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Fix W=1 compile warnings (invalid kerneldoc):
mm/mmu_notifier.c:187: warning: Function parameter or member 'interval_sub' not described in 'mmu_interval_read_bgin'
mm/mmu_notifier.c:708: warning: Function parameter or member 'subscription' not described in 'mmu_notifier_registr'
mm/mmu_notifier.c:708: warning: Excess function parameter 'mn' description in 'mmu_notifier_register'
mm/mmu_notifier.c:880: warning: Function parameter or member 'subscription' not described in 'mmu_notifier_put'
mm/mmu_notifier.c:880: warning: Excess function parameter 'mn' description in 'mmu_notifier_put'
mm/mmu_notifier.c:982: warning: Function parameter or member 'ops' not described in 'mmu_interval_notifier_insert'
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: http://lkml.kernel.org/r/20200728171109.28687-4-krzk@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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The routine cma_init_reserved_areas is designed to activate all
reserved cma areas. It quits when it first encounters an error.
This can leave some areas in a state where they are reserved but
not activated. There is no feedback to code which performed the
reservation. Attempting to allocate memory from areas in such a
state will result in a BUG.
Modify cma_init_reserved_areas to always attempt to activate all
areas. The called routine, cma_activate_area is responsible for
leaving the area in a valid state. No one is making active use
of returned error codes, so change the routine to void.
How to reproduce: This example uses kernelcore, hugetlb and cma
as an easy way to reproduce. However, this is a more general cma
issue.
Two node x86 VM 16GB total, 8GB per node
Kernel command line parameters, kernelcore=4G hugetlb_cma=8G
Related boot time messages,
hugetlb_cma: reserve 8192 MiB, up to 4096 MiB per node
cma: Reserved 4096 MiB at 0x0000000100000000
hugetlb_cma: reserved 4096 MiB on node 0
cma: Reserved 4096 MiB at 0x0000000300000000
hugetlb_cma: reserved 4096 MiB on node 1
cma: CMA area hugetlb could not be activated
# echo 8 > /sys/kernel/mm/hugepages/hugepages-1048576kB/nr_hugepages
BUG: kernel NULL pointer dereference, address: 0000000000000000
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 0 P4D 0
Oops: 0000 [#1] SMP PTI
...
Call Trace:
bitmap_find_next_zero_area_off+0x51/0x90
cma_alloc+0x1a5/0x310
alloc_fresh_huge_page+0x78/0x1a0
alloc_pool_huge_page+0x6f/0xf0
set_max_huge_pages+0x10c/0x250
nr_hugepages_store_common+0x92/0x120
? __kmalloc+0x171/0x270
kernfs_fop_write+0xc1/0x1a0
vfs_write+0xc7/0x1f0
ksys_write+0x5f/0xe0
do_syscall_64+0x4d/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xa9
Fixes: c64be2bb1c6e ("drivers: add Contiguous Memory Allocator")
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Roman Gushchin <guro@fb.com>
Acked-by: Barry Song <song.bao.hua@hisilicon.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Michal Nazarewicz <mina86@mina86.com>
Cc: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: <stable@vger.kernel.org>
Link: http://lkml.kernel.org/r/20200730163123.6451-1-mike.kravetz@oracle.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Once we enable CMA_DEBUGFS, we will get the below errors: directory
'cma-hugetlb' with parent 'cma' already present.
We should have different names for different CMA areas.
Signed-off-by: Barry Song <song.bao.hua@hisilicon.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Acked-by: Roman Gushchin <guro@fb.com>
Link: http://lkml.kernel.org/r/20200616223131.33828-3-song.bao.hua@hisilicon.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Patch series "mm: fix the names of general cma and hugetlb cma", v2.
The current code of CMA can only work when users pass a const string as
name parameter. we need to fix the way to handle names in CMA. On the
other hand, to avoid name conflicts after enabling CMA_DEBUGFS, each
hugetlb should get a different CMA name.
This patch (of 2):
If users give a name saved in stack, the current code will generate magic
pointer. if users don't give a name(NULL), kasprintf() will always return
NULL as we are at the early stage. that means cma_init_reserved_mem()
will return -ENOMEM if users set name parameter as NULL.
[natechancellor@gmail.com: return cma->name directly in cma_get_name]
Link: https://github.com/ClangBuiltLinux/linux/issues/1063
Link: http://lkml.kernel.org/r/20200623015840.621964-1-natechancellor@gmail.com
Signed-off-by: Barry Song <song.bao.hua@hisilicon.com>
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Acked-by: Roman Gushchin <guro@fb.com>
Link: http://lkml.kernel.org/r/20200616223131.33828-2-song.bao.hua@hisilicon.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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In some case the cma area could not be activated, but the cma_alloc be
used under this case, then the kernel will crash caused by NULL pointer
dereference.
Add bitmap valid check in cma_alloc to avoid this issue.
Signed-off-by: Jianqun Xu <jay.xu@rock-chips.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Link: http://lkml.kernel.org/r/20200615010123.15596-1-jay.xu@rock-chips.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Add following new vmstat events which will help in validating THP
migration without split. Statistics reported through these new VM events
will help in performance debugging.
1. THP_MIGRATION_SUCCESS
2. THP_MIGRATION_FAILURE
3. THP_MIGRATION_SPLIT
In addition, these new events also update normal page migration statistics
appropriately via PGMIGRATE_SUCCESS and PGMIGRATE_FAILURE. While here,
this updates current trace event 'mm_migrate_pages' to accommodate now
available THP statistics.
[akpm@linux-foundation.org: s/hpage_nr_pages/thp_nr_pages/]
[ziy@nvidia.com: v2]
Link: http://lkml.kernel.org/r/C5E3C65C-8253-4638-9D3C-71A61858BB8B@nvidia.com
[anshuman.khandual@arm.com: s/thp_nr_pages/hpage_nr_pages/]
Link: http://lkml.kernel.org/r/1594287583-16568-1-git-send-email-anshuman.khandual@arm.com
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Zi Yan <ziy@nvidia.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Link: http://lkml.kernel.org/r/1594080415-27924-1-git-send-email-anshuman.khandual@arm.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Since commit 3917c80280c93a7123f ("thp: change CoW semantics for
anon-THP"), the CoW page fault of THP has been rewritten, debug_cow is not
used anymore. So, just remove it.
Signed-off-by: Yang Shi <yang.shi@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Link: http://lkml.kernel.org/r/1592270980-116062-1-git-send-email-yang.shi@linux.alibaba.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Patch series "mm/migrate: optimize migrate_vma_setup() for holes".
A simple optimization for migrate_vma_*() when the source vma is not an
anonymous vma and a new test case to exercise it.
This patch (of 2):
When migrating system memory to device private memory, if the source
address range is a valid VMA range and there is no memory or a zero page,
the source PFN array is marked as valid but with no PFN.
This lets the device driver allocate private memory and clear it, then
insert the new device private struct page into the CPU's page tables when
migrate_vma_pages() is called. migrate_vma_pages() only inserts the new
page if the VMA is an anonymous range.
There is no point in telling the device driver to allocate device private
memory and then not migrate the page. Instead, mark the source PFN array
entries as not migrating to avoid this overhead.
[rcampbell@nvidia.com: v2]
Link: http://lkml.kernel.org/r/20200710194840.7602-2-rcampbell@nvidia.com
Signed-off-by: Ralph Campbell <rcampbell@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Jason Gunthorpe <jgg@mellanox.com>
Cc: "Bharata B Rao" <bharata@linux.ibm.com>
Cc: Shuah Khan <shuah@kernel.org>
Link: http://lkml.kernel.org/r/20200710194840.7602-1-rcampbell@nvidia.com
Link: http://lkml.kernel.org/r/20200709165711.26584-1-rcampbell@nvidia.com
Link: http://lkml.kernel.org/r/20200709165711.26584-2-rcampbell@nvidia.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Commit c0d0381ade79 ("hugetlbfs: use i_mmap_rwsem for more pmd sharing
synchronization") requires callers of huge_pte_alloc to hold i_mmap_rwsem
in at least read mode. This is because the explicit locking in
huge_pmd_share (called by huge_pte_alloc) was removed. When restructuring
the code, the call to huge_pte_alloc in the else block at the beginning of
hugetlb_fault was missed.
