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Before commit c5b5a3dd2c1f ("mm: thp: refactor NUMA fault handling"), the
TLB flushing is done in do_huge_pmd_numa_page() itself via
flush_tlb_range().
But after commit c5b5a3dd2c1f ("mm: thp: refactor NUMA fault handling"),
the TLB flushing is done in migrate_pages() as in the following code path
anyway.
do_huge_pmd_numa_page
migrate_misplaced_page
migrate_pages
So now, the TLB flushing code in do_huge_pmd_numa_page() becomes
unnecessary. So the code is deleted in this patch to simplify the code.
This is only code cleanup, there's no visible performance difference.
The mmu_notifier_invalidate_range() in do_huge_pmd_numa_page() is
deleted too. Because migrate_pages() takes care of that too when CPU
TLB is flushed.
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: "Huang, Ying" <[email protected]>
Reviewed-by: Zi Yan <[email protected]>
Reviewed-by: Yang Shi <[email protected]>
Cc: Dan Carpenter <[email protected]>
Cc: Mel Gorman <[email protected]>
Cc: Christian Borntraeger <[email protected]>
Cc: Gerald Schaefer <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Hugh Dickins <[email protected]>
Cc: Andrea Arcangeli <[email protected]>
Cc: Kirill A. Shutemov <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Vasily Gorbik <[email protected]>
Cc: Paolo Bonzini <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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flush_kernel_dcache_page is a rather confusing interface that implements a
subset of flush_dcache_page by not being able to properly handle page
cache mapped pages.
The only callers left are in the exec code as all other previous callers
were incorrect as they could have dealt with page cache pages. Replace
the calls to flush_kernel_dcache_page with calls to flush_dcache_page,
which for all architectures does either exactly the same thing, can
contains one or more of the following:
1) an optimization to defer the cache flush for page cache pages not
mapped into userspace
2) additional flushing for mapped page cache pages if cache aliases
are possible
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Christoph Hellwig <[email protected]>
Acked-by: Linus Torvalds <[email protected]>
Reviewed-by: Ira Weiny <[email protected]>
Cc: Alex Shi <[email protected]>
Cc: Geoff Levand <[email protected]>
Cc: Greentime Hu <[email protected]>
Cc: Guo Ren <[email protected]>
Cc: Helge Deller <[email protected]>
Cc: "James E.J. Bottomley" <[email protected]>
Cc: Nick Hu <[email protected]>
Cc: Paul Cercueil <[email protected]>
Cc: Rich Felker <[email protected]>
Cc: Russell King <[email protected]>
Cc: Thomas Bogendoerfer <[email protected]>
Cc: Ulf Hansson <[email protected]>
Cc: Vincent Chen <[email protected]>
Cc: Yoshinori Sato <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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Pages used in scatterlist can be mapped page cache pages (and often are),
so we must use flush_dcache_page here instead of the more limited
flush_kernel_dcache_page that is intended for highmem pages only.
Also remove the PageSlab check given that page_mapping_file as used by the
flush_dcache_page implementations already contains that check.
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Christoph Hellwig <[email protected]>
Acked-by: Linus Torvalds <[email protected]>
Cc: Alex Shi <[email protected]>
Cc: Geoff Levand <[email protected]>
Cc: Greentime Hu <[email protected]>
Cc: Guo Ren <[email protected]>
Cc: Helge Deller <[email protected]>
Cc: "James E.J. Bottomley" <[email protected]>
Cc: Nick Hu <[email protected]>
Cc: Paul Cercueil <[email protected]>
Cc: Rich Felker <[email protected]>
Cc: Russell King <[email protected]>
Cc: Thomas Bogendoerfer <[email protected]>
Cc: Ulf Hansson <[email protected]>
Cc: Vincent Chen <[email protected]>
Cc: Yoshinori Sato <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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Pages passed to block drivers can be mapped page cache pages, so we must
use flush_dcache_page here instead of the more limited
flush_kernel_dcache_page that is intended for highmem pages only.
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Christoph Hellwig <[email protected]>
Acked-by: Linus Torvalds <[email protected]>
Cc: Alex Shi <[email protected]>
Cc: Geoff Levand <[email protected]>
Cc: Greentime Hu <[email protected]>
Cc: Guo Ren <[email protected]>
Cc: Helge Deller <[email protected]>
Cc: "James E.J. Bottomley" <[email protected]>
Cc: Nick Hu <[email protected]>
Cc: Paul Cercueil <[email protected]>
Cc: Rich Felker <[email protected]>
Cc: Russell King <[email protected]>
Cc: Thomas Bogendoerfer <[email protected]>
Cc: Ulf Hansson <[email protected]>
Cc: Vincent Chen <[email protected]>
Cc: Yoshinori Sato <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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Patch series "_kernel_dcache_page fixes and removal".
While looking to convert the block layer away from kmap_atomic towards
kmap_local_page and prefeably the helpers that abstract it away I noticed
that a few block drivers directly or implicitly call
flush_kernel_dcache_page before kunmapping a page that has been written
to.
flush_kernel_dcache_page is documented to to be used in such cases, but
flush_dcache_page is actually required when the page could be in the page
cache and mapped to userspace, which is pretty much always the case when
kmapping an arbitrary page. Unfortunately the documentation doesn't
exactly make that clear, which lead to this misused. And it turns out
that only the copy_strings / copy_string_kernel in the exec code were
actually correct users of flush_kernel_dcache_page, which is why I think
we should just remove it and eat the very minor overhead in exec rather
than confusing poor driver writers.
This patch (of 6):
MIPS now implements flush_kernel_dcache_page (as an alias to
flush_dcache_page).
Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Christoph Hellwig <[email protected]>
Acked-by: Linus Torvalds <[email protected]>
Cc: "James E.J. Bottomley" <[email protected]>
Cc: Russell King <[email protected]>
Cc: Guo Ren <[email protected]>
Cc: Thomas Bogendoerfer <[email protected]>
Cc: Nick Hu <[email protected]>
Cc: Greentime Hu <[email protected]>
Cc: Vincent Chen <[email protected]>
Cc: Helge Deller <[email protected]>
Cc: Yoshinori Sato <[email protected]>
Cc: Rich Felker <[email protected]>
Cc: Geoff Levand <[email protected]>
Cc: Paul Cercueil <[email protected]>
Cc: Ulf Hansson <[email protected]>
Cc: Alex Shi <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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There is a spelling mistake in an error message. Fix it.
