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When unmapping a hugepage range, huge_pte_clear() is used to clear the
page table entries that are marked as not present. huge_pte_clear()
internally just ends up calling pte_clear() which does not correctly
deal with hugepages consisting of contiguous page table entries.
Add a size argument to address this issue and allow architectures to
override huge_pte_clear() by wrapping it in a #ifndef block.
Update s390 implementation with the size parameter as well.
Note that the change only affects huge_pte_clear() - the other generic
hugetlb functions don't need any change.
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Punit Agrawal <[email protected]>
Acked-by: Martin Schwidefsky <[email protected]> [s390 bits]
Cc: Heiko Carstens <[email protected]>
Cc: Arnd Bergmann <[email protected]>
Cc: "Aneesh Kumar K.V" <[email protected]>
Cc: Mike Kravetz <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Will Deacon <[email protected]>
Cc: Naoya Horiguchi <[email protected]>
Cc: "Kirill A. Shutemov" <[email protected]>
Cc: Steve Capper <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Hillf Danton <[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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A poisoned or migrated hugepage is stored as a swap entry in the page
tables. On architectures that support hugepages consisting of
contiguous page table entries (such as on arm64) this leads to ambiguity
in determining the page table entry to return in huge_pte_offset() when
a poisoned entry is encountered.
Let's remove the ambiguity by adding a size parameter to convey
additional information about the requested address. Also fixup the
definition/usage of huge_pte_offset() throughout the tree.
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Punit Agrawal <[email protected]>
Acked-by: Steve Capper <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Will Deacon <[email protected]>
Cc: Tony Luck <[email protected]>
Cc: Fenghua Yu <[email protected]>
Cc: James Hogan <[email protected]> (odd fixer:METAG ARCHITECTURE)
Cc: Ralf Baechle <[email protected]> (supporter:MIPS)
Cc: "James E.J. Bottomley" <[email protected]>
Cc: Helge Deller <[email protected]>
Cc: Benjamin Herrenschmidt <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: Martin Schwidefsky <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Yoshinori Sato <[email protected]>
Cc: Rich Felker <[email protected]>
Cc: "David S. Miller" <[email protected]>
Cc: Chris Metcalf <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: "H. Peter Anvin" <[email protected]>
Cc: Alexander Viro <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Mike Kravetz <[email protected]>
Cc: Naoya Horiguchi <[email protected]>
Cc: "Aneesh Kumar K.V" <[email protected]>
Cc: "Kirill A. Shutemov" <[email protected]>
Cc: Hillf Danton <[email protected]>
Cc: Mark Rutland <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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When speculatively taking references to a hugepage using
page_cache_add_speculative() in gup_huge_pmd(), it is assumed that the
page returned by pmd_page() is the head page. Although normally true,
this assumption doesn't hold when the hugepage comprises of successive
page table entries such as when using contiguous bit on arm64 at PTE or
PMD levels.
This can be addressed by ensuring that the page passed to
page_cache_add_speculative() is the real head or by de-referencing the
head page within the function.
We take the first approach to keep the usage pattern aligned with
page_cache_get_speculative() where users already pass the appropriate
page, i.e., the de-referenced head.
Apply the same logic to fix gup_huge_[pud|pgd]() as well.
[[email protected]: fix arm64 ltp failure]
Link: http://lkml.kernel.org/r/[email protected]
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Punit Agrawal <[email protected]>
Acked-by: Steve Capper <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: "Kirill A. Shutemov" <[email protected]>
Cc: Aneesh Kumar K.V <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Will Deacon <[email protected]>
Cc: Naoya Horiguchi <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Hillf Danton <[email protected]>
Cc: Mike Kravetz <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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When operating on hugepages with DEBUG_VM enabled, the GUP code checks
the compound head for each tail page prior to calling
page_cache_add_speculative. This is broken, because on the fast-GUP
path (where we don't hold any page table locks) we can be racing with a
concurrent invocation of split_huge_page_to_list.
split_huge_page_to_list deals with this race by using page_ref_freeze to
freeze the page and force concurrent GUPs to fail whilst the component
pages are modified. This modification includes clearing the
compound_head field for the tail pages, so checking this prior to a
successful call to page_cache_add_speculative can lead to false
positives: In fact, page_cache_add_speculative *already* has this check
once the page refcount has been successfully updated, so we can simply
remove the broken calls to VM_BUG_ON_PAGE.
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Will Deacon <[email protected]>
Signed-off-by: Punit Agrawal <[email protected]>
Acked-by: Steve Capper <[email protected]>
Acked-by: Kirill A. Shutemov <[email protected]>
Cc: Aneesh Kumar K.V <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Naoya Horiguchi <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Hillf Danton <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Mike Kravetz <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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We don't need to call huge_ptep_offset as our accessors are already
supplied with the pte_t *. This patch removes those spurious calls.
[[email protected]: resolve rebase conflicts due to patch re-ordering]
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Steve Capper <[email protected]>
Signed-off-by: Punit Agrawal <[email protected]>
Cc: David Woods <[email protected]>
Cc: Kirill A. Shutemov <[email protected]>
Cc: Aneesh Kumar K.V <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Naoya Horiguchi <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Hillf Danton <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Mike Kravetz <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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Patch series "Support for contiguous pte hugepages", v4.
This patchset updates the hugetlb code to fix issues arising from
contiguous pte hugepages (such as on arm64). Compared to v3, This
version addresses a build failure on arm64 by including two cleanup
patches. Other than the arm64 cleanups, the rest are generic code
changes. The remaining arm64 support based on these patches will be
posted separately. The patches are based on v4.12-rc2. Previous
related postings can be found at [0], [1], [2], and [3].
The patches fall into three categories -
* Patch 1-2 - arm64 cleanups required to greatly simplify changing
huge_pte_offset() prototype in Patch 5.
Catalin, Will - are you happy for these patches to go via mm?
* Patches 3-4 address issues with gup
* Patches 5-8 relate to passing a size argument to hugepage helpers to
disambiguate the size of the referred page. These changes are
required to enable arch code to properly handle swap entries for
contiguous pte hugepages.
The changes to huge_pte_offset() (patch 5) touch multiple
architectures but I've managed to minimise these changes for the
other affected functions - huge_pte_clear() and set_huge_pte_at().
These patches gate the enabling of contiguous hugepages support on arm64
which has been requested for systems using !4k page granule.
The ARM64 architecture supports two flavours of hugepages -
* Block mappings at the pud/pmd level
These are regular hugepages where a pmd or a pud page table entry
points to a block of memory. Depending on the PAGE_SIZE in use the
following size of block mappings are supported -
PMD PUD
--- ---
4K: 2M 1G
16K: 32M
64K: 512M
For certain applications/usecases such as HPC and large enterprise
workloads, folks are using 64k page size but the minimum hugepage size
of 512MB isn't very practical.
To overcome this ...
* Using the Contiguous bit
The architecture provides a contiguous bit in the translation table
entry which acts as a hint to the mmu to indicate that it is one of a
contiguous set of entries that can be cached in a single TLB entry.
We use the contiguous bit in Linux to increase the mapping size at the
pmd and pte (last) level.
The number of supported contiguous entries varies by page size and
level of the page table.
Using the contiguous bit allows additional hugepage sizes -
CONT PTE PMD CONT PMD PUD
-------- --- -------- ---
4K: 64K 2M 32M 1G
16K: 2M 32M 1G
64K: 2M 512M 16G
Of these, 64K with 4K and 2M with 64K pages have been explicitly
requested by a few different users.
Entries with the contiguous bit set are required to be modified all
together - which makes things like memory poisoning and migration
impossible to do correctly without knowing the size of hugepage being
dealt with - the reason for adding size parameter to a few of the
hugepage helpers in this series.
This patch (of 8):
As we regularly check for contiguous pte's in the huge accessors, remove
this extra check from find_num_contig.
[[email protected]: resolve rebase conflicts due to patch re-ordering]
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Steve Capper <[email protected]>
Signed-off-by: Punit Agrawal <[email protected]>
Cc: David Woods <[email protected]>
Cc: Kirill A. Shutemov <[email protected]>
Cc: Aneesh Kumar K.V <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Naoya Horiguchi <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Hillf Danton <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Mike Kravetz <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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pte_offset_map_lock() finds and takes ptl, and returns pte. But some
callers return without unlocking the ptl when pte == NULL, which seems
weird.