Unfortunately, that else clause is exercised when there is no page table
entry. This will likely lead to a call to huge_pmd_share. If
huge_pmd_share thinks pmd sharing is possible, it will traverse the
mapping tree (i_mmap) without holding i_mmap_rwsem. If someone else is
modifying the tree, bad things such as addressing exceptions or worse
could happen.
Simply remove the else clause. It should have been removed previously.
The code following the else will call huge_pte_alloc with the appropriate
locking.
To prevent this type of issue in the future, add routines to assert that
i_mmap_rwsem is held, and call these routines in huge pmd sharing
routines.
Fixes: c0d0381ade79 ("hugetlbfs: use i_mmap_rwsem for more pmd sharing synchronization")
Suggested-by: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: "Kirill A.Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Prakash Sangappa <prakash.sangappa@oracle.com>
Cc: <stable@vger.kernel.org>
Link: http://lkml.kernel.org/r/e670f327-5cf9-1959-96e4-6dc7cc30d3d5@oracle.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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When the OOM killer finds a victim and tryies to kill it, if the victim is
already exiting, the task mm will be NULL and no process will be killed.
But the dump_header() has been already executed, so it will be strange to
dump so much information without killing a process. We'd better show some
helpful information to indicate why this happens.
Suggested-by: David Rientjes <rientjes@google.com>
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Cc: Qian Cai <cai@lca.pw>
Link: http://lkml.kernel.org/r/20200721010127.17238-1-laoar.shao@gmail.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Recently we found an issue on our production environment that when memcg
oom is triggered the oom killer doesn't chose the process with largest
resident memory but chose the first scanned process. Note that all
processes in this memcg have the same oom_score_adj, so the oom killer
should chose the process with largest resident memory.
Bellow is part of the oom info, which is enough to analyze this issue.
[7516987.983223] memory: usage 16777216kB, limit 16777216kB, failcnt 52843037
[7516987.983224] memory+swap: usage 16777216kB, limit 9007199254740988kB, failcnt 0
[7516987.983225] kmem: usage 301464kB, limit 9007199254740988kB, failcnt 0
[...]
[7516987.983293] [ pid ] uid tgid total_vm rss pgtables_bytes swapents oom_score_adj name
[7516987.983510] [ 5740] 0 5740 257 1 32768 0 -998 pause
[7516987.983574] [58804] 0 58804 4594 771 81920 0 -998 entry_point.bas
[7516987.983577] [58908] 0 58908 7089 689 98304 0 -998 cron
[7516987.983580] [58910] 0 58910 16235 5576 163840 0 -998 supervisord
[7516987.983590] [59620] 0 59620 18074 1395 188416 0 -998 sshd
[7516987.983594] [59622] 0 59622 18680 6679 188416 0 -998 python
[7516987.983598] [59624] 0 59624 1859266 5161 548864 0 -998 odin-agent
[7516987.983600] [59625] 0 59625 707223 9248 983040 0 -998 filebeat
[7516987.983604] [59627] 0 59627 416433 64239 774144 0 -998 odin-log-agent
[7516987.983607] [59631] 0 59631 180671 15012 385024 0 -998 python3
[7516987.983612] [61396] 0 61396 791287 3189 352256 0 -998 client
[7516987.983615] [61641] 0 61641 1844642 29089 946176 0 -998 client
[7516987.983765] [ 9236] 0 9236 2642 467 53248 0 -998 php_scanner
[7516987.983911] [42898] 0 42898 15543 838 167936 0 -998 su
[7516987.983915] [42900] 1000 42900 3673 867 77824 0 -998 exec_script_vr2
[7516987.983918] [42925] 1000 42925 36475 19033 335872 0 -998 python
[7516987.983921] [57146] 1000 57146 3673 848 73728 0 -998 exec_script_J2p
[7516987.983925] [57195] 1000 57195 186359 22958 491520 0 -998 python2
[7516987.983928] [58376] 1000 58376 275764 14402 290816 0 -998 rosmaster
[7516987.983931] [58395] 1000 58395 155166 4449 245760 0 -998 rosout
[7516987.983935] [58406] 1000 58406 18285584 3967322 37101568 0 -998 data_sim
[7516987.984221] oom-kill:constraint=CONSTRAINT_MEMCG,nodemask=(null),cpuset=3aa16c9482ae3a6f6b78bda68a55d32c87c99b985e0f11331cddf05af6c4d753,mems_allowed=0-1,oom_memcg=/kubepods/podf1c273d3-9b36-11ea-b3df-246e9693c184,task_memcg=/kubepods/podf1c273d3-9b36-11ea-b3df-246e9693c184/1f246a3eeea8f70bf91141eeaf1805346a666e225f823906485ea0b6c37dfc3d,task=pause,pid=5740,uid=0
[7516987.984254] Memory cgroup out of memory: Killed process 5740 (pause) total-vm:1028kB, anon-rss:4kB, file-rss:0kB, shmem-rss:0kB
[7516988.092344] oom_reaper: reaped process 5740 (pause), now anon-rss:0kB, file-rss:0kB, shmem-rss:0kB
We can find that the first scanned process 5740 (pause) was killed, but
its rss is only one page. That is because, when we calculate the oom
badness in oom_badness(), we always ignore the negtive point and convert
all of these negtive points to 1. Now as oom_score_adj of all the
processes in this targeted memcg have the same value -998, the points of
these processes are all negtive value. As a result, the first scanned
process will be killed.
The oom_socre_adj (-998) in this memcg is set by kubelet, because it is a
a Guaranteed pod, which has higher priority to prevent from being killed
by system oom.
To fix this issue, we should make the calculation of oom point more
accurate. We can achieve it by convert the chosen_point from 'unsigned
long' to 'long'.
[cai@lca.pw: reported a issue in the previous version]
[mhocko@suse.com: fixed the issue reported by Cai]
[mhocko@suse.com: add the comment in proc_oom_score()]
[laoar.shao@gmail.com: v3]
Link: http://lkml.kernel.org/r/1594396651-9931-1-git-send-email-laoar.shao@gmail.com
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tested-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Qian Cai <cai@lca.pw>
Link: http://lkml.kernel.org/r/1594309987-9919-1-git-send-email-laoar.shao@gmail.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Previous implementatoin calls untagged_addr() before error check, while if
the error check failed and return EINVAL, the untagged_addr() call is just
useless work.
Signed-off-by: Wenchao Hao <haowenchao22@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/20200801090825.5597-1-haowenchao22@gmail.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Fix W=1 compile warnings (invalid kerneldoc):
mm/mempolicy.c:137: warning: Function parameter or member 'node' not described in 'numa_map_to_online_node'
mm/mempolicy.c:137: warning: Excess function parameter 'nid' description in 'numa_map_to_online_node'
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/20200728171109.28687-3-krzk@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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There is no compact_defer_limit. It should be compact_defer_shift in
use. and add compact_order_failed explanation.
Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Link: http://lkml.kernel.org/r/3bd60e1b-a74e-050d-ade4-6e8f54e00b92@linux.alibaba.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Proactive compaction uses per-node/zone "fragmentation score" which is
always in range [0, 100], so use unsigned type of these scores as well as
for related constants.
Signed-off-by: Nitin Gupta <nigupta@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Baoquan He <bhe@redhat.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Iurii Zaikin <yzaikin@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Link: http://lkml.kernel.org/r/20200618010319.13159-1-nigupta@nvidia.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Fix compile error when COMPACTION_HPAGE_ORDER is assigned to
HUGETLB_PAGE_ORDER. The correct way to check if this constant is defined
is to check for CONFIG_HUGETLBFS.
Reported-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Nitin Gupta <nigupta@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tested-by: Nathan Chancellor <natechancellor@gmail.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Link: http://lkml.kernel.org/r/20200623064544.25766-1-nigupta@nvidia.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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For some applications, we need to allocate almost all memory as hugepages.
However, on a running system, higher-order allocations can fail if the
memory is fragmented. Linux kernel currently does on-demand compaction as
we request more hugepages, but this style of compaction incurs very high
latency. Experiments with one-time full memory compaction (followed by
hugepage allocations) show that kernel is able to restore a highly
fragmented memory state to a fairly compacted memory state within <1 sec
for a 32G system. Such data suggests that a more proactive compaction can
help us allocate a large fraction of memory as hugepages keeping
allocation latencies low.
For a more proactive compaction, the approach taken here is to define a
new sysctl called 'vm.compaction_proactiveness' which dictates bounds for
external fragmentation which kcompactd tries to maintain.
The tunable takes a value in range [0, 100], with a default of 20.
