09 Jun, 2020
1 commit
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'Idle page tracking' users can pass random pfn that might be mapped to an
offline page. To avoid accessing such pages, this commit modifies the
'page_idle_get_page()' to use 'pfn_to_online_page()' instead of
'pfn_valid()' and 'pfn_to_page()' combination, so that the pfn mapped to
an offline page can be skipped.Reported-by: David Hildenbrand
Signed-off-by: SeongJae Park
Signed-off-by: Andrew Morton
Reviewed-by: David Hildenbrand
Reviewed-by: Pankaj Gupta
Link: http://lkml.kernel.org/r/20200605092502.18018-2-sjpark@amazon.com
Signed-off-by: Linus Torvalds
29 Jun, 2019
1 commit
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Currently the calcuation of end_pfn can round up the pfn number to more
than the actual maximum number of pfns, causing an Oops. Fix this by
ensuring end_pfn is never more than max_pfn.This can be easily triggered when on systems where the end_pfn gets
rounded up to more than max_pfn using the idle-page stress-ng stress test:sudo stress-ng --idle-page 0
BUG: unable to handle kernel paging request at 00000000000020d8
#PF error: [normal kernel read fault]
PGD 0 P4D 0
Oops: 0000 [#1] SMP PTI
CPU: 1 PID: 11039 Comm: stress-ng-idle- Not tainted 5.0.0-5-generic #6-Ubuntu
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014
RIP: 0010:page_idle_get_page+0xc8/0x1a0
Code: 0f b1 0a 75 7d 48 8b 03 48 89 c2 48 c1 e8 33 83 e0 07 48 c1 ea 36 48 8d 0c 40 4c 8d 24 88 49 c1 e4 07 4c 03 24 d5 00 89 c3 be 8b 44 24 58 48 8d b8 80 a1 02 00 e8 07 d5 77 00 48 8b 53 08 48
RSP: 0018:ffffafd7c672fde8 EFLAGS: 00010202
RAX: 0000000000000005 RBX: ffffe36341fff700 RCX: 000000000000000f
RDX: 0000000000000284 RSI: 0000000000000275 RDI: 0000000001fff700
RBP: ffffafd7c672fe00 R08: ffffa0bc34056410 R09: 0000000000000276
R10: ffffa0bc754e9b40 R11: ffffa0bc330f6400 R12: 0000000000002080
R13: ffffe36341fff700 R14: 0000000000080000 R15: ffffa0bc330f6400
FS: 00007f0ec1ea5740(0000) GS:ffffa0bc7db00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000000020d8 CR3: 0000000077d68000 CR4: 00000000000006e0
Call Trace:
page_idle_bitmap_write+0x8c/0x140
sysfs_kf_bin_write+0x5c/0x70
kernfs_fop_write+0x12e/0x1b0
__vfs_write+0x1b/0x40
vfs_write+0xab/0x1b0
ksys_write+0x55/0xc0
__x64_sys_write+0x1a/0x20
do_syscall_64+0x5a/0x110
entry_SYSCALL_64_after_hwframe+0x44/0xa9Link: http://lkml.kernel.org/r/20190618124352.28307-1-colin.king@canonical.com
Fixes: 33c3fc71c8cf ("mm: introduce idle page tracking")
Signed-off-by: Colin Ian King
Reviewed-by: Andrew Morton
Acked-by: Vladimir Davydov
Cc: Michal Hocko
Cc: Mike Rapoport
Cc: Mel Gorman
Cc: Stephen Rothwell
Cc: Andrey Ryabinin
Cc:
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
06 Mar, 2019
1 commit
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We have common pattern to access lru_lock from a page pointer:
zone_lru_lock(page_zone(page))Which is silly, because it unfolds to this:
&NODE_DATA(page_to_nid(page))->node_zones[page_zonenum(page)]->zone_pgdat->lru_lock
while we can simply do
&NODE_DATA(page_to_nid(page))->lru_lockRemove zone_lru_lock() function, since it's only complicate things. Use
'page_pgdat(page)->lru_lock' pattern instead.[aryabinin@virtuozzo.com: a slightly better version of __split_huge_page()]
Link: http://lkml.kernel.org/r/20190301121651.7741-1-aryabinin@virtuozzo.com
Link: http://lkml.kernel.org/r/20190228083329.31892-2-aryabinin@virtuozzo.com
Signed-off-by: Andrey Ryabinin
Acked-by: Vlastimil Babka
Acked-by: Mel Gorman
Cc: Johannes Weiner
Cc: Michal Hocko
Cc: Rik van Riel
Cc: William Kucharski
Cc: John Hubbard
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
31 Oct, 2018
1 commit
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Move remaining definitions and declarations from include/linux/bootmem.h
into include/linux/memblock.h and remove the redundant header.The includes were replaced with the semantic patch below and then
semi-automated removal of duplicated '#include@@
@@
- #include
+ #include[sfr@canb.auug.org.au: dma-direct: fix up for the removal of linux/bootmem.h]
Link: http://lkml.kernel.org/r/20181002185342.133d1680@canb.auug.org.au
[sfr@canb.auug.org.au: powerpc: fix up for removal of linux/bootmem.h]