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Colin Ian King <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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There are several test cases in the vm directory are still using exit 0
when they need to be skipped. Use the kselftest framework to skip code
instead so it can help us to distinguish the return status.
Criterion to filter out what should be fixed in vm directory:
grep -r "exit 0" -B1 | grep -i skip
This change might cause some false-positives if people are running these
test scripts directly and only checking their return codes, which will
change from 0 to 4. However I think the impact should be small as most of
our scripts here are already using this skip code. And there will be no
such issue if running them with the kselftest framework.
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Po-Hsu Lin <[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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The memcg->event_list_lock is usually taken in the normal context but when
the userspace closes the corresponding eventfd, eventfd_release through
memcg_event_wake takes memcg->event_list_lock with interrupts disabled.
This is not an issue on its own but it creates a nested dependency from
eventfd_ctx->wqh.lock to memcg->event_list_lock.
Independently, for unrelated eventfd, eventfd_signal() can be called in
the irq context, thus making eventfd_ctx->wqh.lock an irq lock. For
example, FPGA DFL driver, VHOST VPDA driver and couple of VFIO drivers.
This will force memcg->event_list_lock to be an irqsafe lock as well.
One way to break the nested dependency between eventfd_ctx->wqh.lock and
memcg->event_list_lock is to add an indirection. However the simplest
solution would be to make memcg->event_list_lock irqsafe. This is cgroup
v1 feature, is in maintenance and may get deprecated in near future. So,
no need to add more code.
BTW this has been discussed previously [1] but there weren't irq users of
eventfd_signal() at the time.
[1] https://www.spinics.net/lists/cgroups/msg06248.html
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Shakeel Butt <[email protected]>
Cc: Tejun Heo <[email protected]>
Cc: Johannes Weiner <[email protected]>
Cc: Michal Hocko <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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Thomas and Vlastimil have noticed that the comment in drain_local_stock
doesn't quite make sense. It talks about a synchronization with the
memory hotplug but there is no actual memory hotplug involvement here. I
meant to talk about cpu hotplug here. Fix that up and hopefuly make the
comment more helpful by referencing the cpu hotplug callback as well.
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Michal Hocko <[email protected]>
Acked-by: Vlastimil Babka <[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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Add 'else' to save some atomic ops in obj_stock_flush_required() when
flush is already true. No functional change intended here.
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Miaohe Lin <[email protected]>
Reviewed-by: Shakeel Butt <[email protected]>
Reviewed-by: Muchun Song <[email protected]>
Acked-by: Roman Gushchin <[email protected]>
Acked-by: Michal Hocko <[email protected]>
Cc: Vladimir Davydov <[email protected]>
Cc: Muchun Song <[email protected]>
Cc: Matthew Wilcox (Oracle) <[email protected]>
Cc: Alex Shi <[email protected]>
Cc: Wei Yang <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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Since commit 2d146aa3aa84 ("mm: memcontrol: switch to rstat"), last user
of memcg_stat_item_in_bytes() is gone. And since commit fa40d1ee9f15
("mm: vmscan: memcontrol: remove mem_cgroup_select_victim_node()"), only
the declaration of mem_cgroup_select_victim_node() is remained here.
Remove them.
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Miaohe Lin <[email protected]>
Reviewed-by: Shakeel Butt <[email protected]>
Reviewed-by: Muchun Song <[email protected]>
Acked-by: Roman Gushchin <[email protected]>
Acked-by: Michal Hocko <[email protected]>
Cc: Alex Shi <[email protected]>
Cc: Matthew Wilcox (Oracle) <[email protected]>
Cc: Vladimir Davydov <[email protected]>
Cc: Wei Yang <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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Since commit c843966c556d ("mm: allow swappiness that prefers reclaiming
anon over the file workingset") has expended the swappiness value to make
swap to be preferred in some systems. We should also change the memcg
swappiness restriction to allow memcg swap-preferred.
Link: https://lkml.kernel.org/r/d77469b90c45c49953ccbc51e54a1d465bc18f70.1627626255.git.baolin.wang@linux.alibaba.com
Fixes: c843966c556d ("mm: allow swappiness that prefers reclaiming anon over the file workingset")
Signed-off-by: Baolin Wang <[email protected]>
Acked-by: Michal Hocko <[email protected]>
Cc: Johannes Weiner <[email protected]>
Cc: Vladimir Davydov <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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set_active_memcg() uses in_interrupt() check to select proper storage for
cgroup: pointer on task struct or per-cpu pointer.
It isn't fully correct: obsoleted in_interrupt() includes tasks with
disabled BH. It's better to use '!in_task()' instead.
Link: https://lkml.org/lkml/2021/7/26/487
Link: https://lkml.kernel.org/r/[email protected]
Fixes: 37d5985c003d ("mm: kmem: prepare remote memcg charging infra for interrupt contexts")
Signed-off-by: Vasily Averin <[email protected]>
Reviewed-by: Shakeel Butt <[email protected]>
Cc: Johannes Weiner <[email protected]>
Cc: Michal Hocko <[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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We used to have per-cpu memcg and lruvec stats and the readers have to
traverse and sum the stats from each cpu. This summing was racy and may
expose transient negative values. So, an explicit check was added to
avoid such scenarios. Now these stats are moved to rstat infrastructure
and are no more per-cpu, so we can remove the fixup for transient negative
values.
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Shakeel Butt <[email protected]>
Acked-by: Roman Gushchin <[email protected]>
Reviewed-by: David Hildenbrand <[email protected]>
Acked-by: Michal Hocko <[email protected]>
Cc: Johannes Weiner <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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Each task can request own LDT and force the kernel to allocate up to 64Kb
memory per-mm.
There are legitimate workloads with hundreds of processes and there can be
hundreds of workloads running on large machines. The unaccounted memory
can cause isolation issues between the workloads particularly on highly
utilized machines.
It makes sense to account for this objects to restrict the host's memory
consumption from inside the memcg-limited container.
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Vasily Averin <[email protected]>
Acked-by: Borislav Petkov <[email protected]>
Reviewed-by: Shakeel Butt <[email protected]>
Cc: Alexander Viro <[email protected]>
Cc: Alexey Dobriyan <[email protected]>
Cc: Andrei Vagin <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Christian Brauner <[email protected]>
Cc: Dmitry Safonov <[email protected]>
Cc: "Eric W. Biederman" <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: "H. Peter Anvin" <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: "J. Bruce Fields" <[email protected]>
Cc: Jeff Layton <[email protected]>
Cc: Jens Axboe <[email protected]>
Cc: Jiri Slaby <[email protected]>
Cc: Johannes Weiner <[email protected]>
Cc: Kirill Tkhai <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Oleg Nesterov <[email protected]>
Cc: Roman Gushchin <[email protected]>
Cc: Serge Hallyn <[email protected]>
Cc: Tejun Heo <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Vladimir Davydov <[email protected]>
Cc: Yutian Yang <[email protected]>
Cc: Zefan Li <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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A program may create multiple interval timers using timer_create(). For
each timer the kernel preallocates a "queued real-time signal",
Consequently, the number of timers is limited by the RLIMIT_SIGPENDING
resource limit. The allocated object is quite small, ~250 bytes, but even
the default signal limits allow to consume up to 100 megabytes per user.