Note that a previous version of this patch [1] was found to introduce too
many tunables (per-order extfrag{low, high}), but this one reduces them to
just one sysctl. Also, the new tunable is an opaque value instead of
asking for specific bounds of "external fragmentation", which would have
been difficult to estimate. The internal interpretation of this opaque
value allows for future fine-tuning.
Currently, we use a simple translation from this tunable to [low, high]
"fragmentation score" thresholds (low=100-proactiveness, high=low+10%).
The score for a node is defined as weighted mean of per-zone external
fragmentation. A zone's present_pages determines its weight.
To periodically check per-node score, we reuse per-node kcompactd threads,
which are woken up every 500 milliseconds to check the same. If a node's
score exceeds its high threshold (as derived from user-provided
proactiveness value), proactive compaction is started until its score
reaches its low threshold value. By default, proactiveness is set to 20,
which implies threshold values of low=80 and high=90.
This patch is largely based on ideas from Michal Hocko [2]. See also the
LWN article [3].
Performance data
================
System: x64_64, 1T RAM, 80 CPU threads.
Kernel: 5.6.0-rc3 + this patch
echo madvise | sudo tee /sys/kernel/mm/transparent_hugepage/enabled
echo madvise | sudo tee /sys/kernel/mm/transparent_hugepage/defrag
Before starting the driver, the system was fragmented from a userspace
program that allocates all memory and then for each 2M aligned section,
frees 3/4 of base pages using munmap. The workload is mainly anonymous
userspace pages, which are easy to move around. I intentionally avoided
unmovable pages in this test to see how much latency we incur when
hugepage allocations hit direct compaction.
1. Kernel hugepage allocation latencies
With the system in such a fragmented state, a kernel driver then allocates
as many hugepages as possible and measures allocation latency:
(all latency values are in microseconds)
- With vanilla 5.6.0-rc3
percentile latency
–––––––––– –––––––
5 7894
10 9496
25 12561
30 15295
40 18244
50 21229
60 27556
75 30147
80 31047
90 32859
95 33799
Total 2M hugepages allocated = 383859 (749G worth of hugepages out of 762G
total free => 98% of free memory could be allocated as hugepages)
- With 5.6.0-rc3 + this patch, with proactiveness=20
sysctl -w vm.compaction_proactiveness=20
percentile latency
–––––––––– –––––––
5 2
10 2
25 3
30 3
40 3
50 4
60 4
75 4
80 4
90 5
95 429
Total 2M hugepages allocated = 384105 (750G worth of hugepages out of 762G
total free => 98% of free memory could be allocated as hugepages)
2. JAVA heap allocation
In this test, we first fragment memory using the same method as for (1).
Then, we start a Java process with a heap size set to 700G and request the
heap to be allocated with THP hugepages. We also set THP to madvise to
allow hugepage backing of this heap.
/usr/bin/time
java -Xms700G -Xmx700G -XX:+UseTransparentHugePages -XX:+AlwaysPreTouch
The above command allocates 700G of Java heap using hugepages.
- With vanilla 5.6.0-rc3
17.39user 1666.48system 27:37.89elapsed
- With 5.6.0-rc3 + this patch, with proactiveness=20
8.35user 194.58system 3:19.62elapsed
Elapsed time remains around 3:15, as proactiveness is further increased.
Note that proactive compaction happens throughout the runtime of these
workloads. The situation of one-time compaction, sufficient to supply
hugepages for following allocation stream, can probably happen for more
extreme proactiveness values, like 80 or 90.
In the above Java workload, proactiveness is set to 20. The test starts
with a node's score of 80 or higher, depending on the delay between the
fragmentation step and starting the benchmark, which gives more-or-less
time for the initial round of compaction. As t he benchmark consumes
hugepages, node's score quickly rises above the high threshold (90) and
proactive compaction starts again, which brings down the score to the low
threshold level (80). Repeat.
bpftrace also confirms proactive compaction running 20+ times during the
runtime of this Java benchmark. kcompactd threads consume 100% of one of
the CPUs while it tries to bring a node's score within thresholds.
Backoff behavior
================
Above workloads produce a memory state which is easy to compact. However,
if memory is filled with unmovable pages, proactive compaction should
essentially back off. To test this aspect:
- Created a kernel driver that allocates almost all memory as hugepages
followed by freeing first 3/4 of each hugepage.
- Set proactiveness=40
- Note that proactive_compact_node() is deferred maximum number of times
with HPAGE_FRAG_CHECK_INTERVAL_MSEC of wait between each check
(=> ~30 seconds between retries).
[1] https://patchwork.kernel.org/patch/11098289/
[2] https://lore.kernel.org/linux-mm/20161230131412.GI13301@dhcp22.suse.cz/
[3] https://lwn.net/Articles/817905/
Signed-off-by: Nitin Gupta <nigupta@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tested-by: Oleksandr Natalenko <oleksandr@redhat.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Khalid Aziz <khalid.aziz@oracle.com>
Reviewed-by: Oleksandr Natalenko <oleksandr@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Khalid Aziz <khalid.aziz@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Nitin Gupta <ngupta@nitingupta.dev>
Cc: Oleksandr Natalenko <oleksandr@redhat.com>
Link: http://lkml.kernel.org/r/20200616204527.19185-1-nigupta@nvidia.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
Now that workingset detection is implemented for anonymous LRU, we don't
need large inactive list to allow detecting frequently accessed pages
before they are reclaimed, anymore. This effectively reverts the
temporary measure put in by commit "mm/vmscan: make active/inactive ratio
as 1:1 for anon lru".
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Hugh Dickins <hughd@google.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Minchan Kim <minchan@kernel.org>
Link: http://lkml.kernel.org/r/1595490560-15117-7-git-send-email-iamjoonsoo.kim@lge.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
This patch implements workingset detection for anonymous LRU. All the
infrastructure is implemented by the previous patches so this patch just
activates the workingset detection by installing/retrieving the shadow
entry and adding refault calculation.
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Hugh Dickins <hughd@google.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Minchan Kim <minchan@kernel.org>
Link: http://lkml.kernel.org/r/1595490560-15117-6-git-send-email-iamjoonsoo.kim@lge.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
Workingset detection for anonymous page will be implemented in the
following patch and it requires to store the shadow entries into the
swapcache. This patch implements an infrastructure to store the shadow
entry in the swapcache.
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Link: http://lkml.kernel.org/r/1595490560-15117-5-git-send-email-iamjoonsoo.kim@lge.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
To prepare the workingset detection for anon LRU, this patch splits
workingset event counters for refault, activate and restore into anon and
file variants, as well as the refaults counter in struct lruvec.
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Hugh Dickins <hughd@google.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Minchan Kim <minchan@kernel.org>
Link: http://lkml.kernel.org/r/1595490560-15117-4-git-send-email-iamjoonsoo.kim@lge.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
In current implementation, newly created or swap-in anonymous page is
started on active list. Growing active list results in rebalancing
active/inactive list so old pages on active list are demoted to inactive
list. Hence, the page on active list isn't protected at all.
Following is an example of this situation.
Assume that 50 hot pages on active list. Numbers denote the number of
pages on active/inactive list (active | inactive).
1. 50 hot pages on active list
50(h) | 0
2. workload: 50 newly created (used-once) pages
50(uo) | 50(h)
3. workload: another 50 newly created (used-once) pages
50(uo) | 50(uo), swap-out 50(h)
This patch tries to fix this issue. Like as file LRU, newly created or
swap-in anonymous pages will be inserted to the inactive list. They are
promoted to active list if enough reference happens. This simple
modification changes the above example as following.
1. 50 hot pages on active list
50(h) | 0
2. workload: 50 newly created (used-once) pages
50(h) | 50(uo)
3. workload: another 50 newly created (used-once) pages
50(h) | 50(uo), swap-out 50(uo)
As you can see, hot pages on active list would be protected.
Note that, this implementation has a drawback that the page cannot be
promoted and will be swapped-out if re-access interval is greater than the
size of inactive list but less than the size of total(active+inactive).
To solve this potential issue, following patch will apply workingset
detection similar to the one that's already applied to file LRU.
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Hugh Dickins <hughd@google.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Minchan Kim <minchan@kernel.org>
Link: http://lkml.kernel.org/r/1595490560-15117-3-git-send-email-iamjoonsoo.kim@lge.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
Patch series "workingset protection/detection on the anonymous LRU list", v7.
