user/sven/linux.git/include/linux/migrate.h, branch v3.16.46

mm/balloon_compaction: redesign ballooned pages management

2016-06-15T20:29:35Z

commit d6d86c0a7f8ddc5b38cf089222cb1d9540762dc2 upstream. Sasha Levin reported KASAN splash inside isolate_migratepages_range(). Problem is in the function __is_movable_balloon_page() which tests AS_BALLOON_MAP in page->mapping->flags. This function has no protection against anonymous pages. As result it tried to check address space flags inside struct anon_vma. Further investigation shows more problems in current implementation: * Special branch in __unmap_and_move() never works: balloon_page_movable() checks page flags and page_count. In __unmap_and_move() page is locked, reference counter is elevated, thus balloon_page_movable() always fails. As a result execution goes to the normal migration path. virtballoon_migratepage() returns MIGRATEPAGE_BALLOON_SUCCESS instead of MIGRATEPAGE_SUCCESS, move_to_new_page() thinks this is an error code and assigns newpage->mapping to NULL. Newly migrated page lose connectivity with balloon an all ability for further migration. * lru_lock erroneously required in isolate_migratepages_range() for isolation ballooned page. This function releases lru_lock periodically, this makes migration mostly impossible for some pages. * balloon_page_dequeue have a tight race with balloon_page_isolate: balloon_page_isolate could be executed in parallel with dequeue between picking page from list and locking page_lock. Race is rare because they use trylock_page() for locking. This patch fixes all of them. Instead of fake mapping with special flag this patch uses special state of page->_mapcount: PAGE_BALLOON_MAPCOUNT_VALUE = -256. Buddy allocator uses PAGE_BUDDY_MAPCOUNT_VALUE = -128 for similar purpose. Storing mark directly in struct page makes everything safer and easier. PagePrivate is used to mark pages present in page list (i.e. not isolated, like PageLRU for normal pages). It replaces special rules for reference counter and makes balloon migration similar to migration of normal pages. This flag is protected by page_lock together with link to the balloon device. Signed-off-by: Konstantin Khlebnikov Reported-by: Sasha Levin Link: http://lkml.kernel.org/p/53E6CEAA.9020105@oracle.com Cc: Rafael Aquini Cc: Andrey Ryabinin Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds [bwh: Backported to 3.16: - Remove an additional check for MIGRATEPAGE_BALLOON_SUCCESS in __unmap_and_move() - Adjust context] Signed-off-by: Ben Hutchings Cc: Jiri Kosina Cc: jian wang

mm, migration: add destination page freeing callback

2014-06-04T23:54:06Z

Memory migration uses a callback defined by the caller to determine how to allocate destination pages. When migration fails for a source page, however, it frees the destination page back to the system. This patch adds a memory migration callback defined by the caller to determine how to free destination pages. If a caller, such as memory compaction, builds its own freelist for migration targets, this can reuse already freed memory instead of scanning additional memory. If the caller provides a function to handle freeing of destination pages, it is called when page migration fails. If the caller passes NULL then freeing back to the system will be handled as usual. This patch introduces no functional change. Signed-off-by: David Rientjes Reviewed-by: Naoya Horiguchi Acked-by: Mel Gorman Acked-by: Vlastimil Babka Cc: Greg Thelen Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm/migrate: remove unused function, fail_migrate_page()

2014-01-22T00:19:49Z

fail_migrate_page() isn't used anywhere, so remove it. Signed-off-by: Joonsoo Kim Acked-by: Christoph Lameter Reviewed-by: Naoya Horiguchi Reviewed-by: Wanpeng Li Cc: Rafael Aquini Cc: Vlastimil Babka Cc: Wanpeng Li Cc: Mel Gorman Cc: Rik van Riel Cc: Zhang Yanfei Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm/migrate: remove putback_lru_pages, fix comment on putback_movable_pages

