From cf608ac19c95804dc2df43b1f4f9e068aa9034ab Mon Sep 17 00:00:00 2001 From: Minchan Kim Date: Tue, 26 Oct 2010 14:21:29 -0700 Subject: mm: compaction: fix COMPACTPAGEFAILED counting Presently update_nr_listpages() doesn't have a role. That's because lists passed is always empty just after calling migrate_pages. The migrate_pages cleans up page list which have failed to migrate before returning by aaa994b3. [PATCH] page migration: handle freeing of pages in migrate_pages() Do not leave pages on the lists passed to migrate_pages(). Seems that we will not need any postprocessing of pages. This will simplify the handling of pages by the callers of migrate_pages(). At that time, we thought we don't need any postprocessing of pages. But the situation is changed. The compaction need to know the number of failed to migrate for COMPACTPAGEFAILED stat This patch makes new rule for caller of migrate_pages to call putback_lru_pages. So caller need to clean up the lists so it has a chance to postprocess the pages. [suggested by Christoph Lameter] Signed-off-by: Minchan Kim Cc: Hugh Dickins Cc: Andi Kleen Reviewed-by: Mel Gorman Reviewed-by: Wu Fengguang Acked-by: Christoph Lameter Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/migrate.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) (limited to 'mm/migrate.c') diff --git a/mm/migrate.c b/mm/migrate.c index d917ac3207f5..35e454189966 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -883,8 +883,9 @@ out: * * The function returns after 10 attempts or if no pages * are movable anymore because to has become empty - * or no retryable pages exist anymore. All pages will be - * returned to the LRU or freed. + * or no retryable pages exist anymore. + * Caller should call putback_lru_pages to return pages to the LRU + * or free list. * * Return: Number of pages not migrated or error code. */ @@ -931,8 +932,6 @@ out: if (!swapwrite) current->flags &= ~PF_SWAPWRITE; - putback_lru_pages(from); - if (rc) return rc; @@ -1087,9 +1086,12 @@ set_status: } err = 0; - if (!list_empty(&pagelist)) + if (!list_empty(&pagelist)) { err = migrate_pages(&pagelist, new_page_node, (unsigned long)pm, 0); + if (err) + putback_lru_pages(&pagelist); + } up_read(&mm->mmap_sem); return err; -- cgit v1.2.3-59-g8ed1b