* PROBLEM
In current implementation, newly created or swap-in anonymous page is
started on the active list. Growing the active list results in
rebalancing active/inactive list so old pages on the active list are
demoted to the inactive list. Hence, hot page on the active list isn't
protected at all.
Following is an example of this situation.
Assume that 50 hot pages on active list and system can contain total 100
pages. Numbers denote the number of pages on active/inactive list (active
| inactive). (h) stands for hot pages and (uo) stands for used-once
pages.
1. 50 hot pages on active list
50(h) | 0
2. workload: 50 newly created (used-once) pages
50(uo) | 50(h)
3. workload: another 50 newly created (used-once) pages
50(uo) | 50(uo), swap-out 50(h)
As we can see, hot pages are swapped-out and it would cause swap-in later.
* SOLUTION
Since this is what we want to avoid, this patchset implements workingset
protection. Like as the file LRU list, newly created or swap-in anonymous
page is started on the inactive list. Also, like as the file LRU list, if
enough reference happens, the page will be promoted. This simple
modification changes the above example as following.
1. 50 hot pages on active list
50(h) | 0
2. workload: 50 newly created (used-once) pages
50(h) | 50(uo)
3. workload: another 50 newly created (used-once) pages
50(h) | 50(uo), swap-out 50(uo)
hot pages remains in the active list. :)
* EXPERIMENT
I tested this scenario on my test bed and confirmed that this problem
happens on current implementation. I also checked that it is fixed by
this patchset.
* SUBJECT
workingset detection
* PROBLEM
Later part of the patchset implements the workingset detection for the
anonymous LRU list. There is a corner case that workingset protection
could cause thrashing. If we can avoid thrashing by workingset detection,
we can get the better performance.
Following is an example of thrashing due to the workingset protection.
1. 50 hot pages on active list
50(h) | 0
2. workload: 50 newly created (will be hot) pages
50(h) | 50(wh)
3. workload: another 50 newly created (used-once) pages
50(h) | 50(uo), swap-out 50(wh)
4. workload: 50 (will be hot) pages
50(h) | 50(wh), swap-in 50(wh)
5. workload: another 50 newly created (used-once) pages
50(h) | 50(uo), swap-out 50(wh)
6. repeat 4, 5
Without workingset detection, this kind of workload cannot be promoted and
thrashing happens forever.
* SOLUTION
Therefore, this patchset implements workingset detection. All the
infrastructure for workingset detecion is already implemented, so there is
not much work to do. First, extend workingset detection code to deal with
the anonymous LRU list. Then, make swap cache handles the exceptional
value for the shadow entry. Lastly, install/retrieve the shadow value
into/from the swap cache and check the refault distance.
* EXPERIMENT
I made a test program to imitates above scenario and confirmed that
problem exists. Then, I checked that this patchset fixes it.
My test setup is a virtual machine with 8 cpus and 6100MB memory. But,
the amount of the memory that the test program can use is about 280 MB.
This is because the system uses large ram-backed swap and large ramdisk to
capture the trace.
Test scenario is like as below.
1. allocate cold memory (512MB)
2. allocate hot-1 memory (96MB)
3. activate hot-1 memory (96MB)
4. allocate another hot-2 memory (96MB)
5. access cold memory (128MB)
6. access hot-2 memory (96MB)
7. repeat 5, 6
Since hot-1 memory (96MB) is on the active list, the inactive list can
contains roughly 190MB pages. hot-2 memory's re-access interval (96+128
MB) is more 190MB, so it cannot be promoted without workingset detection
and swap-in/out happens repeatedly. With this patchset, workingset
detection works and promotion happens. Therefore, swap-in/out occurs
less.
Here is the result. (average of 5 runs)
type swap-in swap-out
base 863240 989945
patch 681565 809273
As we can see, patched kernel do less swap-in/out.
* OVERALL TEST (ebizzy using modified random function)
ebizzy is the test program that main thread allocates lots of memory and
child threads access them randomly during the given times. Swap-in will
happen if allocated memory is larger than the system memory.
The random function that represents the zipf distribution is used to make
hot/cold memory. Hot/cold ratio is controlled by the parameter. If the
parameter is high, hot memory is accessed much larger than cold one. If
the parameter is low, the number of access on each memory would be
similar. I uses various parameters in order to show the effect of
patchset on various hot/cold ratio workload.
My test setup is a virtual machine with 8 cpus, 1024 MB memory and 5120 MB
ram swap.
Result format is as following.
param: 1-1024-0.1
- 1 (number of thread)
- 1024 (allocated memory size, MB)
- 0.1 (zipf distribution alpha,
0.1 works like as roughly uniform random,
1.3 works like as small portion of memory is hot and the others are cold)
pswpin: smaller is better
std: standard deviation
improvement: negative is better
* single thread
param pswpin std improvement
base 1-1024.0-0.1 14101983.40 79441.19
prot 1-1024.0-0.1 14065875.80 136413.01 ( -0.26 )
detect 1-1024.0-0.1 13910435.60 100804.82 ( -1.36 )
base 1-1024.0-0.7 7998368.80 43469.32
prot 1-1024.0-0.7 7622245.80 88318.74 ( -4.70 )
detect 1-1024.0-0.7 7618515.20 59742.07 ( -4.75 )
base 1-1024.0-1.3 1017400.80 38756.30
prot 1-1024.0-1.3 940464.60 29310.69 ( -7.56 )
detect 1-1024.0-1.3 945511.40 24579.52 ( -7.07 )
base 1-1280.0-0.1 22895541.40 50016.08
prot 1-1280.0-0.1 22860305.40 51952.37 ( -0.15 )
detect 1-1280.0-0.1 22705565.20 93380.35 ( -0.83 )
base 1-1280.0-0.7 13717645.60 46250.65
prot 1-1280.0-0.7 12935355.80 64754.43 ( -5.70 )
detect 1-1280.0-0.7 13040232.00 63304.00 ( -4.94 )
base 1-1280.0-1.3 1654251.40 4159.68
prot 1-1280.0-1.3 1522680.60 33673.50 ( -7.95 )
detect 1-1280.0-1.3 1599207.00 70327.89 ( -3.33 )
base 1-1536.0-0.1 31621775.40 31156.28
prot 1-1536.0-0.1 31540355.20 62241.36 ( -0.26 )
detect 1-1536.0-0.1 31420056.00 123831.27 ( -0.64 )
base 1-1536.0-0.7 19620760.60 60937.60
prot 1-1536.0-0.7 18337839.60 56102.58 ( -6.54 )
detect 1-1536.0-0.7 18599128.00 75289.48 ( -5.21 )
base 1-1536.0-1.3 2378142.40 20994.43
prot 1-1536.0-1.3 2166260.60 48455.46 ( -8.91 )
detect 1-1536.0-1.3 2183762.20 16883.24 ( -8.17 )
base 1-1792.0-0.1 40259714.80 90750.70
prot 1-1792.0-0.1 40053917.20 64509.47 ( -0.51 )
detect 1-1792.0-0.1 39949736.40 104989.64 ( -0.77 )
base 1-1792.0-0.7 25704884.40 69429.68
prot 1-1792.0-0.7 23937389.00 79945.60 ( -6.88 )
detect 1-1792.0-0.7 24271902.00 35044.30 ( -5.57 )
base 1-1792.0-1.3 3129497.00 32731.86
prot 1-1792.0-1.3 2796994.40 19017.26 ( -10.62 )
detect 1-1792.0-1.3 2886840.40 33938.82 ( -7.75 )
base 1-2048.0-0.1 48746924.40 50863.88
prot 1-2048.0-0.1 48631954.40 24537.30 ( -0.24 )
detect 1-2048.0-0.1 48509419.80 27085.34 ( -0.49 )
base 1-2048.0-0.7 32046424.40 78624.22
prot 1-2048.0-0.7 29764182.20 86002.26 ( -7.12 )
detect 1-2048.0-0.7 30250315.80 101282.14 ( -5.60 )
base 1-2048.0-1.3 3916723.60 24048.55
prot 1-2048.0-1.3 3490781.60 33292.61 ( -10.87 )
detect 1-2048.0-1.3 3585002.20 44942.04 ( -8.47 )
* multi thread
param pswpin std improvement
base 8-1024.0-0.1 16219822.60 329474.01
prot 8-1024.0-0.1 15959494.00 654597.45 ( -1.61 )
detect 8-1024.0-0.1 15773790.80 502275.25 ( -2.75 )
base 8-1024.0-0.7 9174107.80 537619.33
prot 8-1024.0-0.7 8571915.00 385230.08 ( -6.56 )
detect 8-1024.0-0.7 8489484.20 364683.00 ( -7.46 )
base 8-1024.0-1.3 1108495.60 83555.98
prot 8-1024.0-1.3 1038906.20 63465.20 ( -6.28 )
detect 8-1024.0-1.3 941817.80 32648.80 ( -15.04 )
base 8-1280.0-0.1 25776114.20 450480.45