Link: http://lkml.kernel.org/r/20181005161406.73ef8727@canb.auug.org.au
[sfr@canb.auug.org.au: x86/kaslr, ACPI/NUMA: fix for linux/bootmem.h removal]
Link: http://lkml.kernel.org/r/20181008190341.5e396491@canb.auug.org.au
Link: http://lkml.kernel.org/r/1536927045-23536-30-git-send-email-rppt@linux.vnet.ibm.com
Signed-off-by: Mike Rapoport
Signed-off-by: Stephen Rothwell
Acked-by: Michal Hocko
Cc: Catalin Marinas
Cc: Chris Zankel
Cc: "David S. Miller"
Cc: Geert Uytterhoeven
Cc: Greentime Hu
Cc: Greg Kroah-Hartman
Cc: Guan Xuetao
Cc: Ingo Molnar
Cc: "James E.J. Bottomley"
Cc: Jonas Bonn
Cc: Jonathan Corbet
Cc: Ley Foon Tan
Cc: Mark Salter
Cc: Martin Schwidefsky
Cc: Matt Turner
Cc: Michael Ellerman
Cc: Michal Simek
Cc: Palmer Dabbelt
Cc: Paul Burton
Cc: Richard Kuo
Cc: Richard Weinberger
Cc: Rich Felker
Cc: Russell King
Cc: Serge Semin
Cc: Thomas Gleixner
Cc: Tony Luck
Cc: Vineet Gupta
Cc: Yoshinori Sato
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
15 Jun, 2018
1 commit
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mm/*.c files use symbolic and octal styles for permissions.
Using octal and not symbolic permissions is preferred by many as more
readable.https://lkml.org/lkml/2016/8/2/1945
Prefer the direct use of octal for permissions.
Done using
$ scripts/checkpatch.pl -f --types=SYMBOLIC_PERMS --fix-inplace mm/*.c
and some typing.Before: $ git grep -P -w "0[0-7]{3,3}" mm | wc -l
44
After: $ git grep -P -w "0[0-7]{3,3}" mm | wc -l
86Miscellanea:
o Whitespace neatening around these conversions.
Link: http://lkml.kernel.org/r/2e032ef111eebcd4c5952bae86763b541d373469.1522102887.git.joe@perches.com
Signed-off-by: Joe Perches
Acked-by: David Rientjes
Acked-by: Michal Hocko
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
06 Apr, 2018
1 commit
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For PTE-mapped THP, the compound THP has not been split to normal 4K
pages yet, the whole THP is considered referenced if any one of sub page
is referenced.When walking PTE-mapped THP by pvmw, all relevant PTEs will be checked
to retrieve referenced bit. But, the current code just returns the
result of the last PTE. If the last PTE has not referenced, the
referenced flag will be cleared.Just set referenced when ptep{pmdp}_clear_young_notify() returns true.
Link: http://lkml.kernel.org/r/1518212451-87134-1-git-send-email-yang.shi@linux.alibaba.com
Signed-off-by: Yang Shi
Reported-by: Gang Deng
Suggested-by: Kirill A. Shutemov
Reviewed-by: Andrew Morton
Cc: "Kirill A. Shutemov"
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
02 Nov, 2017
1 commit
-
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.By default all files without license information are under the default
license of the kernel, which is GPL version 2.Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.How this work was done:
Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if
Reviewed-by: Philippe Ombredanne
Reviewed-by: Thomas Gleixner
Signed-off-by: Greg Kroah-Hartman
07 Sep, 2017
1 commit
-
attribute_group are not supposed to change at runtime. All functions
working with attribute_group provided by work with const
attribute_group. So mark the non-const structs as const.Link: http://lkml.kernel.org/r/1501157221-3832-1-git-send-email-arvind.yadav.cs@gmail.com
Signed-off-by: Arvind Yadav
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
04 May, 2017
1 commit
-
rmap_one's return value controls whether rmap_work should contine to
scan other ptes or not so it's target for changing to boolean. Return
true if the scan should be continued. Otherwise, return false to stop
the scanning.This patch makes rmap_one's return value to boolean.
Link: http://lkml.kernel.org/r/1489555493-14659-10-git-send-email-minchan@kernel.org
Signed-off-by: Minchan Kim
Cc: Anshuman Khandual
Cc: Hillf Danton
Cc: Johannes Weiner
Cc: Kirill A. Shutemov
Cc: Michal Hocko
Cc: Naoya Horiguchi
Cc: Vlastimil Babka
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
25 Feb, 2017
1 commit
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For PTE-mapped THP page_check_address_transhuge() is not adequate: it
cannot find all relevant PTEs, only the first one.iLet's switch it to page_vma_mapped_walk().
I don't think it's subject for stable@: it's not fatal.