Git history said that !pte check in change_pte_range() was introduced in
commit 1ad9f620c3a2 ("mm: numa: recheck for transhuge pages under lock
during protection changes") and still remains after commit 175ad4f1e7a2
("mm: mprotect: use pmd_trans_unstable instead of taking the pmd_lock")
which partially reverts 1ad9f620c3a2. So I think that it's just dead
code.
Many other caller of pte_offset_map_lock() never check NULL return, so
let's do likewise.
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Naoya Horiguchi <[email protected]>
Acked-by: Vlastimil Babka <[email protected]>
Cc: Mel Gorman <[email protected]>
Cc: Johannes Weiner <[email protected]>
Cc: Andrea Arcangeli <[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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The functions are not used in some configurations. Adding the attribute
fixes the following warnings when building with clang:
mm/page_alloc.c:409:19: error: function 'bad_range' is not needed and
will not be emitted [-Werror,-Wunneeded-internal-declaration]
mm/page_alloc.c:1106:30: error: unused function 'meminit_pfn_in_nid'
[-Werror,-Wunused-function]
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Matthias Kaehlcke <[email protected]>
Cc: Vlastimil Babka <[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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POWER9 supports hugepages of size 2M and 1G in radix MMU mode. This
patch enables the usage of 1G page size for hugetlbfs. This also update
the helper such we can do 1G page allocation at runtime.
We still don't enable 1G page size on DD1 version. This is to avoid
doing workaround mentioned in commit 6d3a0379ebdc ("powerpc/mm: Add
radix__tlb_flush_pte_p9_dd1()").
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Aneesh Kumar K.V <[email protected]>
Cc: Michael Ellerman <[email protected]> (powerpc)
Cc: Anshuman Khandual <[email protected]>
Cc: Benjamin Herrenschmidt <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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This moves the #ifdef in C code to a Kconfig dependency. Also we move
the gigantic_page_supported() function to be arch specific.
This allows architectures to conditionally enable runtime allocation of
gigantic huge page. Architectures like ppc64 supports different
gigantic huge page size (16G and 1G) based on the translation mode
selected. This provides an opportunity for ppc64 to enable runtime
allocation only w.r.t 1G hugepage.
No functional change in this patch.
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Aneesh Kumar K.V <[email protected]>
Cc: Michael Ellerman <[email protected]> (powerpc)
Cc: Anshuman Khandual <[email protected]>
Cc: Benjamin Herrenschmidt <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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Allow hash tables to scale with memory but at slower pace, when
HASH_ADAPT is provided every time memory quadruples the sizes of hash
tables will only double instead of quadrupling as well. This algorithm
starts working only when memory size reaches a certain point, currently
set to 64G.
This is example of dentry hash table size, before and after four various
memory configurations:
MEMORY SCALE HASH_SIZE
old new old new
8G 13 13 8M 8M
16G 13 13 16M 16M
32G 13 13 32M 32M
64G 13 13 64M 64M
128G 13 14 128M 64M
256G 13 14 256M 128M
512G 13 15 512M 128M
1024G 13 15 1024M 256M
2048G 13 16 2048M 256M
4096G 13 16 4096M 512M
8192G 13 17 8192M 512M
16384G 13 17 16384M 1024M
32768G 13 18 32768M 1024M
65536G 13 18 65536M 2048M
The effect of this change on runtime is undetectable as filesystem
growth is not proportional to machine memory size as is currently
assumed. The change effects only large memory machine. Additional
tuning might be needed, but that can be done by the clients of the
kmem_cache_create interface, not the generic cache allocator itself.
The adaptive hashing is disabled on 32 bit systems to avoid confusion of
whether base should be different for smaller systems, and to avoid
overflows.
[[email protected]: drop HASH_ADAPT]
Link: http://lkml.kernel.org/r/[email protected]
[[email protected]: UL -> ULL fix]
Link: http://lkml.kernel.org/r/[email protected]
[[email protected]: disable adaptive hash on 32 bit systems]
Link: http://lkml.kernel.org/r/[email protected]
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Pavel Tatashin <[email protected]>
Signed-off-by: Michal Hocko <[email protected]>
Acked-by: Michal Hocko <[email protected]>
Cc: David Miller <[email protected]>
Cc: Al Viro <[email protected]>
Cc: Babu Moger <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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Update dcache, inode, pid, mountpoint, and mount hash tables to use
HASH_ZERO, and remove initialization after allocations. In case of
places where HASH_EARLY was used such as in __pv_init_lock_hash the
zeroed hash table was already assumed, because memblock zeroes the
memory.
CPU: SPARC M6, Memory: 7T
Before fix:
Dentry cache hash table entries: 1073741824
Inode-cache hash table entries: 536870912
Mount-cache hash table entries: 16777216
Mountpoint-cache hash table entries: 16777216
ftrace: allocating 20414 entries in 40 pages
Total time: 11.798s
After fix:
Dentry cache hash table entries: 1073741824
Inode-cache hash table entries: 536870912
Mount-cache hash table entries: 16777216
Mountpoint-cache hash table entries: 16777216
ftrace: allocating 20414 entries in 40 pages
Total time: 3.198s
CPU: Intel Xeon E5-2630, Memory: 2.2T:
Before fix:
Dentry cache hash table entries: 536870912
Inode-cache hash table entries: 268435456
Mount-cache hash table entries: 8388608
Mountpoint-cache hash table entries: 8388608
CPU: Physical Processor ID: 0
Total time: 3.245s
After fix:
Dentry cache hash table entries: 536870912
Inode-cache hash table entries: 268435456
Mount-cache hash table entries: 8388608
Mountpoint-cache hash table entries: 8388608
CPU: Physical Processor ID: 0
Total time: 3.244s
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Pavel Tatashin <[email protected]>
Reviewed-by: Babu Moger <[email protected]>
Cc: David Miller <[email protected]>
Cc: Al Viro <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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Add a new flag HASH_ZERO which when provided grantees that the hash
table that is returned by alloc_large_system_hash() is zeroed. In most
cases that is what is needed by the caller. Use page level allocator's
__GFP_ZERO flags to zero the memory. It is using memset() which is
efficient method to zero memory and is optimized for most platforms.
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Pavel Tatashin <[email protected]>
Reviewed-by: Babu Moger <[email protected]>
Cc: David Miller <[email protected]>
Cc: Al Viro <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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Link: http://lkml.kernel.org/r/1494926612-23928-10-git-send-email-aneesh.kumar@linux.vnet.ibm.com
Signed-off-by: Aneesh Kumar K.V <[email protected]>
Cc: Anshuman Khandual <[email protected]>
Cc: Naoya Horiguchi <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: Benjamin Herrenschmidt <[email protected]>
Cc: Mike Kravetz <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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With generic code now handling hugetlb entries at pgd level and also
supporting hugepage directory format, we can now remove the powerpc
sepcific follow_huge_addr implementation.
Link: http://lkml.kernel.org/r/1494926612-23928-9-git-send-email-aneesh.kumar@linux.vnet.ibm.com
Signed-off-by: Aneesh Kumar K.V <[email protected]>
Cc: Anshuman Khandual <[email protected]>
Cc: Naoya Horiguchi <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: Benjamin Herrenschmidt <[email protected]>
Cc: Mike Kravetz <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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Link: http://lkml.kernel.org/r/1494926612-23928-8-git-send-email-aneesh.kumar@linux.vnet.ibm.com
Signed-off-by: Aneesh Kumar K.V <[email protected]>
Cc: Anshuman Khandual <[email protected]>
Cc: Naoya Horiguchi <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: Benjamin Herrenschmidt <[email protected]>
Cc: Mike Kravetz <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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Architectures like ppc64 supports hugepage size that is not mapped to
any of of the page table levels. Instead they add an alternate page
table entry format called hugepage directory (hugepd). hugepd indicates
that the page table entry maps to a set of hugetlb pages. Add support
for this in generic follow_page_mask code. We already support this
format in the generic gup code.
The default implementation prints warning and returns NULL. We will add
ppc64 support in later patches
Link: http://lkml.kernel.org/r/1494926612-23928-7-git-send-email-aneesh.kumar@linux.vnet.ibm.com
Signed-off-by: Aneesh Kumar K.V <[email protected]>
Cc: Anshuman Khandual <[email protected]>
Cc: Naoya Horiguchi <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: Benjamin Herrenschmidt <[email protected]>
Cc: Mike Kravetz <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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This enable to use the hugepd_t type early. No functional change in
this patch.