prot 8-1280.0-0.1 25430847.00 465627.07 ( -1.34 )
detect 8-1280.0-0.1 25282555.00 465666.55 ( -1.91 )
base 8-1280.0-0.7 15218968.00 702007.69
prot 8-1280.0-0.7 13957947.80 492643.86 ( -8.29 )
detect 8-1280.0-0.7 14158331.20 238656.02 ( -6.97 )
base 8-1280.0-1.3 1792482.80 30512.90
prot 8-1280.0-1.3 1577686.40 34002.62 ( -11.98 )
detect 8-1280.0-1.3 1556133.00 22944.79 ( -13.19 )
base 8-1536.0-0.1 33923761.40 575455.85
prot 8-1536.0-0.1 32715766.20 300633.51 ( -3.56 )
detect 8-1536.0-0.1 33158477.40 117764.51 ( -2.26 )
base 8-1536.0-0.7 20628907.80 303851.34
prot 8-1536.0-0.7 19329511.20 341719.31 ( -6.30 )
detect 8-1536.0-0.7 20013934.00 385358.66 ( -2.98 )
base 8-1536.0-1.3 2588106.40 130769.20
prot 8-1536.0-1.3 2275222.40 89637.06 ( -12.09 )
detect 8-1536.0-1.3 2365008.40 124412.55 ( -8.62 )
base 8-1792.0-0.1 43328279.20 946469.12
prot 8-1792.0-0.1 41481980.80 525690.89 ( -4.26 )
detect 8-1792.0-0.1 41713944.60 406798.93 ( -3.73 )
base 8-1792.0-0.7 27155647.40 536253.57
prot 8-1792.0-0.7 24989406.80 502734.52 ( -7.98 )
detect 8-1792.0-0.7 25524806.40 263237.87 ( -6.01 )
base 8-1792.0-1.3 3260372.80 137907.92
prot 8-1792.0-1.3 2879187.80 63597.26 ( -11.69 )
detect 8-1792.0-1.3 2892962.20 33229.13 ( -11.27 )
base 8-2048.0-0.1 50583989.80 710121.48
prot 8-2048.0-0.1 49599984.40 228782.42 ( -1.95 )
detect 8-2048.0-0.1 50578596.00 660971.66 ( -0.01 )
base 8-2048.0-0.7 33765479.60 812659.55
prot 8-2048.0-0.7 30767021.20 462907.24 ( -8.88 )
detect 8-2048.0-0.7 32213068.80 211884.24 ( -4.60 )
base 8-2048.0-1.3 3941675.80 28436.45
prot 8-2048.0-1.3 3538742.40 76856.08 ( -10.22 )
detect 8-2048.0-1.3 3579397.80 58630.95 ( -9.19 )
As we can see, all the cases show improvement. Especially, test case with
zipf distribution 1.3 show more improvements. It means that if there is a
hot/cold tendency in anon pages, this patchset works better.
This patch (of 6):
Current implementation of LRU management for anonymous page has some
problems. Most important one is that it doesn't protect the workingset,
that is, pages on the active LRU list. Although, this problem will be
fixed in the following patchset, the preparation is required and this
patch does it.
What following patch does is to implement workingset protection. After
the following patchset, newly created or swap-in pages will start their
lifetime on the inactive list. If inactive list is too small, there is
not enough chance to be referenced and the page cannot become the
workingset.
In order to provide the newly anonymous or swap-in pages enough chance to
be referenced again, this patch makes active/inactive LRU ratio as 1:1.
This is just a temporary measure. Later patch in the series introduces
workingset detection for anonymous LRU that will be used to better decide
if pages should start on the active and inactive list. Afterwards this
patch is effectively reverted.
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Matthew Wilcox <willy@infradead.org>
Link: http://lkml.kernel.org/r/1595490560-15117-1-git-send-email-iamjoonsoo.kim@lge.com
Link: http://lkml.kernel.org/r/1595490560-15117-2-git-send-email-iamjoonsoo.kim@lge.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
In the reservation routine, we only check whether the cpuset meets the
memory allocation requirements. But we ignore the mempolicy of MPOL_BIND
case. If someone mmap hugetlb succeeds, but the subsequent memory
allocation may fail due to mempolicy restrictions and receives the SIGBUS
signal. This can be reproduced by the follow steps.
1) Compile the test case.
cd tools/testing/selftests/vm/
gcc map_hugetlb.c -o map_hugetlb
2) Pre-allocate huge pages. Suppose there are 2 numa nodes in the
system. Each node will pre-allocate one huge page.
echo 2 > /proc/sys/vm/nr_hugepages
3) Run test case(mmap 4MB). We receive the SIGBUS signal.
numactl --membind=3D0 ./map_hugetlb 4
With this patch applied, the mmap will fail in the step 3) and throw
"mmap: Cannot allocate memory".
[akpm@linux-foundation.org: include sched.h for `current']
Reported-by: Jianchao Guo <guojianchao@bytedance.com>
Suggested-by: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michel Lespinasse <walken@google.com>
Cc: Baoquan He <bhe@redhat.com>
Link: http://lkml.kernel.org/r/20200728034938.14993-1-songmuchun@bytedance.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
Memory cgroups are using large chunks of percpu memory to store vmstat
data. Yet this memory is not accounted at all, so in the case when there
are many (dying) cgroups, it's not exactly clear where all the memory is.
Because the size of memory cgroup internal structures can dramatically
exceed the size of object or page which is pinning it in the memory, it's
not a good idea to simply ignore it. It actually breaks the isolation
between cgroups.
Let's account the consumed percpu memory to the parent cgroup.
[guro@fb.com: add WARN_ON_ONCE()s, per Johannes]
Link: http://lkml.kernel.org/r/20200811170611.GB1507044@carbon.DHCP.thefacebook.com
Signed-off-by: Roman Gushchin <guro@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Dennis Zhou <dennis@kernel.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Tobin C. Harding <tobin@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Waiman Long <longman@redhat.com>
Cc: Bixuan Cui <cuibixuan@huawei.com>
Cc: Michal Koutný <mkoutny@suse.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Link: http://lkml.kernel.org/r/20200623184515.4132564-5-guro@fb.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
Percpu memory can represent a noticeable chunk of the total memory
consumption, especially on big machines with many CPUs. Let's track
percpu memory usage for each memcg and display it in memory.stat.
A percpu allocation is usually scattered over multiple pages (and nodes),
and can be significantly smaller than a page. So let's add a byte-sized
counter on the memcg level: MEMCG_PERCPU_B. Byte-sized vmstat infra
created for slabs can be perfectly reused for percpu case.
[guro@fb.com: v3]
Link: http://lkml.kernel.org/r/20200623184515.4132564-4-guro@fb.com
Signed-off-by: Roman Gushchin <guro@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Dennis Zhou <dennis@kernel.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Tobin C. Harding <tobin@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Waiman Long <longman@redhat.com>
Cc: Bixuan Cui <cuibixuan@huawei.com>
Cc: Michal Koutný <mkoutny@suse.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Link: http://lkml.kernel.org/r/20200608230819.832349-4-guro@fb.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
Percpu memory is becoming more and more widely used by various subsystems,
and the total amount of memory controlled by the percpu allocator can make
a good part of the total memory.
As an example, bpf maps can consume a lot of percpu memory, and they are
created by a user. Also, some cgroup internals (e.g. memory controller
statistics) can be quite large. On a machine with many CPUs and big
number of cgroups they can consume hundreds of megabytes.
So the lack of memcg accounting is creating a breach in the memory
isolation. Similar to the slab memory, percpu memory should be accounted
by default.
To implement the perpcu accounting it's possible to take the slab memory
accounting as a model to follow. Let's introduce two types of percpu
chunks: root and memcg. What makes memcg chunks different is an
additional space allocated to store memcg membership information. If
__GFP_ACCOUNT is passed on allocation, a memcg chunk should be be used.
If it's possible to charge the corresponding size to the target memory
cgroup, allocation is performed, and the memcg ownership data is recorded.
