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2016-03-15kallsyms: add support for relative offsets in kallsyms address tableArd Biesheuvel5-19/+126
Similar to how relative extables are implemented, it is possible to emit the kallsyms table in such a way that it contains offsets relative to some anchor point in the kernel image rather than absolute addresses. On 64-bit architectures, it cuts the size of the kallsyms address table in half, since offsets between kernel symbols can typically be expressed in 32 bits. This saves several hundreds of kilobytes of permanent .rodata on average. In addition, the kallsyms address table is no longer subject to dynamic relocation when CONFIG_RELOCATABLE is in effect, so the relocation work done after decompression now doesn't have to do relocation updates for all these values. This saves up to 24 bytes (i.e., the size of a ELF64 RELA relocation table entry) per value, which easily adds up to a couple of megabytes of uncompressed __init data on ppc64 or arm64. Even if these relocation entries typically compress well, the combined size reduction of 2.8 MB uncompressed for a ppc64_defconfig build (of which 2.4 MB is __init data) results in a ~500 KB space saving in the compressed image. Since it is useful for some architectures (like x86) to retain the ability to emit absolute values as well, this patch also adds support for capturing both absolute and relative values when KALLSYMS_ABSOLUTE_PERCPU is in effect, by emitting absolute per-cpu addresses as positive 32-bit values, and addresses relative to the lowest encountered relative symbol as negative values, which are subtracted from the runtime address of this base symbol to produce the actual address. Support for the above is enabled by default for all architectures except IA-64 and Tile-GX, whose symbols are too far apart to capture in this manner. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Tested-by: Guenter Roeck <linux@roeck-us.net> Reviewed-by: Kees Cook <keescook@chromium.org> Tested-by: Kees Cook <keescook@chromium.org> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Ingo Molnar <mingo@kernel.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Michal Marek <mmarek@suse.cz> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15kallsyms: don't overload absolute symbol type for percpu symbolsArd Biesheuvel1-2/+12
Commit c6bda7c988a5 ("kallsyms: fix percpu vars on x86-64 with relocation") overloaded the 'A' (absolute) symbol type to signify that a symbol is not subject to dynamic relocation. However, the original A type does not imply that at all, and depending on the version of the toolchain, many A type symbols are emitted that are in fact relative to the kernel text, i.e., if the kernel is relocated at runtime, these symbols should be updated as well. For instance, on sparc32, the following symbols are emitted as absolute (kindly provided by Guenter Roeck): f035a420 A _etext f03d9000 A _sdata f03de8c4 A jiffies f03f8860 A _edata f03fc000 A __init_begin f041bdc8 A __init_text_end f0423000 A __bss_start f0423000 A __init_end f044457d A __bss_stop f044457d A _end On x86_64, similar behavior can be observed: ffffffff81a00000 A __end_rodata_hpage_align ffffffff81b19000 A __vvar_page ffffffff81d3d000 A _end Even if only a couple of them pass the symbol range check that results in them to be taken into account for the final kallsyms symbol table, it is obvious that 'A' does not mean the symbol does not need to be updated at relocation time, and overloading its meaning to signify that is perhaps not a good idea. So instead, add a new percpu_absolute member to struct sym_entry, and when --absolute-percpu is in effect, use it to record symbols whose addresses should be emitted as final values rather than values that still require relocation at runtime. That way, we can drop the check against the 'A' type. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Tested-by: Guenter Roeck <linux@roeck-us.net> Reviewed-by: Kees Cook <keescook@chromium.org> Tested-by: Kees Cook <keescook@chromium.org> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Ingo Molnar <mingo@kernel.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Michal Marek <mmarek@suse.cz> Acked-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15x86: kallsyms: disable absolute percpu symbols on !SMPArd Biesheuvel2-1/+5
scripts/kallsyms.c has a special --absolute-percpu command line option which deals with the zero based per cpu offsets that are used when building for SMP on x86_64. This means that the option should only be passed in that case, so add a Kconfig symbol with the correct predicate, and use that instead. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Tested-by: Guenter Roeck <linux@roeck-us.net> Reviewed-by: Kees Cook <keescook@chromium.org> Tested-by: Kees Cook <keescook@chromium.org> Acked-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Ingo Molnar <mingo@kernel.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Michal Marek <mmarek@suse.cz> Cc: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15checkpatch: fix another left brace warningGeyslan G. Bem1-1/+1
