forked from Minki/linux
0e247386d9
22 Commits
| Author | SHA1 | Message | Date | |
|---|---|---|---|---|
Yafang Shao
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b6cfab7ad1 |
mm, compaction: some tracepoints should be defined only when CONFIG_COMPACTION is set
Only mm_compaction_isolate_{free, migrate}pages may be used when
CONFIG_COMPACTION is not set. All others are used only when
CONFIG_COMPACTION is set.
After this change, if CONFIG_COMPACTION is not set, the tracepoints that
only work when CONFIG_COMPACTION is set will not be exposed to userspace.
Without this change, they will always be exposed in debugfs whether
CONFIG_COMPACTION is set or not. This is an improvement.
Link: http://lkml.kernel.org/r/1552440403-11780-1-git-send-email-laoar.shao@gmail.com
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Yafang Shao
|
b1746b991d |
mm: compaction: show gfp flag names in try_to_compact_pages tracepoint
Showing the gfp flag names instead of the gfp_mask makes trace more convenient. Link: http://lkml.kernel.org/r/1552527998-13162-1-git-send-email-laoar.shao@gmail.com Signed-off-by: Yafang Shao <laoar.shao@gmail.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Greg Kroah-Hartman
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b24413180f |
License cleanup: add SPDX GPL-2.0 license identifier to files with no license
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 <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
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Michal Hocko
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aff28015fe |
mm, trace: extract COMPACTION_STATUS and ZONE_TYPE to a common header
COMPACTION_STATUS resp. ZONE_TYPE are currently used to translate enum compact_result resp. struct zone index into their symbolic names for an easier post processing. The follow up patch would like to reuse this as well. The code involves some preprocessor black magic which is better not duplicated elsewhere so move it to a common mm tracing relate header. Link: http://lkml.kernel.org/r/20161220130135.15719-2-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: David Rientjes <rientjes@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Vlastimil Babka
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cf378319d3 |
mm, compaction: rename COMPACT_PARTIAL to COMPACT_SUCCESS
COMPACT_PARTIAL has historically meant that compaction returned after doing some work without fully compacting a zone. It however didn't distinguish if compaction terminated because it succeeded in creating the requested high-order page. This has changed recently and now we only return COMPACT_PARTIAL when compaction thinks it succeeded, or the high-order watermark check in compaction_suitable() passes and no compaction needs to be done. So at this point we can make the return value clearer by renaming it to COMPACT_SUCCESS. The next patch will remove some redundant tests for success where compaction just returned COMPACT_SUCCESS. Link: http://lkml.kernel.org/r/20160810091226.6709-4-vbabka@suse.cz Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Tested-by: Lorenzo Stoakes <lstoakes@gmail.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: David Rientjes <rientjes@google.com> Cc: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Vlastimil Babka
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a5508cd83f |
mm, compaction: introduce direct compaction priority
In the context of direct compaction, for some types of allocations we would like the compaction to either succeed or definitely fail while trying as hard as possible. Current async/sync_light migration mode is insufficient, as there are heuristics such as caching scanner positions, marking pageblocks as unsuitable or deferring compaction for a zone. At least the final compaction attempt should be able to override these heuristics. To communicate how hard compaction should try, we replace migration mode with a new enum compact_priority and change the relevant function signatures. In compact_zone_order() where struct compact_control is constructed, the priority is mapped to suitable control flags. This patch itself has no functional change, as the current priority levels are mapped back to the same migration modes as before. Expanding them will be done next. Note that !CONFIG_COMPACTION variant of try_to_compact_pages() is removed, as the only caller exists under CONFIG_COMPACTION. Link: http://lkml.kernel.org/r/20160721073614.24395-8-vbabka@suse.cz Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Michal Hocko
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c8f7de0bfa |
mm, compaction: distinguish between full and partial COMPACT_COMPLETE
COMPACT_COMPLETE now means that compaction and free scanner met. This is not very useful information if somebody just wants to use this feedback and make any decisions based on that. The current caller might be a poor guy who just happened to scan tiny portion of the zone and that could be the reason no suitable pages were compacted. Make sure we distinguish the full and partial zone walks. Consumers should treat COMPACT_PARTIAL_SKIPPED as a potential success and be optimistic in retrying. The existing users of COMPACT_COMPLETE are conservatively changed to use COMPACT_PARTIAL_SKIPPED as well but some of them should be probably reconsidered and only defer the compaction only for COMPACT_COMPLETE with the new semantic. This patch shouldn't introduce any functional changes. Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com> Cc: David Rientjes <rientjes@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Joonsoo Kim <js1304@gmail.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Vladimir Davydov <vdavydov@virtuozzo.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Michal Hocko
