| Date | Wed, 9 Oct 2013 10:31:23 -0700 | From | tip-bot for Rik van Riel <> | Subject | [tip:sched/core] mm: numa: Copy cpupid on page migration |
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Commit-ID: 7851a45cd3f6198bf542c30e27b330e8eeb3736c Gitweb: http://git.kernel.org/tip/7851a45cd3f6198bf542c30e27b330e8eeb3736c Author: Rik van Riel <riel@redhat.com> AuthorDate: Mon, 7 Oct 2013 11:29:23 +0100 Committer: Ingo Molnar <mingo@kernel.org> CommitDate: Wed, 9 Oct 2013 14:47:51 +0200
mm: numa: Copy cpupid on page migration
After page migration, the new page has the nidpid unset. This makes every fault on a recently migrated page look like a first numa fault, leading to another page migration.
Copying over the nidpid at page migration time should prevent erroneous migrations of recently migrated pages.
Signed-off-by: Rik van Riel <riel@redhat.com> Signed-off-by: Mel Gorman <mgorman@suse.de> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1381141781-10992-46-git-send-email-mgorman@suse.de Signed-off-by: Ingo Molnar <mingo@kernel.org> --- mm/migrate.c | 9 +++++++++ 1 file changed, 9 insertions(+)
diff --git a/mm/migrate.c b/mm/migrate.c index ff53774..44c1fa9 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -443,6 +443,8 @@ int migrate_huge_page_move_mapping(struct address_space *mapping, */ void migrate_page_copy(struct page *newpage, struct page *page) { + int cpupid; + if (PageHuge(page) || PageTransHuge(page)) copy_huge_page(newpage, page); else @@ -479,6 +481,13 @@ void migrate_page_copy(struct page *newpage, struct page *page) __set_page_dirty_nobuffers(newpage); } + /* + * Copy NUMA information to the new page, to prevent over-eager + * future migrations of this same page. + */ + cpupid = page_cpupid_xchg_last(page, -1); + page_cpupid_xchg_last(newpage, cpupid); + mlock_migrate_page(newpage, page); ksm_migrate_page(newpage, page); /*
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