This patch escapes a regex that uses left brace. Using checkpatch.pl with Perl 5.22.0 generates the warning: "Unescaped left brace in regex is deprecated, passed through in regex;" Comment from regcomp.c in Perl source: "Currently we don't warn when the lbrace is at the start of a construct. This catches it in the middle of a literal string, or when it's the first thing after something like "\b"." This works as a complement to 4e5d56bd ("checkpatch: fix left brace warning"). Signed-off-by: Geyslan G. Bem <geyslan@gmail.com> Signed-off-by: Joe Perches <joe@perches.com> Suggested-by: Peter Senna Tschudin <peter.senna@gmail.com> Cc: Eddie Kovsky <ewk@edkovsky.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15checkpatch: improve UNSPECIFIED_INT test for bare signed/unsigned usesJoe Perches1-4/+8
Improve the test to allow casts to (unsigned) or (signed) to be found and fixed if desired. Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15checkpatch: warn on bare unsigned or signed declarations without intJoe Perches1-0/+20
Kernel style prefers "unsigned int <foo>" over "unsigned <foo>" and "signed int <foo>" over "signed <foo>". Emit a warning for these simple signed/unsigned <foo> declarations. Fix it too if desired. Signed-off-by: Joe Perches <joe@perches.com> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15checkpatch: exclude asm volatile from complex macro checkJoe Perches1-0/+3
asm volatile and all its variants like __asm__ __volatile__ ("<foo>") are reported as errors with "Macros with with complex values should be enclosed in parentheses". Make an exception for these asm volatile macro definitions by converting the "asm volatile" to "asm_volatile" so it appears as a single function call and the error isn't reported. Signed-off-by: Joe Perches <joe@perches.com> Reported-by: Jeff Merkey <linux.mdb@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15mm: memcontrol: drop unnecessary lru locking from mem_cgroup_migrate()Johannes Weiner1-2/+1
Migration accounting in the memory controller used to have to handle both oldpage and newpage being on the LRU already; fuse's page cache replacement used to pass a recycled newpage that had been uncharged but not freed and removed from the LRU, and the memcg migration code used to uncharge oldpage to "pass on" the existing charge to newpage. Nowadays, pages are no longer uncharged when truncated from the page cache, but rather only at free time, so if a LRU page is recycled in page cache replacement it'll also still be charged. And we bail out of the charge transfer altogether in that case. Tell commit_charge() that we know newpage is not on the LRU, to avoid taking the zone->lru_lock unnecessarily from the migration path. But also, oldpage is no longer uncharged inside migration. We only use oldpage for its page->mem_cgroup and page size, so we don't care about its LRU state anymore either. Remove any mention from the kernel doc. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Suggested-by: Hugh Dickins <hughd@google.com> Acked-by: Vladimir Davydov <vdavydov@virtuozzo.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Mateusz Guzik <mguzik@redhat.com> Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15mm: migrate: consolidate mem_cgroup_migrate() callsJohannes Weiner1-7/+2
Rather than scattering mem_cgroup_migrate() calls all over the place, have a single call from a safe place where every migration operation eventually ends up in - migrate_page_copy(). Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Suggested-by: Hugh Dickins <hughd@google.com> Acked-by: Vladimir Davydov <vdavydov@virtuozzo.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Mateusz Guzik <mguzik@redhat.com> Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15mm/compaction: speed up pageblock_pfn_to_page() when zone is contiguousJoonsoo Kim7-52/+105
There is a performance drop report due to hugepage allocation and in there half of cpu time are spent on pageblock_pfn_to_page() in compaction [1]. In that workload, compaction is triggered to make hugepage but most of pageblocks are un-available for compaction due to pageblock type and skip bit so compaction usually fails. Most costly operations in this case is to find valid pageblock while scanning whole zone range. To check if pageblock is valid to compact, valid pfn within pageblock is required and we can obtain it by calling pageblock_pfn_to_page(). This function checks whether pageblock is in a single zone and return valid pfn if possible. Problem is that we need to check it every time before scanning pageblock even if we re-visit it and this turns out to be very expensive in this workload. Although we have no way to skip this pageblock check in the system where hole exists at arbitrary position, we can use cached value for zone continuity and just do pfn_to_page() in the system where hole doesn't exist. This optimization considerably speeds up in above workload. Before vs After Max: 1096 MB/s vs 1325 MB/s Min: 635 MB/s 1015 MB/s Avg: 899 MB/s 1194 MB/s Avg is improved by roughly 30% [2]. [1]: http://www.spinics.net/lists/linux-mm/msg97378.html [2]: https://lkml.org/lkml/2015/12/9/23 [akpm@linux-foundation.org: don't forget to restore zone->contiguous on error path, per Vlastimil] Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Reported-by: Aaron Lu <aaron.lu@intel.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Tested-by: Aaron Lu <aaron.lu@intel.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Rik van Riel <riel@redhat.com> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15mm/compaction: pass only pageblock aligned range to pageblock_pfn_to_pageJoonsoo Kim1-11/+30