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1d4746d395 |
mm, compaction: distinguish COMPACT_DEFERRED from COMPACT_SKIPPED
try_to_compact_pages() can currently return COMPACT_SKIPPED even when the compaction is defered for some zone just because zone DMA is skipped in 99% of cases due to watermark checks. This makes COMPACT_DEFERRED basically unusable for the page allocator as a feedback mechanism. Make sure we distinguish those two states properly and switch their ordering in the enum. This would mean that the COMPACT_SKIPPED will be returned only when all eligible zones are skipped. As a result COMPACT_DEFERRED handling for THP in __alloc_pages_slowpath will be more precise and we would bail out rather than reclaim. Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com> Cc: David Rientjes <rientjes@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Joonsoo Kim <js1304@gmail.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Vladimir Davydov <vdavydov@virtuozzo.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Vlastimil Babka
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698b1b3064 |
mm, compaction: introduce kcompactd
Memory compaction can be currently performed in several contexts: - kswapd balancing a zone after a high-order allocation failure - direct compaction to satisfy a high-order allocation, including THP page fault attemps - khugepaged trying to collapse a hugepage - manually from /proc The purpose of compaction is two-fold. The obvious purpose is to satisfy a (pending or future) high-order allocation, and is easy to evaluate. The other purpose is to keep overal memory fragmentation low and help the anti-fragmentation mechanism. The success wrt the latter purpose is more The current situation wrt the purposes has a few drawbacks: - compaction is invoked only when a high-order page or hugepage is not available (or manually). This might be too late for the purposes of keeping memory fragmentation low. - direct compaction increases latency of allocations. Again, it would be better if compaction was performed asynchronously to keep fragmentation low, before the allocation itself comes. - (a special case of the previous) the cost of compaction during THP page faults can easily offset the benefits of THP. - kswapd compaction appears to be complex, fragile and not working in some scenarios. It could also end up compacting for a high-order allocation request when it should be reclaiming memory for a later order-0 request. To improve the situation, we should be able to benefit from an equivalent of kswapd, but for compaction - i.e. a background thread which responds to fragmentation and the need for high-order allocations (including hugepages) somewhat proactively. One possibility is to extend the responsibilities of kswapd, which could however complicate its design too much. It should be better to let kswapd handle reclaim, as order-0 allocations are often more critical than high-order ones. Another possibility is to extend khugepaged, but this kthread is a single instance and tied to THP configs. This patch goes with the option of a new set of per-node kthreads called kcompactd, and lays the foundations, without introducing any new tunables. The lifecycle mimics kswapd kthreads, including the memory hotplug hooks. For compaction, kcompactd uses the standard compaction_suitable() and ompact_finished() criteria and the deferred compaction functionality. Unlike direct compaction, it uses only sync compaction, as there's no allocation latency to minimize. This patch doesn't yet add a call to wakeup_kcompactd. The kswapd compact/reclaim loop for high-order pages will be replaced by waking up kcompactd in the next patch with the description of what's wrong with the old approach. Waking up of the kcompactd threads is also tied to kswapd activity and follows these rules: - we don't want to affect any fastpaths, so wake up kcompactd only from the slowpath, as it's done for kswapd - if kswapd is doing reclaim, it's more important than compaction, so don't invoke kcompactd until kswapd goes to sleep - the target order used for kswapd is passed to kcompactd Future possible future uses for kcompactd include the ability to wake up kcompactd on demand in special situations, such as when hugepages are not available (currently not done due to __GFP_NO_KSWAPD) or when a fragmentation event (i.e. __rmqueue_fallback()) occurs. It's also possible to perform periodic compaction with kcompactd. [arnd@arndb.de: fix build errors with kcompactd] [paul.gortmaker@windriver.com: don't use modular references for non modular code] Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Rik van Riel <riel@redhat.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: David Rientjes <rientjes@google.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Vlastimil Babka
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420adbe9fc |
mm, tracing: unify mm flags handling in tracepoints and printk