Link: http://lkml.kernel.org/r/1494926612-23928-6-git-send-email-aneesh.kumar@linux.vnet.ibm.com
Signed-off-by: Aneesh Kumar K.V <[email protected]>
Cc: Anshuman Khandual <[email protected]>
Cc: Naoya Horiguchi <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: Benjamin Herrenschmidt <[email protected]>
Cc: Mike Kravetz <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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ppc64 supports pgd hugetlb entries. Add code to handle hugetlb pgd
entries to follow_page_mask so that ppc64 can switch to it to handle
hugetlbe entries.
Link: http://lkml.kernel.org/r/1494926612-23928-5-git-send-email-aneesh.kumar@linux.vnet.ibm.com
Signed-off-by: Anshuman Khandual <[email protected]>
Signed-off-by: Aneesh Kumar K.V <[email protected]>
Cc: Naoya Horiguchi <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: Benjamin Herrenschmidt <[email protected]>
Cc: Mike Kravetz <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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We will be using this later from the ppc64 code. Change the return type
to bool.
Link: http://lkml.kernel.org/r/1494926612-23928-4-git-send-email-aneesh.kumar@linux.vnet.ibm.com
Signed-off-by: Aneesh Kumar K.V <[email protected]>
Reviewed-by: Naoya Horiguchi <[email protected]>
Cc: Anshuman Khandual <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: Benjamin Herrenschmidt <[email protected]>
Cc: Mike Kravetz <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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Makes code reading easy. No functional changes in this patch. In a
followup patch, we will be updating the follow_page_mask to handle
hugetlb hugepd format so that archs like ppc64 can switch to the generic
version. This split helps in doing that nicely.
Link: http://lkml.kernel.org/r/1494926612-23928-3-git-send-email-aneesh.kumar@linux.vnet.ibm.com
Signed-off-by: Aneesh Kumar K.V <[email protected]>
Reviewed-by: Naoya Horiguchi <[email protected]>
Cc: Anshuman Khandual <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: Benjamin Herrenschmidt <[email protected]>
Cc: Mike Kravetz <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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Patch series "HugeTLB migration support for PPC64", v2.
This patch (of 9):
The right interface to use to set a hugetlb pte entry is set_huge_pte_at.
Use that instead of set_pte_at.
Link: http://lkml.kernel.org/r/1494926612-23928-2-git-send-email-aneesh.kumar@linux.vnet.ibm.com
Signed-off-by: Aneesh Kumar K.V <[email protected]>
Reviewed-by: Naoya Horiguchi <[email protected]>
Cc: Anshuman Khandual <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: Benjamin Herrenschmidt <[email protected]>
Cc: Mike Kravetz <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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Though migrating gigantic HugeTLB pages does not sound much like real
world use case, they can be affected by memory errors. Hence migration
at the PGD level HugeTLB pages should be supported just to enable soft
and hard offline use cases.
While allocating the new gigantic HugeTLB page, it should not matter
whether new page comes from the same node or not. There would be very
few gigantic pages on the system afterall, we should not be bothered
about node locality when trying to save a big page from crashing.
This change renames dequeu_huge_page_node() function as dequeue_huge
_page_node_exact() preserving it's original functionality. Now the new
dequeue_huge_page_node() function scans through all available online nodes
to allocate a huge page for the NUMA_NO_NODE case and just falls back
calling dequeu_huge_page_node_exact() for all other cases.
[[email protected]: make hstate_is_gigantic() inline]
Link: http://lkml.kernel.org/r/[email protected]
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Anshuman Khandual <[email protected]>
Signed-off-by: Arnd Bergmann <[email protected]>
Cc: "Aneesh Kumar K.V" <[email protected]>
Cc: Naoya Horiguchi <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
|
|
Calculation of start end end in __wake_userfault function are not used
and can be removed.
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Mike Rapoport <[email protected]>
Cc: Andrea Arcangeli <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
|
|
Commit dd0db88d8094 ("userfaultfd: non-cooperative: rollback
userfaultfd_exit") removed userfaultfd callback from exit() which makes
the include of <linux/userfaultfd_k.h> unnecessary.
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Mike Rapoport <[email protected]>
Cc: Andrea Arcangeli <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
|
|
zone_for_memory doesn't have any user anymore as well as the whole zone
shifting infrastructure so drop them all.
This shouldn't introduce any functional changes.
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Michal Hocko <[email protected]>
Acked-by: Vlastimil Babka <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: Andrea Arcangeli <[email protected]>
Cc: Balbir Singh <[email protected]>
Cc: Dan Williams <[email protected]>
Cc: Daniel Kiper <[email protected]>
Cc: David Rientjes <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Igor Mammedov <[email protected]>
Cc: Jerome Glisse <[email protected]>
Cc: Joonsoo Kim <[email protected]>
Cc: Martin Schwidefsky <[email protected]>
Cc: Mel Gorman <[email protected]>
Cc: Reza Arbab <[email protected]>
Cc: Tobias Regnery <[email protected]>
Cc: Toshi Kani <[email protected]>
Cc: Vitaly Kuznetsov <[email protected]>
Cc: Xishi Qiu <[email protected]>
Cc: Yasuaki Ishimatsu <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
|
|
Tobias has reported following section mismatches introduced by "mm,
memory_hotplug: do not associate hotadded memory to zones until online".
WARNING: mm/built-in.o(.text+0x5a1c2): Section mismatch in reference from the function move_pfn_range_to_zone() to the function .meminit.text:memmap_init_zone()
The function move_pfn_range_to_zone() references
the function __meminit memmap_init_zone().
This is often because move_pfn_range_to_zone lacks a __meminit
annotation or the annotation of memmap_init_zone is wrong.
WARNING: mm/built-in.o(.text+0x5a25b): Section mismatch in reference from the function move_pfn_range_to_zone() to the function .meminit.text:init_currently_empty_zone()
The function move_pfn_range_to_zone() references
the function __meminit init_currently_empty_zone().
This is often because move_pfn_range_to_zone lacks a __meminit
annotation or the annotation of init_currently_empty_zone is wrong.
WARNING: vmlinux.o(.text+0x188aa2): Section mismatch in reference from the function move_pfn_range_to_zone() to the function .meminit.text:memmap_init_zone()
The function move_pfn_range_to_zone() references
the function __meminit memmap_init_zone().
This is often because move_pfn_range_to_zone lacks a __meminit
annotation or the annotation of memmap_init_zone is wrong.
WARNING: vmlinux.o(.text+0x188b3b): Section mismatch in reference from the function move_pfn_range_to_zone() to the function .meminit.text:init_currently_empty_zone()
The function move_pfn_range_to_zone() references
the function __meminit init_currently_empty_zone().
This is often because move_pfn_range_to_zone lacks a __meminit
annotation or the annotation of init_currently_empty_zone is wrong.
Both memmap_init_zone and init_currently_empty_zone are marked __meminit
but move_pfn_range_to_zone is used outside of __meminit sections (e.g.
devm_memremap_pages) so we have to hide it from the checker by __ref
annotation.
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Michal Hocko <[email protected]>
Reported-by: Tobias Regnery <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: Andrea Arcangeli <[email protected]>
Cc: Balbir Singh <[email protected]>
Cc: Dan Williams <[email protected]>
Cc: Daniel Kiper <[email protected]>
Cc: David Rientjes <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Igor Mammedov <[email protected]>
Cc: Jerome Glisse <[email protected]>
Cc: Joonsoo Kim <[email protected]>
Cc: Martin Schwidefsky <[email protected]>
Cc: Mel Gorman <[email protected]>
Cc: Reza Arbab <[email protected]>
Cc: Toshi Kani <[email protected]>
Cc: Vitaly Kuznetsov <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Cc: Xishi Qiu <[email protected]>
Cc: Yasuaki Ishimatsu <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
|
|
arch_add_memory gets for_device argument which then controls whether we
want to create memblocks for created memory sections. Simplify the
logic by telling whether we want memblocks directly rather than going
through pointless negation. This also makes the api easier to
understand because it is clear what we want rather than nothing telling
for_device which can mean anything.
This shouldn't introduce any functional change.