pageblock_pfn_to_page() is used to check there is valid pfn and all pages in the pageblock is in a single zone. If there is a hole in the pageblock, passing arbitrary position to pageblock_pfn_to_page() could cause to skip whole pageblock scanning, instead of just skipping the hole page. For deterministic behaviour, it's better to always pass pageblock aligned range to pageblock_pfn_to_page(). It will also help further optimization on pageblock_pfn_to_page() in the following patch. Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Aaron Lu <aaron.lu@intel.com> Cc: David Rientjes <rientjes@google.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Rik van Riel <riel@redhat.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15mm/compaction: fix invalid free_pfn and compact_cached_free_pfnJoonsoo Kim1-4/+5
free_pfn and compact_cached_free_pfn are the pointer that remember restart position of freepage scanner. When they are reset or invalid, we set them to zone_end_pfn because freepage scanner works in reverse direction. But, because zone range is defined as [zone_start_pfn, zone_end_pfn), zone_end_pfn is invalid to access. Therefore, we should not store it to free_pfn and compact_cached_free_pfn. Instead, we need to store zone_end_pfn - 1 to them. There is one more thing we should consider. Freepage scanner scan reversely by pageblock unit. If free_pfn and compact_cached_free_pfn are set to middle of pageblock, it regards that sitiation as that it already scans front part of pageblock so we lose opportunity to scan there. To fix-up, this patch do round_down() to guarantee that reset position will be pageblock aligned. Note that thanks to the current pageblock_pfn_to_page() implementation, actual access to zone_end_pfn doesn't happen until now. But, following patch will change pageblock_pfn_to_page() so this patch is needed from now on. Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Acked-by: David Rientjes <rientjes@google.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Aaron Lu <aaron.lu@intel.com> Cc: Mel Gorman <mgorman@suse.de> 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>
2016-03-15mm/memblock.c: remove unnecessary memblock_type variableAlexander Kuleshov1-6/+2
We define struct memblock_type *type in the memblock_add_region() and memblock_reserve_region() functions only for passing it to the memlock_add_range() and memblock_reserve_range() functions. Let's remove these variables and will pass a type directly. Signed-off-by: Alexander Kuleshov <kuleshovmail@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15x86: also use debug_pagealloc_enabled() for free_init_pagesChristian Borntraeger1-14/+15
we want to couple all debugging features with debug_pagealloc_enabled() and not with the config option CONFIG_DEBUG_PAGEALLOC. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Suggested-by: David Rientjes <rientjes@google.com> Acked-by: David Rientjes <rientjes@google.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Laura Abbott <labbott@fedoraproject.org> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15s390: query dynamic DEBUG_PAGEALLOC settingChristian Borntraeger2-9/+7
We can use debug_pagealloc_enabled() to check if we can map the identity mapping with 1MB/2GB pages as well as to print the current setting in dump_stack. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Acked-by: David Rientjes <rientjes@google.com> Cc: Laura Abbott <labbott@fedoraproject.org> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15x86: query dynamic DEBUG_PAGEALLOC settingChristian Borntraeger3-16/+10
We can use debug_pagealloc_enabled() to check if we can map the identity mapping with 2MB pages. We can also add the state into the dump_stack output. The patch does not touch the code for the 1GB pages, which ignored CONFIG_DEBUG_PAGEALLOC. Do we need to fence this as well? Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: David Rientjes <rientjes@google.com> Cc: Laura Abbott <labbott@fedoraproject.org> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15thp: cleanup split_huge_page()Kirill A. Shutemov1-13/+7
After one of bugfixes to freeze_page(), we don't have freezed pages in rmap, therefore mapcount of all subpages of freezed THP is zero. And we have assert for that. Let's drop code which deal with non-zero mapcount of subpages. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15mm: use linear_page_index() in do_fault()Matthew Wilcox1-2/+1
do_fault() assumes that PAGE_SIZE is the same as PAGE_CACHE_SIZE. Use linear_page_index() to calculate pgoff in the correct units. Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15mm: remove unnecessary uses of lock_page_memcg()Johannes Weiner5-20/+8
