- 25 Feb, 2017 40 commits
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Niklas Söderlund authored
While working on a thermal driver I encounter a scenario where the divisor could be negative, instead of adding local code to handle this I though I first try to add support for this in DIV_ROUND_CLOSEST. Add support to DIV_ROUND_CLOSEST for negative divisors if both dividend and divisor variable types are signed. This should not alter current behavior for users of the macro as previously negative divisors where not supported. Before: DIV_ROUND_CLOSEST( 59, 4) = 15 DIV_ROUND_CLOSEST( 59, -4) = -14 DIV_ROUND_CLOSEST( -59, 4) = -15 DIV_ROUND_CLOSEST( -59, -4) = 14 After: DIV_ROUND_CLOSEST( 59, 4) = 15 DIV_ROUND_CLOSEST( 59, -4) = -15 DIV_ROUND_CLOSEST( -59, 4) = -15 DIV_ROUND_CLOSEST( -59, -4) = 15 [akpm@linux-foundation.org: fix comment, per Guenter] Link: http://lkml.kernel.org/r/20161222102217.29011-1-niklas.soderlund+renesas@ragnatech.seSigned-off-by:
Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se> Reviewed-by:
Guenter Roeck <linux@roeck-us.net> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Matthew Wilcox authored
This saves 32 bytes on my x86-64 build, mostly due to alignment considerations and sharing more code between find_next_bit and find_next_zero_bit, but it does save a couple of instructions. There's really two parts to this commit: - First, the first half of the test: (!nbits || start >= nbits) is trivially a subset of the second half, since nbits and start are both unsigned - Second, while looking at the disassembly, I noticed that GCC was predicting the branch taken. Since this is a failure case, it's clearly the less likely of the two branches, so add an unlikely() to override GCC's heuristics. [mawilcox@microsoft.com: v2] Link: http://lkml.kernel.org/r/1483709016-1834-1-git-send-email-mawilcox@linuxonhyperv.com Link: http://lkml.kernel.org/r/1483709016-1834-1-git-send-email-mawilcox@linuxonhyperv.comSigned-off-by:
Matthew Wilcox <mawilcox@microsoft.com> Acked-by:
Yury Norov <ynorov@caviumnetworks.com> Acked-by:
Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by:
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Geert Uytterhoeven authored
Allow to compile the atomic64 test code either to a loadable module, or builtin into the kernel. Link: http://lkml.kernel.org/r/1483470276-10517-3-git-send-email-geert@linux-m68k.orgSigned-off-by:
Geert Uytterhoeven <geert@linux-m68k.org> Reviewed-by:
Andy Shevchenko <andy.shevchenko@gmail.com> Signed-off-by:
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Geert Uytterhoeven authored
Extract the glob test code into its own source file, to allow to compile it either to a loadable module, or builtin into the kernel. Link: http://lkml.kernel.org/r/1483470276-10517-2-git-send-email-geert@linux-m68k.orgSigned-off-by:
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Geert Uytterhoeven authored
Extract the crc32 test code into its own source file, to allow to compile it either to a loadable module, or builtin into the kernel. Link: http://lkml.kernel.org/r/1483470276-10517-1-git-send-email-geert@linux-m68k.orgSigned-off-by:
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Bhumika Goyal authored
The object notes_attr of type bin_attribute is not modified after getting initailized by ksysfs_init. Apart from initialization in ksysfs_init it is also passed as an argument to the function sysfs_create_bin_file but this argument is of type const. Therefore, add __ro_after_init to its declaration. Link: http://lkml.kernel.org/r/1486839969-16891-1-git-send-email-bhumirks@gmail.comSigned-off-by:
Bhumika Goyal <bhumirks@gmail.com> Acked-by:
Kees Cook <keescook@chromium.org> Signed-off-by:
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Viresh Kumar authored
NOTIFY_STOP_MASK (0x8000) has only one bit set and there is no need to compare output of "ret & NOTIFY_STOP_MASK" to NOTIFY_STOP_MASK. We just need to make sure the output is non-zero, that's it. Link: http://lkml.kernel.org/r/88ee58264a2bfab1c97ffc8ac753e25f55f57c10.1483593065.git.viresh.kumar@linaro.orgSigned-off-by:
Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by:
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Yisheng Xie authored
With CONFIG_BALLOON_COMPACTION=y the kernel will mount balloon_mnt for balloon page migration when we probe a virtio_balloon device. However we do not unmount it when removing the device. Fix this. Fixes: b1123ea6 ("mm: balloon: use general non-lru movable page feature") Link: http://lkml.kernel.org/r/1486531318-35189-1-git-send-email-xieyisheng1@huawei.comSigned-off-by:
Yisheng Xie <xieyisheng1@huawei.com> Acked-by:
Minchan Kim <minchan@kernel.org> Cc: Rafael Aquini <aquini@redhat.com> Cc: Konstantin Khlebnikov <koct9i@gmail.com> Cc: Gioh Kim <gi-oh.kim@profitbricks.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Michal Hocko <mhocko@kernel.org> Cc: Michael S. Tsirkin <mst@redhat.com> Cc: Jason Wang <jasowang@redhat.com> Cc: Hanjun Guo <guohanjun@huawei.com> Cc: Xishi Qiu <qiuxishi@huawei.com> Cc: <stable@vger.kernel.org> Signed-off-by:
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Kees Cook authored
The CHECK_DATA_CORRUPTION() macro was designed to have callers do something meaningful/protective on failure. However, using "return false" in the macro too strictly limits the design patterns of callers. Instead, let callers handle the logic test directly, but make sure that the result IS checked by forcing __must_check (which appears to not be able to be used directly on macro expressions). Link: http://lkml.kernel.org/r/20170206204547.GA125312@beastSigned-off-by:
Arnd Bergmann <arnd@arndb.de> Signed-off-by:
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Gideon Israel Dsouza authored
There is <linux/compiler.h> which provides macros for various gcc specific constructs. Eg: __weak for __attribute__((weak)). I've cleaned all instances of gcc specific attributes with the right macros for all files under /arch/m68k Link: http://lkml.kernel.org/r/1485540901-1988-3-git-send-email-gidisrael@gmail.comSigned-off-by:
Gideon Israel Dsouza <gidisrael@gmail.com> Cc: Greg Ungerer <gerg@linux-m68k.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by:
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Gideon Israel Dsouza authored
Add __mode(x) into compiler-gcc.h as part of a cleanup task I've taken up, to replace gcc specific attributes with macros. The next patch is a cleanup of the m68k subsystem and it requires a new macro to wrap __attribute__ ((mode (...))) Link: http://lkml.kernel.org/r/1485540901-1988-2-git-send-email-gidisrael@gmail.comSigned-off-by:
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Masahiro Yamada authored
The timer APIs this header needs are ktime_get(), ktime_add_us(), and ktime_compare(). So, including <linux/ktime.h> seems enough. This commit will cut unnecessary header file parsing. Link: http://lkml.kernel.org/r/1481679225-10885-1-git-send-email-yamada.masahiro@socionext.comSigned-off-by:
Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by:
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Mike Frysinger authored
Commit 63159f5d ("uapi: Use __kernel_long_t in struct mq_attr") changed the types from long to __kernel_long_t, but didn't add a linux/types.h include. Code that tries to include this header directly breaks: /usr/include/linux/mqueue.h:26:2: error: unknown type name '__kernel_long_t' __kernel_long_t mq_flags; /* message queue flags */ This also upsets configure tests for this header: checking linux/mqueue.h usability... no checking linux/mqueue.h presence... yes configure: WARNING: linux/mqueue.h: present but cannot be compiled configure: WARNING: linux/mqueue.h: check for missing prerequisite headers? configure: WARNING: linux/mqueue.h: see the Autoconf documentation configure: WARNING: linux/mqueue.h: section "Present But Cannot Be Compiled" configure: WARNING: linux/mqueue.h: proceeding with the compiler's result checking for linux/mqueue.h... no Link: http://lkml.kernel.org/r/20170119194644.4403-1-vapier@gentoo.orgSigned-off-by:
Mike Frysinger <vapier@gentoo.org> Signed-off-by:
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Lafcadio Wluiki authored
Previously, the hidepid parameter was checked by comparing literal integers 0, 1, 2. Let's add a proper enum for this, to make the checking more expressive: 0 → HIDEPID_OFF 1 → HIDEPID_NO_ACCESS 2 → HIDEPID_INVISIBLE This changes the internal labelling only, the userspace-facing interface remains unmodified, and still works with literal integers 0, 1, 2. No functional changes. Link: http://lkml.kernel.org/r/1484572984-13388-2-git-send-email-djalal@gmail.comSigned-off-by:Lafcadio Wluiki <wluikil@gmail.com> Signed-off-by:
Djalal Harouni <tixxdz@gmail.com> Acked-by:
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Alexey Dobriyan authored
After staring at this code for a while I've figured using small 2-entry array describing ARGV and ENVP is the way to address code duplication critique. Link: http://lkml.kernel.org/r/20170105185724.GA12027@avx2Signed-off-by:
Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by:
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Geliang Tang authored
To make the code clearer, use rb_entry() instead of container_of() to deal with rbtree. Link: http://lkml.kernel.org/r/4fd1f82818665705ce75c5156a060ae7caa8e0a9.1482160150.git.geliangtang@gmail.comSigned-off-by:
Geliang Tang <geliangtang@gmail.com> Cc: Jan Kara <jack@suse.cz> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: "David S. Miller" <davem@davemloft.net> Cc: Juergen Gross <jgross@suse.com> Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com> Cc: Seth Forshee <seth.forshee@canonical.com> Signed-off-by:
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Davidlohr Bueso authored
Given that the arch does not add its own implementations, simply use the asm-generic/current.h (generic-y) header instead of duplicating code. Link: http://lkml.kernel.org/r/1485992878-4780-2-git-send-email-dave@stgolabs.netSigned-off-by:
Davidlohr Bueso <dbueso@suse.de> Cc: Richard Henderson <rth@twiddle.net> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Matt Turner <mattst88@gmail.com> Signed-off-by:
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Sudip Mukherjee authored
The build of frv defconfig gives warning: arch/frv/mb93090-mb00/pci-frv.c:176:5: warning: ignoring return value of 'pci_assign_resource', declared with attribute warn_unused_result Just print an error message to silence the warning. We can not do much here on error. Link: http://lkml.kernel.org/r/1484256471-5379-1-git-send-email-sudipm.mukherjee@gmail.comSigned-off-by:
Sudip Mukherjee <sudip.mukherjee@codethink.co.uk> Cc: David Howells <dhowells@redhat.com> Signed-off-by:
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Greg Thelen authored
Make a kasan test which uses a SLAB_ACCOUNT slab cache. If the test is run within a non default memcg, then it uncovers the bug fixed by "kasan: drain quarantine of memcg slab objects"[1]. If run without fix [1] it shows "Slab cache still has objects", and the kmem_cache structure is leaked. Here's an unpatched kernel test: $ dmesg -c > /dev/null $ mkdir /sys/fs/cgroup/memory/test $ echo $$ > /sys/fs/cgroup/memory/test/tasks $ modprobe test_kasan 2> /dev/null $ dmesg | grep -B1 still [ 123.456789] kasan test: memcg_accounted_kmem_cache allocate memcg accounted object [ 124.456789] kmem_cache_destroy test_cache: Slab cache still has objects Kernels with fix [1] don't have the "Slab cache still has objects" warning or the underlying leak. The new test runs and passes in the default (root) memcg, though in the root memcg it won't uncover the problem fixed by [1]. Link: http://lkml.kernel.org/r/1482257462-36948-2-git-send-email-gthelen@google.comSigned-off-by:
Greg Thelen <gthelen@google.com> Reviewed-by:
Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Alexander Potapenko <glider@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by:
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Greg Thelen authored
Per memcg slab accounting and kasan have a problem with kmem_cache destruction. - kmem_cache_create() allocates a kmem_cache, which is used for allocations from processes running in root (top) memcg. - Processes running in non root memcg and allocating with either __GFP_ACCOUNT or from a SLAB_ACCOUNT cache use a per memcg kmem_cache. - Kasan catches use-after-free by having kfree() and kmem_cache_free() defer freeing of objects. Objects are placed in a quarantine. - kmem_cache_destroy() destroys root and non root kmem_caches. It takes care to drain the quarantine of objects from the root memcg's kmem_cache, but ignores objects associated with non root memcg. This causes leaks because quarantined per memcg objects refer to per memcg kmem cache being destroyed. To see the problem: 1) create a slab cache with kmem_cache_create(,,,SLAB_ACCOUNT,) 2) from non root memcg, allocate and free a few objects from cache 3) dispose of the cache with kmem_cache_destroy() kmem_cache_destroy() will trigger a "Slab cache still has objects" warning indicating that the per memcg kmem_cache structure was leaked. Fix the leak by draining kasan quarantined objects allocated from non root memcg. Racing memcg deletion is tricky, but handled. kmem_cache_destroy() => shutdown_memcg_caches() => __shutdown_memcg_cache() => shutdown_cache() flushes per memcg quarantined objects, even if that memcg has been rmdir'd and gone through memcg_deactivate_kmem_caches(). This leak only affects destroyed SLAB_ACCOUNT kmem caches when kasan is enabled. So I don't think it's worth patching stable kernels. Link: http://lkml.kernel.org/r/1482257462-36948-1-git-send-email-gthelen@google.comSigned-off-by:Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Alexander Potapenko <glider@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by:
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Nathan Fontenot authored
Commit 31bc3858 ("add automatic onlining policy for the newly added memory") provides the capability to have added memory automatically onlined during add, but this appears to be slightly broken. The current implementation uses walk_memory_range() to call online_memory_block, which uses memory_block_change_state() to online the memory. Instead, we should be calling device_online() for the memory block in online_memory_block(). This would online the memory (the memory bus online routine memory_subsys_online() called from device_online calls memory_block_change_state()) and properly update the device struct offline flag. As a result of the current implementation, attempting to remove a memory block after adding it using auto online fails. This is because doing a remove, for instance echo offline > /sys/devices/system/memory/memoryXXX/state uses device_offline() which checks the dev->offline flag. Link: http://lkml.kernel.org/r/20170222220744.8119.19687.stgit@ltcalpine2-lp14.aus.stglabs.ibm.comSigned-off-by:
Nathan Fontenot <nfont@linux.vnet.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michael Roth <mdroth@linux.vnet.ibm.com> Signed-off-by:
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Minchan Kim authored
With rw_page, page_endio is used for completing IO on a page and it propagates write error to the address space if the IO fails. The problem is it accesses page->mapping directly which might be okay for file-backed pages but it shouldn't for anonymous page. Otherwise, it can corrupt one of field from anon_vma under us and system goes panic randomly. swap_writepage bdev_writepage ops->rw_page I encountered the BUG during developing new zram feature and it was really hard to figure it out because it made random crash, somtime mmap_sem lockdep, sometime other places where places never related to zram/zsmalloc, and not reproducible with some configuration. When I consider how that bug is subtle and people do fast-swap test with brd, it's worth to add stable mark, I think. Fixes: dd6bd0d9 ("swap: use bdev_read_page() / bdev_write_page()") Signed-off-by:Michal Hocko <mhocko@suse.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: <stable@vger.kernel.org> Signed-off-by:
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Aneesh Kumar K.V authored
We are using the wrong flag value in task_numa_falt function. This can result in us doing wrong numa fault statistics update, because we update num_pages_migrate and numa_fault_locality etc based on the flag argument passed. Fixes: bae473a4 ("mm: introduce fault_env") Link: http://lkml.kernel.org/r/1487498395-9544-1-git-send-email-aneesh.kumar@linux.vnet.ibm.comSigned-off-by:
Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Acked-by:
Hillf Danton <hillf.zj@alibaba-inc.com> Acked-by:
Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Rik van Riel <riel@surriel.com> Cc: Mel Gorman <mgorman@techsingularity.net> Signed-off-by:
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Aneesh Kumar K.V authored
Do the prot_none/FOLL_NUMA check after we are sure this is a THP pte. Archs can implement prot_none such that it can return true for regular pmd entries. Link: http://lkml.kernel.org/r/1487498326-8734-1-git-send-email-aneesh.kumar@linux.vnet.ibm.comSigned-off-by:
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Miles Chen authored
cleanup rest of dma_addr_t and phys_addr_t type casting in mm use %pad for dma_addr_t use %pa for phys_addr_t Link: http://lkml.kernel.org/r/1486618489-13912-1-git-send-email-miles.chen@mediatek.comSigned-off-by:
Miles Chen <miles.chen@mediatek.com> Signed-off-by:
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Yisheng Xie authored
The class index and fullness group are not encoded in (first)page->mapping any more, after commit 3783689a ("zsmalloc: introduce zspage structure"). Instead, they are store in struct zspage. Just delete this unneeded comment. Link: http://lkml.kernel.org/r/1486620822-36826-1-git-send-email-xieyisheng1@huawei.comSigned-off-by:
Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Reviewed-by:
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Wei Yang authored
arch_zone_lowest/highest_possible_pfn[] is set to 0 and [ZONE_MOVABLE] is skipped in the loop. No need to reset them to 0 again. This patch just removes the redundant code. Link: http://lkml.kernel.org/r/20170209141731.60208-1-richard.weiyang@gmail.comSigned-off-by:
Wei Yang <richard.weiyang@gmail.com> Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Michal Hocko <mhocko@suse.com> Signed-off-by:
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Yisheng Xie authored
We had used page->lru to link the component pages (except the first page) of a zspage, and used INIT_LIST_HEAD(&page->lru) to init it. Therefore, to get the last page's next page, which is NULL, we had to use page flag PG_Private_2 to identify it. But now, we use page->freelist to link all of the pages in zspage and init the page->freelist as NULL for last page, so no need to use PG_Private_2 anymore. This remove redundant SetPagePrivate2 in create_page_chain and ClearPagePrivate2 in reset_page(). Save a few cycles for migration of zsmalloc page :) Link: http://lkml.kernel.org/r/1487076509-49270-1-git-send-email-xieyisheng1@huawei.comSigned-off-by:
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Vinayak Menon authored
At the end of a window period, if the reclaimed pages is greater than scanned, an unsigned underflow can result in a huge pressure value and thus a critical event. Reclaimed pages is found to go higher than scanned because of the addition of reclaimed slab pages to reclaimed in shrink_node without a corresponding increment to scanned pages. Minchan Kim mentioned that this can also happen in the case of a THP page where the scanned is 1 and reclaimed could be 512. Link: http://lkml.kernel.org/r/1486641577-11685-1-git-send-email-vinmenon@codeaurora.orgSigned-off-by:
Vinayak Menon <vinmenon@codeaurora.org> Acked-by:
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Hugh Dickins authored
Remove the prototypes for shmem_mapping() and shmem_zero_setup() from linux/mm.h, since they are already provided in linux/shmem_fs.h. But shmem_fs.h must then provide the inline stub for shmem_mapping() when CONFIG_SHMEM is not set, and a few more cfiles now need to #include it. Link: http://lkml.kernel.org/r/alpine.LSU.2.11.1702081658250.1549@eggly.anvilsSigned-off-by:
Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Simek <monstr@monstr.eu> Cc: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by:
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Gavin Shan authored
When @node_reclaim_node isn't 0, the page allocator tries to reclaim pages if the amount of free memory in the zones are below the low watermark. On Power platform, none of NUMA nodes are scanned for page reclaim because no nodes match the condition in zone_allows_reclaim(). On Power platform, RECLAIM_DISTANCE is set to 10 which is the distance of Node-A to Node-A. So the preferred node even won't be scanned for page reclaim. __alloc_pages_nodemask() get_page_from_freelist() zone_allows_reclaim() Anton proposed the test code as below: # cat alloc.c : int main(int argc, char *argv[]) { void *p; unsigned long size; unsigned long start, end; start = time(NULL); size = strtoul(argv[1], NULL, 0); printf("To allocate %ldGB memory\n", size); size <<= 30; p = malloc(size); assert(p); memset(p, 0, size); end = time(NULL); printf("Used time: %ld seconds\n", end - start); sleep(3600); return 0; } The system I use for testing has two NUMA nodes. Both have 128GB memory. In below scnario, the page caches on node#0 should be reclaimed when it encounters pressure to accommodate request of allocation. # echo 2 > /proc/sys/vm/zone_reclaim_mode; \ sync; \ echo 3 > /proc/sys/vm/drop_caches; \ # taskset -c 0 cat file.32G > /dev/null; \ grep FilePages /sys/devices/system/node/node0/meminfo Node 0 FilePages: 33619712 kB # taskset -c 0 ./alloc 128 # grep FilePages /sys/devices/system/node/node0/meminfo Node 0 FilePages: 33619840 kB # grep MemFree /sys/devices/system/node/node0/meminfo Node 0 MemFree: 186816 kB With the patch applied, the pagecache on node-0 is reclaimed when its free memory is running out. It's the expected behaviour. # echo 2 > /proc/sys/vm/zone_reclaim_mode; \ sync; \ echo 3 > /proc/sys/vm/drop_caches # taskset -c 0 cat file.32G > /dev/null; \ grep FilePages /sys/devices/system/node/node0/meminfo Node 0 FilePages: 33605568 kB # taskset -c 0 ./alloc 128 # grep FilePages /sys/devices/system/node/node0/meminfo Node 0 FilePages: 1379520 kB # grep MemFree /sys/devices/system/node/node0/meminfo Node 0 MemFree: 317120 kB Fixes: 5f7a75ac ("mm: page_alloc: do not cache reclaim distances") Link: http://lkml.kernel.org/r/1486532455-29613-1-git-send-email-gwshan@linux.vnet.ibm.comSigned-off-by:Gavin Shan <gwshan@linux.vnet.ibm.com> Acked-by:
Mel Gorman <mgorman@suse.de> Acked-by:
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zhong jiang authored
When mainline introduced commit a96dfddb ("base/memory, hotplug: fix a kernel oops in show_valid_zones()"), it obtained the valid start and end pfn from the given pfn range. The valid start pfn can fix the actual issue, but it introduced another issue. The valid end pfn will may exceed the given end_pfn. Although the incorrect overflow will not result in actual problem at present, but I think it need to be fixed. [toshi.kani@hpe.com: remove assumption that end_pfn is aligned by MAX_ORDER_NR_PAGES] Fixes: a96dfddb ("base/memory, hotplug: fix a kernel oops in show_valid_zones()") Link: http://lkml.kernel.org/r/1486467299-22648-1-git-send-email-zhongjiang@huawei.comSigned-off-by:
zhong jiang <zhongjiang@huawei.com> Signed-off-by:
Toshi Kani <toshi.kani@hpe.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Mel Gorman <mgorman@techsingularity.net> Signed-off-by:
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zhouxianrong authored
The idea is that without doing more calculations we extend zero pages to same element pages for zram. zero page is special case of same element page with zero element. 1. the test is done under android 7.0 2. startup too many applications circularly 3. sample the zero pages, same pages (none-zero element) and total pages in function page_zero_filled the result is listed as below: ZERO SAME TOTAL 36214 17842 598196 ZERO/TOTAL SAME/TOTAL (ZERO+SAME)/TOTAL ZERO/SAME AVERAGE 0.060631909 0.024990816 0.085622726 2.663825038 STDEV 0.00674612 0.005887625 0.009707034 2.115881328 MAX 0.069698422 0.030046087 0.094975336 7.56043956 MIN 0.03959586 0.007332205 0.056055193 1.928985507 from the above data, the benefit is about 2.5% and up to 3% of total swapout pages. The defect of the patch is that when we recovery a page from non-zero element the operations are low efficient for partial read. This patch extends zero_page to same_page so if there is any user to have monitored zero_pages, he will be surprised if the number is increased but it's not harmful, I believe. [minchan@kernel.org: do not free same element pages in zram_meta_free] Link: http://lkml.kernel.org/r/20170207065741.GA2567@bbox Link: http://lkml.kernel.org/r/1483692145-75357-1-git-send-email-zhouxianrong@huawei.com Link: http://lkml.kernel.org/r/1486307804-27903-1-git-send-email-minchan@kernel.orgSigned-off-by:
zhouxianrong <zhouxianrong@huawei.com> Signed-off-by:
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Steven Rostedt (VMware) authored
The likely/unlikely profiler noticed that the unlikely statement in wb_domain_writeout_inc() is constantly wrong. This is due to the "not" (!) being outside the unlikely statement. It is likely that dom->period_time will be set, but unlikely that it wont be. Move the not into the unlikely statement. Link: http://lkml.kernel.org/r/20170206120035.3c2e2b91@gandalf.local.homeSigned-off-by:
Steven Rostedt (VMware) <rostedt@goodmis.org> Reviewed-by:
Jan Kara <jack@suse.cz> Signed-off-by:
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Aneesh Kumar K.V authored
With this our protnone becomes a present pte with READ/WRITE/EXEC bit cleared. By default we also set _PAGE_PRIVILEGED on such pte. This is now used to help us identify a protnone pte that as saved write bit. For such pte, we will clear the _PAGE_PRIVILEGED bit. The pte still remain non-accessible from both user and kernel. [aneesh.kumar@linux.vnet.ibm.com: v3] Link: http://lkml.kernel.org/r/1487498625-10891-4-git-send-email-aneesh.kumar@linux.vnet.ibm.com Link: http://lkml.kernel.org/r/1487050314-3892-3-git-send-email-aneesh.kumar@linux.vnet.ibm.comSigned-off-by:
Michael Neuling <mikey@neuling.org> Cc: Rik van Riel <riel@surriel.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Paul Mackerras <paulus@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Michael Ellerman <michaele@au1.ibm.com> Signed-off-by:
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Aneesh Kumar K.V authored
Without this KSM will consider the page write protected, but a numa fault can later mark the page writable. This can result in memory corruption. Link: http://lkml.kernel.org/r/1487498625-10891-3-git-send-email-aneesh.kumar@linux.vnet.ibm.comSigned-off-by:
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Aneesh Kumar K.V authored
Patch series "Numabalancing preserve write fix", v2. This patch series address an issue w.r.t THP migration and autonuma preserve write feature. migrate_misplaced_transhuge_page() cannot deal with concurrent modification of the page. It does a page copy without following the migration pte sequence. IIUC, this was done to keep the migration simpler and at the time of implemenation we didn't had THP page cache which would have required a more elaborate migration scheme. That means thp autonuma migration expect the protnone with saved write to be done such that both kernel and user cannot update the page content. This patch series enables archs like ppc64 to do that. We are good with the hash translation mode with the current code, because we never create a hardware page table entry for a protnone pte. This patch (of 2): Autonuma preserves the write permission across numa fault to avoid taking a writefault after a numa fault (Commit: b191f9b1 " mm: numa: preserve PTE write permissions across a NUMA hinting fault"). Architecture can implement protnone in different ways and some may choose to implement that by clearing Read/ Write/Exec bit of pte. Setting the write bit on such pte can result in wrong behaviour. Fix this up by allowing arch to override how to save the write bit on a protnone pte. [aneesh.kumar@linux.vnet.ibm.com: don't mark pte saved write in case of dirty_accountable] Link: http://lkml.kernel.org/r/1487942884-16517-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com [aneesh.kumar@linux.vnet.ibm.com: v3] Link: http://lkml.kernel.org/r/1487498625-10891-2-git-send-email-aneesh.kumar@linux.vnet.ibm.com Link: http://lkml.kernel.org/r/1487050314-3892-2-git-send-email-aneesh.kumar@linux.vnet.ibm.comSigned-off-by:
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Aneesh Kumar K.V authored
Architectures like ppc64, use privilege access bit to mark pte non accessible. This implies that kernel can do a copy_to_user to an address marked for numa fault. This also implies that there can be a parallel hardware update for the pte. set_pte_at cannot be used in such scenarios. Hence switch the pte update to use ptep_get_and_clear and set_pte_at combination. [akpm@linux-foundation.org: remove unwanted ppc change, per Aneesh] Link: http://lkml.kernel.org/r/1486400776-28114-1-git-send-email-aneesh.kumar@linux.vnet.ibm.comSigned-off-by:
Rik van Riel <riel@redhat.com> Acked-by:
Mel Gorman <mgorman@techsingularity.net> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by:
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Steven Rostedt (VMware) authored
Running my likely/unlikely profiler, I discovered that the test in shmem_write_begin() that tests for info->seals as unlikely, is always incorrect. This is because shmem_get_inode() sets info->seals to have F_SEAL_SEAL set by default, and it is unlikely to be cleared when shmem_write_begin() is called. Thus, the if statement is very likely. But as the if statement block only cares about F_SEAL_WRITE and F_SEAL_GROW, change the test to only test those two bits. Link: http://lkml.kernel.org/r/20170203105656.7aec6237@gandalf.local.homeSigned-off-by:
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Mel Gorman authored
Hillf Danton pointed out that since commit 1d82de61 ("mm, vmscan: make kswapd reclaim in terms of nodes") that PGDAT_WRITEBACK is no longer cleared. It was not noticed as triggering it requires pages under writeback to cycle twice through the LRU and before kswapd gets stalled. Historically, such issues tended to occur on small machines writing heavily to slow storage such as a USB stick. Once kswapd stalls, direct reclaim stalls may be higher but due to the fact that memory pressure is required, it would not be very noticable. Michal Hocko suggested removing the flag entirely but the conservative fix is to restore the intended PGDAT_WRITEBACK behaviour and clear the flag when a suitable zone is balanced. Fixes: 1d82de61 ("mm, vmscan: make kswapd reclaim in terms of nodes") Link: http://lkml.kernel.org/r/20170203203222.gq7hk66yc36lpgtb@suse.deSigned-off-by:
Johannes Weiner <hannes@cmpxchg.org> Acked-by:
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