2014-01-22T00:19:49Z

Some part of putback_lru_pages() and putback_movable_pages() is duplicated, so it could confuse us what we should use. We can remove putback_lru_pages() since it is not really needed now. This makes us undestand and maintain the code more easily. And comment on putback_movable_pages() is stale now, so fix it. Signed-off-by: Joonsoo Kim Reviewed-by: Wanpeng Li Cc: Christoph Lameter Cc: Naoya Horiguchi Cc: Rafael Aquini Cc: Vlastimil Babka Cc: Wanpeng Li Cc: Mel Gorman Cc: Rik van Riel Cc: Vlastimil Babka Cc: Zhang Yanfei Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

aio/migratepages: make aio migrate pages sane

2013-12-21T22:56:08Z

The arbitrary restriction on page counts offered by the core migrate_page_move_mapping() code results in rather suspicious looking fiddling with page reference counts in the aio_migratepage() operation. To fix this, make migrate_page_move_mapping() take an extra_count parameter that allows aio to tell the code about its own reference count on the page being migrated. While cleaning up aio_migratepage(), make it validate that the old page being passed in is actually what aio_migratepage() expects to prevent misbehaviour in the case of races. Signed-off-by: Benjamin LaHaise

mm: numa: avoid unnecessary disruption of NUMA hinting during migration

2013-12-19T03:04:51Z

do_huge_pmd_numa_page() handles the case where there is parallel THP migration. However, by the time it is checked the NUMA hinting information has already been disrupted. This patch adds an earlier check with some helpers. Signed-off-by: Mel Gorman Reviewed-by: Rik van Riel Cc: Alex Thorlton Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: numa: Scan pages with elevated page_mapcount

2013-10-09T10:40:32Z

Currently automatic NUMA balancing is unable to distinguish between false shared versus private pages except by ignoring pages with an elevated page_mapcount entirely. This avoids shared pages bouncing between the nodes whose task is using them but that is ignored quite a lot of data. This patch kicks away the training wheels in preparation for adding support for identifying shared/private pages is now in place. The ordering is so that the impact of the shared/private detection can be easily measured. Note that the patch does not migrate shared, file-backed within vmas marked VM_EXEC as these are generally shared library pages. Migrating such pages is not beneficial as there is an expectation they are read-shared between caches and iTLB and iCache pressure is generally low. Signed-off-by: Mel Gorman Reviewed-by: Rik van Riel Cc: Andrea Arcangeli Cc: Johannes Weiner Cc: Srikar Dronamraju Signed-off-by: Peter Zijlstra Link: http://lkml.kernel.org/r/1381141781-10992-28-git-send-email-mgorman@suse.de Signed-off-by: Ingo Molnar

Merge git://git.kvack.org/~bcrl/aio-next

2013-09-13T17:55:58Z

Pull aio changes from Ben LaHaise: "First off, sorry for this pull request being late in the merge window. Al had raised a couple of concerns about 2 items in the series below. I addressed the first issue (the race introduced by Gu's use of mm_populate()), but he has not provided any further details on how he wants to rework the anon_inode.c changes (which were sent out months ago but have yet to be commented on). The bulk of the changes have been sitting in the -next tree for a few months, with all the issues raised being addressed" * git://git.kvack.org/~bcrl/aio-next: (22 commits) aio: rcu_read_lock protection for new rcu_dereference calls aio: fix race in ring buffer page lookup introduced by page migration support aio: fix rcu sparse warnings introduced by ioctx table lookup patch aio: remove unnecessary debugging from aio_free_ring() aio: table lookup: verify ctx pointer staging/lustre: kiocb->ki_left is removed aio: fix error handling and rcu usage in "convert the ioctx list to table lookup v3" aio: be defensive to ensure request batching is non-zero instead of BUG_ON() aio: convert the ioctx list to table lookup v3 aio: double aio_max_nr in calculations aio: Kill ki_dtor aio: Kill ki_users aio: Kill unneeded kiocb members aio: Kill aio_rw_vect_retry() aio: Don't use ctx->tail unnecessarily aio: io_cancel() no longer returns the io_event aio: percpu ioctx refcount aio: percpu reqs_available aio: reqs_active -> reqs_available aio: fix build when migration is disabled ...

mm: soft-offline: use migrate_pages() instead of migrate_huge_page()

2013-09-11T22:57:47Z

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 Acked-by: Andi Kleen Reviewed-by: Wanpeng Li Acked-by: Hillf Danton Cc: Mel Gorman Cc: Hugh Dickins Cc: KOSAKI Motohiro Cc: Michal Hocko Cc: Rik van Riel Cc: "Aneesh Kumar K.V" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

fs/aio: Add support to aio ring pages migration

2013-07-16T13:32:18Z

As the aio job will pin the ring pages, that will lead to mem migrated failed. In order to fix this problem we use an anon inode to manage the aio ring pages, and setup the migratepage callback in the anon inode's address space, so that when mem migrating the aio ring pages will be moved to other mem node safely. Signed-off-by: Gu Zheng Signed-off-by: Benjamin LaHaise