In tracepoints, it's possible to print gfp flags in a human-friendly format through a macro show_gfp_flags(), which defines a translation array and passes is to __print_flags(). Since the following patch will introduce support for gfp flags printing in printk(), it would be nice to reuse the array. This is not straightforward, since __print_flags() can't simply reference an array defined in a .c file such as mm/debug.c - it has to be a macro to allow the macro magic to communicate the format to userspace tools such as trace-cmd. The solution is to create a macro __def_gfpflag_names which is used both in show_gfp_flags(), and to define the gfpflag_names[] array in mm/debug.c. On the other hand, mm/debug.c also defines translation tables for page flags and vma flags, and desire was expressed (but not implemented in this series) to use these also from tracepoints. Thus, this patch also renames the events/gfpflags.h file to events/mmflags.h and moves the table definitions there, using the same macro approach as for gfpflags. This allows translating all three kinds of mm-specific flags both in tracepoints and printk. Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Michal Hocko <mhocko@suse.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Sasha Levin <sasha.levin@oracle.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Mel Gorman <mgorman@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Vlastimil Babka
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2d1e10412c |
mm, compaction: distinguish contended status in tracepoints
Compaction returns prematurely with COMPACT_PARTIAL when contended or has fatal signal pending. This is ok for the callers, but might be misleading in the traces, as the usual reason to return COMPACT_PARTIAL is that we think the allocation should succeed. After this patch we distinguish the premature ending condition in the mm_compaction_finished and mm_compaction_end tracepoints. The contended status covers the following reasons: - lock contention or need_resched() detected in async compaction - fatal signal pending - too many pages isolated in the zone (only for async compaction) Further distinguishing the exact reason seems unnecessary for now. Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Mel Gorman <mgorman@suse.de> Cc: David Rientjes <rientjes@google.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Ingo Molnar <mingo@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Vlastimil Babka
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1743d05060 |
mm, compaction: export tracepoints zone names to userspace
Some compaction tracepoints use zone->name to print which zone is being compacted. This works for in-kernel printing, but not userspace trace printing of raw captured trace such as via trace-cmd report. This patch uses zone_idx() instead of zone->name as the raw value, and when printing, converts the zone_type to string using the appropriate EM() macros and some ugly tricks to overcome the problem that half the values depend on CONFIG_ options and one does not simply use #ifdef inside of #define. trace-cmd output before: transhuge-stres-4235 [000] 453.149280: mm_compaction_finished: node=0 zone=ffffffff81815d7a order=9 ret=partial after: transhuge-stres-4235 [000] 453.149280: mm_compaction_finished: node=0 zone=Normal order=9 ret=partial Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Steven Rostedt <rostedt@goodmis.org> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: David Rientjes <rientjes@google.com> Cc: Valentin Rothberg <valentinrothberg@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Vlastimil Babka
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fa6c7b46aa |
mm, compaction: export tracepoints status strings to userspace
Some compaction tracepoints convert the integer return values to strings using the compaction_status_string array. This works for in-kernel printing, but not userspace trace printing of raw captured trace such as via trace-cmd report. This patch converts the private array to appropriate tracepoint macros that result in proper userspace support. trace-cmd output before: transhuge-stres-4235 [000] 453.149280: mm_compaction_finished: node=0 zone=ffffffff81815d7a order=9 ret= after: transhuge-stres-4235 [000] 453.149280: mm_compaction_finished: node=0 zone=ffffffff81815d7a order=9 ret=partial Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Steven Rostedt <rostedt@goodmis.org> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Joonsoo Kim
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24e2716f63 |
mm/compaction: add tracepoint to observe behaviour of compaction defer
Compaction deferring logic is heavy hammer that block the way to the compaction. It doesn't consider overall system state, so it could prevent user from doing compaction falsely. In other words, even if system has enough range of memory to compact, compaction would be skipped due to compaction deferring logic. This patch add new tracepoint to understand work of deferring logic. This will also help to check compaction success and fail. Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Mel Gorman <mgorman@suse.de> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Joonsoo Kim
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837d026d56 |
mm/compaction: more trace to understand when/why compaction start/finish
It is not well analyzed that when/why compaction start/finish or not. With these new tracepoints, we can know much more about start/finish reason of compaction. I can find following bug with these tracepoint. http://www.spinics.net/lists/linux-mm/msg81582.html Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Mel Gorman <mgorman@suse.de> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Joonsoo Kim
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e34d85f0e3 |
mm/compaction: print current range where compaction work
It'd be useful to know current range where compaction work for detailed analysis. With it, we can know pageblock where we actually scan and isolate, and, how much pages we try in that pageblock and can guess why it doesn't become freepage with pageblock order roughly. Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Mel Gorman <mgorman@suse.de> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Joonsoo Kim