System-wide allocations are performed using root chunks, so there is no
additional memory overhead.
To implement a fast reparenting of percpu memory on memcg removal, we
don't store mem_cgroup pointers directly: instead we use obj_cgroup API,
introduced for slab accounting.
[akpm@linux-foundation.org: fix CONFIG_MEMCG_KMEM=n build errors and warning]
[akpm@linux-foundation.org: move unreachable code, per Roman]
[cuibixuan@huawei.com: mm/percpu: fix 'defined but not used' warning]
Link: http://lkml.kernel.org/r/6d41b939-a741-b521-a7a2-e7296ec16219@huawei.com
Signed-off-by: Roman Gushchin <guro@fb.com>
Signed-off-by: Bixuan Cui <cuibixuan@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Dennis Zhou <dennis@kernel.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Tobin C. Harding <tobin@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Waiman Long <longman@redhat.com>
Cc: Bixuan Cui <cuibixuan@huawei.com>
Cc: Michal Koutný <mkoutny@suse.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Link: http://lkml.kernel.org/r/20200623184515.4132564-3-guro@fb.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
Patch series "mm: memcg accounting of percpu memory", v3.
This patchset adds percpu memory accounting to memory cgroups. It's based
on the rework of the slab controller and reuses concepts and features
introduced for the per-object slab accounting.
Percpu memory is becoming more and more widely used by various subsystems,
and the total amount of memory controlled by the percpu allocator can make
a good part of the total memory.
As an example, bpf maps can consume a lot of percpu memory, and they are
created by a user. Also, some cgroup internals (e.g. memory controller
statistics) can be quite large. On a machine with many CPUs and big
number of cgroups they can consume hundreds of megabytes.
So the lack of memcg accounting is creating a breach in the memory
isolation. Similar to the slab memory, percpu memory should be accounted
by default.
Percpu allocations by their nature are scattered over multiple pages, so
they can't be tracked on the per-page basis. So the per-object tracking
introduced by the new slab controller is reused.
The patchset implements charging of percpu allocations, adds memcg-level
statistics, enables accounting for percpu allocations made by memory
cgroup internals and provides some basic tests.
To implement the accounting of percpu memory without a significant memory
and performance overhead the following approach is used: all accounted
allocations are placed into a separate percpu chunk (or chunks). These
chunks are similar to default chunks, except that they do have an attached
vector of pointers to obj_cgroup objects, which is big enough to save a
pointer for each allocated object. On the allocation, if the allocation
has to be accounted (__GFP_ACCOUNT is passed, the allocating process
belongs to a non-root memory cgroup, etc), the memory cgroup is getting
charged and if the maximum limit is not exceeded the allocation is
performed using a memcg-aware chunk. Otherwise -ENOMEM is returned or the
allocation is forced over the limit, depending on gfp (as any other kernel
memory allocation). The memory cgroup information is saved in the
obj_cgroup vector at the corresponding offset. On the release time the
memcg information is restored from the vector and the cgroup is getting
uncharged. Unaccounted allocations (at this point the absolute majority
of all percpu allocations) are performed in the old way, so no additional
overhead is expected.
To avoid pinning dying memory cgroups by outstanding allocations,
obj_cgroup API is used instead of directly saving memory cgroup pointers.
obj_cgroup is basically a pointer to a memory cgroup with a standalone
reference counter. The trick is that it can be atomically swapped to
point at the parent cgroup, so that the original memory cgroup can be
released prior to all objects, which has been charged to it. Because all
charges and statistics are fully recursive, it's perfectly correct to
uncharge the parent cgroup instead. This scheme is used in the slab
memory accounting, and percpu memory can just follow the scheme.
This patch (of 5):
To implement accounting of percpu memory we need the information about the
size of freed object. Return it from pcpu_free_area().
Signed-off-by: Roman Gushchin <guro@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Dennis Zhou <dennis@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Tobin C. Harding <tobin@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Waiman Long <longman@redhat.com>
cC: Michal Koutnýutny@suse.com>
Cc: Bixuan Cui <cuibixuan@huawei.com>
Cc: Michal Koutný <mkoutny@suse.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Link: http://lkml.kernel.org/r/20200623184515.4132564-1-guro@fb.com
Link: http://lkml.kernel.org/r/20200608230819.832349-1-guro@fb.com
Link: http://lkml.kernel.org/r/20200608230819.832349-2-guro@fb.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild
Pull Kbuild updates from Masahiro Yamada:
- run the checker (e.g. sparse) after the compiler
- remove unneeded cc-option tests for old compiler flags
- fix tar-pkg to install dtbs
- introduce ccflags-remove-y and asflags-remove-y syntax
- allow to trace functions in sub-directories of lib/
- introduce hostprogs-always-y and userprogs-always-y syntax
- various Makefile cleanups
* tag 'kbuild-v5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
kbuild: stop filtering out $(GCC_PLUGINS_CFLAGS) from cc-option base
kbuild: include scripts/Makefile.* only when relevant CONFIG is enabled
kbuild: introduce hostprogs-always-y and userprogs-always-y
kbuild: sort hostprogs before passing it to ifneq
kbuild: move host .so build rules to scripts/gcc-plugins/Makefile
kbuild: Replace HTTP links with HTTPS ones
kbuild: trace functions in subdirectories of lib/
kbuild: introduce ccflags-remove-y and asflags-remove-y
kbuild: do not export LDFLAGS_vmlinux
kbuild: always create directories of targets
powerpc/boot: add DTB to 'targets'
kbuild: buildtar: add dtbs support
kbuild: remove cc-option test of -ffreestanding
kbuild: remove cc-option test of -fno-stack-protector
Revert "kbuild: Create directory for target DTB"
kbuild: run the checker after the compiler
|
|
Merge misc updates from Andrew Morton:
- a few MM hotfixes
- kthread, tools, scripts, ntfs and ocfs2
- some of MM
Subsystems affected by this patch series: kthread, tools, scripts, ntfs,
ocfs2 and mm (hofixes, pagealloc, slab-generic, slab, slub, kcsan,
debug, pagecache, gup, swap, shmem, memcg, pagemap, mremap, mincore,
sparsemem, vmalloc, kasan, pagealloc, hugetlb and vmscan).
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (162 commits)
mm: vmscan: consistent update to pgrefill
mm/vmscan.c: fix typo
khugepaged: khugepaged_test_exit() check mmget_still_valid()
khugepaged: retract_page_tables() remember to test exit
khugepaged: collapse_pte_mapped_thp() protect the pmd lock
khugepaged: collapse_pte_mapped_thp() flush the right range
mm/hugetlb: fix calculation of adjust_range_if_pmd_sharing_possible
mm: thp: replace HTTP links with HTTPS ones
mm/page_alloc: fix memalloc_nocma_{save/restore} APIs
mm/page_alloc.c: skip setting nodemask when we are in interrupt
mm/page_alloc: fallbacks at most has 3 elements
mm/page_alloc: silence a KASAN false positive
mm/page_alloc.c: remove unnecessary end_bitidx for [set|get]_pfnblock_flags_mask()
mm/page_alloc.c: simplify pageblock bitmap access
mm/page_alloc.c: extract the common part in pfn_to_bitidx()
mm/page_alloc.c: replace the definition of NR_MIGRATETYPE_BITS with PB_migratetype_bits
mm/shuffle: remove dynamic reconfiguration
mm/memory_hotplug: document why shuffle_zone() is relevant
mm/page_alloc: remove nr_free_pagecache_pages()
mm: remove vm_total_pages
...
|
|
The vmstat pgrefill is useful together with pgscan and pgsteal stats to
measure the reclaim efficiency. However vmstat's pgrefill is not updated
consistently at system level. It gets updated for both global and memcg
reclaim however pgscan and pgsteal are updated for only global reclaim.
So, update pgrefill only for global reclaim. If someone is interested in
the stats representing both system level as well as memcg level reclaim,
then consult the root memcg's memory.stat instead of /proc/vmstat.
Signed-off-by: Shakeel Butt <shakeelb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Yafang Shao <laoar.shao@gmail.com>
Acked-by: Roman Gushchin <guro@fb.com>
Acked-by: Chris Down <chris@chrisdown.name>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Link: http://lkml.kernel.org/r/20200711011459.1159929-1-shakeelb@google.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
Change "optizimation" to "optimization".