It makes sense to account for them to limit the host's memory consumption
from inside the memcg-limited container.
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Vasily Averin <[email protected]>
Reviewed-by: Thomas Gleixner <[email protected]>
Reviewed-by: Shakeel Butt <[email protected]>
Cc: Alexander Viro <[email protected]>
Cc: Alexey Dobriyan <[email protected]>
Cc: Andrei Vagin <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Christian Brauner <[email protected]>
Cc: Dmitry Safonov <[email protected]>
Cc: "Eric W. Biederman" <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: "H. Peter Anvin" <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: "J. Bruce Fields" <[email protected]>
Cc: Jeff Layton <[email protected]>
Cc: Jens Axboe <[email protected]>
Cc: Jiri Slaby <[email protected]>
Cc: Johannes Weiner <[email protected]>
Cc: Kirill Tkhai <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Oleg Nesterov <[email protected]>
Cc: Roman Gushchin <[email protected]>
Cc: Serge Hallyn <[email protected]>
Cc: Tejun Heo <[email protected]>
Cc: Vladimir Davydov <[email protected]>
Cc: Yutian Yang <[email protected]>
Cc: Zefan Li <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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When a user send a signal to any another processes it forces the kernel to
allocate memory for 'struct sigqueue' objects. The number of signals is
limited by RLIMIT_SIGPENDING resource limit, but even the default settings
allow each user to consume up to several megabytes of memory.
It makes sense to account for these allocations to restrict the host's
memory consumption from inside the memcg-limited container.
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Vasily Averin <[email protected]>
Reviewed-by: Shakeel Butt <[email protected]>
Cc: Alexander Viro <[email protected]>
Cc: Alexey Dobriyan <[email protected]>
Cc: Andrei Vagin <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Christian Brauner <[email protected]>
Cc: Dmitry Safonov <[email protected]>
Cc: "Eric W. Biederman" <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: "H. Peter Anvin" <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: "J. Bruce Fields" <[email protected]>
Cc: Jeff Layton <[email protected]>
Cc: Jens Axboe <[email protected]>
Cc: Jiri Slaby <[email protected]>
Cc: Johannes Weiner <[email protected]>
Cc: Kirill Tkhai <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Oleg Nesterov <[email protected]>
Cc: Roman Gushchin <[email protected]>
Cc: Serge Hallyn <[email protected]>
Cc: Tejun Heo <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Vladimir Davydov <[email protected]>
Cc: Yutian Yang <[email protected]>
Cc: Zefan Li <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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When user creates IPC objects it forces kernel to allocate memory for
these long-living objects.
It makes sense to account them to restrict the host's memory consumption
from inside the memcg-limited container.
This patch enables accounting for IPC shared memory segments, messages
semaphores and semaphore's undo lists.
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Vasily Averin <[email protected]>
Reviewed-by: Shakeel Butt <[email protected]>
Cc: Alexander Viro <[email protected]>
Cc: Alexey Dobriyan <[email protected]>
Cc: Andrei Vagin <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Christian Brauner <[email protected]>
Cc: Dmitry Safonov <[email protected]>
Cc: "Eric W. Biederman" <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: "H. Peter Anvin" <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: "J. Bruce Fields" <[email protected]>
Cc: Jeff Layton <[email protected]>
Cc: Jens Axboe <[email protected]>
Cc: Jiri Slaby <[email protected]>
Cc: Johannes Weiner <[email protected]>
Cc: Kirill Tkhai <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Oleg Nesterov <[email protected]>
Cc: Roman Gushchin <[email protected]>
Cc: Serge Hallyn <[email protected]>
Cc: Tejun Heo <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Vladimir Davydov <[email protected]>
Cc: Yutian Yang <[email protected]>
Cc: Zefan Li <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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Container admin can create new namespaces and force kernel to allocate up
to several pages of memory for the namespaces and its associated
structures.
Net and uts namespaces have enabled accounting for such allocations. It
makes sense to account for rest ones to restrict the host's memory
consumption from inside the memcg-limited container.
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Vasily Averin <[email protected]>
Acked-by: Serge Hallyn <[email protected]>
Acked-by: Christian Brauner <[email protected]>
Acked-by: Kirill Tkhai <[email protected]>
Reviewed-by: Shakeel Butt <[email protected]>
Cc: Alexander Viro <[email protected]>
Cc: Alexey Dobriyan <[email protected]>
Cc: Andrei Vagin <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Dmitry Safonov <[email protected]>
Cc: "Eric W. Biederman" <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: "H. Peter Anvin" <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: "J. Bruce Fields" <[email protected]>
Cc: Jeff Layton <[email protected]>
Cc: Jens Axboe <[email protected]>
Cc: Jiri Slaby <[email protected]>
Cc: Johannes Weiner <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Oleg Nesterov <[email protected]>
Cc: Roman Gushchin <[email protected]>
Cc: Tejun Heo <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Vladimir Davydov <[email protected]>
Cc: Yutian Yang <[email protected]>
Cc: Zefan Li <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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fasync_struct is used by almost all character device drivers to set up the
fasync queue, and for regular files by the file lease code. This
structure is quite small but long-living and it can be assigned for any
open file.
It makes sense to account for its allocations to restrict the host's
memory consumption from inside the memcg-limited container.
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Vasily Averin <[email protected]>
Reviewed-by: Shakeel Butt <[email protected]>
Cc: Alexander Viro <[email protected]>
Cc: Alexey Dobriyan <[email protected]>
Cc: Andrei Vagin <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Christian Brauner <[email protected]>
Cc: Dmitry Safonov <[email protected]>
Cc: "Eric W. Biederman" <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: "H. Peter Anvin" <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: "J. Bruce Fields" <[email protected]>
Cc: Jeff Layton <[email protected]>
Cc: Jens Axboe <[email protected]>
Cc: Jiri Slaby <[email protected]>
Cc: Johannes Weiner <[email protected]>
Cc: Kirill Tkhai <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Oleg Nesterov <[email protected]>
Cc: Roman Gushchin <[email protected]>
Cc: Serge Hallyn <[email protected]>
Cc: Tejun Heo <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Vladimir Davydov <[email protected]>
Cc: Yutian Yang <[email protected]>
Cc: Zefan Li <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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User can create file locks for each open file and force kernel to allocate
small but long-living objects per each open file.