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16c4a097a0 |
mm/compaction: enhance tracepoint output for compaction begin/end
We now have tracepoint for begin event of compaction and it prints start position of both scanners, but, tracepoint for end event of compaction doesn't print finish position of both scanners. It'd be also useful to know finish position of both scanners so this patch add it. It will help to find odd behavior or problem on compaction internal logic. And mode is added to both begin/end tracepoint output, since according to mode, compaction behavior is quite different. And lastly, status format is changed to string rather than status number for readability. [akpm@linux-foundation.org: fix sparse warning] Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Mel Gorman <mgorman@suse.de> Cc: David Rientjes <rientjes@google.com> Cc: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Joonsoo Kim
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4645f06334 |
mm/compaction: change tracepoint format from decimal to hexadecimal
To check the range that compaction is working, tracepoint print start/end pfn of zone and start pfn of both scanner with decimal format. Since we manage all pages in order of 2 and it is well represented by hexadecimal, this patch change the tracepoint format from decimal to hexadecimal. This would improve readability. For example, it makes us easily notice whether current scanner try to compact previously attempted pageblock or not. Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Mel Gorman <mgorman@suse.de> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Vlastimil Babka
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f8c9301fa5 |
mm/compaction: do not count migratepages when unnecessary
During compaction, update_nr_listpages() has been used to count remaining non-migrated and free pages after a call to migrage_pages(). The freepages counting has become unneccessary, and it turns out that migratepages counting is also unnecessary in most cases. The only situation when it's needed to count cc->migratepages is when migrate_pages() returns with a negative error code. Otherwise, the non-negative return value is the number of pages that were not migrated, which is exactly the count of remaining pages in the cc->migratepages list. Furthermore, any non-zero count is only interesting for the tracepoint of mm_compaction_migratepages events, because after that all remaining unmigrated pages are put back and their count is set to 0. This patch therefore removes update_nr_listpages() completely, and changes the tracepoint definition so that the manual counting is done only when the tracepoint is enabled, and only when migrate_pages() returns a negative error code. Furthermore, migrate_pages() and the tracepoints won't be called when there's nothing to migrate. This potentially avoids some wasted cycles and reduces the volume of uninteresting mm_compaction_migratepages events where "nr_migrated=0 nr_failed=0". In the stress-highalloc mmtest, this was about 75% of the events. The mm_compaction_isolate_migratepages event is better for determining that nothing was isolated for migration, and this one was just duplicating the info. Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> Acked-by: Michal Nazarewicz <mina86@mina86.com> Cc: Christoph Lameter <cl@linux.com> Cc: Rik van Riel <riel@redhat.com> Acked-by: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Mel Gorman
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0eb927c0ab |
mm: compaction: trace compaction begin and end
The broad goal of the series is to improve allocation success rates for
huge pages through memory compaction, while trying not to increase the
compaction overhead. The original objective was to reintroduce
capturing of high-order pages freed by the compaction, before they are
split by concurrent activity. However, several bugs and opportunities
for simple improvements were found in the current implementation, mostly
through extra tracepoints (which are however too ugly for now to be
considered for sending).
The patches mostly deal with two mechanisms that reduce compaction
overhead, which is caching the progress of migrate and free scanners,
and marking pageblocks where isolation failed to be skipped during
further scans.
Patch 1 (from mgorman) adds tracepoints that allow calculate time spent in
compaction and potentially debug scanner pfn values.
Patch 2 encapsulates the some functionality for handling deferred compactions
for better maintainability, without a functional change
type is not determined without being actually needed.
Patch 3 fixes a bug where cached scanner pfn's are sometimes reset only after
they have been read to initialize a compaction run.
Patch 4 fixes a bug where scanners meeting is sometimes not properly detected
and can lead to multiple compaction attempts quitting early without
doing any work.
Patch 5 improves the chances of sync compaction to process pageblocks that
async compaction has skipped due to being !MIGRATE_MOVABLE.
Patch 6 improves the chances of sync direct compaction to actually do anything
when called after async compaction fails during allocation slowpath.
The impact of patches were validated using mmtests's stress-highalloc
benchmark with mmtests's stress-highalloc benchmark on a x86_64 machine
with 4GB memory.
Due to instability of the results (mostly related to the bugs fixed by
patches 2 and 3), 10 iterations were performed, taking min,mean,max
values for success rates and mean values for time and vmstat-based
metrics.