Signed-off-by: dylan-meiners <spacct.spacct@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Link: http://lkml.kernel.org/r/20200609185144.10049-1-spacct.spacct@gmail.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
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Move collapse_huge_page()'s mmget_still_valid() check into
khugepaged_test_exit() itself. collapse_huge_page() is used for anon THP
only, and earned its mmget_still_valid() check because it inserts a huge
pmd entry in place of the page table's pmd entry; whereas
collapse_file()'s retract_page_tables() or collapse_pte_mapped_thp()
merely clears the page table's pmd entry. But core dumping without mmap
lock must have been as open to mistaking a racily cleared pmd entry for a
page table at physical page 0, as exit_mmap() was. And we certainly have
no interest in mapping as a THP once dumping core.
Fixes: 59ea6d06cfa9 ("coredump: fix race condition between collapse_huge_page() and core dumping")
Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Song Liu <songliubraving@fb.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: <stable@vger.kernel.org> [4.8+]
Link: http://lkml.kernel.org/r/alpine.LSU.2.11.2008021217020.27773@eggly.anvils
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
Only once have I seen this scenario (and forgot even to notice what forced
the eventual crash): a sequence of "BUG: Bad page map" alerts from
vm_normal_page(), from zap_pte_range() servicing exit_mmap();
pmd:00000000, pte values corresponding to data in physical page 0.
The pte mappings being zapped in this case were supposed to be from a huge
page of ext4 text (but could as well have been shmem): my belief is that
it was racing with collapse_file()'s retract_page_tables(), found *pmd
pointing to a page table, locked it, but *pmd had become 0 by the time
start_pte was decided.
In most cases, that possibility is excluded by holding mmap lock; but
exit_mmap() proceeds without mmap lock. Most of what's run by khugepaged
checks khugepaged_test_exit() after acquiring mmap lock:
khugepaged_collapse_pte_mapped_thps() and hugepage_vma_revalidate() do so,
for example. But retract_page_tables() did not: fix that.
The fix is for retract_page_tables() to check khugepaged_test_exit(),
after acquiring mmap lock, before doing anything to the page table.
Getting the mmap lock serializes with __mmput(), which briefly takes and
drops it in __khugepaged_exit(); then the khugepaged_test_exit() check on
mm_users makes sure we don't touch the page table once exit_mmap() might
reach it, since exit_mmap() will be proceeding without mmap lock, not
expecting anyone to be racing with it.
Fixes: f3f0e1d2150b ("khugepaged: add support of collapse for tmpfs/shmem pages")
Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Song Liu <songliubraving@fb.com>
Cc: <stable@vger.kernel.org> [4.8+]
Link: http://lkml.kernel.org/r/alpine.LSU.2.11.2008021215400.27773@eggly.anvils
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
When retract_page_tables() removes a page table to make way for a huge
pmd, it holds huge page lock, i_mmap_lock_write, mmap_write_trylock and
pmd lock; but when collapse_pte_mapped_thp() does the same (to handle the
case when the original mmap_write_trylock had failed), only
mmap_write_trylock and pmd lock are held.
That's not enough. One machine has twice crashed under load, with "BUG:
spinlock bad magic" and GPF on 6b6b6b6b6b6b6b6b. Examining the second
crash, page_vma_mapped_walk_done()'s spin_unlock of pvmw->ptl (serving
page_referenced() on a file THP, that had found a page table at *pmd)
discovers that the page table page and its lock have already been freed by
the time it comes to unlock.
Follow the example of retract_page_tables(), but we only need one of huge
page lock or i_mmap_lock_write to secure against this: because it's the
narrower lock, and because it simplifies collapse_pte_mapped_thp() to know
the hpage earlier, choose to rely on huge page lock here.
Fixes: 27e1f8273113 ("khugepaged: enable collapse pmd for pte-mapped THP")
Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Song Liu <songliubraving@fb.com>
Cc: <stable@vger.kernel.org> [5.4+]
Link: http://lkml.kernel.org/r/alpine.LSU.2.11.2008021213070.27773@eggly.anvils
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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pmdp_collapse_flush() should be given the start address at which the huge
page is mapped, haddr: it was given addr, which at that point has been
used as a local variable, incremented to the end address of the extent.
Found by source inspection while chasing a hugepage locking bug, which I
then could not explain by this. At first I thought this was very bad;
then saw that all of the page translations that were not flushed would
actually still point to the right pages afterwards, so harmless; then
realized that I know nothing of how different architectures and models
cache intermediate paging structures, so maybe it matters after all -
particularly since the page table concerned is immediately freed.
Much easier to fix than to think about.
Fixes: 27e1f8273113 ("khugepaged: enable collapse pmd for pte-mapped THP")
Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Song Liu <songliubraving@fb.com>
Cc: <stable@vger.kernel.org> [5.4+]
Link: http://lkml.kernel.org/r/alpine.LSU.2.11.2008021204390.27773@eggly.anvils
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
This is found by code observation only.
Firstly, the worst case scenario should assume the whole range was covered
by pmd sharing. The old algorithm might not work as expected for ranges
like (1g-2m, 1g+2m), where the adjusted range should be (0, 1g+2m) but the
expected range should be (0, 2g).
Since at it, remove the loop since it should not be required. With that,
the new code should be faster too when the invalidating range is huge.
Mike said:
: With range (1g-2m, 1g+2m) within a vma (0, 2g) the existing code will only
: adjust to (0, 1g+2m) which is incorrect.
:
: We should cc stable. The original reason for adjusting the range was to
: prevent data corruption (getting wrong page). Since the range is not
: always adjusted correctly, the potential for corruption still exists.
:
: However, I am fairly confident that adjust_range_if_pmd_sharing_possible
: is only gong to be called in two cases:
:
: 1) for a single page
: 2) for range == entire vma
:
: In those cases, the current code should produce the correct results.
:
: To be safe, let's just cc stable.
Fixes: 017b1660df89 ("mm: migration: fix migration of huge PMD shared pages")
Signed-off-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: <stable@vger.kernel.org>
Link: http://lkml.kernel.org/r/20200730201636.74778-1-peterx@redhat.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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|
Rationale:
Reduces attack surface on kernel devs opening the links for MITM
as HTTPS traffic is much harder to manipulate.
Deterministic algorithm:
For each file:
If not .svg:
For each line:
If doesn't contain `xmlns`:
For each link, `http://[^# ]*(?:\w|/)`:
If neither `gnu\.org/license`, nor `mozilla\.org/MPL`:
If both the HTTP and HTTPS versions
return 200 OK and serve the same content:
Replace HTTP with HTTPS.
[akpm@linux-foundation.org: fix amd.com URL, per Vlastimil]
Signed-off-by: Alexander A. Klimov <grandmaster@al2klimov.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Link: http://lkml.kernel.org/r/20200713164345.36088-1-grandmaster@al2klimov.de
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
Currently, memalloc_nocma_{save/restore} API that prevents CMA area
in page allocation is implemented by using current_gfp_context(). However,
there are two problems of this implementation.
First, this doesn't work for allocation fastpath. In the fastpath,
original gfp_mask is used since current_gfp_context() is introduced in
order to control reclaim and it is on slowpath. So, CMA area can be
allocated through the allocation fastpath even if
memalloc_nocma_{save/restore} APIs are used. Currently, there is just
one user for these APIs and it has a fallback method to prevent actual
problem.
Second, clearing __GFP_MOVABLE in current_gfp_context() has a side effect
to exclude the memory on the ZONE_MOVABLE for allocation target.
To fix these problems, this patch changes the implementation to exclude
CMA area in page allocation. Main point of this change is using the
alloc_flags. alloc_flags is mainly used to control allocation so it fits
for excluding CMA area in allocation.
Fixes: d7fefcc8de91 (mm/cma: add PF flag to force non cma alloc)
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Roman Gushchin <guro@fb.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: "Aneesh Kumar K . V" <aneesh.kumar@linux.ibm.com>
Link: http://lkml.kernel.org/r/1595468942-29687-1-git-send-email-iamjoonsoo.kim@lge.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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When we are in the interrupt context, it is irrelevant to the current task
context. If we use current task's mems_allowed, we can be fair to alloc
pages in the fast path and fall back to slow path memory allocation when
the current node(which is the current task mems_allowed) does not have
enough memory to allocate. In this case, it slows down the memory
allocation speed of interrupt context. So we can skip setting the
nodemask to allow any node to allocate memory, so that fast path
allocation can success.