It makes sense to account for these objects to limit the host's memory
consumption from inside the memcg-limited container.
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Vasily Averin <[email protected]>
Reviewed-by: Shakeel Butt <[email protected]>
Cc: Alexander Viro <[email protected]>
Cc: Alexey Dobriyan <[email protected]>
Cc: Andrei Vagin <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Christian Brauner <[email protected]>
Cc: Dmitry Safonov <[email protected]>
Cc: "Eric W. Biederman" <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: "H. Peter Anvin" <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: "J. Bruce Fields" <[email protected]>
Cc: Jeff Layton <[email protected]>
Cc: Jens Axboe <[email protected]>
Cc: Jiri Slaby <[email protected]>
Cc: Johannes Weiner <[email protected]>
Cc: Kirill Tkhai <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Oleg Nesterov <[email protected]>
Cc: Roman Gushchin <[email protected]>
Cc: Serge Hallyn <[email protected]>
Cc: Tejun Heo <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Vladimir Davydov <[email protected]>
Cc: Yutian Yang <[email protected]>
Cc: Zefan Li <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
|
|
User can call select/poll system calls with a large number of assigned
file descriptors and force kernel to allocate up to several pages of
memory till end of these sleeping system calls. We have here long-living
unaccounted per-task allocations.
It makes sense to account for these allocations to restrict the host's
memory consumption from inside the memcg-limited container.
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Vasily Averin <[email protected]>
Reviewed-by: Shakeel Butt <[email protected]>
Cc: Alexander Viro <[email protected]>
Cc: Alexey Dobriyan <[email protected]>
Cc: Andrei Vagin <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Christian Brauner <[email protected]>
Cc: Dmitry Safonov <[email protected]>
Cc: "Eric W. Biederman" <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: "H. Peter Anvin" <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: "J. Bruce Fields" <[email protected]>
Cc: Jeff Layton <[email protected]>
Cc: Jens Axboe <[email protected]>
Cc: Jiri Slaby <[email protected]>
Cc: Johannes Weiner <[email protected]>
Cc: Kirill Tkhai <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Oleg Nesterov <[email protected]>
Cc: Roman Gushchin <[email protected]>
Cc: Serge Hallyn <[email protected]>
Cc: Tejun Heo <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Vladimir Davydov <[email protected]>
Cc: Yutian Yang <[email protected]>
Cc: Zefan Li <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
|
|
Patch series "memcg accounting from OpenVZ", v7.
OpenVZ uses memory accounting 20+ years since v2.2.x linux kernels.
Initially we used our own accounting subsystem, then partially committed
it to upstream, and a few years ago switched to cgroups v1. Now we're
rebasing again, revising our old patches and trying to push them upstream.
We try to protect the host system from any misuse of kernel memory
allocation triggered by untrusted users inside the containers.
Patch-set is addressed mostly to cgroups maintainers and cgroups@ mailing
list, though I would be very grateful for any comments from maintainersi
of affected subsystems or other people added in cc:
Compared to the upstream, we additionally account the following kernel objects:
- network devices and its Tx/Rx queues
- ipv4/v6 addresses and routing-related objects
- inet_bind_bucket cache objects
- VLAN group arrays
- ipv6/sit: ip_tunnel_prl
- scm_fp_list objects used by SCM_RIGHTS messages of Unix sockets
- nsproxy and namespace objects itself
- IPC objects: semaphores, message queues and share memory segments
- mounts
- pollfd and select bits arrays
- signals and posix timers
- file lock
- fasync_struct used by the file lease code and driver's fasync queues
- tty objects
- per-mm LDT
We have an incorrect/incomplete/obsoleted accounting for few other kernel
objects: sk_filter, af_packets, netlink and xt_counters for iptables.
They require rework and probably will be dropped at all.
Also we're going to add an accounting for nft, however it is not ready
yet.
We have not tested performance on upstream, however, our performance team
compares our current RHEL7-based production kernel and reports that they
are at least not worse as the according original RHEL7 kernel.
This patch (of 10):
The kernel allocates ~400 bytes of 'struct mount' for any new mount.
Creating a new mount namespace clones most of the parent mounts, and this
can be repeated many times. Additionally, each mount allocates up to
PATH_MAX=4096 bytes for mnt->mnt_devname.
It makes sense to account for these allocations to restrict the host's
memory consumption from inside the memcg-limited container.
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Vasily Averin <[email protected]>
Reviewed-by: Shakeel Butt <[email protected]>
Acked-by: Christian Brauner <[email protected]>
Cc: Tejun Heo <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Johannes Weiner <[email protected]>
Cc: Vladimir Davydov <[email protected]>
Cc: Roman Gushchin <[email protected]>
Cc: Yutian Yang <[email protected]>
Cc: Alexander Viro <[email protected]>
Cc: Alexey Dobriyan <[email protected]>
Cc: Andrei Vagin <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Dmitry Safonov <[email protected]>
Cc: "Eric W. Biederman" <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: "H. Peter Anvin" <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: "J. Bruce Fields" <[email protected]>
Cc: Jeff Layton <[email protected]>
Cc: Jens Axboe <[email protected]>
Cc: Jiri Slaby <[email protected]>
Cc: Kirill Tkhai <[email protected]>
Cc: Oleg Nesterov <[email protected]>
Cc: Serge Hallyn <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Zefan Li <[email protected]>
Cc: Borislav Petkov <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
|
|
This patch adds accounting flags to fs_context and legacy_fs_context
allocation sites so that kernel could correctly charge these objects.
We have written a PoC to demonstrate the effect of the missing-charging
bugs. The PoC takes around 1,200MB unaccounted memory, while it is
charged for only 362MB memory usage. We evaluate the PoC on QEMU x86_64
v5.2.90 + Linux kernel v5.10.19 + Debian buster. All the limitations
including ulimits and sysctl variables are set as default. Specifically,
the hard NOFILE limit and nr_open in sysctl are both 1,048,576.