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Michal Hocko <[email protected]>
Tested-by: Dan Williams <[email protected]>
Acked-by: Vlastimil Babka <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: Andrea Arcangeli <[email protected]>
Cc: Balbir Singh <[email protected]>
Cc: Daniel Kiper <[email protected]>
Cc: David Rientjes <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Igor Mammedov <[email protected]>
Cc: Jerome Glisse <[email protected]>
Cc: Joonsoo Kim <[email protected]>
Cc: Martin Schwidefsky <[email protected]>
Cc: Mel Gorman <[email protected]>
Cc: Reza Arbab <[email protected]>
Cc: Tobias Regnery <[email protected]>
Cc: Toshi Kani <[email protected]>
Cc: Vitaly Kuznetsov <[email protected]>
Cc: Xishi Qiu <[email protected]>
Cc: Yasuaki Ishimatsu <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
|
|
Heiko Carstens has noticed that he can generate overlapping zones for
ZONE_DMA and ZONE_NORMAL:
DMA [mem 0x0000000000000000-0x000000007fffffff]
Normal [mem 0x0000000080000000-0x000000017fffffff]
$ cat /sys/devices/system/memory/block_size_bytes
10000000
$ cat /sys/devices/system/memory/memory5/valid_zones
DMA
$ echo 0 > /sys/devices/system/memory/memory5/online
$ cat /sys/devices/system/memory/memory5/valid_zones
Normal
$ echo 1 > /sys/devices/system/memory/memory5/online
Normal
$ cat /proc/zoneinfo
Node 0, zone DMA
spanned 524288 <-----
present 458752
managed 455078
start_pfn: 0 <-----
Node 0, zone Normal
spanned 720896
present 589824
managed 571648
start_pfn: 327680 <-----
The reason is that we assume that the default zone for kernel onlining
is ZONE_NORMAL. This was a simplification introduced by the memory
hotplug rework and it is easily fixable by checking the range overlap in
the zone order and considering the first matching zone as the default
one. If there is no such zone then assume ZONE_NORMAL as we have been
doing so far.
Fixes: "mm, memory_hotplug: do not associate hotadded memory to zones until online"
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Michal Hocko <[email protected]>
Reported-by: Heiko Carstens <[email protected]>
Tested-by: Heiko Carstens <[email protected]>
Acked-by: Vlastimil Babka <[email protected]>
Cc: Dan Williams <[email protected]>
Cc: Reza Arbab <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
|
|
Heiko Carstens has noticed that the MMOP_ONLINE_KEEP is broken currently
$ grep . memory3?/valid_zones
memory34/valid_zones:Normal Movable
memory35/valid_zones:Normal Movable
memory36/valid_zones:Normal Movable
memory37/valid_zones:Normal Movable
$ echo online_movable > memory34/state
$ grep . memory3?/valid_zones
memory34/valid_zones:Movable
memory35/valid_zones:Movable
memory36/valid_zones:Movable
memory37/valid_zones:Movable
$ echo online > memory36/state
$ grep . memory3?/valid_zones
memory34/valid_zones:Movable
memory36/valid_zones:Normal
memory37/valid_zones:Movable
so we have effectively punched a hole into the movable zone.
The problem is that move_pfn_range() check for MMOP_ONLINE_KEEP is
wrong. It only checks whether the given range is already part of the
movable zone which is not the case here as only memory34 is in the zone.
Fix this by using allow_online_pfn_range(..., MMOP_ONLINE_KERNEL) if
that is false then we can be sure that movable onlining is the right
thing to do.
Fixes: "mm, memory_hotplug: do not associate hotadded memory to zones until online"
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Michal Hocko <[email protected]>
Reported-by: Heiko Carstens <[email protected]>
Tested-by: Heiko Carstens <[email protected]>
Acked-by: Vlastimil Babka <[email protected]>
Cc: Dan Williams <[email protected]>
Cc: Reza Arbab <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
|
|
The current memory hotplug implementation relies on having all the
struct pages associate with a zone/node during the physical hotplug
phase (arch_add_memory->__add_pages->__add_section->__add_zone). In the
vast majority of cases this means that they are added to ZONE_NORMAL.
This has been so since 9d99aaa31f59 ("[PATCH] x86_64: Support memory
hotadd without sparsemem") and it wasn't a big deal back then because
movable onlining didn't exist yet.
Much later memory hotplug wanted to (ab)use ZONE_MOVABLE for movable
onlining 511c2aba8f07 ("mm, memory-hotplug: dynamic configure movable
memory and portion memory") and then things got more complicated.
Rather than reconsidering the zone association which was no longer
needed (because the memory hotplug already depended on SPARSEMEM) a
convoluted semantic of zone shifting has been developed. Only the
currently last memblock or the one adjacent to the zone_movable can be
onlined movable. This essentially means that the online type changes as
the new memblocks are added.
Let's simulate memory hot online manually
$ echo 0x100000000 > /sys/devices/system/memory/probe
$ grep . /sys/devices/system/memory/memory32/valid_zones
Normal Movable
$ echo $((0x100000000+(128<<20))) > /sys/devices/system/memory/probe
$ grep . /sys/devices/system/memory/memory3?/valid_zones
/sys/devices/system/memory/memory32/valid_zones:Normal
/sys/devices/system/memory/memory33/valid_zones:Normal Movable
$ echo $((0x100000000+2*(128<<20))) > /sys/devices/system/memory/probe
$ grep . /sys/devices/system/memory/memory3?/valid_zones
/sys/devices/system/memory/memory32/valid_zones:Normal
/sys/devices/system/memory/memory33/valid_zones:Normal
/sys/devices/system/memory/memory34/valid_zones:Normal Movable
$ echo online_movable > /sys/devices/system/memory/memory34/state
$ grep . /sys/devices/system/memory/memory3?/valid_zones
/sys/devices/system/memory/memory32/valid_zones:Normal
/sys/devices/system/memory/memory33/valid_zones:Normal Movable
/sys/devices/system/memory/memory34/valid_zones:Movable Normal
This is an awkward semantic because an udev event is sent as soon as the
block is onlined and an udev handler might want to online it based on
some policy (e.g. association with a node) but it will inherently race
with new blocks showing up.
This patch changes the physical online phase to not associate pages with
any zone at all. All the pages are just marked reserved and wait for
the onlining phase to be associated with the zone as per the online
request. There are only two requirements
- existing ZONE_NORMAL and ZONE_MOVABLE cannot overlap
- ZONE_NORMAL precedes ZONE_MOVABLE in physical addresses
the latter one is not an inherent requirement and can be changed in the
future. It preserves the current behavior and made the code slightly
simpler. This is subject to change in future.
This means that the same physical online steps as above will lead to the
following state: Normal Movable
/sys/devices/system/memory/memory32/valid_zones:Normal Movable
/sys/devices/system/memory/memory33/valid_zones:Normal Movable
/sys/devices/system/memory/memory32/valid_zones:Normal Movable
/sys/devices/system/memory/memory33/valid_zones:Normal Movable
/sys/devices/system/memory/memory34/valid_zones:Normal Movable
/sys/devices/system/memory/memory32/valid_zones:Normal Movable
/sys/devices/system/memory/memory33/valid_zones:Normal Movable
/sys/devices/system/memory/memory34/valid_zones:Movable
Implementation:
The current move_pfn_range is reimplemented to check the above
requirements (allow_online_pfn_range) and then updates the respective
zone (move_pfn_range_to_zone), the pgdat and links all the pages in the
pfn range with the zone/node. __add_pages is updated to not require the
zone and only initializes sections in the range. This allowed to
simplify the arch_add_memory code (s390 could get rid of quite some of
code).
devm_memremap_pages is the only user of arch_add_memory which relies on
the zone association because it only hooks into the memory hotplug only
half way. It uses it to associate the new memory with ZONE_DEVICE but
doesn't allow it to be {on,off}lined via sysfs. This means that this
particular code path has to call move_pfn_range_to_zone explicitly.
The original zone shifting code is kept in place and will be removed in
the follow up patch for an easier review.
Please note that this patch also changes the original behavior when
offlining a memory block adjacent to another zone (Normal vs. Movable)
used to allow to change its movable type. This will be handled later.