There are several users that nest lock_page_memcg() inside lock_page() to prevent page->mem_cgroup from changing. But the page lock prevents pages from moving between cgroups, so that is unnecessary overhead. Remove lock_page_memcg() in contexts with locked contexts and fix the debug code in the page stat functions to be okay with the page lock. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Vladimir Davydov <vdavydov@virtuozzo.com> Cc: Michal Hocko <mhocko@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15mm: simplify lock_page_memcg()Johannes Weiner12-117/+88
Now that migration doesn't clear page->mem_cgroup of live pages anymore, it's safe to make lock_page_memcg() and the memcg stat functions take pages, and spare the callers from memcg objects. [akpm@linux-foundation.org: fix warnings] Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Suggested-by: Vladimir Davydov <vdavydov@virtuozzo.com> Acked-by: Vladimir Davydov <vdavydov@virtuozzo.com> Cc: Michal Hocko <mhocko@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15mm: migrate: do not touch page->mem_cgroup of live pagesJohannes Weiner6-25/+20
Changing a page's memcg association complicates dealing with the page, so we want to limit this as much as possible. Page migration e.g. does not have to do that. Just like page cache replacement, it can forcibly charge a replacement page, and then uncharge the old page when it gets freed. Temporarily overcharging the cgroup by a single page is not an issue in practice, and charging is so cheap nowadays that this is much preferrable to the headache of messing with live pages. The only place that still changes the page->mem_cgroup binding of live pages is when pages move along with a task to another cgroup. But that path isolates the page from the LRU, takes the page lock, and the move lock (lock_page_memcg()). That means page->mem_cgroup is always stable in callers that have the page isolated from the LRU or locked. Lighter unlocked paths, like writeback accounting, can use lock_page_memcg(). [akpm@linux-foundation.org: fix build] [vdavydov@virtuozzo.com: fix lockdep splat] Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Vladimir Davydov <vdavydov@virtuozzo.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Greg Thelen <gthelen@google.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>
2016-03-15mm: workingset: per-cgroup cache thrash detectionJohannes Weiner5-57/+134
Cache thrash detection (see a528910e12ec "mm: thrash detection-based file cache sizing" for details) currently only works on the system level, not inside cgroups. Worse, as the refaults are compared to the global number of active cache, cgroups might wrongfully get all their refaults activated when their pages are hotter than those of others. Move the refault machinery from the zone to the lruvec, and then tag eviction entries with the memcg ID. This makes the thrash detection work correctly inside cgroups. [sergey.senozhatsky@gmail.com: do not return from workingset_activation() with locked rcu and page] Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Reviewed-by: Vladimir Davydov <vdavydov@virtuozzo.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15mm: workingset: eviction buckets for bigmem/lowbit machinesJohannes Weiner1-1/+29
For per-cgroup thrash detection, we need to store the memcg ID inside the radix tree cookie as well. However, on 32 bit that doesn't leave enough bits for the eviction timestamp to cover the necessary range of recently evicted pages. The radix tree entry would look like this: [ RADIX_TREE_EXCEPTIONAL(2) | ZONEID(2) | MEMCGID(16) | EVICTION(12) ] 12 bits means 4096 pages, means 16M worth of recently evicted pages. But refaults are actionable up to distances covering half of memory. To not miss refaults, we have to stretch out the range at the cost of how precisely we can tell when a page was evicted. This way we can shave off lower bits from the eviction timestamp until the necessary range is covered. E.g. grouping evictions into 1M buckets (256 pages) will stretch the longest representable refault distance to 4G. This patch implements eviction buckets that are automatically sized according to the available bits and the necessary refault range, in preparation for per-cgroup thrash detection. The maximum actionable distance is currently half of memory, but to support memory hotplug of up to 200% of boot-time memory, we size the buckets to cover double the distance. Beyond that, thrashing won't be detectable anymore. During boot, the kernel will print out the exact parameters, like so: [ 0.113929] workingset: timestamp_bits=12 max_order=18 bucket_order=6 In this example, there are 12 radix entry bits available for the eviction timestamp, to cover a maximum distance of 2^18 pages (this is a 1G machine). Consequently, evictions must be grouped into buckets of 2^6 pages, or 256K. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Vladimir Davydov <vdavydov@virtuozzo.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15mm: workingset: separate shadow unpacking and refault calculationJohannes Weiner1-28/+28
Per-cgroup thrash detection will need to derive a live memcg from the eviction cookie, and doing that inside unpack_shadow() will get nasty with the reference handling spread over two functions. In preparation, make unpack_shadow() clearly about extracting static data, and let workingset_refault() do all the higher-level handling. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Vladimir Davydov <vdavydov@virtuozzo.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15mm: workingset: #define radix entry eviction maskJohannes Weiner1-4/+6