/*------------------------- POC code ----------------------------*/
#define _GNU_SOURCE
#include <sys/types.h>
#include <sys/file.h>
#include <time.h>
#include <sys/wait.h>
#include <stdint.h>
#include <stdlib.h>
#include <unistd.h>
#include <stdio.h>
#include <signal.h>
#include <sched.h>
#include <fcntl.h>
#include <linux/mount.h>
#define errExit(msg) do { perror(msg); exit(EXIT_FAILURE); \
} while (0)
#define STACK_SIZE (8 * 1024)
#ifndef __NR_fsopen
#define __NR_fsopen 430
#endif
static inline int fsopen(const char *fs_name, unsigned int flags)
{
return syscall(__NR_fsopen, fs_name, flags);
}
static char thread_stack[512][STACK_SIZE];
int thread_fn(void* arg)
{
for (int i = 0; i< 800000; ++i) {
int fsfd = fsopen("nfs", FSOPEN_CLOEXEC);
if (fsfd == -1) {
errExit("fsopen");
}
}
while(1);
return 0;
}
int main(int argc, char *argv[]) {
int thread_pid;
for (int i = 0; i < 1; ++i) {
thread_pid = clone(thread_fn, thread_stack[i] + STACK_SIZE, \
SIGCHLD, NULL);
}
while(1);
return 0;
}
/*-------------------------- end --------------------------------*/
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Yutian Yang <[email protected]>
Reviewed-by: Shakeel Butt <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Johannes Weiner <[email protected]>
Cc: Vladimir Davydov <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
|
|
At the moment memcg stats are read in four contexts:
1. memcg stat user interfaces
2. dirty throttling
3. page fault
4. memory reclaim
Currently the kernel flushes the stats for first two cases. Flushing the
stats for remaining two casese may have performance impact. Always
flushing the memcg stats on the page fault code path may negatively
impacts the performance of the applications. In addition flushing in the
memory reclaim code path, though treated as slowpath, can become the
source of contention for the global lock taken for stat flushing because
when system or memcg is under memory pressure, many tasks may enter the
reclaim path.
This patch uses following mechanisms to solve these challenges:
1. Periodically flush the stats from root memcg every 2 seconds. This
will time limit the out of sync stats.
2. Asynchronously flush the stats after fixed number of stat updates.
In the worst case the stat can be out of sync by O(nr_cpus * BATCH) for
2 seconds.
3. For avoiding thundering herd to flush the stats particularly from
the memory reclaim context, introduce memcg local spinlock and let only
one flusher active at a time. This could have been done through
cgroup_rstat_lock lock but that lock is used by other subsystem and for
userspace reading memcg stats. So, it is better to keep flushers
introduced by this patch decoupled from cgroup_rstat_lock. However we
would have to use irqsafe version of rstat flush but that is fine as
this code path will be flushing for whole tree and do the work for
everyone. No one will be waiting for that worker.
[[email protected]: fix sleep-in-wrong context bug]
Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Shakeel Butt <[email protected]>
Tested-by: Marek Szyprowski <[email protected]>
Cc: Hillf Danton <[email protected]>
Cc: Huang Ying <[email protected]>
Cc: Johannes Weiner <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Michal Koutný <[email protected]>
Cc: Muchun Song <[email protected]>
Cc: Roman Gushchin <[email protected]>
Cc: Tejun Heo <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
|
|
The commit 2d146aa3aa84 ("mm: memcontrol: switch to rstat") switched memcg
stats to rstat infrastructure but skipped the conversion of the lruvec
stats as such stats are read in the performance critical code paths and
flushing stats may have impacted the performances of the applications.
This patch converts the lruvec stats to rstat and later patches add
mechanisms to keep the performance impact to minimum.
The rstat conversion comes with the price i.e. memory cost. Effectively
this patch reverts the savings done by the commit f3344adf38bd ("mm:
memcontrol: optimize per-lruvec stats counter memory usage"). However
this cost is justified due to negative impact of the inaccurate lruvec
stats on many heuristics. One such case is reported in [1].
The memory reclaim code is filled with plethora of heuristics and many of
those heuristics reads the lruvec stats. So, inaccurate stats can make
such heuristics ineffective. [1] reports the impact of inaccurate lruvec
stats on the "cache trim mode" heuristic. Inaccurate lruvec stats can
impact the deactivation and aging anon heuristics as well.
[1] https://lore.kernel.org/linux-mm/[email protected]/
Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Shakeel Butt <[email protected]>
Cc: Tejun Heo <[email protected]>
Cc: Johannes Weiner <[email protected]>
Cc: Muchun Song <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Roman Gushchin <[email protected]>
Cc: Huang Ying <[email protected]>
Cc: Hillf Danton <[email protected]>
Cc: Michal Koutný <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
|
|
Commit 5d097056c9a0 ("kmemcg: account certain kmem allocations to memcg")
enabled memcg accounting for pids allocated from init_pid_ns.pid_cachep,
but forgot to adjust the setting for nested pid namespaces. As a result,
pid memory is not accounted exactly where it is really needed, inside
memcg-limited containers with their own pid namespaces.
Pid was one the first kernel objects enabled for memcg accounting.
init_pid_ns.pid_cachep marked by SLAB_ACCOUNT and we can expect that any
new pids in the system are memcg-accounted.
Though recently I've noticed that it is wrong. nested pid namespaces
creates own slab caches for pid objects, nested pids have increased size
because contain id both for all parent and for own pid namespaces. The
problem is that these slab caches are _NOT_ marked by SLAB_ACCOUNT, as a
result any pids allocated in nested pid namespaces are not
memcg-accounted.
Pid struct in nested pid namespace consumes up to 500 bytes memory, 100000
such objects gives us up to ~50Mb unaccounted memory, this allow container
to exceed assigned memcg limits.
Link: https://lkml.kernel.org/r/[email protected]
Fixes: 5d097056c9a0 ("kmemcg: account certain kmem allocations to memcg")
Cc: [email protected]
Signed-off-by: Vasily Averin <[email protected]>
Reviewed-by: Michal Koutný <[email protected]>
Reviewed-by: Shakeel Butt <[email protected]>
Acked-by: Christian Brauner <[email protected]>
Acked-by: Roman Gushchin <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Johannes Weiner <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
|
|
Inline mem_cgroup_try_charge_swap, mem_cgroup_uncharge_swap and
cgroup_throttle_swaprate functions to perform mem_cgroup_disabled static
key check inline before calling the main body of the function. This
minimizes the memcg overhead in the pagefault and exit_mmap paths when
memcgs are disabled using cgroup_disable=memory command-line option. This
change results in ~1% overhead reduction when running PFT test [1]
comparing {CONFIG_MEMCG=n} against {CONFIG_MEMCG=y, cgroup_disable=memory}
configuration on an 8-core ARM64 Android device.