[[email protected]: simplify zone_intersects()]
Link: http://lkml.kernel.org/r/[email protected]
[[email protected]: remove duplicate call for set_page_links]
Link: http://lkml.kernel.org/r/[email protected]
[[email protected]: remove unused local `i']
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Michal Hocko <[email protected]>
Signed-off-by: Wei Yang <[email protected]>
Tested-by: Dan Williams <[email protected]>
Tested-by: Reza Arbab <[email protected]>
Acked-by: Heiko Carstens <[email protected]> # For s390 bits
Acked-by: Vlastimil Babka <[email protected]>
Cc: Martin Schwidefsky <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: Andrea Arcangeli <[email protected]>
Cc: Balbir Singh <[email protected]>
Cc: Daniel Kiper <[email protected]>
Cc: David Rientjes <[email protected]>
Cc: Igor Mammedov <[email protected]>
Cc: Jerome Glisse <[email protected]>
Cc: Joonsoo Kim <[email protected]>
Cc: Mel Gorman <[email protected]>
Cc: Tobias Regnery <[email protected]>
Cc: Toshi Kani <[email protected]>
Cc: Vitaly Kuznetsov <[email protected]>
Cc: Xishi Qiu <[email protected]>
Cc: Yasuaki Ishimatsu <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
|
|
pagetypeinfo_showblockcount_print skips over invalid pfns but it would
report pages which are offline because those have a valid pfn. Their
migrate type is misleading at best.
Now that we have pfn_to_online_page() we can use it instead of
pfn_valid() and fix this.
[[email protected]: fix build]
Link: http://lkml.kernel.org/r/[email protected]
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Michal Hocko <[email protected]>
Reported-by: Joonsoo Kim <[email protected]>
Acked-by: Vlastimil Babka <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: Andrea Arcangeli <[email protected]>
Cc: Balbir Singh <[email protected]>
Cc: Dan Williams <[email protected]>
Cc: Daniel Kiper <[email protected]>
Cc: David Rientjes <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Igor Mammedov <[email protected]>
Cc: Jerome Glisse <[email protected]>
Cc: Martin Schwidefsky <[email protected]>
Cc: Mel Gorman <[email protected]>
Cc: Reza Arbab <[email protected]>
Cc: Tobias Regnery <[email protected]>
Cc: Toshi Kani <[email protected]>
Cc: Vitaly Kuznetsov <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Cc: Xishi Qiu <[email protected]>
Cc: Yasuaki Ishimatsu <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
|
|
__first_valid_page skips over invalid pfns in the range but it might
still stumble over offline pages. At least start_isolate_page_range
will mark those set_migratetype_isolate. This doesn't represent any
immediate AFAICS because alloc_contig_range will fail to isolate those
pages but it relies on not fully initialized page which will become a
problem later when we stop associating offline pages to zones. Use
pfn_to_online_page to handle this.
This is more a preparatory patch than a fix.
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Michal Hocko <[email protected]>
Acked-by: Vlastimil Babka <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: Andrea Arcangeli <[email protected]>
Cc: Balbir Singh <[email protected]>
Cc: Dan Williams <[email protected]>
Cc: Daniel Kiper <[email protected]>
Cc: David Rientjes <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Igor Mammedov <[email protected]>
Cc: Jerome Glisse <[email protected]>
Cc: Joonsoo Kim <[email protected]>
Cc: Martin Schwidefsky <[email protected]>
Cc: Mel Gorman <[email protected]>
Cc: Reza Arbab <[email protected]>
Cc: Tobias Regnery <[email protected]>
Cc: Toshi Kani <[email protected]>
Cc: Vitaly Kuznetsov <[email protected]>
Cc: Xishi Qiu <[email protected]>
Cc: Yasuaki Ishimatsu <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
|
|
__reset_isolation_suitable walks the whole zone pfn range and it tries
to jump over holes by checking the zone for each page. It might still
stumble over offline pages, though. Skip those by checking
pfn_to_online_page()
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Michal Hocko <[email protected]>
Acked-by: Vlastimil Babka <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: Andrea Arcangeli <[email protected]>
Cc: Balbir Singh <[email protected]>
Cc: Dan Williams <[email protected]>
Cc: Daniel Kiper <[email protected]>
Cc: David Rientjes <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Igor Mammedov <[email protected]>
Cc: Jerome Glisse <[email protected]>
Cc: Joonsoo Kim <[email protected]>
Cc: Martin Schwidefsky <[email protected]>
Cc: Mel Gorman <[email protected]>
Cc: Reza Arbab <[email protected]>
Cc: Tobias Regnery <[email protected]>
Cc: Toshi Kani <[email protected]>
Cc: Vitaly Kuznetsov <[email protected]>
Cc: Xishi Qiu <[email protected]>
Cc: Yasuaki Ishimatsu <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
|
|
__pageblock_pfn_to_page has two users currently, set_zone_contiguous
which checks whether the given zone contains holes and
pageblock_pfn_to_page which then carefully returns a first valid page
from the given pfn range for the given zone. This doesn't handle zones
which are not fully populated though. Memory pageblocks can be offlined
or might not have been onlined yet. In such a case the zone should be
considered to have holes otherwise pfn walkers can touch and play with
offline pages.
Current callers of pageblock_pfn_to_page in compaction seem to work
properly right now because they only isolate PageBuddy
(isolate_freepages_block) or PageLRU resp. __PageMovable
(isolate_migratepages_block) which will be always false for these pages.
It would be safer to skip these pages altogether, though.
In order to do this patch adds a new memory section state
(SECTION_IS_ONLINE) which is set in memory_present (during boot time) or
in online_pages_range during the memory hotplug. Similarly
offline_mem_sections clears the bit and it is called when the memory
range is offlined.
pfn_to_online_page helper is then added which check the mem section and
only returns a page if it is onlined already.
Use the new helper in __pageblock_pfn_to_page and skip the whole page
block in such a case.
[[email protected]: check valid section number in pfn_to_online_page (Vlastimil),
mark sections online after all struct pages are initialized in
online_pages_range (Vlastimil)]
Link: http://lkml.kernel.org/r/[email protected]
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Michal Hocko <[email protected]>
Acked-by: Vlastimil Babka <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: Andrea Arcangeli <[email protected]>
Cc: Balbir Singh <[email protected]>
Cc: Dan Williams <[email protected]>
Cc: Daniel Kiper <[email protected]>
Cc: David Rientjes <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Igor Mammedov <[email protected]>
Cc: Jerome Glisse <[email protected]>
Cc: Joonsoo Kim <[email protected]>
Cc: Martin Schwidefsky <[email protected]>
Cc: Mel Gorman <[email protected]>
Cc: Reza Arbab <[email protected]>
Cc: Tobias Regnery <[email protected]>
Cc: Toshi Kani <[email protected]>
Cc: Vitaly Kuznetsov <[email protected]>
Cc: Xishi Qiu <[email protected]>
Cc: Yasuaki Ishimatsu <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
|
|
is_pageblock_removable_nolock() relies on having zone association to
examine all the page blocks to check whether they are movable or free.
This is just wasting of cycles when the memblock is offline. Later
patch in the series will also change the time when the page is
associated with a zone so we let's bail out early if the memblock is
offline.
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Michal Hocko <[email protected]>
Reported-by: Igor Mammedov <[email protected]>
Acked-by: Vlastimil Babka <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: Andrea Arcangeli <[email protected]>
Cc: Balbir Singh <[email protected]>
Cc: Dan Williams <[email protected]>
Cc: Daniel Kiper <[email protected]>
Cc: David Rientjes <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Jerome Glisse <[email protected]>
Cc: Joonsoo Kim <[email protected]>
Cc: Martin Schwidefsky <[email protected]>
Cc: Mel Gorman <[email protected]>
Cc: Reza Arbab <[email protected]>
Cc: Tobias Regnery <[email protected]>
Cc: Toshi Kani <[email protected]>
Cc: Vitaly Kuznetsov <[email protected]>
Cc: Xishi Qiu <[email protected]>
Cc: Yasuaki Ishimatsu <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
|
|
Memory hotplug (add_memory_resource) has to reinitialize node
infrastructure if the node is offline (one which went through the
complete add_memory(); remove_memory() cycle). That involves node
registration to the kobj infrastructure (register_node), the proper
association with cpus (register_cpu_under_node) and finally creation of
node<->memblock symlinks (link_mem_sections).
The last part requires to know node_start_pfn and node_spanned_pages
which we currently have but a leter patch will postpone this
initialization to the onlining phase which happens later. In fact we do
not need to rely on the early pgdat initialization even now because the
currently hot added pfn range is currently known.
Split register_one_node into core which does all the common work for the
boot time NUMA initialization and the hotplug (__register_one_node).
register_one_node keeps the full initialization while hotplug calls
__register_one_node and manually calls link_mem_sections for the proper
range.
This shouldn't introduce any functional change.
