- 20 May, 2016 40 commits
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Hugh Dickins authored
Make a few cleanups in mm/shmem.c, before going on to complicate it. shmem_alloc_page() will become more complicated: we can't afford to to have that complication duplicated between a CONFIG_NUMA version and a !CONFIG_NUMA version, so rearrange the #ifdef'ery there to yield a single shmem_swapin() and a single shmem_alloc_page(). Yes, it's a shame to inflict the horrid pseudo-vma on non-NUMA configurations, but eliminating it is a larger cleanup: I have an alloc_pages_mpol() patchset not yet ready - mpol handling is subtle and bug-prone, and changed yet again since my last version. Move __SetPageLocked, __SetPageSwapBacked from shmem_getpage_gfp() to shmem_alloc_page(): that SwapBacked flag will be useful in future, to help to distinguish different cases appropriately. And the SGP_DIRTY variant of SGP_CACHE is hard to understand and of little use (IIRC it dates back to when shmem_getpage() returned the page unlocked): kill it and do the necessary in shmem_file_read_iter(). But an arm64 build then complained that info may be uninitialized (where shmem_getpage_gfp() deletes a freshly alloced page beyond eof), and advancing to an "sgp <= SGP_CACHE" test jogged it back to reality. Signed-off-by:
Hugh Dickins <hughd@google.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Andres Lagar-Cavilla <andreslc@google.com> Cc: Yang Shi <yang.shi@linaro.org> Cc: Ning Qu <quning@gmail.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Konstantin Khlebnikov <koct9i@gmail.com> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Hugh Dickins authored
v3.16 commit 07a42788 ("mm: shmem: avoid atomic operation during shmem_getpage_gfp") rightly replaced one instance of SetPageSwapBacked by __SetPageSwapBacked, pointing out that the newly allocated page is not yet visible to other users (except speculative get_page_unless_zero- ers, who may not update page flags before their further checks). That was part of a series in which Mel was focused on tmpfs profiles: but almost all SetPageSwapBacked uses can be so optimized, with the same justification. Remove ClearPageSwapBacked from __read_swap_cache_async() error path: it's not an error to free a page with PG_swapbacked set. Follow a convention of __SetPageLocked, __SetPageSwapBacked instead of doing it differently in different places; but that's for tidiness - if the ordering actually mattered, we should not be using the __variants. There's probably scope for further __SetPageFlags in other places, but SwapBacked is the one I'm interested in at the moment. Signed-off-by:
Mel Gorman <mgorman@techsingularity.net> Cc: Konstantin Khlebnikov <koct9i@gmail.com> Signed-off-by:
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Hugh Dickins authored
Konstantin Khlebnikov pointed out (nearly four years ago, when lumpy reclaim was removed) that lru_size can be updated by -nr_taken once per call to isolate_lru_pages(), instead of page by page. Update it inside isolate_lru_pages(), or at its two callsites? I chose to update it at the callsites, rearranging and grouping the updates by nr_taken and nr_scanned together in both. With one exception, mem_cgroup_update_lru_size(,lru,) is then used where __mod_zone_page_state(,NR_LRU_BASE+lru,) is used; and we shall be adding some more calls in a future commit. Make the code a little smaller and simpler by incorporating stat update in lru_size update. The exception was move_active_pages_to_lru(), which aggregated the pgmoved stat update separately from the individual lru_size updates; but I still think this a simplification worth making. However, the __mod_zone_page_state is not peculiar to mem_cgroups: so better use the name update_lru_size, calls mem_cgroup_update_lru_size when CONFIG_MEMCG. Signed-off-by:
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Hugh Dickins authored
Though debug kernels have a VM_BUG_ON to help protect from misaccounting lru_size, non-debug kernels are liable to wrap it around: and then the vast unsigned long size draws page reclaim into a loop of repeatedly doing nothing on an empty list, without even a cond_resched(). That soft lockup looks confusingly like an over-busy reclaim scenario, with lots of contention on the lru_lock in shrink_inactive_list(): yet has a totally different origin. Help differentiate with a custom warning in mem_cgroup_update_lru_size(), even in non-debug kernels; and reset the size to avoid the lockup. But the particular bug which suggested this change was mine alone, and since fixed. Make it a WARN_ONCE: the first occurrence is the most informative, a flurry may follow, yet even when rate-limited little more is learnt. Signed-off-by:
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Konstantin Khlebnikov authored
Nobody uses it. Signed-off-by:
Konstantin Khlebnikov <koct9i@gmail.com> Signed-off-by:
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Joonsoo Kim authored
node_page_state() manually adds statistics per each zone and returns total value for all zones. Whenever we add a new zone, we need to consider this function and it's really troublesome. Make it handle all zones by itself. Signed-off-by:
Joonsoo Kim <iamjoonsoo.kim@lge.com> Reviewed-by:
Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Cc: Rik van Riel <riel@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Laura Abbott <lauraa@codeaurora.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Cc: Michal Nazarewicz <mina86@mina86.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by:
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Joonsoo Kim authored
nr_free_highpages() manually adds statistics per each highmem zone and returns a total value for them. Whenever we add a new highmem zone, we need to consider this function and it's really troublesome. Make it handle all highmem zones by itself. Signed-off-by:
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Joonsoo Kim authored
ZONE_MOVABLE could be treated as highmem so we need to consider it for accurate statistics. And, in following patches, ZONE_CMA will be introduced and it can be treated as highmem, too. So, instead of manually adding stat of ZONE_MOVABLE, looping all zones and check whether the zone is highmem or not and add stat of the zone which can be treated as highmem. Signed-off-by:
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Joonsoo Kim authored
ZONE_MOVABLE could be treated as highmem so we need to consider it for accurate calculation of dirty pages. And, in following patches, ZONE_CMA will be introduced and it can be treated as highmem, too. So, instead of manually adding stat of ZONE_MOVABLE, looping all zones and check whether the zone is highmem or not and add stat of the zone which can be treated as highmem. Signed-off-by:
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Joonsoo Kim authored
There is a system thats node's pfns are overlapped as follows: -----pfn--------> N0 N1 N2 N0 N1 N2 Therefore, we need to care this overlapping when iterating pfn range. mark_free_pages() iterates requested zone's pfn range and unset all range's bitmap first. And then it marks freepages in a zone to the bitmap. If there is an overlapping zone, above unset could clear previous marked bit and reference to this bitmap in the future will cause the problem. To prevent it, this patch adds a zone check in mark_free_pages(). Signed-off-by:
Vlastimil Babka <vbabka@suse.cz> Cc: Rik van Riel <riel@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Laura Abbott <lauraa@codeaurora.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Cc: Michal Nazarewicz <mina86@mina86.com> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by:
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Joonsoo Kim authored
There is a system thats node's pfns are overlapped as follows: -----pfn--------> N0 N1 N2 N0 N1 N2 Therefore, we need to care this overlapping when iterating pfn range. There are one place in page_owner.c that iterates pfn range and it doesn't consider this overlapping. Add it. Without this patch, above system could over count early allocated page number before page_owner is activated. Signed-off-by:
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Joonsoo Kim authored
There is a system thats node's pfns are overlapped as follows: -----pfn--------> N0 N1 N2 N0 N1 N2 Therefore, we need to care this overlapping when iterating pfn range. There are two places in vmstat.c that iterates pfn range and they don't consider this overlapping. Add it. Without this patch, above system could over count pageblock number on a zone. Signed-off-by:
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Joonsoo Kim authored
__offline_isolated_pages() and test_pages_isolated() are used by memory hotplug. These functions require that range is in a single zone but there is no code to do this because memory hotplug checks it before calling these functions. To avoid confusing future user of these functions, this patch adds comments to them. Signed-off-by:
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Joonsoo Kim authored
This patchset deals with some problematic sites that iterate pfn ranges. There is a system thats node's pfns are overlapped as follows: -----pfn--------> N0 N1 N2 N0 N1 N2 Therefore, we need to take care of this overlapping when iterating pfn range. I audit many iterating sites that uses pfn_valid(), pfn_valid_within(), zone_start_pfn and etc. and others looks safe to me. This is a preparation step for a new CMA implementation, ZONE_CMA (https://lkml.org/lkml/2015/2/12/95), because it would be easily overlapped with other zones. But, zone overlap check is also needed for the general case so I send it separately. This patch (of 5): alloc_gigantic_page() uses alloc_contig_range() and this requires that the requested range is in a single zone. To satisfy this requirement, add this check to pfn_range_valid_gigantic(). Signed-off-by:
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Andrew Morton authored
It's huge. Uninlining it saves 206 bytes per callsite. Shaves 4924 bytes from the x86_64 allmodconfig vmlinux. [akpm@linux-foundation.org: coding-style fixes] Cc: Steve Capper <steve.capper@arm.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by:
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Chanho Min authored
is_highmem() can be simplified by use of is_highmem_idx(). This patch removes redundant code and will make it easier to maintain if the zone policy is changed or a new zone is added. (akpm: saves me 25 bytes of text per is_highmem() callsite) Signed-off-by:
Chanho Min <chanho.min@lge.com> Reviewed-by:
Dan Williams <dan.j.williams@intel.com> Cc: Michal Hocko <mhocko@kernel.org> Signed-off-by:
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Vlastimil Babka authored
The goal of direct compaction is to quickly make a high-order page available for the pending allocation. Within an aligned block of pages of desired order, a single allocated page that cannot be isolated for migration means that the block cannot fully merge to a buddy page that would satisfy the allocation request. Therefore we can reduce the allocation stall by skipping the rest of the block immediately on isolation failure. For async compaction, this also means a higher chance of succeeding until it detects contention. We however shouldn't completely sacrifice the second objective of compaction, which is to reduce overal long-term memory fragmentation. As a compromise, perform the eager skipping only in direct async compaction, while sync compaction (including kcompactd) remains thorough. Testing was done using stress-highalloc from mmtests, configured for order-4 GFP_KERNEL allocations: 4.6-rc1 4.6-rc1 before after Success 1 Min 24.00 ( 0.00%) 27.00 (-12.50%) Success 1 Mean 30.20 ( 0.00%) 31.60 ( -4.64%) Success 1 Max 37.00 ( 0.00%) 35.00 ( 5.41%) Success 2 Min 42.00 ( 0.00%) 32.00 ( 23.81%) Success 2 Mean 44.00 ( 0.00%) 44.80 ( -1.82%) Success 2 Max 48.00 ( 0.00%) 52.00 ( -8.33%) Success 3 Min 91.00 ( 0.00%) 92.00 ( -1.10%) Success 3 Mean 92.20 ( 0.00%) 92.80 ( -0.65%) Success 3 Max 94.00 ( 0.00%) 93.00 ( 1.06%) We can see that success rates are unaffected by the skipping. 4.6-rc1 4.6-rc1 before after User 2587.42 2566.53 System 482.89 471.20 Elapsed 1395.68 1382.00 Times are not so useful metric for this benchmark as main portion is the interfering kernel builds, but results do hint at reduced system times. 4.6-rc1 4.6-rc1 before after Direct pages scanned 163614 159608 Kswapd pages scanned 2070139 2078790 Kswapd pages reclaimed 2061707 2069757 Direct pages reclaimed 163354 159505 Reduced direct reclaim was unintended, but could be explained by more successful first attempt at (async) direct compaction, which is attempted before the first reclaim attempt in __alloc_pages_slowpath(). Compaction stalls 33052 39853 Compaction success 12121 19773 Compaction failures 20931 20079 Compaction is indeed more successful, and thus less likely to get deferred, so there are also more direct compaction stalls. Page migrate success 3781876 3326819 Page migrate failure 45817 41774 Compaction pages isolated 7868232 6941457 Compaction migrate scanned 168160492 127269354 Compaction migrate prescanned 0 0 Compaction free scanned 2522142582 2326342620 Compaction free direct alloc 0 0 Compaction free dir. all. miss 0 0 Compaction cost 5252 4476 The patch reduces migration scanned pages by 25% thanks to the eager skipping. [hughd@google.com: prevent nr_isolated_* from going negative] Signed-off-by: -
Vlastimil Babka authored
Compaction drains the local pcplists each time migration scanner moves away from a cc->order aligned block where it isolated pages for migration, so that the pages freed by migrations can merge into higher orders. The detection is currently coarser than it could be. The cc->last_migrated_pfn variable should track the lowest pfn that was isolated for migration. But it is set to the pfn where isolate_migratepages_block() starts scanning, which is typically the first pfn of the pageblock. There, the scanner might fail to isolate several order-aligned blocks, and then isolate COMPACT_CLUSTER_MAX in another block. This would cause the pcplists drain to be performed, although the scanner didn't yet finish the block where it isolated from. This patch thus makes cc->last_migrated_pfn handling more accurate by setting it to the pfn of an actually isolated page in isolate_migratepages_block(). Although practical effects of this patch are likely low, it arguably makes the intent of the code more obvious. Also the next patch will make async direct compaction skip blocks more aggressively, and draining pcplists due to skipped blocks is wasteful. Signed-off-by:
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Vlastimil Babka authored
Compaction code has accumulated numerous instances of manual calculations of the first (inclusive) and last (exclusive) pfn of a pageblock (or a smaller block of given order), given a pfn within the pageblock. Wrap these calculations by introducing pageblock_start_pfn(pfn) and pageblock_end_pfn(pfn) macros. [vbabka@suse.cz: fix crash in get_pfnblock_flags_mask() from isolate_freepages():] Signed-off-by:
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Konstantin Khlebnikov authored
This check effectively catches anon vma hierarchy inconsistence and some vma corruptions. It was effective for catching corner cases in anon vma reusing logic. For now this code seems stable so check could be hidden under CONFIG_DEBUG_VM and replaced with WARN because it's not so fatal. Signed-off-by:
Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Suggested-by:
Vasily Averin <vvs@virtuozzo.com> Acked-by:
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Andrew Morton authored
This code was pretty obscure and was relying upon obscure side-effects of next_node(-1, ...) and was relying upon NUMA_NO_NODE being equal to -1. Clean that all up and document the function's intent. Acked-by:
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Andrew Morton authored
Instead of open-coding it. Signed-off-by:
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Li Zhang authored
__free_pages_boot_core has parameter pfn which is not used at all. Remove it. Signed-off-by:
Li Zhang <zhlcindy@linux.vnet.ibm.com> Reviewed-by:
Pan Xinhui <xinhui.pan@linux.vnet.ibm.com> Signed-off-by:
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Michal Hocko authored
> The comment seems to have not much to do with the code? I guess the comment tries to say that the code path is triggered when we charge the page which happens _before_ it is added to the LRU list and so last_scanned_node might contain the stale data. Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by:
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Yaowei Bai authored
Make vma_migratable() return bool due to this particular function only using either one or zero as its return value. Signed-off-by:
Yaowei Bai <baiyaowei@cmss.chinamobile.com> Signed-off-by:
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Yaowei Bai authored
Make is_vmalloc_addr() return bool to improve readability due to this particular function only using either one or zero as its return value. Signed-off-by:
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Yaowei Bai authored
Make is_mem_section_removable() return bool to improve readability due to this particular function only using either one or zero as its return value. Signed-off-by:
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Yaowei Bai authored
Make is_vm_hugetlb_page() return bool to improve readability due to this particular function only using either one or zero as its return value. Signed-off-by:
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Vaishali Thakkar authored
Update setup_hugepagesz() to call hugetlb_bad_size() when unsupported hugepage size is found. Signed-off-by:
Vaishali Thakkar <vaishali.thakkar@oracle.com> Reviewed-by:
Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Reviewed-by:
Mike Kravetz <mike.kravetz@oracle.com> Acked-by:
Michal Hocko <mhocko@suse.com> Cc: Hillf Danton <hillf.zj@alibaba-inc.com> Cc: Yaowei Bai <baiyaowei@cmss.chinamobile.com> Cc: Dominik Dingel <dingel@linux.vnet.ibm.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by:
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Vaishali Thakkar authored
Update setup_hugepagesz() to call hugetlb_bad_size() when unsupported hugepage size is found. Signed-off-by:
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Vaishali Thakkar authored
Update setup_hugepagesz() to call hugetlb_bad_size() when unsupported hugepage size is found. Signed-off-by:
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Vaishali Thakkar authored
Update setup_hugepagesz() to call hugetlb_bad_size() when unsupported hugepage size is found. Signed-off-by:
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Vaishali Thakkar authored
Update setup_hugepagesz() to call hugetlb_bad_size() when unsupported hugepage size is found. Signed-off-by:
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Vaishali Thakkar authored
When any unsupported hugepage size is specified, 'hugepagesz=' and 'hugepages=' should be ignored during command line parsing until any supported hugepage size is found. But currently incorrect number of hugepages are allocated when unsupported size is specified as it fails to ignore the 'hugepages=' command. Test case: Note that this is specific to x86 architecture. Boot the kernel with command line option 'hugepagesz=256M hugepages=X'. After boot, dmesg output shows that X number of hugepages of the size 2M is pre-allocated instead of 0. So, to handle such command line options, introduce new routine hugetlb_bad_size. The routine hugetlb_bad_size sets the global variable parsed_valid_hugepagesz. We are using parsed_valid_hugepagesz to save the state when unsupported hugepagesize is found so that we can ignore the 'hugepages=' parameters after that and then reset the variable when supported hugepage size is found. The routine hugetlb_bad_size can be called while setting 'hugepagesz=' parameter in an architecture specific code. Signed-off-by:
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Mike Kravetz authored
It was observed that minimum size accounting associated with the hugetlbfs min_size mount option may not perform optimally and as expected. As huge pages/reservations are released from the filesystem and given back to the global pools, they are reserved for subsequent filesystem use as long as the subpool reserved count is less than subpool minimum size. It does not take into account used pages within the filesystem. The filesystem size limits are not exceeded and this is technically not a bug. However, better behavior would be to wait for the number of used pages/reservations associated with the filesystem to drop below the minimum size before taking reservations to satisfy minimum size. An optimization is also made to the hugepage_subpool_get_pages() routine which is called when pages/reservations are allocated. This does not change behavior, but simply avoids the accounting if all reservations have already been taken (subpool reserved count == 0). Signed-off-by:
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Andrew Morton authored
Lots of code does node = next_node(node, XXX); if (node == MAX_NUMNODES) node = first_node(XXX); so create next_node_in() to do this and use it in various places. [mhocko@suse.com: use next_node_in() helper] Acked-by:
Michal Hocko <mhocko@kernel.org> Signed-off-by:
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Rasmus Villemoes authored
Attach the malloc attribute to a few allocation functions. This helps gcc generate better code by telling it that the return value doesn't alias any existing pointers (which is even more valuable given the pessimizations implied by -fno-strict-aliasing). A simple example of what this allows gcc to do can be seen by looking at the last part of drm_atomic_helper_plane_reset: plane->state = kzalloc(sizeof(*plane->state), GFP_KERNEL); if (plane->state) { plane->state->plane = plane; plane->state->rotation = BIT(DRM_ROTATE_0); } which compiles to e8 99 bf d6 ff callq ffffffff8116d540 <kmem_cache_alloc_trace> 48 85 c0 test %rax,%rax 48 89 83 40 02 00 00 mov %rax,0x240(%rbx) 74 11 je ffffffff814015c4 <drm_atomic_helper_plane_reset+0x64> 48 89 18 mov %rbx,(%rax) 48 8b 83 40 02 00 00 mov 0x240(%rbx),%rax [*] c7 40 40 01 00 00 00 movl $0x1,0x40(%rax) With this patch applied, the instruction at [*] is elided, since the store to plane->state->plane is known to not alter the value of plane->state. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by:Rasmus Villemoes <linux@rasmusvillemoes.dk> 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> Cc: Andi Kleen <ak@linux.intel.com> Signed-off-by:
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Rasmus Villemoes authored
gcc as far back as at least 3.04 documents the function attribute __malloc__. Add a shorthand for attaching that to a function declaration. This was also suggested by Andi Kleen way back in 2002 [1], but didn't get applied, perhaps because gcc at that time generated the exact same code with and without this attribute. This attribute tells the compiler that the return value (if non-NULL) can be assumed not to alias any other valid pointers at the time of the call. Please note that the documentation for a range of gcc versions (starting from around 4.7) contained a somewhat confusing and self-contradicting text: The malloc attribute is used to tell the compiler that a function may be treated as if any non-NULL pointer it returns cannot alias any other pointer valid when the function returns and *that the memory has undefined content*. [...] Standard functions with this property include malloc and *calloc*. (emphasis mine). The intended meaning has later been clarified [2]: This tells the compiler that a function is malloc-like, i.e., that the pointer P returned by the function cannot alias any other pointer valid when the function returns, and moreover no pointers to valid objects occur in any storage addressed by P. What this means is that we can apply the attribute to kmalloc and friends, and it is ok for the returned memory to have well-defined contents (__GFP_ZERO). But it is not ok to apply it to kmemdup(), nor to other functions which both allocate and possibly initialize the memory with existing pointers. So unless someone is doing something pretty perverted kstrdup() should also be a fine candidate. [1] http://thread.gmane.org/gmane.linux.kernel/57172 [2] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=56955Signed-off-by:
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Joonsoo Kim authored
Many developers already know that field for reference count of the struct page is _count and atomic type. They would try to handle it directly and this could break the purpose of page reference count tracepoint. To prevent direct _count modification, this patch rename it to _refcount and add warning message on the code. After that, developer who need to handle reference count will find that field should not be accessed directly. [akpm@linux-foundation.org: fix comments, per Vlastimil] [akpm@linux-foundation.org: Documentation/vm/transhuge.txt too] [sfr@canb.auug.org.au: sync ethernet driver changes] Signed-off-by:
Stephen Rothwell <sfr@canb.auug.org.au> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: "David S. Miller" <davem@davemloft.net> Cc: Sunil Goutham <sgoutham@cavium.com> Cc: Chris Metcalf <cmetcalf@mellanox.com> Cc: Manish Chopra <manish.chopra@qlogic.com> Cc: Yuval Mintz <yuval.mintz@qlogic.com> Cc: Tariq Toukan <tariqt@mellanox.com> Cc: Saeed Mahameed <saeedm@mellanox.com> Signed-off-by:
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Joonsoo Kim authored
page_reference manipulation functions are introduced to track down reference count change of the page. Use it instead of direct modification of _count. Signed-off-by:
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