This is a compile-time constant, no need to calculate it on refault. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Vladimir Davydov <vdavydov@virtuozzo.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15mm: memcontrol: generalize locking for the page->mem_cgroup bindingJohannes Weiner9-67/+67
These patches tag the page cache radix tree eviction entries with the memcg an evicted page belonged to, thus making per-cgroup LRU reclaim work properly and be as adaptive to new cache workingsets as global reclaim already is. This should have been part of the original thrash detection patch series, but was deferred due to the complexity of those patches. This patch (of 5): So far the only sites that needed to exclude charge migration to stabilize page->mem_cgroup have been per-cgroup page statistics, hence the name mem_cgroup_begin_page_stat(). But per-cgroup thrash detection will add another site that needs to ensure page->mem_cgroup lifetime. Rename these locking functions to the more generic lock_page_memcg() and unlock_page_memcg(). Since charge migration is a cgroup1 feature only, we might be able to delete it at some point, and these now easy to identify locking sites along with it. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Suggested-by: Vladimir Davydov <vdavydov@virtuozzo.com> Acked-by: Vladimir Davydov <vdavydov@virtuozzo.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15mm, vmscan: make zone_reclaimable_pages more preciseMichal Hocko1-7/+7
zone_reclaimable_pages() is used in should_reclaim_retry() which uses it to calculate the target for the watermark check. This means that precise numbers are important for the correct decision. zone_reclaimable_pages uses zone_page_state which can contain stale data with per-cpu diffs not synced yet (the last vmstat_update might have run 1s in the past). Use zone_page_state_snapshot() in zone_reclaimable_pages() instead. None of the current callers is in a hot path where getting the precise value (which involves per-cpu iteration) would cause an unreasonable overhead. Signed-off-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Suggested-by: David Rientjes <rientjes@google.com> Acked-by: David Rientjes <rientjes@google.com> Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15mm/madvise: update comment on sys_madvise()Naoya Horiguchi1-0/+14
Some new MADV_* advices are not documented in sys_madvise() comment. So let's update it. [akpm@linux-foundation.org: modifications suggested by Michal] Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Minchan Kim <minchan@kernel.org> Cc: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Jason Baron <jbaron@redhat.com> Cc: Chen Gong <gong.chen@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15mm: vmscan: do not clear SHRINKER_NUMA_AWARE if nr_node_ids == 1Vladimir Davydov1-8/+0
Currently, on shrinker registration we clear SHRINKER_NUMA_AWARE if there's the only NUMA node present. The comment states that this will allow us to save some small loop time later. It used to be true when this code was added (see commit 1d3d4437eae1b ("vmscan: per-node deferred work")), but since commit 6b4f7799c6a57 ("mm: vmscan: invoke slab shrinkers from shrink_zone()") it doesn't make any difference. Anyway, running on non-NUMA machine shouldn't make a shrinker NUMA unaware, so zap this hunk. Signed-off-by: Vladimir Davydov <vdavydov@virtuozzo.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15xen_balloon: support memory auto onlining policyVitaly Kuznetsov2-9/+25
Add support for the newly added kernel memory auto onlining policy to Xen ballon driver. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Suggested-by: Daniel Kiper <daniel.kiper@oracle.com> Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com> Acked-by: David Vrabel <david.vrabel@citrix.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Daniel Kiper <daniel.kiper@oracle.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Tang Chen <tangchen@cn.fujitsu.com> Cc: David Rientjes <rientjes@google.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Xishi Qiu <qiuxishi@huawei.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Igor Mammedov <imammedo@redhat.com> Cc: Kay Sievers <kay@vrfy.org> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15memory-hotplug: add automatic onlining policy for the newly added memoryVitaly Kuznetsov6-8/+75
Currently, all newly added memory blocks remain in 'offline' state unless someone onlines them, some linux distributions carry special udev rules like: SUBSYSTEM=="memory", ACTION=="add", ATTR{state}=="offline", ATTR{state}="online" to make this happen automatically. This is not a great solution for virtual machines where memory hotplug is being used to address high memory pressure situations as such onlining is slow and a userspace process doing this (udev) has a chance of being killed by the OOM killer as it will probably require to allocate some memory. Introduce default policy for the newly added memory blocks in /sys/devices/system/memory/auto_online_blocks file with two possible values: "offline" which preserves the current behavior and "online" which causes all newly added memory blocks to go online as soon as they're added. The default is "offline". Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Daniel Kiper <daniel.kiper@oracle.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Tang Chen <tangchen@cn.fujitsu.com> Cc: David Vrabel <david.vrabel@citrix.com> Acked-by: David Rientjes <rientjes@google.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Xishi Qiu <qiuxishi@huawei.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Igor Mammedov <imammedo@redhat.com> Cc: Kay Sievers <kay@vrfy.org> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15mm/memory.c: make apply_to_page_range() more robustMika Penttilä1-1/+3
Arm and arm64 used to trigger this BUG_ON() - this has now been fixed. But a WARN_ON() here is sufficient to catch future buggy callers. Signed-off-by: Mika Penttilä <mika.penttila@nextfour.com> Reviewed-by: Pekka Enberg <penberg@kernel.org> 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>
2016-03-15mm/mempolicy.c: skip VM_HUGETLB and VM_MIXEDMAP VMA for lazy mbindLiang Chen1-1/+3
VM_HUGETLB and VM_MIXEDMAP vma needs to be excluded to avoid compound pages being marked for migration and unexpected COWs when handling hugetlb fault. Thanks to Naoya Horiguchi for reminding me on these checks. Signed-off-by: Liang Chen <liangchen.linux@gmail.com> Signed-off-by: Gavin Guo <gavin.guo@canonical.com> Suggested-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Acked-by: David Rientjes <rientjes@google.com> Cc: SeongJae Park <sj38.park@gmail.com> Cc: Rik van Riel <riel@redhat.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>
2016-03-15mm/memory-failure.c: remove useless "undef"sWang Xiaoqiang1-2/+0
Remove the useless #undef, since the corresponding #define has already been removed. Signed-off-by: Wang Xiaoqiang <wangxq10@lzu.edu.cn> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15mm/madvise: pass return code of memory_failure() to userspaceNaoya Horiguchi1-2/+3
Currently the return value of memory_failure() is not passed to userspace when madvise(MADV_HWPOISON) is used. This is inconvenient for test programs that want to know the result of error handling. So let's return it to the caller as we already do in the MADV_SOFT_OFFLINE case. Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Chen Gong <gong.chen@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15mm, sl[au]b: print gfp_flags as strings in slab_out_of_memory()Vlastimil Babka2-8/+6
We can now print gfp_flags more human-readable. Make use of this in slab_out_of_memory() for SLUB and SLAB. Also convert the SLAB variant it to pr_warn() along the way. Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: David Rientjes <rientjes@google.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15mm/page_poisoning.c: allow for zero poisoningLaura Abbott7-5/+60
By default, page poisoning uses a poison value (0xaa) on free. If this is changed to 0, the page is not only sanitized but zeroing on alloc with __GFP_ZERO can be skipped as well. The tradeoff is that detecting corruption from the poisoning is harder to detect. This feature also cannot be used with hibernation since pages are not guaranteed to be zeroed after hibernation. Credit to Grsecurity/PaX team for inspiring this work Signed-off-by: Laura Abbott <labbott@fedoraproject.org> Acked-by: Rafael J. Wysocki <rjw@rjwysocki.net> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Michal Hocko <mhocko@suse.com> Cc: Kees Cook <keescook@chromium.org> Cc: Mathias Krause <minipli@googlemail.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Jianyu Zhan <nasa4836@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15mm/page_poison.c: enable PAGE_POISONING as a separate optionLaura Abbott6-14/+89
Page poisoning is currently set up as a feature if architectures don't have architecture debug page_alloc to allow unmapping of pages. It has uses apart from that though. Clearing of the pages on free provides an increase in security as it helps to limit the risk of information leaks. Allow page poisoning to be enabled as a separate option independent of kernel_map pages since the two features do separate work. Because of how hiberanation is implemented, the checks on alloc cannot occur if hibernation is enabled. The runtime alloc checks can also be enabled with an option when !HIBERNATION. Credit to Grsecurity/PaX team for inspiring this work Signed-off-by: Laura Abbott <labbott@fedoraproject.org> Cc: Rafael J. Wysocki <rjw@rjwysocki.net> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Michal Hocko <mhocko@suse.com> Cc: Kees Cook <keescook@chromium.org> Cc: Mathias Krause <minipli@googlemail.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Jianyu Zhan <nasa4836@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15mm, debug: move bad flags printing to bad_page()Vlastimil Babka3-12/+11
Since bad_page() is the only user of the badflags parameter of dump_page_badflags(), we can move the code to bad_page() and simplify a bit. The dump_page_badflags() function is renamed to __dump_page() and can still be called separately from dump_page() for temporary debug prints where page_owner info is not desired. The only user-visible change is that page->mem_cgroup is printed before the bad flags. Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Michal Hocko <mhocko@suse.com> 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>