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Michal Hocko <[email protected]>
Acked-by: Vlastimil Babka <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: Andrea Arcangeli <[email protected]>
Cc: Balbir Singh <[email protected]>
Cc: Dan Williams <[email protected]>
Cc: Daniel Kiper <[email protected]>
Cc: David Rientjes <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Igor Mammedov <[email protected]>
Cc: Jerome Glisse <[email protected]>
Cc: Joonsoo Kim <[email protected]>
Cc: Martin Schwidefsky <[email protected]>
Cc: Mel Gorman <[email protected]>
Cc: Reza Arbab <[email protected]>
Cc: Tobias Regnery <[email protected]>
Cc: Toshi Kani <[email protected]>
Cc: Vitaly Kuznetsov <[email protected]>
Cc: Xishi Qiu <[email protected]>
Cc: Yasuaki Ishimatsu <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
|
|
Device memory hotplug hooks into regular memory hotplug only half way.
It needs memory sections to track struct pages but there is no
need/desire to associate those sections with memory blocks and export
them to the userspace via sysfs because they cannot be onlined anyway.
This is currently expressed by for_device argument to arch_add_memory
which then makes sure to associate the given memory range with
ZONE_DEVICE. register_new_memory then relies on is_zone_device_section
to distinguish special memory hotplug from the regular one. While this
works now, later patches in this series want to move __add_zone outside
of arch_add_memory path so we have to come up with something else.
Add want_memblock down the __add_pages path and use it to control
whether the section->memblock association should be done.
arch_add_memory then just trivially want memblock for everything but
for_device hotplug.
remove_memory_section doesn't need is_zone_device_section either. We
can simply skip all the memblock specific cleanup if there is no
memblock for the given section.
This shouldn't introduce any functional change.
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Michal Hocko <[email protected]>
Tested-by: Dan Williams <[email protected]>
Acked-by: Vlastimil Babka <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: Andrea Arcangeli <[email protected]>
Cc: Balbir Singh <[email protected]>
Cc: Daniel Kiper <[email protected]>
Cc: David Rientjes <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Igor Mammedov <[email protected]>
Cc: Jerome Glisse <[email protected]>
Cc: Joonsoo Kim <[email protected]>
Cc: Martin Schwidefsky <[email protected]>
Cc: Mel Gorman <[email protected]>
Cc: Reza Arbab <[email protected]>
Cc: Tobias Regnery <[email protected]>
Cc: Toshi Kani <[email protected]>
Cc: Vitaly Kuznetsov <[email protected]>
Cc: Xishi Qiu <[email protected]>
Cc: Yasuaki Ishimatsu <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
|
|
Commit c04fc586c1a4 ("mm: show node to memory section relationship with
symlinks in sysfs") has added means to export memblock<->node
association into the sysfs. It has also introduced get_nid_for_pfn
which is a rather confusing counterpart of pfn_to_nid which checks also
whether the pfn page is already initialized (page_initialized).
This is done by checking page::lru != NULL which doesn't make any sense
at all. Nothing in this path really relies on the lru list being used
or initialized. Just remove it because this will become a problem with
later patches.
Thanks to Reza Arbab for testing which revealed this to be a problem
(http://lkml.kernel.org/r/[email protected])
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Michal Hocko <[email protected]>
Acked-by: Vlastimil Babka <[email protected]>
Cc: Reza Arbab <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: Andrea Arcangeli <[email protected]>
Cc: Balbir Singh <[email protected]>
Cc: Dan Williams <[email protected]>
Cc: Daniel Kiper <[email protected]>
Cc: David Rientjes <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Igor Mammedov <[email protected]>
Cc: Jerome Glisse <[email protected]>
Cc: Joonsoo Kim <[email protected]>
Cc: Martin Schwidefsky <[email protected]>
Cc: Mel Gorman <[email protected]>
Cc: Tobias Regnery <[email protected]>
Cc: Toshi Kani <[email protected]>
Cc: Vitaly Kuznetsov <[email protected]>
Cc: Xishi Qiu <[email protected]>
Cc: Yasuaki Ishimatsu <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
|
|
The primary purpose of this helper is to query the node state so use the
node id directly. This is a preparatory patch for later changes.
This shouldn't introduce any functional change
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Michal Hocko <[email protected]>
Reviewed-by: Yasuaki Ishimatsu <[email protected]>
Acked-by: Vlastimil Babka <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: Andrea Arcangeli <[email protected]>
Cc: Balbir Singh <[email protected]>
Cc: Dan Williams <[email protected]>
Cc: Daniel Kiper <[email protected]>
Cc: David Rientjes <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Igor Mammedov <[email protected]>
Cc: Jerome Glisse <[email protected]>
Cc: Joonsoo Kim <[email protected]>
Cc: Martin Schwidefsky <[email protected]>
Cc: Mel Gorman <[email protected]>
Cc: Reza Arbab <[email protected]>
Cc: Tobias Regnery <[email protected]>
Cc: Toshi Kani <[email protected]>
Cc: Vitaly Kuznetsov <[email protected]>
Cc: Xishi Qiu <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
|
|
Patch series "mm: make movable onlining suck less", v4.
Movable onlining is a real hack with many downsides - mainly
reintroduction of lowmem/highmem issues we used to have on 32b systems -
but it is the only way to make the memory hotremove more reliable which
is something that people are asking for.
The current semantic of memory movable onlinening is really cumbersome,
however. The main reason for this is that the udev driven approach is
basically unusable because udev races with the memory probing while only
the last memory block or the one adjacent to the existing zone_movable
are allowed to be onlined movable. In short the criterion for the
successful online_movable changes under udev's feet. A reliable udev
approach would require a 2 phase approach where the first successful
movable online would have to check all the previous blocks and online
them in descending order. This is hard to be considered sane.
This patchset aims at making the onlining semantic more usable. First
of all it allows to online memory movable as long as it doesn't clash
with the existing ZONE_NORMAL. That means that ZONE_NORMAL and
ZONE_MOVABLE cannot overlap. Currently I preserve the original ordering
semantic so the zone always precedes the movable zone but I have plans
to remove this restriction in future because it is not really necessary.
First 3 patches are cleanups which should be ready to be merged right
away (unless I have missed something subtle of course).
Patch 4 deals with ZONE_DEVICE dependencies down the __add_pages path.
Patch 5 deals with implicit assumptions of register_one_node on pgdat
initialization.
Patches 6-10 deal with offline holes in the zone for pfn walkers. I
hope I got all of them right but people familiar with compaction should
double check this.
Patch 11 is the core of the change. In order to make it easier to
review I have tried it to be as minimalistic as possible and the large
code removal is moved to patch 14.
Patch 12 is a trivial follow up cleanup. Patch 13 fixes sparse warnings
and finally patch 14 removes the unused code.
I have tested the patches in kvm:
# qemu-system-x86_64 -enable-kvm -monitor pty -m 2G,slots=4,maxmem=4G -numa node,mem=1G -numa node,mem=1G ...
and then probed the additional memory by
(qemu) object_add memory-backend-ram,id=mem1,size=1G
(qemu) device_add pc-dimm,id=dimm1,memdev=mem1
Then I have used this simple script to probe the memory block by hand
# cat probe_memblock.sh
#!/bin/sh
BLOCK_NR=$1
# echo $((0x100000000+$BLOCK_NR*(128<<20))) > /sys/devices/system/memory/probe
# for i in $(seq 10); do sh probe_memblock.sh $i; done
# grep . /sys/devices/system/memory/memory3?/valid_zones 2>/dev/null
/sys/devices/system/memory/memory33/valid_zones:Normal Movable
/sys/devices/system/memory/memory34/valid_zones:Normal Movable
/sys/devices/system/memory/memory35/valid_zones:Normal Movable
/sys/devices/system/memory/memory36/valid_zones:Normal Movable
/sys/devices/system/memory/memory37/valid_zones:Normal Movable
/sys/devices/system/memory/memory38/valid_zones:Normal Movable
/sys/devices/system/memory/memory39/valid_zones:Normal Movable
The main difference to the original implementation is that all new
memblocks can be both online_kernel and online_movable initially because
there is no clash obviously. For the comparison the original
implementation would have
/sys/devices/system/memory/memory33/valid_zones:Normal
/sys/devices/system/memory/memory34/valid_zones:Normal
/sys/devices/system/memory/memory35/valid_zones:Normal
/sys/devices/system/memory/memory36/valid_zones:Normal
/sys/devices/system/memory/memory37/valid_zones:Normal
/sys/devices/system/memory/memory38/valid_zones:Normal
/sys/devices/system/memory/memory39/valid_zones:Normal Movable
Now
# echo online_movable > /sys/devices/system/memory/memory34/state
# grep . /sys/devices/system/memory/memory3?/valid_zones 2>/dev/null
/sys/devices/system/memory/memory33/valid_zones:Normal Movable
/sys/devices/system/memory/memory34/valid_zones:Movable
/sys/devices/system/memory/memory35/valid_zones:Movable
/sys/devices/system/memory/memory36/valid_zones:Movable
/sys/devices/system/memory/memory37/valid_zones:Movable
/sys/devices/system/memory/memory38/valid_zones:Movable
/sys/devices/system/memory/memory39/valid_zones:Movable
Block 33 can still be online both kernel and movable while all
the remaining can be only movable.
