnq1cr78yuMv16cy
[11]: https://lore.kernel.org/lkml/[email protected]/
[12]: https://lore.kernel.org/lkml/[email protected]/
[13]: https://lore.kernel.org/lkml/[email protected]/
[14]: https://lore.kernel.org/lkml/[email protected]/
[15]: https://lore.kernel.org/lkml/[email protected]/
[16]: https://lore.kernel.org/lkml/[email protected]/
[17]: https://lore.kernel.org/lkml/CAGXu5jL8PciZAXvOvCeCU3wKUEB_dU-O3q0tDw4uB_ojMvDEew@mail.gmail.com/
[18]: https://lore.kernel.org/lkml/[email protected]/
[19]: https://lore.kernel.org/lkml/[email protected]/
[20]: https://lore.kernel.org/lkml/[email protected]/
[21]: https://lore.kernel.org/lkml/[email protected]/
[22]: https://lore.kernel.org/lkml/[email protected]/
[23]: https://lwn.net/Articles/773459/
[24]: https://lore.kernel.org/lkml/[email protected]/
[25]: https://lore.kernel.org/lkml/CAK8P3a0ej9NcJM8wXNPbcGUyOUZYX+VLoDFdbenW3s3114oQZw@mail.gmail.com/
Cc: "Eric W. Biederman" <[email protected]>
Cc: Jann Horn <[email protected]>
Cc: Andy Lutomirsky <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Oleg Nesterov <[email protected]>
Cc: Al Viro <[email protected]>
Cc: Florian Weimer <[email protected]>
Signed-off-by: Christian Brauner <[email protected]>
Reviewed-by: Tycho Andersen <[email protected]>
Reviewed-by: Kees Cook <[email protected]>
Reviewed-by: David Howells <[email protected]>
Acked-by: Arnd Bergmann <[email protected]>
Acked-by: Thomas Gleixner <[email protected]>
Acked-by: Serge Hallyn <[email protected]>
Acked-by: Aleksa Sarai <[email protected]>
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git://git.kernel.org/pub/scm/linux/kernel/git/j.anaszewski/linux-leds
Pull LED updates from Jacek Anaszewski:
- finalize previously announced support for initialization of pattern
triggers from Device Tree
- fix for null deref on firmware load failure in leds-lp55xx-common.c
* tag 'leds-for-5.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/j.anaszewski/linux-leds:
leds: lp55xx: fix null deref on firmware load failure
leds: trigger: timer: Add initialization from Device Tree
leds: trigger: oneshot: Add initialization from Device Tree
leds: trigger: pattern: Add pattern initialization from Device Tree
leds: Add helper for getting default pattern from Device Tree
dt-bindings: leds: Add pattern initialization from Device Tree
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git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi
Pull spi updates from Mark Brown:
"A fairly quiet release for SPI, the biggest thing is the conversion to
use GPIO descriptors which is now 90% done but still needs some
stragglers converting.
Summary:
- Support for inter-word delays
- Conversion of the core and most drivers to use GPIO descriptors for
GPIO controlled chip selects
- New drivers for NXP FlexSPI and QuadSPI, SiFive and Spreadtrum"
* tag 'spi-v5.1' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi: (104 commits)
spi: sh-msiof: Restrict bits per word to 8/16/24/32 on R-Car Gen2/3
spi: sifive: Remove redundant dev_err call in sifive_spi_probe()
spi: sifive: Remove spi_master_put in sifive_spi_remove()
spi: spi-gpio: fix SPI_CS_HIGH capability
spi: pxa2xx: Setup maximum supported DMA transfer length
spi: sifive: Add driver for the SiFive SPI controller
spi: sifive: Add DT documentation for SiFive SPI controller
spi: sprd: Add a prefix for SPI DMA channel macros
spi: sprd: spi: sprd: Add DMA mode support
dt-bindings: spi: Add the DMA properties for the SPI dma mode
spi: sprd: Add the SPI irq function for the SPI DMA mode
dt-bindings: spi: imx: Add an entry for the i.MX8QM compatible
spi: use gpio[d]_set_value_cansleep for setting chipselect GPIO
spi: gpio: Advertise support for SPI_CS_HIGH
spi: sh-msiof: Replace spi_master by spi_controller
spi: sh-hspi: Replace spi_master by spi_controller
spi: rspi: Replace spi_master by spi_controller
spi: atmel-quadspi: add support for sam9x60 qspi controller
dt-bindings: spi: atmel-quadspi: QuadSPI driver for Microchip SAM9X60
spi: atmel-quadspi: add support for named peripheral clock
...
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git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator
Pull regulator updates from Mark Brown:
"The bulk of the standout changes in this release are cleanups, with
the core work being a combination of factoring out common code into
helpers and the completion of the conversion of the core to use GPIO
descriptors.
Summary:
- Addition of helper functions for current limits and conversion of
drivers to use them by Axel Lin.
- Lots and lots of cleanups from Axel Lin.
- Conversion of the core to use GPIO descriptors rather than numbers
by Linus Walleij.
- New drivers for Maxim MAX77650 and ROHM BD70528"
* tag 'regulator-v5.1' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator: (131 commits)
regulator: mc13xxx: Constify regulator_ops variables
regulator: palmas: Constify palmas_smps_ramp_delay array
regulator: wm831x-dcdc: Convert to use regulator_set/get_current_limit_regmap
regulator: pv88090: Convert to use regulator_set/get_current_limit_regmap
regulator: pv88080: Convert to use regulator_set/get_current_limit_regmap
regulator: pv88060: Convert to use regulator_set/get_current_limit_regmap
regulator: max77650: Convert to use regulator_set/get_current_limit_regmap
regulator: lp873x: Convert to use regulator_set/get_current_limit_regmap
regulator: lp872x: Convert to use regulator_set/get_current_limit_regmap
regulator: da9210: Convert to use regulator_set/get_current_limit_regmap
regulator: da9055: Convert to use regulator_set/get_current_limit_regmap
regulator: core: Add set/get_current_limit helpers for regmap users
regulator: Fix comment for csel_reg and csel_mask
regulator: stm32-vrefbuf: add power management support
regulator: 88pm8607: Remove unused fields from struct pm8607_regulator_info
regulator: 88pm8607: Simplify pm8607_list_voltage implementation
regulator: cpcap: Constify omap4_regulators and xoom_regulators
regulator: cpcap: Remove unused vsel_shift from struct cpcap_regulator
dt-bindings: regulator: tps65218: rectify units of LS3
dt-bindings: regulator: add LS2 load switch documentation
...
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