[1] https://lkml.org/lkml/2006/8/29/294 also used in mmtests suite
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Suren Baghdasaryan <[email protected]>
Reviewed-by: Shakeel Butt <[email protected]>
Reviewed-by: Muchun Song <[email protected]>
Acked-by: Johannes Weiner <[email protected]>
Acked-by: Michal Hocko <[email protected]>
Cc: Tejun Heo <[email protected]>
Cc: Roman Gushchin <[email protected]>
Cc: Yang Shi <[email protected]>
Cc: Alex Shi <[email protected]>
Cc: Wei Yang <[email protected]>
Cc: Jens Axboe <[email protected]>
Cc: Joonsoo Kim <[email protected]>
Cc: David Hildenbrand <[email protected]>
Cc: Matthew Wilcox (Oracle) <[email protected]>
Cc: Alistair Popple <[email protected]>
Cc: Minchan Kim <[email protected]>
Cc: Miaohe Lin <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
|
|
Inline mem_cgroup_{charge/uncharge} and mem_cgroup_uncharge_list functions
functions to perform mem_cgroup_disabled static key check inline before
calling the main body of the function. This minimizes the memcg overhead
in the pagefault and exit_mmap paths when memcgs are disabled using
cgroup_disable=memory command-line option.
This change results in ~0.4% overhead reduction when running PFT test [1]
comparing {CONFIG_MEMCG=n} against {CONFIG_MEMCG=y, cgroup_disable=memory}
configuration on an 8-core ARM64 Android device.
[1] https://lkml.org/lkml/2006/8/29/294 also used in mmtests suite
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Suren Baghdasaryan <[email protected]>
Reviewed-by: Shakeel Butt <[email protected]>
Reviewed-by: Muchun Song <[email protected]>
Acked-by: Michal Hocko <[email protected]>
Acked-by: Johannes Weiner <[email protected]>
Cc: Alex Shi <[email protected]>
Cc: Alistair Popple <[email protected]>
Cc: David Hildenbrand <[email protected]>
Cc: Jens Axboe <[email protected]>
Cc: Joonsoo Kim <[email protected]>
Cc: Matthew Wilcox (Oracle) <[email protected]>
Cc: Miaohe Lin <[email protected]>
Cc: Minchan Kim <[email protected]>
Cc: Roman Gushchin <[email protected]>
Cc: Tejun Heo <[email protected]>
Cc: Wei Yang <[email protected]>
Cc: Yang Shi <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
|
|
functions
Add mem_cgroup_disabled check in vmpressure, mem_cgroup_uncharge_swap and
cgroup_throttle_swaprate functions. This minimizes the memcg overhead in
the pagefault and exit_mmap paths when memcgs are disabled using
cgroup_disable=memory command-line option.
This change results in ~2.1% overhead reduction when running PFT test [1]
comparing {CONFIG_MEMCG=n, CONFIG_MEMCG_SWAP=n} against {CONFIG_MEMCG=y,
CONFIG_MEMCG_SWAP=y, cgroup_disable=memory} configuration on an 8-core
ARM64 Android device.
[1] https://lkml.org/lkml/2006/8/29/294 also used in mmtests suite
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Suren Baghdasaryan <[email protected]>
Reviewed-by: Shakeel Butt <[email protected]>
Reviewed-by: Muchun Song <[email protected]>
Acked-by: Johannes Weiner <[email protected]>
Acked-by: Michal Hocko <[email protected]>
Cc: Alex Shi <[email protected]>
Cc: Alistair Popple <[email protected]>
Cc: David Hildenbrand <[email protected]>
Cc: Jens Axboe <[email protected]>
Cc: Joonsoo Kim <[email protected]>
Cc: Matthew Wilcox (Oracle) <[email protected]>
Cc: Miaohe Lin <[email protected]>
Cc: Minchan Kim <[email protected]>
Cc: Roman Gushchin <[email protected]>
Cc: Tejun Heo <[email protected]>
Cc: Wei Yang <[email protected]>
Cc: Yang Shi <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
|
|
drivers/gpu/drm/i915/gem/i915_gem_shmem.c contains a shmem_writeback()
which calls shmem_writepage() from a shrinker: that usually works well
enough; but if /sys/kernel/mm/transparent_hugepage/shmem_enabled has been
set to "always" (intended to be usable) or "force" (forces huge everywhere
for easy testing), shmem_writepage() is surprised to be called with a huge
page, and crashes on the VM_BUG_ON_PAGE(PageCompound) (I did not find out
where the crash happens when CONFIG_DEBUG_VM is off).
LRU page reclaim always splits the shmem huge page first: I'd prefer not
to demand that of i915, so check and split compound in shmem_writepage().
Patch history: when first sent last year
http://lkml.kernel.org/r/[email protected]
https://lore.kernel.org/linux-mm/20200919042009.bomzxmrg7%[email protected]/
Matthew Wilcox noticed that tail pages were wrongly left clean. This
version brackets the split with Set and Clear PageDirty as he suggested:
which works very well, even if it falls short of our aspirations. And
recently I realized that the crash is not limited to the testing option
"force", but affects "always" too: which is more important to fix.
Link: https://lkml.kernel.org/r/[email protected]
Fixes: 2d6692e642e7 ("drm/i915: Start writeback from the shrinker")
Signed-off-by: Hugh Dickins <[email protected]>
Reviewed-by: Shakeel Butt <[email protected]>
Acked-by: Yang Shi <[email protected]>
Cc: "Kirill A. Shutemov" <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Cc: Miaohe Lin <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Mike Kravetz <[email protected]>
Cc: Rik van Riel <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
|
|
4.18 commit 89fdcd262fd4 ("mm: shmem: make stat.st_blksize return huge
page size if THP is on") added is_huge_enabled() to decide st_blksize: if
hugeness is to be defined per file, that will need to be replaced by
shmem_is_huge().
This does give a different answer (No) for small files on a
"huge=within_size" mount: but that can be considered a minor bugfix. And
a different answer (No) for default files on a "huge=advise" mount: I'm
reluctant to complicate it, just to reproduce the same debatable answer as
before.