First, the default GFP_HIGHUSER_MOVABLE allocations were tested with the
patches stacked on top of v3.13-rc2. Patch 2 is OK to serve as baseline
due to no functional changes in 1 and 2. Comments below.
stress-highalloc
3.13-rc2 3.13-rc2 3.13-rc2 3.13-rc2 3.13-rc2
2-nothp 3-nothp 4-nothp 5-nothp 6-nothp
Success 1 Min 9.00 ( 0.00%) 10.00 (-11.11%) 43.00 (-377.78%) 43.00 (-377.78%) 33.00 (-266.67%)
Success 1 Mean 27.50 ( 0.00%) 25.30 ( 8.00%) 45.50 (-65.45%) 45.90 (-66.91%) 46.30 (-68.36%)
Success 1 Max 36.00 ( 0.00%) 36.00 ( 0.00%) 47.00 (-30.56%) 48.00 (-33.33%) 52.00 (-44.44%)
Success 2 Min 10.00 ( 0.00%) 8.00 ( 20.00%) 46.00 (-360.00%) 45.00 (-350.00%) 35.00 (-250.00%)
Success 2 Mean 26.40 ( 0.00%) 23.50 ( 10.98%) 47.30 (-79.17%) 47.60 (-80.30%) 48.10 (-82.20%)
Success 2 Max 34.00 ( 0.00%) 33.00 ( 2.94%) 48.00 (-41.18%) 50.00 (-47.06%) 54.00 (-58.82%)
Success 3 Min 65.00 ( 0.00%) 63.00 ( 3.08%) 85.00 (-30.77%) 84.00 (-29.23%) 85.00 (-30.77%)
Success 3 Mean 76.70 ( 0.00%) 70.50 ( 8.08%) 86.20 (-12.39%) 85.50 (-11.47%) 86.00 (-12.13%)
Success 3 Max 87.00 ( 0.00%) 86.00 ( 1.15%) 88.00 ( -1.15%) 87.00 ( 0.00%) 87.00 ( 0.00%)
3.13-rc2 3.13-rc2 3.13-rc2 3.13-rc2 3.13-rc2
2-nothp 3-nothp 4-nothp 5-nothp 6-nothp
User 6437.72 6459.76 5960.32 5974.55 6019.67
System 1049.65 1049.09 1029.32 1031.47 1032.31
Elapsed 1856.77 1874.48 1949.97 1994.22 1983.15
3.13-rc2 3.13-rc2 3.13-rc2 3.13-rc2 3.13-rc2
2-nothp 3-nothp 4-nothp 5-nothp 6-nothp
Minor Faults 253952267 254581900 250030122 250507333 250157829
Major Faults 420 407 506 530 530
Swap Ins 4 9 9 6 6
Swap Outs 398 375 345 346 333
Direct pages scanned 197538 189017 298574 287019 299063
Kswapd pages scanned 1809843 1801308 1846674 1873184 1861089
Kswapd pages reclaimed 1806972 1798684 1844219 1870509 1858622
Direct pages reclaimed 197227 188829 298380 286822 298835
Kswapd efficiency 99% 99% 99% 99% 99%
Kswapd velocity 953.382 970.449 952.243 934.569 922.286
Direct efficiency 99% 99% 99% 99% 99%
Direct velocity 104.058 101.832 153.961 143.200 148.205
Percentage direct scans 9% 9% 13% 13% 13%
Zone normal velocity 347.289 359.676 348.063 339.933 332.983
Zone dma32 velocity 710.151 712.605 758.140 737.835 737.507
Zone dma velocity 0.000 0.000 0.000 0.000 0.000
Page writes by reclaim 557.600 429.000 353.600 426.400 381.800
Page writes file 159 53 7 79 48
Page writes anon 398 375 345 346 333
Page reclaim immediate 825 644 411 575 420
Sector Reads 2781750 2769780 2878547 2939128 2910483
Sector Writes 12080843 12083351 12012892 12002132 12010745
Page rescued immediate 0 0 0 0 0
Slabs scanned
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David Howells
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a1ce39288e |
UAPI: (Scripted) Convert #include "..." to #include <path/...> in kernel system headers
Convert #include "..." to #include <path/...> in kernel system headers. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Acked-by: Dave Jones <davej@redhat.com> |
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Mel Gorman
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b7aba6984d |
mm: compaction: add trace events for memory compaction activity
In preparation for a patches promoting the use of memory compaction over lumpy reclaim, this patch adds trace points for memory compaction activity. Using them, we can monitor the scanning activity of the migration and free page scanners as well as the number and success rates of pages passed to page migration. Signed-off-by: Mel Gorman <mel@csn.ul.ie> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Rik van Riel <riel@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Andy Whitcroft <apw@shadowen.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |