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2013-09-11memblock, numa: binary search node idYinghai Lu
Current early_pfn_to_nid() on arch that support memblock go over memblock.memory one by one, so will take too many try near the end. We can use existing memblock_search to find the node id for given pfn, that could save some time on bigger system that have many entries memblock.memory array. Here are the timing differences for several machines. In each case with the patch less time was spent in __early_pfn_to_nid(). 3.11-rc5 with patch difference (%) -------- ---------- -------------- UV1: 256 nodes 9TB: 411.66 402.47 -9.19 (2.23%) UV2: 255 nodes 16TB: 1141.02 1138.12 -2.90 (0.25%) UV2: 64 nodes 2TB: 128.15 126.53 -1.62 (1.26%) UV2: 32 nodes 2TB: 121.87 121.07 -0.80 (0.66%) Time in seconds. Signed-off-by: Yinghai Lu <yinghai@kernel.org> Cc: Tejun Heo <tj@kernel.org> Acked-by: Russ Anderson <rja@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11mbind: add BUG_ON(!vma) in new_vma_page()Naoya Horiguchi
new_vma_page() is called only by page migration called from do_mbind(), where pages to be migrated are queued into a pagelist by queue_pages_range(). queue_pages_range() confirms that a queued page belongs to some vma, so !vma case is not supposed to be happen. This patch adds BUG_ON() to catch this unexpected case. Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11mm/mempolicy: rename check_*range to queue_pages_*rangeNaoya Horiguchi
The function check_range() (and its family) is not well-named, because it does not only checking something, but moving pages from list to list to do page migration for them. So queue_pages_*range is more desirable name. Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Wanpeng Li <liwanp@linux.vnet.ibm.com> Cc: Hillf Danton <dhillf@gmail.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Hugh Dickins <hughd@google.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: Rik van Riel <riel@redhat.com> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11mm: prepare to remove /proc/sys/vm/hugepages_treat_as_movableNaoya Horiguchi
Now hugepage migration is enabled, although restricted on pmd-based hugepages for now (due to lack of testing.) So we should allocate migratable hugepages from ZONE_MOVABLE if possible. This patch makes GFP flags in hugepage allocation dependent on migration support, not only the value of hugepages_treat_as_movable. It provides no change on the behavior for architectures which do not support hugepage migration, Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Acked-by: Andi Kleen <ak@linux.intel.com> Reviewed-by: Wanpeng Li <liwanp@linux.vnet.ibm.com> Cc: Hillf Danton <dhillf@gmail.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Hugh Dickins <hughd@google.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: Rik van Riel <riel@redhat.com> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11mm: migrate: check movability of hugepage in unmap_and_move_huge_page()Naoya Horiguchi
Currently hugepage migration works well only for pmd-based hugepages (mainly due to lack of testing,) so we had better not enable migration of other levels of hugepages until we are ready for it. Some users of hugepage migration (mbind, move_pages, and migrate_pages) do page table walk and check pud/pmd_huge() there, so they are safe. But the other users (softoffline and memory hotremove) don't do this, so without this patch they can try to migrate unexpected types of hugepages. To prevent this, we introduce hugepage_migration_support() as an architecture dependent check of whether hugepage are implemented on a pmd basis or not. And on some architecture multiple sizes of hugepages are available, so hugepage_migration_support() also checks hugepage size. Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Hillf Danton <dhillf@gmail.com> Cc: Wanpeng Li <liwanp@linux.vnet.ibm.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Hugh Dickins <hughd@google.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: Rik van Riel <riel@redhat.com> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11mm: memory-hotplug: enable memory hotplug to handle hugepageNaoya Horiguchi
Until now we can't offline memory blocks which contain hugepages because a hugepage is considered as an unmovable page. But now with this patch series, a hugepage has become movable, so by using hugepage migration we can offline such memory blocks. What's different from other users of hugepage migration is that we need to decompose all the hugepages inside the target memory block into free buddy pages after hugepage migration, because otherwise free hugepages remaining in the memory block intervene the memory offlining. For this reason we introduce new functions dissolve_free_huge_page() and dissolve_free_huge_pages(). Other than that, what this patch does is straightforwardly to add hugepage migration code, that is, adding hugepage code to the functions which scan over pfn and collect hugepages to be migrated, and adding a hugepage allocation function to alloc_migrate_target(). As for larger hugepages (1GB for x86_64), it's not easy to do hotremove over them because it's larger than memory block. So we now simply leave it to fail as it is. [yongjun_wei@trendmicro.com.cn: remove duplicated include] Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Acked-by: Andi Kleen <ak@linux.intel.com> Cc: Hillf Danton <dhillf@gmail.com> Cc: Wanpeng Li <liwanp@linux.vnet.ibm.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Hugh Dickins <hughd@google.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: Rik van Riel <riel@redhat.com> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11mm: migrate: remove VM_HUGETLB from vma flag check in vma_migratable()Naoya Horiguchi
Enable hugepage migration from migrate_pages(2), move_pages(2), and mbind(2). Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Acked-by: Hillf Danton <dhillf@gmail.com> Acked-by: Andi Kleen <ak@linux.intel.com> Reviewed-by: Wanpeng Li <liwanp@linux.vnet.ibm.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Hugh Dickins <hughd@google.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: Rik van Riel <riel@redhat.com> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11mm: mbind: add hugepage migration code to mbind()Naoya Horiguchi
Extend do_mbind() to handle vma with VM_HUGETLB set. We will be able to migrate hugepage with mbind(2) after applying the enablement patch which comes later in this series. Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Acked-by: Andi Kleen <ak@linux.intel.com> Reviewed-by: Wanpeng Li <liwanp@linux.vnet.ibm.com> Acked-by: Hillf Danton <dhillf@gmail.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Hugh Dickins <hughd@google.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: Rik van Riel <riel@redhat.com> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11mm: migrate: add hugepage migration code to move_pages()Naoya Horiguchi
Extend move_pages() to handle vma with VM_HUGETLB set. We will be able to migrate hugepage with move_pages(2) after applying the enablement patch which comes later in this series. We avoid getting refcount on tail pages of hugepage, because unlike thp, hugepage is not split and we need not care about races with splitting. And migration of larger (1GB for x86_64) hugepage are not enabled. Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Acked-by: Andi Kleen <ak@linux.intel.com> Reviewed-by: Wanpeng Li <liwanp@linux.vnet.ibm.com> Cc: Hillf Danton <dhillf@gmail.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Hugh Dickins <hughd@google.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: Rik van Riel <riel@redhat.com> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11migrate: add hugepage migration code to migrate_pages()Naoya Horiguchi
Extend check_range() to handle vma with VM_HUGETLB set. We will be able to migrate hugepage with migrate_pages(2) after applying the enablement patch which comes later in this series. Note that for larger hugepages (covered by pud entries, 1GB for x86_64 for example), we simply skip it now. Note that using pmd_huge/pud_huge assumes that hugepages are pointed to by pmd/pud. This is not true in some architectures implementing hugepage with other mechanisms like ia64, but it's OK because pmd_huge/pud_huge simply return 0 in such arch and page walker simply ignores such hugepages. Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Acked-by: Andi Kleen <ak@linux.intel.com> Reviewed-by: Wanpeng Li <liwanp@linux.vnet.ibm.com> Acked-by: Hillf Danton <dhillf@gmail.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Hugh Dickins <hughd@google.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: Rik van Riel <riel@redhat.com> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11mm: soft-offline: use migrate_pages() instead of migrate_huge_page()Naoya Horiguchi
Currently migrate_huge_page() takes a pointer to a hugepage to be migrated as an argument, instead of taking a pointer to the list of hugepages to be migrated. This behavior was introduced in commit 189ebff28 ("hugetlb: simplify migrate_huge_page()"), and was OK because until now hugepage migration is enabled only for soft-offlining which migrates only one hugepage in a single call. But the situation will change in the later patches in this series which enable other users of page migration to support hugepage migration. They can kick migration for both of normal pages and hugepages in a single call, so we need to go back to original implementation which uses linked lists to collect the hugepages to be migrated. With this patch, soft_offline_huge_page() switches to use migrate_pages(), and migrate_huge_page() is not used any more. So let's remove it. Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Acked-by: Andi Kleen <ak@linux.intel.com> Reviewed-by: Wanpeng Li <liwanp@linux.vnet.ibm.com> Acked-by: Hillf Danton <dhillf@gmail.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Hugh Dickins <hughd@google.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: Rik van Riel <riel@redhat.com> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11mm: migrate: make core migration code aware of hugepageNaoya Horiguchi
Currently hugepage migration is available only for soft offlining, but it's also useful for some other users of page migration (clearly because users of hugepage can enjoy the benefit of mempolicy and memory hotplug.) So this patchset tries to extend such users to support hugepage migration. The target of this patchset is to enable hugepage migration for NUMA related system calls (migrate_pages(2), move_pages(2), and mbind(2)), and memory hotplug. This patchset does not add hugepage migration for memory compaction, because users of memory compaction mainly expect to construct thp by arranging raw pages, and there's little or no need to compact hugepages. CMA, another user of page migration, can have benefit from hugepage migration, but is not enabled to support it for now (just because of lack of testing and expertise in CMA.) Hugepage migration of non pmd-based hugepage (for example 1GB hugepage in x86_64, or hugepages in architectures like ia64) is not enabled for now (again, because of lack of testing.) As for how these are achived, I extended the API (migrate_pages()) to handle hugepage (with patch 1 and 2) and adjusted code of each caller to check and collect movable hugepages (with patch 3-7). Remaining 2 patches are kind of miscellaneous ones to avoid unexpected behavior. Patch 8 is about making sure that we only migrate pmd-based hugepages. And patch 9 is about choosing appropriate zone for hugepage allocation. My test is mainly functional one, simply kicking hugepage migration via each entry point and confirm that migration is done correctly. Test code is available here: git://github.com/Naoya-Horiguchi/test_hugepage_migration_extension.git And I always run libhugetlbfs test when changing hugetlbfs's code. With this patchset, no regression was found in the test. This patch (of 9): Before enabling each user of page migration to support hugepage, this patch enables the list of pages for migration to link not only LRU pages, but also hugepages. As a result, putback_movable_pages() and migrate_pages() can handle both of LRU pages and hugepages. Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Acked-by: Andi Kleen <ak@linux.intel.com> Reviewed-by: Wanpeng Li <liwanp@linux.vnet.ibm.com> Acked-by: Hillf Danton <dhillf@gmail.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Hugh Dickins <hughd@google.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: Rik van Riel <riel@redhat.com> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11mm, hugetlb: return a reserved page to a reserved pool if failedJoonsoo Kim
If we fail with a reserved page, just calling put_page() is not sufficient, because put_page() invoke free_huge_page() at last step and it doesn't know whether a page comes from a reserved pool or not. So it doesn't do anything related to reserved count. This makes reserve count lower than how we need, because reserve count already decrease in dequeue_huge_page_vma(). This patch fix this situation. Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Davidlohr Bueso <davidlohr@hp.com> Cc: David Gibson <david@gibson.dropbear.id.au> Cc: Wanpeng Li <liwanp@linux.vnet.ibm.com> Cc: Hillf Danton <dhillf@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11mm, hugetlb: grab a page_table_lock after page_cache_releaseJoonsoo Kim
We don't need to grab a page_table_lock when we try to release a page. So, defer to grab a page_table_lock. Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com> Reviewed-by: Davidlohr Bueso <davidlohr@hp.com> Cc: David Gibson <david@gibson.dropbear.id.au> Cc: Wanpeng Li <liwanp@linux.vnet.ibm.com> Cc: Hillf Danton <dhillf@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11mm, hugetlb: remove useless check about mapping typeJoonsoo Kim
is_vma_resv_set(vma, HPAGE_RESV_OWNER) implys that this mapping is for private. So we don't need to check whether this mapping is for shared or not. This patch is just for clean-up. Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Reviewed-by: Davidlohr Bueso <davidlohr@hp.com> Cc: David Gibson <david@gibson.dropbear.id.au> Cc: Wanpeng Li <liwanp@linux.vnet.ibm.com> Cc: Hillf Danton <dhillf@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11mm, hugetlb: fix subpool accounting handlingJoonsoo Kim
If we alloc hugepage with avoid_reserve, we don't dequeue reserved one. So, we should check subpool counter when avoid_reserve. This patch implement it. Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Davidlohr Bueso <davidlohr@hp.com> Cc: David Gibson <david@gibson.dropbear.id.au> Cc: Wanpeng Li <liwanp@linux.vnet.ibm.com> Cc: Hillf Danton <dhillf@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11mm, hugetlb: change variable name reservations to resvJoonsoo Kim
'reservations' is so long name as a variable and we use 'resv_map' to represent 'struct resv_map' in other place. To reduce confusion and unreadability, change it. Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Reviewed-by: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Reviewed-by: Davidlohr Bueso <davidlohr@hp.com> Cc: David Gibson <david@gibson.dropbear.id.au> Cc: Wanpeng Li <liwanp@linux.vnet.ibm.com> Cc: Hillf Danton <dhillf@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11mm, hugetlb: protect reserved pages when soft offlining a hugepageJoonsoo Kim
Don't use the reserve pool when soft offlining a hugepage. Check we have free pages outside the reserve pool before we dequeue the huge page. Otherwise, we can steal other's reserve page. Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Reviewed-by: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Reviewed-by: Davidlohr Bueso <davidlohr@hp.com> Cc: David Gibson <david@gibson.dropbear.id.au> Cc: Wanpeng Li <liwanp@linux.vnet.ibm.com> Cc: Hillf Danton <dhillf@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11mm/hotplug: remove stop_machine() from try_offline_node()Toshi Kani
lock_device_hotplug() serializes hotplug & online/offline operations. The lock is held in common sysfs online/offline interfaces and ACPI hotplug code paths. And here are the code paths: - CPU & Mem online/offline via sysfs online store_online()->lock_device_hotplug() - Mem online via sysfs state: store_mem_state()->lock_device_hotplug() - ACPI CPU & Mem hot-add: acpi_scan_bus_device_check()->lock_device_hotplug() - ACPI CPU & Mem hot-delete: acpi_scan_hot_remove()->lock_device_hotplug() try_offline_node() off-lines a node if all memory sections and cpus are removed on the node. It is called from acpi_processor_remove() and acpi_memory_remove_memory()->remove_memory() paths, both of which are in the ACPI hotplug code. try_offline_node() calls stop_machine() to stop all cpus while checking all cpu status with the assumption that the caller is not protected from CPU hotplug or CPU online/offline operations. However, the caller is always serialized with lock_device_hotplug(). Also, the code needs to be properly serialized with a lock, not by stopping all cpus at a random place with stop_machine(). This patch removes the use of stop_machine() in try_offline_node() and adds comments to try_offline_node() and remove_memory() that lock_device_hotplug() is required. Signed-off-by: Toshi Kani <toshi.kani@hp.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Tang Chen <tangchen@cn.fujitsu.com> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Cc: Wanpeng Li <liwanp@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11mm/hotplug: verify hotplug memory rangeToshi Kani
add_memory() and remove_memory() can only handle a memory range aligned with section. There are problems when an unaligned range is added and then deleted as follows: - add_memory() with an unaligned range succeeds, but __add_pages() called from add_memory() adds a whole section of pages even though a given memory range is less than the section size. - remove_memory() to the added unaligned range hits BUG_ON() in __remove_pages(). This patch changes add_memory() and remove_memory() to check if a given memory range is aligned with section at the beginning. As the result, add_memory() fails with -EINVAL when a given range is unaligned, and does not add such memory range. This prevents remove_memory() to be called with an unaligned range as well. Note that remove_memory() has to use BUG_ON() since this function cannot fail. [akpm@linux-foundation.org: avoid printk warnings] Signed-off-by: Toshi Kani <toshi.kani@hp.com> Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Reviewed-by: Tang Chen <tangchen@cn.fujitsu.com> Reviewed-by: Wanpeng Li <liwanp@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11hugepage: mention libhugetlbfs in docDavidlohr Bueso
Explicitly mention/recommend using the libhugetlbfs test cases when changing related kernel code. Developers that are unaware of the project can easily miss this and introduce potential regressions that may or may not be caught by community review. Also do some cleanups that make the document visually easier to view at a first glance. Signed-off-by: Davidlohr Bueso <davidlohr@hp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11readahead: make context readahead more conservativeFengguang Wu
This helps performance on moderately dense random reads on SSD. Transaction-Per-Second numbers provided by Taobao: QPS case ------------------------------------------------------- 7536 disable context readahead totally w/ patch: 7129 slower size rampup and start RA on the 3rd read 6717 slower size rampup w/o patch: 5581 unmodified context readahead Before, readahead will be started whenever reading page N+1 when it happen to read N recently. After patch, we'll only start readahead when *three* random reads happen to access pages N, N+1, N+2. The probability of this happening is extremely low for pure random reads, unless they are very dense, which actually deserves some readahead. Also start with a smaller readahead window. The impact to interleaved sequential reads should be small, because for a long run stream, the the small readahead window rampup phase is negletable. The context readahead actually benefits clustered random reads on HDD whose seek cost is pretty high. However as SSD is increasingly used for random read workloads it's better for the context readahead to concentrate on interleaved sequential reads. Another SSD rand read test from Miao # file size: 2GB # read IO amount: 625MB sysbench --test=fileio \ --max-requests=10000 \ --num-threads=1 \ --file-num=1 \ --file-block-size=64K \ --file-test-mode=rndrd \ --file-fsync-freq=0 \ --file-fsync-end=off run shows the performance of btrfs grows up from 69MB/s to 121MB/s, ext4 from 104MB/s to 121MB/s. Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Tested-by: Tao Ma <tm@tao.ma> Tested-by: Miao Xie <miaox@cn.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11mm: use zone_is_initialized() instead of if(zone->wait_table)Xishi Qiu
Use "zone_is_initialized()" instead of "if (zone->wait_table)". Simplify the code, no functional change. Signed-off-by: Xishi Qiu <qiuxishi@huawei.com> Cc: Cody P Schafer <cody@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11mm: use zone_is_empty() instead of if(zone->spanned_pages)Xishi Qiu
Use "zone_is_empty()" instead of "if (zone->spanned_pages)". Simplify the code, no functional change. Signed-off-by: Xishi Qiu <qiuxishi@huawei.com> Cc: Cody P Schafer <cody@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11mm: use zone_end_pfn() instead of zone_start_pfn+spanned_pagesXishi Qiu
Use "zone_end_pfn()" instead of "zone->zone_start_pfn + zone->spanned_pages". Simplify the code, no functional change. [akpm@linux-foundation.org: fix build] Signed-off-by: Xishi Qiu <qiuxishi@huawei.com> Cc: Cody P Schafer <cody@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11lib/genalloc.c: fix overflow of ending address of memory chunkJoonyoung Shim
In struct gen_pool_chunk, end_addr means the end address of memory chunk (inclusive), but in the implementation it is treated as address + size of memory chunk (exclusive), so it points to the address plus one instead of correct ending address. The ending address of memory chunk plus one will cause overflow on the memory chunk including the last address of memory map, e.g. when starting address is 0xFFF00000 and size is 0x100000 on 32bit machine, ending address will be 0x100000000. Use correct ending address like starting address + size - 1. [akpm@linux-foundation.org: add comment to struct gen_pool_chunk:end_addr] Signed-off-by: Joonyoung Shim <jy0922.shim@samsung.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11mm/zbud: fix some trivial typos in commentsJianguo Wu
Signed-off-by: Jianguo Wu <wujianguo@huawei.com> Cc: Seth Jennings <sjenning@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11mm/hotplug: remove unnecessary BUG_ON in __offline_pages()Xishi Qiu
I think we can remove "BUG_ON(start_pfn >= end_pfn)" in __offline_pages(), because in memory_block_action() "nr_pages = PAGES_PER_SECTION * sections_per_block" is always greater than 0. memory_block_action() offline_pages() __offline_pages() BUG_ON(start_pfn >= end_pfn) In v2.6.32, If info->length==0, this way may hit this BUG_ON(). acpi_memory_disable_device() remove_memory(info->start_addr, info->length) offline_pages() A later Fujitsu patch renamed this function and the BUG_ON() is unnecessary. Signed-off-by: Xishi Qiu <qiuxishi@huawei.com> Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com> Cc: Toshi Kani <toshi.kani@hp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11mm, vmalloc: use well-defined find_last_bit() funcJoonsoo Kim
Our intention in here is to find last_bit within the region to flush. There is well-defined function, find_last_bit() for this purpose and its performance may be slightly better than current implementation. So change it. Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Reviewed-by: Wanpeng Li <liwanp@linux.vnet.ibm.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11mm, vmalloc: remove useless variable in vmap_blockJoonsoo Kim
vbq in vmap_block isn't used. So remove it. Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Reviewed-by: Wanpeng Li <liwanp@linux.vnet.ibm.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11vmstat: use this_cpu() to avoid irqon/off sequence in refresh_cpu_vm_statsChristoph Lameter
Disabling interrupts repeatedly can be avoided in the inner loop if we use a this_cpu operation. Signed-off-by: Christoph Lameter <cl@linux.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> CC: Tejun Heo <tj@kernel.org> Cc: Joonsoo Kim <js1304@gmail.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11vmstat: create fold_diffChristoph Lameter
Both functions that update global counters use the same mechanism. Create a function that contains the common code. Signed-off-by: Christoph Lameter <cl@linux.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> CC: Tejun Heo <tj@kernel.org> Cc: Joonsoo Kim <js1304@gmail.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11vmstat: create separate function to fold per cpu diffs into local countersChristoph Lameter
The main idea behind this patchset is to reduce the vmstat update overhead by avoiding interrupt enable/disable and the use of per cpu atomics. This patch (of 3): It is better to have a separate folding function because refresh_cpu_vm_stats() also does other things like expire pages in the page allocator caches. If we have a separate function then refresh_cpu_vm_stats() is only called from the local cpu which allows additional optimizations. The folding function is only called when a cpu is being downed and therefore no other processor will be accessing the counters. Also simplifies synchronization. [akpm@linux-foundation.org: fix UP build] Signed-off-by: Christoph Lameter <cl@linux.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> CC: Tejun Heo <tj@kernel.org> Cc: Joonsoo Kim <js1304@gmail.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11swap: clean-up #ifdef in page_mapping()Joonsoo Kim
PageSwapCache() is always false when !CONFIG_SWAP, so compiler properly discard related code. Therefore, we don't need #ifdef explicitly. Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Minchan Kim <minchan@kernel.org> 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>
2013-09-11mm: move pgtable related functions to right placeJoonsoo Kim
pgtable related functions are mostly in pgtable-generic.c. So move remaining functions from memory.c to pgtable-generic.c. Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Minchan Kim <minchan@kernel.org> 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>
2013-09-11mm, page_alloc: add unlikely macro to help compiler optimizationJoonsoo Kim
We rarely allocate a page with ALLOC_NO_WATERMARKS and it is used in slow path. For helping compiler optimization, add unlikely macro to ALLOC_NO_WATERMARKS checking. This patch doesn't have any effect now, because gcc already optimize this properly. But we cannot assume that gcc always does right and nobody re-evaluate if gcc do proper optimization with their change, for example, it is not optimized properly on v3.10. So adding compiler hint here is reasonable. Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Minchan Kim <minchan@kernel.org> 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>
2013-09-11mm/mempolicy: return NULL if node is NUMA_NO_NODE in get_task_policyJianguo Wu
If node == NUMA_NO_NODE, pol is NULL, we should return NULL instead of do "if (!pol->mode)" check. [akpm@linux-foundation.org: reorganise code] Signed-off-by: Jianguo Wu <wujianguo@huawei.com> Cc: Mel Gorman <mgorman@suse.de> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Rik van Riel <riel@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Hanjun Guo <guohanjun@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11mm, hugetlb: decrement reserve count if VM_NORESERVE alloc page cacheJoonsoo Kim
If a vma with VM_NORESERVE allocate a new page for page cache, we should check whether this area is reserved or not. If this address is already reserved by other process(in case of chg == 0), we should decrement reserve count, because this allocated page will go into page cache and currently, there is no way to know that this page comes from reserved pool or not when releasing inode. This may introduce over-counting problem to reserved count. With following example code, you can easily reproduce this situation. Assume 2MB, nr_hugepages = 100 size = 20 * MB; flag = MAP_SHARED; p = mmap(NULL, size, PROT_READ|PROT_WRITE, flag, fd, 0); if (p == MAP_FAILED) { fprintf(stderr, "mmap() failed: %s\n", strerror(errno)); return -1; } flag = MAP_SHARED | MAP_NORESERVE; q = mmap(NULL, size, PROT_READ|PROT_WRITE, flag, fd, 0); if (q == MAP_FAILED) { fprintf(stderr, "mmap() failed: %s\n", strerror(errno)); } q[0] = 'c'; After finish the program, run 'cat /proc/meminfo'. You can see below result. HugePages_Free: 100 HugePages_Rsvd: 1 To fix this, we should check our mapping type and tracked region. If our mapping is VM_NORESERVE, VM_MAYSHARE and chg is 0, this imply that current allocated page will go into page cache which is already reserved region when mapping is created. In this case, we should decrease reserve count. As implementing above, this patch solve the problem. [akpm@linux-foundation.org: fix spelling in comment] Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Reviewed-by: Wanpeng Li <liwanp@linux.vnet.ibm.com> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Acked-by: Hillf Danton <dhillf@gmail.com> Acked-by: Michal Hocko <mhocko@suse.cz> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Rik van Riel <riel@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Hugh Dickins <hughd@google.com> Cc: Davidlohr Bueso <davidlohr.bueso@hp.com> Cc: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11mm, hugetlb: remove decrement_hugepage_resv_vma()Joonsoo Kim
Now, Checking condition of decrement_hugepage_resv_vma() and vma_has_reserves() is same, so we can clean-up this function with vma_has_reserves(). Additionally, decrement_hugepage_resv_vma() has only one call site, so we can remove function and embed it into dequeue_huge_page_vma() directly. This patch implement it. Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Reviewed-by: Wanpeng Li <liwanp@linux.vnet.ibm.com> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Acked-by: Hillf Danton <dhillf@gmail.com> Acked-by: Michal Hocko <mhocko@suse.cz> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Rik van Riel <riel@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Hugh Dickins <hughd@google.com> Cc: Davidlohr Bueso <davidlohr.bueso@hp.com> Cc: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11mm, hugetlb: add VM_NORESERVE check in vma_has_reserves()Joonsoo Kim
If we map the region with MAP_NORESERVE and MAP_SHARED, we can skip to check reserve counting and eventually we cannot be ensured to allocate a huge page in fault time. With following example code, you can easily find this situation. Assume 2MB, nr_hugepages = 100 fd = hugetlbfs_unlinked_fd(); if (fd < 0) return 1; size = 200 * MB; flag = MAP_SHARED; p = mmap(NULL, size, PROT_READ|PROT_WRITE, flag, fd, 0); if (p == MAP_FAILED) { fprintf(stderr, "mmap() failed: %s\n", strerror(errno)); return -1; } size = 2 * MB; flag = MAP_ANONYMOUS | MAP_SHARED | MAP_HUGETLB | MAP_NORESERVE; p = mmap(NULL, size, PROT_READ|PROT_WRITE, flag, -1, 0); if (p == MAP_FAILED) { fprintf(stderr, "mmap() failed: %s\n", strerror(errno)); } p[0] = '0'; sleep(10); During executing sleep(10), run 'cat /proc/meminfo' on another process. HugePages_Free: 99 HugePages_Rsvd: 100 Number of free should be higher or equal than number of reserve, but this aren't. This represent that non reserved shared mapping steal a reserved page. Non reserved shared mapping should not eat into reserve space. If we consider VM_NORESERVE in vma_has_reserve() and return 0 which mean that we don't have reserved pages, then we check that we have enough free pages in dequeue_huge_page_vma(). This prevent to steal a reserved page. With this change, above test generate a SIGBUG which is correct, because all free pages are reserved and non reserved shared mapping can't get a free page. Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Reviewed-by: Wanpeng Li <liwanp@linux.vnet.ibm.com> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Acked-by: Hillf Danton <dhillf@gmail.com> Acked-by: Michal Hocko <mhocko@suse.cz> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Rik van Riel <riel@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Hugh Dickins <hughd@google.com> Cc: Davidlohr Bueso <davidlohr.bueso@hp.com> Cc: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11mm, hugetlb: do not use a page in page cache for cow optimizationJoonsoo Kim
Currently, we use a page with mapped count 1 in page cache for cow optimization. If we find this condition, we don't allocate a new page and copy contents. Instead, we map this page directly. This may introduce a problem that writting to private mapping overwrite hugetlb file directly. You can find this situation with following code. size = 20 * MB; flag = MAP_SHARED; p = mmap(NULL, size, PROT_READ|PROT_WRITE, flag, fd, 0); if (p == MAP_FAILED) { fprintf(stderr, "mmap() failed: %s\n", strerror(errno)); return -1; } p[0] = 's'; fprintf(stdout, "BEFORE STEAL PRIVATE WRITE: %c\n", p[0]); munmap(p, size); flag = MAP_PRIVATE; p = mmap(NULL, size, PROT_READ|PROT_WRITE, flag, fd, 0); if (p == MAP_FAILED) { fprintf(stderr, "mmap() failed: %s\n", strerror(errno)); } p[0] = 'c'; munmap(p, size); flag = MAP_SHARED; p = mmap(NULL, size, PROT_READ|PROT_WRITE, flag, fd, 0); if (p == MAP_FAILED) { fprintf(stderr, "mmap() failed: %s\n", strerror(errno)); return -1; } fprintf(stdout, "AFTER STEAL PRIVATE WRITE: %c\n", p[0]); munmap(p, size); We can see that "AFTER STEAL PRIVATE WRITE: c", not "AFTER STEAL PRIVATE WRITE: s". If we turn off this optimization to a page in page cache, the problem is disappeared. So, I change the trigger condition of optimization. If this page is not AnonPage, we don't do optimization. This makes this optimization turning off for a page cache. Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Acked-by: Michal Hocko <mhocko@suse.cz> Reviewed-by: Wanpeng Li <liwanp@linux.vnet.ibm.com> Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Acked-by: Hillf Danton <dhillf@gmail.com> Cc: Rik van Riel <riel@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Hugh Dickins <hughd@google.com> Cc: Davidlohr Bueso <davidlohr.bueso@hp.com> Cc: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11mm, hugetlb: remove redundant list_empty check in gather_surplus_pages()Joonsoo Kim
If list is empty, list_for_each_entry_safe() doesn't do anything. So, this check is redundant. Remove it. Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Acked-by: Michal Hocko <mhocko@suse.cz> Reviewed-by: Wanpeng Li <liwanp@linux.vnet.ibm.com> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Acked-by: Hillf Danton <dhillf@gmail.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Wanpeng Li <liwanp@linux.vnet.ibm.com> Cc: Rik van Riel <riel@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Hugh Dickins <hughd@google.com> Cc: Davidlohr Bueso <davidlohr.bueso@hp.com> Cc: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11mm, hugetlb: fix and clean-up node iteration code to alloc or freeJoonsoo Kim
Current node iteration code have a minor problem which do one more node rotation if we can't succeed to allocate. For example, if we start to allocate at node 0, we stop to iterate at node 0. Then we start to allocate at node 1 for next allocation. I introduce new macros "for_each_node_mask_to_[alloc|free]" and fix and clean-up node iteration code to alloc or free. This makes code more understandable. Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Acked-by: Hillf Danton <dhillf@gmail.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Wanpeng Li <liwanp@linux.vnet.ibm.com> Cc: Rik van Riel <riel@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Hugh Dickins <hughd@google.com> Cc: Davidlohr Bueso <davidlohr.bueso@hp.com> Cc: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11mm, hugetlb: clean-up alloc_huge_page()Joonsoo Kim
Unify successful allocation paths to make the code more readable. There are no functional changes. Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Acked-by: Michal Hocko <mhocko@suse.cz> Reviewed-by: Wanpeng Li <liwanp@linux.vnet.ibm.com> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Cc: Hillf Danton <dhillf@gmail.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Wanpeng Li <liwanp@linux.vnet.ibm.com> Cc: Rik van Riel <riel@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Hugh Dickins <hughd@google.com> Cc: Davidlohr Bueso <davidlohr.bueso@hp.com> Cc: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11mm, hugetlb: trivial commenting fixJoonsoo Kim
The name of the mutex written in comment is wrong. Fix it. Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Acked-by: Michal Hocko <mhocko@suse.cz> Acked-by: Hillf Danton <dhillf@gmail.com> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Wanpeng Li <liwanp@linux.vnet.ibm.com> Cc: Rik van Riel <riel@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Hugh Dickins <hughd@google.com> Cc: Davidlohr Bueso <davidlohr.bueso@hp.com> Cc: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11mm, hugetlb: move up the code which check availability of free huge pageJoonsoo Kim
In this time we are holding a hugetlb_lock, so hstate values can't be changed. If we don't have any usable free huge page in this time, we don't need to proceed with the processing. So move this code up. Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Acked-by: Michal Hocko <mhocko@suse.cz> Reviewed-by: Wanpeng Li <liwanp@linux.vnet.ibm.com> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Acked-by: Hillf Danton <dhillf@gmail.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Rik van Riel <riel@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Hugh Dickins <hughd@google.com> Cc: Davidlohr Bueso <davidlohr.bueso@hp.com> Cc: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11mm: revert "page-writeback.c: subtract min_free_kbytes from dirtyable memory"Johannes Weiner
This reverts commit 75f7ad8e043d. It was the result of a problem observed with a 3.2 kernel and merged in 3.9, while the issue had been resolved upstream in 3.3 (commit ab8fabd46f81: "mm: exclude reserved pages from dirtyable memory"). The "reserved pages" are a superset of min_free_kbytes, thus this change is redundant and confusing. Revert it. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Paul Szabo <psz@maths.usyd.edu.au> Cc: Rik van Riel <riel@redhat.com> Acked-by: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11mm: page_alloc: fair zone allocator policyJohannes Weiner
Each zone that holds userspace pages of one workload must be aged at a speed proportional to the zone size. Otherwise, the time an individual page gets to stay in memory depends on the zone it happened to be allocated in. Asymmetry in the zone aging creates rather unpredictable aging behavior and results in the wrong pages being reclaimed, activated etc. But exactly this happens right now because of the way the page allocator and kswapd interact. The page allocator uses per-node lists of all zones in the system, ordered by preference, when allocating a new page. When the first iteration does not yield any results, kswapd is woken up and the allocator retries. Due to the way kswapd reclaims zones below the high watermark while a zone can be allocated from when it is above the low watermark, the allocator may keep kswapd running while kswapd reclaim ensures that the page allocator can keep allocating from the first zone in the zonelist for extended periods of time. Meanwhile the other zones rarely see new allocations and thus get aged much slower in comparison. The result is that the occasional page placed in lower zones gets relatively more time in memory, even gets promoted to the active list after its peers have long been evicted. Meanwhile, the bulk of the working set may be thrashing on the preferred zone even though there may be significant amounts of memory available in the lower zones. Even the most basic test -- repeatedly reading a file slightly bigger than memory -- shows how broken the zone aging is. In this scenario, no single page should be able stay in memory long enough to get referenced twice and activated, but activation happens in spades: $ grep active_file /proc/zoneinfo nr_inactive_file 0 nr_active_file 0 nr_inactive_file 0 nr_active_file 8 nr_inactive_file 1582 nr_active_file 11994 $ cat data data data data >/dev/null $ grep active_file /proc/zoneinfo nr_inactive_file 0 nr_active_file 70 nr_inactive_file 258753 nr_active_file 443214 nr_inactive_file 149793 nr_active_file 12021 Fix this with a very simple round robin allocator. Each zone is allowed a batch of allocations that is proportional to the zone's size, after which it is treated as full. The batch counters are reset when all zones have been tried and the allocator enters the slowpath and kicks off kswapd reclaim. Allocation and reclaim is now fairly spread out to all available/allowable zones: $ grep active_file /proc/zoneinfo nr_inactive_file 0 nr_active_file 0 nr_inactive_file 174 nr_active_file 4865 nr_inactive_file 53 nr_active_file 860 $ cat data data data data >/dev/null $ grep active_file /proc/zoneinfo nr_inactive_file 0 nr_active_file 0 nr_inactive_file 666622 nr_active_file 4988 nr_inactive_file 190969 nr_active_file 937 When zone_reclaim_mode is enabled, allocations will now spread out to all zones on the local node, not just the first preferred zone (which on a 4G node might be a tiny Normal zone). Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Mel Gorman <mgorman@suse.de> Reviewed-by: Rik van Riel <riel@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Paul Bolle <paul.bollee@gmail.com> Cc: Zlatko Calusic <zcalusic@bitsync.net> Tested-by: Kevin Hilman <khilman@linaro.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11mm: page_alloc: rearrange watermark checking in get_page_from_freelistJohannes Weiner
Allocations that do not have to respect the watermarks are rare high-priority events. Reorder the code such that per-zone dirty limits and future checks important only to regular page allocations are ignored in these extraordinary situations. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Mel Gorman <mgorman@suse.de> Reviewed-by: Rik van Riel <riel@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Paul Bolle <paul.bollee@gmail.com> Tested-by: Zlatko Calusic <zcalusic@bitsync.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11mm: vmscan: fix numa reclaim balance problem in kswapdJohannes Weiner
The way the page allocator interacts with kswapd creates aging imbalances, where the amount of time a userspace page gets in memory under reclaim pressure is dependent on which zone, which node the allocator took the page frame from. #1 fixes missed kswapd wakeups on NUMA systems, which lead to some nodes falling behind for a full reclaim cycle relative to the other nodes in the system #3 fixes an interaction where kswapd and a continuous stream of page allocations keep the preferred zone of a task between the high and low watermark (allocations succeed + kswapd does not go to sleep) indefinitely, completely underutilizing the lower zones and thrashing on the preferred zone These patches are the aging fairness part of the thrash-detection based file LRU balancing. Andrea recommended to submit them separately as they are bugfixes in their own right. The following test ran a foreground workload (memcachetest) with background IO of various sizes on a 4 node 8G system (similar results were observed with single-node 4G systems): parallelio BAS FAIRALLO BASE FAIRALLOC Ops memcachetest-0M 5170.00 ( 0.00%) 5283.00 ( 2.19%) Ops memcachetest-791M 4740.00 ( 0.00%) 5293.00 ( 11.67%) Ops memcachetest-2639M 2551.00 ( 0.00%) 4950.00 ( 94.04%) Ops memcachetest-4487M 2606.00 ( 0.00%) 3922.00 ( 50.50%) Ops io-duration-0M 0.00 ( 0.00%) 0.00 ( 0.00%) Ops io-duration-791M 55.00 ( 0.00%) 18.00 ( 67.27%) Ops io-duration-2639M 235.00 ( 0.00%) 103.00 ( 56.17%) Ops io-duration-4487M 278.00 ( 0.00%) 173.00 ( 37.77%) Ops swaptotal-0M 0.00 ( 0.00%) 0.00 ( 0.00%) Ops swaptotal-791M 245184.00 ( 0.00%) 0.00 ( 0.00%) Ops swaptotal-2639M 468069.00 ( 0.00%) 108778.00 ( 76.76%) Ops swaptotal-4487M 452529.00 ( 0.00%) 76623.00 ( 83.07%) Ops swapin-0M 0.00 ( 0.00%) 0.00 ( 0.00%) Ops swapin-791M 108297.00 ( 0.00%) 0.00 ( 0.00%) Ops swapin-2639M 169537.00 ( 0.00%) 50031.00 ( 70.49%) Ops swapin-4487M 167435.00 ( 0.00%) 34178.00 ( 79.59%) Ops minorfaults-0M 1518666.00 ( 0.00%) 1503993.00 ( 0.97%) Ops minorfaults-791M 1676963.00 ( 0.00%) 1520115.00 ( 9.35%) Ops minorfaults-2639M 1606035.00 ( 0.00%) 1799717.00 (-12.06%) Ops minorfaults-4487M 1612118.00 ( 0.00%) 1583825.00 ( 1.76%) Ops majorfaults-0M 6.00 ( 0.00%) 0.00 ( 0.00%) Ops majorfaults-791M 13836.00 ( 0.00%) 10.00 ( 99.93%) Ops majorfaults-2639M 22307.00 ( 0.00%) 6490.00 ( 70.91%) Ops majorfaults-4487M 21631.00 ( 0.00%) 4380.00 ( 79.75%) BAS FAIRALLO BASE FAIRALLOC User 287.78 460.97 System 2151.67 3142.51 Elapsed 9737.00 8879.34 BAS FAIRALLO BASE FAIRALLOC Minor Faults 53721925 57188551 Major Faults 392195 15157 Swap Ins 2994854 112770 Swap Outs 4907092 134982 Direct pages scanned 0 41824 Kswapd pages scanned 32975063 8128269 Kswapd pages reclaimed 6323069 7093495 Direct pages reclaimed 0 41824 Kswapd efficiency 19% 87% Kswapd velocity 3386.573 915.414 Direct efficiency 100% 100% Direct velocity 0.000 4.710 Percentage direct scans 0% 0% Zone normal velocity 2011.338 550.661 Zone dma32 velocity 1365.623 369.221 Zone dma velocity 9.612 0.242 Page writes by reclaim 18732404.000 614807.000 Page writes file 13825312 479825 Page writes anon 4907092 134982 Page reclaim immediate 85490 5647 Sector Reads 12080532 483244 Sector Writes 88740508 65438876 Page rescued immediate 0 0 Slabs scanned 82560 12160 Direct inode steals 0 0 Kswapd inode steals 24401 40013 Kswapd skipped wait 0 0 THP fault alloc 6 8 THP collapse alloc 5481 5812 THP splits 75 22 THP fault fallback 0 0 THP collapse fail 0 0 Compaction stalls 0 54 Compaction success 0 45 Compaction failures 0 9 Page migrate success 881492 82278 Page migrate failure 0 0 Compaction pages isolated 0 60334 Compaction migrate scanned 0 53505 Compaction free scanned 0 1537605 Compaction cost 914 86 NUMA PTE updates 46738231 41988419 NUMA hint faults 31175564 24213387 NUMA hint local faults 10427393 6411593 NUMA pages migrated 881492 55344 AutoNUMA cost 156221 121361 The overall runtime was reduced, throughput for both the foreground workload as well as the background IO improved, major faults, swapping and reclaim activity shrunk significantly, reclaim efficiency more than quadrupled. This patch: When the page allocator fails to get a page from all zones in its given zonelist, it wakes up the per-node kswapds for all zones that are at their low watermark. However, with a system under load the free pages in a zone can fluctuate enough that the allocation fails but the kswapd wakeup is also skipped while the zone is still really close to the low watermark. When one node misses a wakeup like this, it won't be aged before all the other node's zones are down to their low watermarks again. And skipping a full aging cycle is an obvious fairness problem. Kswapd runs until the high watermarks are restored, so it should also be woken when the high watermarks are not met. This ages nodes more equally and creates a safety margin for the page counter fluctuation. By using zone_balanced(), it will now check, in addition to the watermark, if compaction requires more order-0 pages to create a higher order page. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Mel Gorman <mgorman@suse.de> Reviewed-by: Rik van Riel <riel@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Paul Bolle <paul.bollee@gmail.com> Tested-by: Zlatko Calusic <zcalusic@bitsync.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>