2016-03-15mm, page_owner: dump page owner info from dump_page()Vlastimil Babka4-0/+37
The page_owner mechanism is useful for dealing with memory leaks. By reading /sys/kernel/debug/page_owner one can determine the stack traces leading to allocations of all pages, and find e.g. a buggy driver. This information might be also potentially useful for debugging, such as the VM_BUG_ON_PAGE() calls to dump_page(). So let's print the stored info from dump_page(). Example output: page:ffffea000292f1c0 count:1 mapcount:0 mapping:ffff8800b2f6cc18 index:0x91d flags: 0x1fffff8001002c(referenced|uptodate|lru|mappedtodisk) page dumped because: VM_BUG_ON_PAGE(1) page->mem_cgroup:ffff8801392c5000 page allocated via order 0, migratetype Movable, gfp_mask 0x24213ca(GFP_HIGHUSER_MOVABLE|__GFP_COLD|__GFP_NOWARN|__GFP_NORETRY) [<ffffffff811682c4>] __alloc_pages_nodemask+0x134/0x230 [<ffffffff811b40c8>] alloc_pages_current+0x88/0x120 [<ffffffff8115e386>] __page_cache_alloc+0xe6/0x120 [<ffffffff8116ba6c>] __do_page_cache_readahead+0xdc/0x240 [<ffffffff8116bd05>] ondemand_readahead+0x135/0x260 [<ffffffff8116be9c>] page_cache_async_readahead+0x6c/0x70 [<ffffffff811604c2>] generic_file_read_iter+0x3f2/0x760 [<ffffffff811e0dc7>] __vfs_read+0xa7/0xd0 page has been migrated, last migrate reason: compaction Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Michal Hocko <mhocko@suse.com> 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>
2016-03-15mm, page_owner: track and print last migrate reasonVlastimil Babka6-4/+50
During migration, page_owner info is now copied with the rest of the page, so the stacktrace leading to free page allocation during migration is overwritten. For debugging purposes, it might be however useful to know that the page has been migrated since its initial allocation. This might happen many times during the lifetime for different reasons and fully tracking this, especially with stacktraces would incur extra memory costs. As a compromise, store and print the migrate_reason of the last migration that occurred to the page. This is enough to distinguish compaction, numa balancing etc. Example page_owner entry after the patch: Page allocated via order 0, mask 0x24200ca(GFP_HIGHUSER_MOVABLE) PFN 628753 type Movable Block 1228 type Movable Flags 0x1fffff80040030(dirty|lru|swapbacked) [<ffffffff811682c4>] __alloc_pages_nodemask+0x134/0x230 [<ffffffff811b6325>] alloc_pages_vma+0xb5/0x250 [<ffffffff81177491>] shmem_alloc_page+0x61/0x90 [<ffffffff8117a438>] shmem_getpage_gfp+0x678/0x960 [<ffffffff8117c2b9>] shmem_fallocate+0x329/0x440 [<ffffffff811de600>] vfs_fallocate+0x140/0x230 [<ffffffff811df434>] SyS_fallocate+0x44/0x70 [<ffffffff8158cc2e>] entry_SYSCALL_64_fastpath+0x12/0x71 Page has been migrated, last migrate reason: compaction Signed-off-by: Vlastimil Babka <vbabka@suse.cz> 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> Cc: Michal Hocko <mhocko@suse.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>
2016-03-15mm, page_owner: copy page owner info during migrationVlastimil Babka3-1/+37
The page_owner mechanism stores gfp_flags of an allocation and stack trace that lead to it. During page migration, the original information is practically replaced by the allocation of free page as the migration target. Arguably this is less useful and might lead to all the page_owner info for migratable pages gradually converge towards compaction or numa balancing migrations. It has also lead to inaccuracies such as one fixed by commit e2cfc91120fa ("mm/page_owner: set correct gfp_mask on page_owner"). This patch thus introduces copying the page_owner info during migration. However, since the fact that the page has been migrated from its original place might be useful for debugging, the next patch will introduce a way to track that information as well. Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Michal Hocko <mhocko@suse.com> 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> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15mm, page_owner: convert page_owner_inited to static keyVlastimil Babka4-21/+21
CONFIG_PAGE_OWNER attempts to impose negligible runtime overhead when enabled during compilation, but not actually enabled during runtime by boot param page_owner=on. This overhead can be further reduced using the static key mechanism, which this patch does. Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Michal Hocko <mhocko@suse.com> 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>
2016-03-15mm, page_owner: print migratetype of page and pageblock, symbolic flagsVlastimil Babka4-30/+23