/proc/zonelist says
Node 0, zone Normal
pages free 0
min 0
low 0
high 0
spanned 0
present 0
--
Node 0, zone Movable
pages free 32753
min 85
low 117
high 149
spanned 32768
present 32768
A new memblock at a lower address will result in a new memblock (32)
which will still allow both Normal and Movable.
# sh probe_memblock.sh 0
# grep . /sys/devices/system/memory/memory3[2-5]/valid_zones 2>/dev/null
/sys/devices/system/memory/memory32/valid_zones:Normal Movable
/sys/devices/system/memory/memory33/valid_zones:Normal Movable
/sys/devices/system/memory/memory34/valid_zones:Movable
/sys/devices/system/memory/memory35/valid_zones:Movable
and online_kernel will convert it to the zone normal properly
while 33 can be still onlined both ways.
# echo online_kernel > /sys/devices/system/memory/memory32/state
# grep . /sys/devices/system/memory/memory3[2-5]/valid_zones 2>/dev/null
/sys/devices/system/memory/memory32/valid_zones:Normal
/sys/devices/system/memory/memory33/valid_zones:Normal Movable
/sys/devices/system/memory/memory34/valid_zones:Movable
/sys/devices/system/memory/memory35/valid_zones:Movable
/proc/zoneinfo will now tell
Node 0, zone Normal
pages free 65441
min 165
low 230
high 295
spanned 65536
present 65536
--
Node 0, zone Movable
pages free 32740
min 82
low 114
high 146
spanned 32768
present 32768
so both zones have one memblock spanned and present.
Onlining 39 should associate this block to the movable zone
# echo online > /sys/devices/system/memory/memory39/state
/proc/zoneinfo will now tell
Node 0, zone Normal
pages free 32765
min 80
low 112
high 144
spanned 32768
present 32768
--
Node 0, zone Movable
pages free 65501
min 160
low 225
high 290
spanned 196608
present 65536
so we will have a movable zone which spans 6 memblocks, 2 present and 4
representing a hole.
Offlining both movable blocks will lead to the zone with no present
pages which is the expected behavior I believe.
# echo offline > /sys/devices/system/memory/memory39/state
# echo offline > /sys/devices/system/memory/memory34/state
# grep -A6 "Movable\|Normal" /proc/zoneinfo
Node 0, zone Normal
pages free 32735
min 90
low 122
high 154
spanned 32768
present 32768
--
Node 0, zone Movable
pages free 0
min 0
low 0
high 0
spanned 196608
present 0
As a bonus we will get a nice cleanup in the memory hotplug codebase.
This patch (of 16):
init_currently_empty_zone doesn't have any error to return yet it is
still an int and callers try to be defensive and try to handle potential
error. Remove this nonsense and simplify all callers.
This patch shouldn't have any visible effect
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Michal Hocko <[email protected]>
Reviewed-by: Yasuaki Ishimatsu <[email protected]>
Acked-by: Balbir Singh <[email protected]>
Acked-by: Vlastimil Babka <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: Andrea Arcangeli <[email protected]>
Cc: Dan Williams <[email protected]>
Cc: Daniel Kiper <[email protected]>
Cc: David Rientjes <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Igor Mammedov <[email protected]>
Cc: Jerome Glisse <[email protected]>
Cc: Joonsoo Kim <[email protected]>
Cc: Martin Schwidefsky <[email protected]>
Cc: Mel Gorman <[email protected]>
Cc: Reza Arbab <[email protected]>
Cc: Tobias Regnery <[email protected]>
Cc: Toshi Kani <[email protected]>
Cc: Vitaly Kuznetsov <[email protected]>
Cc: Xishi Qiu <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
|
|
If there is no compound map for a THP (Transparent Huge Page), it is
possible that the map count of some sub-pages of the THP is 0. So it is
better to split the THP before swapping out. In this way, the sub-pages
not mapped will be freed, and we can avoid the unnecessary swap out
operations for these sub-pages.
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: "Huang, Ying" <[email protected]>
Cc: Johannes Weiner <[email protected]>
Cc: Andrea Arcangeli <[email protected]>
Cc: Ebru Akagunduz <[email protected]>
Cc: Hugh Dickins <[email protected]>
Cc: Kirill A. Shutemov <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Minchan Kim <[email protected]>
Cc: Rik van Riel <[email protected]>
Cc: Shaohua Li <[email protected]>
Cc: Tejun Heo <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
|
|
To swap out THP (Transparent Huage Page), before splitting the THP, the
swap cluster will be allocated and the THP will be added into the swap
cache. But it is possible that the THP cannot be split, so that we must
delete the THP from the swap cache and free the swap cluster. To avoid
that, in this patch, whether the THP can be split is checked firstly.
The check can only be done racy, but it is good enough for most cases.
With the patch, the swap out throughput improves 3.6% (from about
4.16GB/s to about 4.31GB/s) in the vm-scalability swap-w-seq test case
with 8 processes. The test is done on a Xeon E5 v3 system. The swap
device used is a RAM simulated PMEM (persistent memory) device. To test
the sequential swapping out, the test case creates 8 processes, which
sequentially allocate and write to the anonymous pages until the RAM and
part of the swap device is used up.
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: "Huang, Ying" <[email protected]>
Acked-by: Kirill A. Shutemov <[email protected]> [for can_split_huge_page()]
Cc: Johannes Weiner <[email protected]>
Cc: Andrea Arcangeli <[email protected]>
Cc: Ebru Akagunduz <[email protected]>
Cc: Hugh Dickins <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Minchan Kim <[email protected]>
Cc: Rik van Riel <[email protected]>
Cc: Shaohua Li <[email protected]>
Cc: Tejun Heo <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
|
|
The add_to_swap aims to allocate swap_space(ie, swap slot and swapcache)
so if it fails due to lack of space in case of THP or something(hdd swap
but tries THP swapout) *caller* rather than add_to_swap itself should
split the THP page and retry it with base page which is more natural.
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Minchan Kim <[email protected]>
Signed-off-by: "Huang, Ying" <[email protected]>
Acked-by: Johannes Weiner <[email protected]>
Cc: Andrea Arcangeli <[email protected]>
Cc: Ebru Akagunduz <[email protected]>
Cc: Hugh Dickins <[email protected]>
Cc: Kirill A. Shutemov <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Rik van Riel <[email protected]>
Cc: Shaohua Li <[email protected]>
Cc: Tejun Heo <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
|
|
Now, get_swap_page takes struct page and allocates swap space according
to page size(ie, normal or THP) so it would be more cleaner to introduce
put_swap_page which is a counter function of get_swap_page. Then, it
calls right swap slot free function depending on page's size.
[[email protected]: minor cleanup and fix]
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Minchan Kim <[email protected]>
Signed-off-by: "Huang, Ying" <[email protected]>
Acked-by: Johannes Weiner <[email protected]>
Cc: Andrea Arcangeli <[email protected]>
Cc: Ebru Akagunduz <[email protected]>
Cc: Hugh Dickins <[email protected]>
Cc: Kirill A. Shutemov <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Rik van Riel <[email protected]>
Cc: Shaohua Li <[email protected]>
Cc: Tejun Heo <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
|
|
Patch series "THP swap: Delay splitting THP during swapping out", v11.
This patchset is to optimize the performance of Transparent Huge Page
(THP) swap.
Recently, the performance of the storage devices improved so fast that
we cannot saturate the disk bandwidth with single logical CPU when do
page swap out even on a high-end server machine. Because the
performance of the storage device improved faster than that of single
logical CPU. And it seems that the trend will not change in the near
future. On the other hand, the THP becomes more and more popular
because of increased memory size. So it becomes necessary to optimize
THP swap performance.
The advantages of the THP swap support include:
- Batch the swap operations for the THP to reduce lock
acquiring/releasing, including allocating/freeing the swap space,
adding/deleting to/from the swap cache, and writing/reading the swap
space, etc. This will help improve the performance of the THP swap.