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Hugh Dickins <[email protected]>
Reviewed-by: Yang Shi <[email protected]>
Cc: "Kirill A. Shutemov" <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Cc: Miaohe Lin <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Mike Kravetz <[email protected]>
Cc: Rik van Riel <[email protected]>
Cc: Shakeel Butt <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
|
|
Extend shmem_huge_enabled(vma) to shmem_is_huge(vma, inode, index), so
that a consistent set of checks can be applied, even when the inode is
accessed through read/write syscalls (with NULL vma) instead of mmaps (the
index argument is seldom of interest, but required by mount option
"huge=within_size"). Clean up and rearrange the checks a little.
This then replaces the checks which shmem_fault() and shmem_getpage_gfp()
were making, and eliminates the SGP_HUGE and SGP_NOHUGE modes.
Replace a couple of 0s by explicit SHMEM_HUGE_NEVERs; and replace the
obscure !shmem_mapping() symlink check by explicit S_ISLNK() - nothing
else needs that symlink check, so leave it there in shmem_getpage_gfp().
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Hugh Dickins <[email protected]>
Reviewed-by: Yang Shi <[email protected]>
Cc: "Kirill A. Shutemov" <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Cc: Miaohe Lin <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Mike Kravetz <[email protected]>
Cc: Rik van Riel <[email protected]>
Cc: Shakeel Butt <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
|
|
khugepaged's collapse_file() currently uses SGP_NOHUGE to tell
shmem_getpage() not to try allocating a huge page, in the very unlikely
event that a racing hole-punch removes the swapped or fallocated page as
soon as i_pages lock is dropped.
We want to consolidate shmem's huge decisions, removing SGP_HUGE and
SGP_NOHUGE; but cannot quite persuade ourselves that it's okay to regress
the protection in this case - Yang Shi points out that the huge page would
remain indefinitely, charged to root instead of the intended memcg.
collapse_file() should not even allocate a small page in this case: why
proceed if someone is punching a hole? SGP_READ is almost the right flag
here, except that it optimizes away from a fallocated page, with NULL to
tell caller to fill with zeroes (like a hole); whereas collapse_file()'s
sequence relies on using a cache page. Add SGP_NOALLOC just for this.
There are too many consecutive "if (page"s there in shmem_getpage_gfp():
group it better; and fix the outdated "bring it back from swap" comment.
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Hugh Dickins <[email protected]>
Reviewed-by: Yang Shi <[email protected]>
Cc: "Kirill A. Shutemov" <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Cc: Miaohe Lin <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Mike Kravetz <[email protected]>
Cc: Rik van Riel <[email protected]>
Cc: Shakeel Butt <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
|
|
shmem_huge_enabled() is about to be enhanced into shmem_is_huge(), so that
it can be used more widely throughout: before making functional changes,
shift it to its final position (to avoid forward declaration).
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Hugh Dickins <[email protected]>
Reviewed-by: Yang Shi <[email protected]>
Cc: "Kirill A. Shutemov" <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Cc: Miaohe Lin <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Mike Kravetz <[email protected]>
Cc: Rik van Riel <[email protected]>
Cc: Shakeel Butt <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
|
|
5.14 commit e6be37b2e7bd ("mm/huge_memory.c: add missing read-only THP
checking in transparent_hugepage_enabled()") added transhuge_vma_enabled()
as a wrapper for two very different checks (one check is whether the app
has marked its address range not to use THPs, the other check is whether
the app is running in a hierarchy that has been marked never to use THPs).
shmem_huge_enabled() prefers to show those two checks explicitly, as
before.
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Hugh Dickins <[email protected]>
Reviewed-by: Yang Shi <[email protected]>
Cc: "Kirill A. Shutemov" <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Cc: Miaohe Lin <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Mike Kravetz <[email protected]>
Cc: Rik van Riel <[email protected]>
Cc: Shakeel Butt <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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There's a block of code in shmem_setattr() to add the inode to
shmem_unused_huge_shrink()'s shrinklist when lowering i_size: it dates
from before 5.7 changed truncation to do split_huge_page() for itself, and
should have been removed at that time.
I am over-stating that: split_huge_page() can fail (notably if there's an
extra reference to the page at that time), so there might be value in
retrying. But there were already retries as truncation worked through the
tails, and this addition risks repeating unsuccessful retries
indefinitely: I'd rather remove it now, and work on reducing the chance of
split_huge_page() failures separately, if we need to.
Link: https://lkml.kernel.org/r/[email protected]
Fixes: 71725ed10c40 ("mm: huge tmpfs: try to split_huge_page() when punching hole")
Signed-off-by: Hugh Dickins <[email protected]>
Reviewed-by: Yang Shi <[email protected]>
Cc: "Kirill A. Shutemov" <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Cc: Miaohe Lin <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Mike Kravetz <[email protected]>
Cc: Rik van Riel <[email protected]>
Cc: Shakeel Butt <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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A successful shmem_fallocate() guarantees that the extent has been
reserved, even beyond i_size when the FALLOC_FL_KEEP_SIZE flag was used.
But that guarantee is broken by shmem_unused_huge_shrink()'s attempts to
split huge pages and free their excess beyond i_size; and by other uses of
split_huge_page() near i_size.
It's sad to add a shmem inode field just for this, but I did not find a
better way to keep the guarantee. A flag to say KEEP_SIZE has been used
would be cheaper, but I'm averse to unclearable flags. The fallocend
field is not perfect either (many disjoint ranges might be fallocated),
but good enough; and gains another use later on.
Link: https://lkml.kernel.org/r/[email protected]
Fixes: 779750d20b93 ("shmem: split huge pages beyond i_size under memory pressure")
Signed-off-by: Hugh Dickins <[email protected]>
Reviewed-by: Yang Shi <[email protected]>
Cc: "Kirill A. Shutemov" <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Cc: Miaohe Lin <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Mike Kravetz <[email protected]>
Cc: Rik van Riel <[email protected]>
Cc: Shakeel Butt <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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Patch series "huge tmpfs: shmem_is_huge() fixes and cleanups".
A series of huge tmpfs fixes and cleanups.
This patch (of 9):
shmem_fallocate() goes to a lot of trouble to leave its newly allocated
pages !Uptodate, partly to identify and undo them on failure, partly to
leave the overhead of clearing them until later. But the huge page case
did not skip to the end of the extent, walked through the tail pages one
by one, and appeared to work just fine: but in doing so, cleared and
Uptodated the huge page, so there was no way to undo it on failure.
And by setting Uptodate too soon, it messed up both its nr_falloced and
nr_unswapped counts, so that the intended "time to give up" heuristic did
not work at all.
Now advance immediately to the end of the huge extent, with a comment on
why this is more than just an optimization. But although this speeds up
huge tmpfs fallocation, it does leave the clearing until first use, and
some users may have come to appreciate slow fallocate but fast first use:
if they complain, then we can consider adding a pass to clear at the end.
Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Fixes: 800d8c63b2e9 ("shmem: add huge pages support")
Signed-off-by: Hugh Dickins <[email protected]>
Reviewed-by: Yang Shi <[email protected]>
Cc: Shakeel Butt <[email protected]>
Cc: "Kirill A. Shutemov" <[email protected]>
Cc: Miaohe Lin <[email protected]>
Cc: Mike Kravetz <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Rik van Riel <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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It's bad to extern swap_info[] in .c. Include corresponding header file
instead.
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Miaohe Lin <[email protected]>
Cc: Hugh Dickins <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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The forward declaration for shmem_should_replace_page() and
shmem_replace_page() is unnecessary. Remove them.
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Miaohe Lin <[email protected]>
Cc: Hugh Dickins <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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mfill_atomic_install_pte() is introduced to install pte and update mmu
cache since commit bf6ebd97aba0 ("userfaultfd/shmem: modify
shmem_mfill_atomic_pte to use install_pte()"). So we should remove
tlbflush.h as update_mmu_cache() is not called here now.
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Miaohe Lin <[email protected]>
Cc: Hugh Dickins <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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Patch series "Cleanups for shmem".
This series contains cleanups to remove unneeded variable, header file,
function forward declaration and so on. More details can be found in the
respective changelogs.
This patch (of 4):
The local variable ret is always equal to -ENOMEM and never touched. So
remove it and return -ENOMEM directly to simplify the code.
Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Miaohe Lin <[email protected]>
Cc: Hugh Dickins <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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Each CPU has SHMEM_INO_BATCH inodes available in `->ino_batch' which is
per-CPU. Access here is serialized by disabling preemption. If the pool
is empty, it gets reloaded from `->next_ino'. Access here is serialized
by ->stat_lock which is a spinlock_t and can not be acquired with disabled
preemption.
One way around it would make per-CPU ino_batch struct containing the inode
number a local_lock_t.
Another solution is to promote ->stat_lock to a raw_spinlock_t. The
critical sections are short. The mpol_put() must be moved outside of the
critical section to avoid invoking the destructor with disabled
preemption.
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Sebastian Andrzej Siewior <[email protected]>
Acked-by: Hugh Dickins <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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get_kernel_page() was added in 2012 by [1]. It was used for a while for
NFS, but then in 2014, a refactoring [2] removed all callers, and it has
apparently not been used since.
Remove get_kernel_page() because it has no callers.
[1] commit 18022c5d8627 ("mm: add get_kernel_page[s] for pinning of
kernel addresses for I/O")
[2] commit 91f79c43d1b5 ("new helper: iov_iter_get_pages_alloc()")
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: John Hubbard <[email protected]>
Reviewed-by: Christoph Hellwig <[email protected]>
Reviewed-by: David Hildenbrand <[email protected]>
Cc: Mel Gorman <[email protected]>
Cc: Rik van Riel <[email protected]>
Cc: David S. Miller <[email protected]>
Cc: Eric B Munson <[email protected]>
Cc: Eric Paris <[email protected]>
Cc: James Morris <[email protected]>
Cc: Mike Christie <[email protected]>
Cc: Neil Brown <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Sebastian Andrzej Siewior <[email protected]>
Cc: Trond Myklebust <[email protected]>
Cc: Xiaotian Feng <[email protected]>
Cc: Mark Salter <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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We had a recurring situation in which admin procedures setting up
swapfiles would race with test preparation clearing away swapfiles; and
just occasionally that got stuck on a swapfile "(deleted)" which could
never be swapped off. That is not supposed to be possible.
2.6.28 commit f9454548e17c ("don't unlink an active swapfile") admitted
that it was leaving a race window open: now close it.
may_delete() makes the IS_SWAPFILE check (amongst many others) before
inode_lock has been taken on target: now repeat just that simple check in
vfs_unlink() and vfs_rename(), after taking inode_lock.
Which goes most of the way to fixing the race, but swapon() must also
check after it acquires inode_lock, that the file just opened has not
already been unlinked.
Link: https://lkml.kernel.org/r/[email protected]
Fixes: f9454548e17c ("don't unlink an active swapfile")
Signed-off-by: Hugh Dickins <[email protected]>
Reviewed-by: Jan Kara <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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try_get_page() is very similar to try_get_compound_head(), and in fact
try_get_page() has fallen a little behind in terms of maintenance:
try_get_compound_head() handles speculative page references more
thoroughly.
There are only two try_get_page() callsites, so just call
try_get_compound_head() directly from those, and remove try_get_page()
entirely.
Also, seeing as how this changes try_get_compound_head() into a non-static
function, provide some kerneldoc documentation for it.
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: John Hubbard <[email protected]>
Reviewed-by: Christoph Hellwig <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Cc: Christian Borntraeger <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Vasily Gorbik <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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try_grab_page() does the same thing as try_grab_compound_head(..., refs=1,
...), just with a different API. So there is a lot of code duplication
there.
Change try_grab_page() to call try_grab_compound_head(), while keeping the
API contract identical for callers.
Also, now that try_grab_compound_head() always has a caller, remove the
__maybe_unused annotation.
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: John Hubbard <[email protected]>
Reviewed-by: Christoph Hellwig <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Cc: Christian Borntraeger <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Vasily Gorbik <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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Patch series "A few gup refactorings and documentation updates", v3.
While reviewing some of the other things going on around gup.c, I noticed
that the documentation was wrong for a few of the routines that I wrote.
And then I noticed that there was some significant code duplication too.
So this fixes those issues.
This is not entirely risk-free, but after looking closely at this, I think
it's actually a useful improvement, getting rid of the code duplication
here.
This patch (of 3):
The documentation for try_grab_compound_head() and try_grab_page() has
fallen a little out of date. Update and clarify a few points.
Also make it kerneldoc-correct, by adding @args documentation.
Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: John Hubbard <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Cc: Christoph Hellwig <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Vasily Gorbik <[email protected]>
Cc: Christian Borntraeger <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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Use helper PAGE_ALIGNED to check if address is aligned to PAGE_SIZE.
Minor readability improvement.
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Miaohe Lin <[email protected]>
Reviewed-by: John Hubbard <[email protected]>
Reviewed-by: David Hildenbrand <[email protected]>
Reviewed-by: Claudio Imbrenda <[email protected]>
Cc: Jan Kara <[email protected]>
Cc: Kirill A. Shutemov <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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