The information in /sys/kernel/debug/page_owner includes the migratetype of the pageblock the page belongs to. This is also checked against the page's migratetype (as declared by gfp_flags during its allocation), and the page is reported as Fallback if its migratetype differs from the pageblock's one. t This is somewhat misleading because in fact fallback allocation is not the only reason why these two can differ. It also doesn't direcly provide the page's migratetype, although it's possible to derive that from the gfp_flags. It's arguably better to print both page and pageblock's migratetype and leave the interpretation to the consumer than to suggest fallback allocation as the only possible reason. While at it, we can print the migratetypes as string the same way as /proc/pagetypeinfo does, as some of the numeric values depend on kernel configuration. For that, this patch moves the migratetype_names array from #ifdef CONFIG_PROC_FS part of mm/vmstat.c to mm/page_alloc.c and exports it. With the new format strings for flags, we can now also provide symbolic page and gfp flags in the /sys/kernel/debug/page_owner file. This replaces the positional printing of page flags as single letters, which might have looked nicer, but was limited to a subset of flags, and required the user to remember the letters. Example page_owner entry after the patch: Page allocated via order 0, mask 0x24213ca(GFP_HIGHUSER_MOVABLE|__GFP_COLD|__GFP_NOWARN|__GFP_NORETRY) PFN 520 type Movable Block 1 type Movable Flags 0xfffff8001006c(referenced|uptodate|lru|active|mappedtodisk) [<ffffffff811682c4>] __alloc_pages_nodemask+0x134/0x230 [<ffffffff811b4058>] alloc_pages_current+0x88/0x120 [<ffffffff8115e386>] __page_cache_alloc+0xe6/0x120 [<ffffffff8116ba6c>] __do_page_cache_readahead+0xdc/0x240 [<ffffffff8116bd05>] ondemand_readahead+0x135/0x260 [<ffffffff8116bfb1>] page_cache_sync_readahead+0x31/0x50 [<ffffffff81160523>] generic_file_read_iter+0x453/0x760 [<ffffffff811e0d57>] __vfs_read+0xa7/0xd0 Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Michal Hocko <mhocko@suse.com> 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>
2016-03-15mm, oom: print symbolic gfp_flags in oom warningVlastimil Babka1-3/+4
It would be useful to translate gfp_flags into string representation when printing in case of an OOM, especially as the flags have been undergoing some changes recently and the script ./scripts/gfp-translate needs a matching source version to be accurate. Example output: a.out invoked oom-killer: gfp_mask=0x24280ca(GFP_HIGHUSER_MOVABLE|GFP_ZERO), order=0, om_score_adj=0 Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: David Rientjes <rientjes@google.com> 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>
2016-03-15mm, page_alloc: print symbolic gfp_flags on allocation failureVlastimil Babka1-3/+2
It would be useful to translate gfp_flags into string representation when printing in case of an allocation failure, especially as the flags have been undergoing some changes recently and the script ./scripts/gfp-translate needs a matching source version to be accurate. Example output: stapio: page allocation failure: order:9, mode:0x2080020(GFP_ATOMIC) Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: David Rientjes <rientjes@google.com> 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>
2016-03-15mm, debug: replace dump_flags() with the new printk formatsVlastimil Babka1-46/+14
With the new printk format strings for flags, we can get rid of dump_flags() in mm/debug.c. This also fixes dump_vma() which used dump_flags() for printing vma flags. However dump_flags() did a page-flags specific filtering of bits higher than NR_PAGEFLAGS in order to remove the zone id part. For dump_vma() this resulted in removing several VM_* flags from the symbolic translation. Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: David Rientjes <rientjes@google.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>
2016-03-15mm, printk: introduce new format string for flagsVlastimil Babka5-14/+172
In mm we use several kinds of flags bitfields that are sometimes printed for debugging purposes, or exported to userspace via sysfs. To make them easier to interpret independently on kernel version and config, we want to dump also the symbolic flag names. So far this has been done with repeated calls to pr_cont(), which is unreliable on SMP, and not usable for e.g. sysfs export. To get a more reliable and universal solution, this patch extends printk() format string for pointers to handle the page flags (%pGp), gfp_flags (%pGg) and vma flags (%pGv). Existing users of dump_flag_names() are converted and simplified. It would be possible to pass flags by value instead of pointer, but the %p format string for pointers already has extensions for various kernel structures, so it's a good fit, and the extra indirection in a non-critical path is negligible. [linux@rasmusvillemoes.dk: lots of good implementation suggestions] Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Acked-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>
2016-03-15mm, tracing: unify mm flags handling in tracepoints and printkVlastimil Babka10-137/+181
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>
2016-03-15tools, perf: make gfp_compact_table up to dateVlastimil Babka2-20/+29
When updating tracing's show_gfp_flags() I have noticed that perf's gfp_compact_table is also outdated. Fill in the missing flags and place a note in gfp.h to increase chance that future updates are synced. Convert the __GFP_X flags from "GFP_X" to "__GFP_X" strings in line with the previous patch. Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: David Rientjes <rientjes@google.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> Cc: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>