- The THP swap space read/write will be 2M sequential IO. It is
particularly helpful for the swap read, which are usually 4k random
IO. This will improve the performance of the THP swap too.
- It will help the memory fragmentation, especially when the THP is
heavily used by the applications. The 2M continuous pages will be
free up after THP swapping out.
- It will improve the THP utilization on the system with the swap
turned on. Because the speed for khugepaged to collapse the normal
pages into the THP is quite slow. After the THP is split during the
swapping out, it will take quite long time for the normal pages to
collapse back into the THP after being swapped in. The high THP
utilization helps the efficiency of the page based memory management
too.
There are some concerns regarding THP swap in, mainly because possible
enlarged read/write IO size (for swap in/out) may put more overhead on
the storage device. To deal with that, the THP swap in should be turned
on only when necessary. For example, it can be selected via
"always/never/madvise" logic, to be turned on globally, turned off
globally, or turned on only for VMA with MADV_HUGEPAGE, etc.
This patchset is the first step for the THP swap support. The plan is
to delay splitting THP step by step, finally avoid splitting THP during
the THP swapping out and swap out/in the THP as a whole.
As the first step, in this patchset, the splitting huge page is delayed
from almost the first step of swapping out to after allocating the swap
space for the THP and adding the THP into the swap cache. This will
reduce lock acquiring/releasing for the locks used for the swap cache
management.
With the patchset, the swap out throughput improves 15.5% (from about
3.73GB/s to about 4.31GB/s) in the vm-scalability swap-w-seq test case
with 8 processes. The test is done on a Xeon E5 v3 system. The swap
device used is a RAM simulated PMEM (persistent memory) device. To test
the sequential swapping out, the test case creates 8 processes, which
sequentially allocate and write to the anonymous pages until the RAM and
part of the swap device is used up.
This patch (of 5):
In this patch, splitting huge page is delayed from almost the first step
of swapping out to after allocating the swap space for the THP
(Transparent Huge Page) and adding the THP into the swap cache. This
will batch the corresponding operation, thus improve THP swap out
throughput.
This is the first step for the THP swap optimization. The plan is to
delay splitting the THP step by step and avoid splitting the THP
finally.
In this patch, one swap cluster is used to hold the contents of each THP
swapped out. So, the size of the swap cluster is changed to that of the
THP (Transparent Huge Page) on x86_64 architecture (512). For other
architectures which want such THP swap optimization,
ARCH_USES_THP_SWAP_CLUSTER needs to be selected in the Kconfig file for
the architecture. In effect, this will enlarge swap cluster size by 2
times on x86_64. Which may make it harder to find a free cluster when
the swap space becomes fragmented. So that, this may reduce the
continuous swap space allocation and sequential write in theory. The
performance test in 0day shows no regressions caused by this.
In the future of THP swap optimization, some information of the swapped
out THP (such as compound map count) will be recorded in the
swap_cluster_info data structure.
The mem cgroup swap accounting functions are enhanced to support charge
or uncharge a swap cluster backing a THP as a whole.
The swap cluster allocate/free functions are added to allocate/free a
swap cluster for a THP. A fair simple algorithm is used for swap
cluster allocation, that is, only the first swap device in priority list
will be tried to allocate the swap cluster. The function will fail if
the trying is not successful, and the caller will fallback to allocate a
single swap slot instead. This works good enough for normal cases. If
the difference of the number of the free swap clusters among multiple
swap devices is significant, it is possible that some THPs are split
earlier than necessary. For example, this could be caused by big size
difference among multiple swap devices.
The swap cache functions is enhanced to support add/delete THP to/from
the swap cache as a set of (HPAGE_PMD_NR) sub-pages. This may be
enhanced in the future with multi-order radix tree. But because we will
split the THP soon during swapping out, that optimization doesn't make
much sense for this first step.
The THP splitting functions are enhanced to support to split THP in swap
cache during swapping out. The page lock will be held during allocating
the swap cluster, adding the THP into the swap cache and splitting the
THP. So in the code path other than swapping out, if the THP need to be
split, the PageSwapCache(THP) will be always false.
The swap cluster is only available for SSD, so the THP swap optimization
in this patchset has no effect for HDD.
[[email protected]: fix two issues in THP optimize patch]
Link: http://lkml.kernel.org/r/[email protected]
[[email protected]: extensive cleanups and simplifications, reduce code size]
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: "Huang, Ying" <[email protected]>
Signed-off-by: Johannes Weiner <[email protected]>
Suggested-by: Andrew Morton <[email protected]> [for config option]
Acked-by: Kirill A. Shutemov <[email protected]> [for changes in huge_memory.c and huge_mm.h]
Cc: Andrea Arcangeli <[email protected]>
Cc: Ebru Akagunduz <[email protected]>
Cc: Johannes Weiner <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Tejun Heo <[email protected]>
Cc: Hugh Dickins <[email protected]>
Cc: Shaohua Li <[email protected]>
Cc: Minchan Kim <[email protected]>
Cc: Rik van Riel <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
|
|
Standardize the file operation variable names related to all four memory
management /proc interface files. Also change all the symbol
permissions (S_IRUGO) into octal permissions (0444) as it got complaints
from checkpatch.pl. This does not create any functional change to the
interface.
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Anshuman Khandual <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
|
|
Regardless of whether it is same page or not, it's surely write and
stored to zram so we should increase pages_stored stat. Otherwise, user
can see zero value via mm_stats although he writes a lot of pages to
zram.
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Minchan Kim <[email protected]>
Reviewed-by: Sergey Senozhatsky <[email protected]>
Cc: Joonsoo Kim <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
|
|
If a candidate stable_node_dup has been found and it can accept further
merges it can be refiled to the head of the list to speedup next
searches without altering which dup is found and how the dups accumulate
in the chain.
We already refiled it back to the head in the prune_stale_stable_nodes
case, but we didn't refile it if not pruning (which is more common).
And we also refiled it when it was already at the head which is
unnecessary (in the prune_stale_stable_nodes case, nr > 1 means there's
more than one dup in the chain, it doesn't mean it's not already at the
head of the chain).
The stable_node_chain list is single threaded and there's no SMP locking
contention so it should be faster to refile it to the head of the list
also if prune_stale_stable_nodes is false.
Profiling shows the refile happens 1.9% of the time when a dup is found
with a max_page_sharing limit setting of 3 (with max_page_sharing of 2
the refile never happens of course as there's never space for one more
merge) which is reasonably low. At higher max_page_sharing values it
should be much less frequent.
This is just an optimization.
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Andrea Arcangeli <[email protected]>
Cc: Evgheni Dereveanchin <[email protected]>
Cc: Andrey Ryabinin <[email protected]>
Cc: Petr Holasek <[email protected]>
Cc: Hugh Dickins <[email protected]>
Cc: Arjan van de Ven <[email protected]>
Cc: Davidlohr Bueso <[email protected]>
Cc: Gavin Guo <[email protected]>
Cc: Jay Vosburgh <[email protected]>
Cc: Mel Gorman <[email protected]>
Cc: Dan Carpenter <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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Some static checker complains if chain/chain_prune returns a potentially
stale pointer.
There are two output parameters to chain/chain_prune, one is tree_page
the other is stable_node_dup. Like in get_ksm_page the caller has to
check tree_page is NULL before touching the stable_node. Similarly in
chain/chain_prune the caller has to check tree_page before touching the
stable_node_dup returned or the original stable_node passed as
parameter.
Because the tree_page is never returned as a stale pointer, it may be
more intuitive to return tree_page and to pass stable_node_dup for
reference instead of the reverse.
This patch purely swaps the two output parameters of chain/chain_prune
as a cleanup for the static checker and to mimic the get_ksm_page
behavior more closely. There's no change to the caller at all except
the swap, it's purely a cleanup and it is a noop from the caller point
of view.
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Andrea Arcangeli <[email protected]>
Reported-by: Dan Carpenter <[email protected]>
Tested-by: Dan Carpenter <[email protected]>
Cc: Evgheni Dereveanchin <[email protected]>
Cc: Andrey Ryabinin <[email protected]>
Cc: Petr Holasek <[email protected]>
Cc: Hugh Dickins <[email protected]>
Cc: Arjan van de Ven <[email protected]>
Cc: Davidlohr Bueso <[email protected]>
Cc: Gavin Guo <[email protected]>
Cc: Jay Vosburgh <[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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