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Pekka Enberg <penberg@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Link: http://lkml.kernel.org/r/20200706025921.53683-1-songmuchun@bytedance.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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MIGRAGE_TYPES is used to be the mark of end and there are at most 3
elements for the one dimension array.
Reduce to 3 to save little memory.
Signed-off-by: Wei Yang <richard.weiyang@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Link: http://lkml.kernel.org/r/20200625231022.18784-1-richard.weiyang@linux.alibaba.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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kernel_init_free_pages() will use memset() on s390 to clear all pages from
kmalloc_order() which will override KASAN redzones because a redzone was
setup from the end of the allocation size to the end of the last page.
Silence it by not reporting it there. An example of the report is,
BUG: KASAN: slab-out-of-bounds in __free_pages_ok
Write of size 4096 at addr 000000014beaa000
Call Trace:
show_stack+0x152/0x210
dump_stack+0x1f8/0x248
print_address_description.isra.13+0x5e/0x4d0
kasan_report+0x130/0x178
check_memory_region+0x190/0x218
memset+0x34/0x60
__free_pages_ok+0x894/0x12f0
kfree+0x4f2/0x5e0
unpack_to_rootfs+0x60e/0x650
populate_rootfs+0x56/0x358
do_one_initcall+0x1f4/0xa20
kernel_init_freeable+0x758/0x7e8
kernel_init+0x1c/0x170
ret_from_fork+0x24/0x28
Memory state around the buggy address:
000000014bea9f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
000000014bea9f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>000000014beaa000: 03 fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe
^
000000014beaa080: fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe
000000014beaa100: fe fe fe fe fe fe fe fe fe fe fe fe fe fe
Fixes: 6471384af2a6 ("mm: security: introduce init_on_alloc=1 and init_on_free=1 boot options")
Signed-off-by: Qian Cai <cai@lca.pw>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tested-by: Vasily Gorbik <gor@linux.ibm.com>
Acked-by: Vasily Gorbik <gor@linux.ibm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Link: http://lkml.kernel.org/r/20200610052154.5180-1-cai@lca.pw
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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[set|get]_pfnblock_flags_mask()
After previous cleanup, the end_bitidx is not necessary any more.
Signed-off-by: Wei Yang <richard.weiyang@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Mel Gorman <mgorman@suse.de>
Link: http://lkml.kernel.org/r/20200623124201.8199-4-richard.weiyang@linux.alibaba.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Due to commit e58469bafd05 ("mm: page_alloc: use word-based accesses for
get/set pageblock bitmaps"), pageblock bitmap is accessed with word-based
access. This operation could be simplified a little.
Intuitively, if we want to get a bit range [start_idx, end_idx] in a word,
we can do like this:
mask = (1 << (end_bitidx - start_bitidx + 1)) - 1;
ret = (word >> start_idx) & mask;
And also if we want to set a bit range [start_idx, end_idx] with flags, we
can do the same by just shift start_bitidx.
By doing so we reduce some instructions for these two helper functions:
Before Patched
set_pfnblock_flags_mask 209 198(-5%)
get_pfnblock_flags_mask 101 87(-13%)
Since the syntax is changed a little, we need to check the whole 4-bit
migrate_type instead of part of it.
Signed-off-by: Wei Yang <richard.weiyang@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Mel Gorman <mgorman@suse.de>
Link: http://lkml.kernel.org/r/20200623124201.8199-3-richard.weiyang@linux.alibaba.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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The return value calculation is the same both for SPARSEMEM or not.
Just take it out.
Signed-off-by: Wei Yang <richard.weiyang@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Mel Gorman <mgorman@suse.de>
Link: http://lkml.kernel.org/r/20200623124201.8199-2-richard.weiyang@linux.alibaba.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Commit e900a918b098 ("mm: shuffle initial free memory to improve
memory-side-cache utilization") promised "autodetection of a
memory-side-cache (to be added in a follow-on patch)" over a year ago.
The original series included patches [1], however, they were dropped
during review [2] to be followed-up later.
Due to lack of platforms that publish an HMAT, autodetection is currently
not implemented. However, manual activation is actively used [3]. Let's
simplify for now and re-add when really (ever?) needed.
[1] https://lkml.kernel.org/r/154510700291.1941238.817190985966612531.stgit@dwillia2-desk3.amr.corp.intel.com
[2] https://lkml.kernel.org/r/154690326478.676627.103843791978176914.stgit@dwillia2-desk3.amr.corp.intel.com
[3] https://lkml.kernel.org/r/CAPcyv4irwGUU2x+c6b4L=KbB1dnasNKaaZd6oSpYjL9kfsnROQ@mail.gmail.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Wei Yang <richard.weiyang@linux.alibaba.com>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Dan Williams <dan.j.williams@intel.com>
Link: http://lkml.kernel.org/r/20200624094741.9918-4-david@redhat.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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It's not completely obvious why we have to shuffle the complete zone -
introduced in commit e900a918b098 ("mm: shuffle initial free memory to
improve memory-side-cache utilization") - because some sort of shuffling
is already performed when onlining pages via __free_one_page(), placing
MAX_ORDER-1 pages either to the head or the tail of the freelist. Let's
document why we have to shuffle the complete zone when exposing larger,
contiguous physical memory areas to the buddy.
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Link: http://lkml.kernel.org/r/20200624094741.9918-3-david@redhat.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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nr_free_pagecache_pages() isn't used outside page_alloc.c anymore - and
the name does not really help to understand what's going on. Let's
open-code it instead and add a comment.
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Wei Yang <richard.weiyang@gmail.com>
Reviewed-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Huang Ying <ying.huang@intel.com>
Link: http://lkml.kernel.org/r/20200619132410.23859-3-david@redhat.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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The global variable "vm_total_pages" is a relic from older days. There is
only a single user that reads the variable - build_all_zonelists() - and
the first thing it does is update it.
Use a local variable in build_all_zonelists() instead and remove the
global variable.
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Wei Yang <richard.weiyang@gmail.com>
Reviewed-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Minchan Kim <minchan@kernel.org>
Link: http://lkml.kernel.org/r/20200619132410.23859-2-david@redhat.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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When boosting is enabled, it is observed that rate of atomic order-0
allocation failures are high due to the fact that free levels in the
system are checked with ->watermark_boost offset. This is not a problem
for sleepable allocations but for atomic allocations which looks like
regression.
This problem is seen frequently on system setup of Android kernel running
on Snapdragon hardware with 4GB RAM size. When no extfrag event occurred
in the system, ->watermark_boost factor is zero, thus the watermark
configurations in the system are:
_watermark = (
[WMARK_MIN] = 1272, --> ~5MB
[WMARK_LOW] = 9067, --> ~36MB
[WMARK_HIGH] = 9385), --> ~38MB
watermark_boost = 0
After launching some memory hungry applications in Android which can cause
extfrag events in the system to an extent that ->watermark_boost can be
set to max i.e. default boost factor makes it to 150% of high watermark.
_watermark = (
[WMARK_MIN] = 1272, --> ~5MB
[WMARK_LOW] = 9067, --> ~36MB
[WMARK_HIGH] = 9385), --> ~38MB
watermark_boost = 14077, -->~57MB
With default system configuration, for an atomic order-0 allocation to
succeed, having free memory of ~2MB will suffice. But boosting makes the
min_wmark to ~61MB thus for an atomic order-0 allocation to be successful
system should have minimum of ~23MB of free memory(from calculations of
zone_watermark_ok(), min = 3/4(min/2)). But failures are observed despite
system is having ~20MB of free memory. In the testing, this is
reproducible as early as first 300secs since boot and with furtherlowram
configurations(<2GB) it is observed as early as first 150secs since boot.
These failures can be avoided by excluding the ->watermark_boost in
watermark caluculations for atomic order-0 allocations.
[akpm@linux-foundation.org: fix comment grammar, reflow comment]
[charante@codeaurora.org: fix suggested by Mel Gorman]
Link: http://lkml.kernel.org/r/31556793-57b1-1c21-1a9d-22674d9bd938@codeaurora.org
Signed-off-by: Charan Teja Reddy <charante@codeaurora.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Vinayak Menon <vinmenon@codeaurora.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Link: http://lkml.kernel.org/r/1589882284-21010-1-git-send-email-charante@codeaurora.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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