Link: http://lkml.kernel.org/r/20170129173858.45174-5-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov
Cc: Vladimir Davydov
Cc: Andrea Arcangeli
Cc: Hillf Danton
Cc: Hugh Dickins
Cc: Johannes Weiner
Cc: Oleg Nesterov
Cc: Peter Zijlstra
Cc: Rik van Riel
Cc: Srikar Dronamraju
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
29 Jul, 2016
1 commit
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Node-based reclaim requires node-based LRUs and locking. This is a
preparation patch that just moves the lru_lock to the node so later
patches are easier to review. It is a mechanical change but note this
patch makes contention worse because the LRU lock is hotter and direct
reclaim and kswapd can contend on the same lock even when reclaiming
from different zones.Link: http://lkml.kernel.org/r/1467970510-21195-3-git-send-email-mgorman@techsingularity.net
Signed-off-by: Mel Gorman
Reviewed-by: Minchan Kim
Acked-by: Johannes Weiner
Acked-by: Vlastimil Babka
Cc: Hillf Danton
Cc: Joonsoo Kim
Cc: Michal Hocko
Cc: Rik van Riel
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
16 Jan, 2016
3 commits
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page_referenced_one() and page_idle_clear_pte_refs_one() duplicate the
code for looking up pte of a (possibly transhuge) page. Move this code
to a new helper function, page_check_address_transhuge(), and make the
above mentioned functions use it.This is just a cleanup, no functional changes are intended.
Signed-off-by: Vladimir Davydov
Reviewed-by: Kirill A. Shutemov
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Both page_referenced() and page_idle_clear_pte_refs_one() assume that
THP can only be mapped with PMD, so there's no reason to look on PTEs
for PageTransHuge() pages. That's no true anymore: THP can be mapped
with PTEs too.The patch removes PageTransHuge() test from the functions and opencode
page table check.[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Kirill A. Shutemov
Cc: Vladimir Davydov
Cc: Andrea Arcangeli
Cc: Hugh Dickins
Cc: Naoya Horiguchi
Cc: Sasha Levin
Cc: Minchan Kim
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
With new refcounting we don't need to mark PMDs splitting. Let's drop
code to handle this.Signed-off-by: Kirill A. Shutemov
Tested-by: Sasha Levin
Tested-by: Aneesh Kumar K.V
Acked-by: Vlastimil Babka
Acked-by: Jerome Marchand
Cc: Andrea Arcangeli
Cc: Hugh Dickins
Cc: Dave Hansen
Cc: Mel Gorman
Cc: Rik van Riel
Cc: Naoya Horiguchi
Cc: Steve Capper
Cc: Johannes Weiner
Cc: Michal Hocko
Cc: Christoph Lameter
Cc: David Rientjes
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
11 Sep, 2015
1 commit
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Knowing the portion of memory that is not used by a certain application or
memory cgroup (idle memory) can be useful for partitioning the system
efficiently, e.g. by setting memory cgroup limits appropriately.
Currently, the only means to estimate the amount of idle memory provided
by the kernel is /proc/PID/{clear_refs,smaps}: the user can clear the
access bit for all pages mapped to a particular process by writing 1 to
clear_refs, wait for some time, and then count smaps:Referenced. However,
this method has two serious shortcomings:- it does not count unmapped file pages
- it affects the reclaimer logicTo overcome these drawbacks, this patch introduces two new page flags,
Idle and Young, and a new sysfs file, /sys/kernel/mm/page_idle/bitmap.
A page's Idle flag can only be set from userspace by setting bit in
/sys/kernel/mm/page_idle/bitmap at the offset corresponding to the page,
and it is cleared whenever the page is accessed either through page tables
(it is cleared in page_referenced() in this case) or using the read(2)
system call (mark_page_accessed()). Thus by setting the Idle flag for
pages of a particular workload, which can be found e.g. by reading
/proc/PID/pagemap, waiting for some time to let the workload access its
working set, and then reading the bitmap file, one can estimate the amount
of pages that are not used by the workload.The Young page flag is used to avoid interference with the memory
reclaimer. A page's Young flag is set whenever the Access bit of a page
table entry pointing to the page is cleared by writing to the bitmap file.
If page_referenced() is called on a Young page, it will add 1 to its
return value, therefore concealing the fact that the Access bit was
cleared.Note, since there is no room for extra page flags on 32 bit, this feature
uses extended page flags when compiled on 32 bit.[akpm@linux-foundation.org: fix build]
[akpm@linux-foundation.org: kpageidle requires an MMU]
[akpm@linux-foundation.org: decouple from page-flags rework]
Signed-off-by: Vladimir Davydov
Reviewed-by: Andres Lagar-Cavilla
Cc: Minchan Kim
Cc: Raghavendra K T
Cc: Johannes Weiner
Cc: Michal Hocko
Cc: Greg Thelen
Cc: Michel Lespinasse
Cc: David Rientjes
Cc: Pavel Emelyanov
Cc: Cyrill Gorcunov
Cc: Jonathan Corbet
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
