From: Yisheng Xie <xieyisheng1@xxxxxxxxxx> Subject: mm/migration: make isolate_movable_page() return int type Patch series "HWPOISON: soft offlining for non-lru movable page", v6. After Minchan's commit bda807d44454 ("mm: migrate: support non-lru movable page migration"), some type of non-lru page like zsmalloc and virtio-balloon page also support migration. Therefore, we can: 1) soft offlining no-lru movable pages, which means when memory corrected errors occur on a non-lru movable page, we can stop to use it by migrating data onto another page and disable the original (maybe half-broken) one. 2) enable memory hotplug for non-lru movable pages, i.e. we may offline blocks, which include such pages, by using non-lru page migration. This patchset is heavily dependent on non-lru movable page migration. This patch (of 4): Change the return type of isolate_movable_page() from bool to int. It will return 0 when isolate movable page successfully, and return -EBUSY when it isolates failed. There is no functional change within this patch but prepare for later patch. [xieyisheng1@xxxxxxxxxx: v6] Link: http://lkml.kernel.org/r/1486108770-630-2-git-send-email-xieyisheng1@xxxxxxxxxx Link: http://lkml.kernel.org/r/1485867981-16037-2-git-send-email-ysxie@xxxxxxxxxxx Signed-off-by: Yisheng Xie <xieyisheng1@xxxxxxxxxx> Suggested-by: Michal Hocko <mhocko@xxxxxxxxxx> Acked-by: Minchan Kim <minchan@xxxxxxxxxx> Cc: Andi Kleen <ak@xxxxxxxxxxxxxxx> Cc: Hanjun Guo <guohanjun@xxxxxxxxxx> Cc: Johannes Weiner <hannes@xxxxxxxxxxx> Cc: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx> Cc: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx> Cc: Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx> Cc: Reza Arbab <arbab@xxxxxxxxxxxxxxxxxx> Cc: Taku Izumi <izumi.taku@xxxxxxxxxxxxxx> Cc: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx> Cc: Vlastimil Babka <vbabka@xxxxxxx> Cc: Xishi Qiu <qiuxishi@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- include/linux/migrate.h | 2 +- mm/compaction.c | 2 +- mm/migrate.c | 6 +++--- 3 files changed, 5 insertions(+), 5 deletions(-) diff -puN include/linux/migrate.h~mm-migration-make-isolate_movable_page-return-int-type include/linux/migrate.h --- a/include/linux/migrate.h~mm-migration-make-isolate_movable_page-return-int-type +++ a/include/linux/migrate.h @@ -37,7 +37,7 @@ extern int migrate_page(struct address_s struct page *, struct page *, enum migrate_mode); extern int migrate_pages(struct list_head *l, new_page_t new, free_page_t free, unsigned long private, enum migrate_mode mode, int reason); -extern bool isolate_movable_page(struct page *page, isolate_mode_t mode); +extern int isolate_movable_page(struct page *page, isolate_mode_t mode); extern void putback_movable_page(struct page *page); extern int migrate_prep(void); diff -puN mm/compaction.c~mm-migration-make-isolate_movable_page-return-int-type mm/compaction.c --- a/mm/compaction.c~mm-migration-make-isolate_movable_page-return-int-type +++ a/mm/compaction.c @@ -802,7 +802,7 @@ isolate_migratepages_block(struct compac locked = false; } - if (isolate_movable_page(page, isolate_mode)) + if (!isolate_movable_page(page, isolate_mode)) goto isolate_success; } diff -puN mm/migrate.c~mm-migration-make-isolate_movable_page-return-int-type mm/migrate.c --- a/mm/migrate.c~mm-migration-make-isolate_movable_page-return-int-type +++ a/mm/migrate.c @@ -74,7 +74,7 @@ int migrate_prep_local(void) return 0; } -bool isolate_movable_page(struct page *page, isolate_mode_t mode) +int isolate_movable_page(struct page *page, isolate_mode_t mode) { struct address_space *mapping; @@ -125,14 +125,14 @@ bool isolate_movable_page(struct page *p __SetPageIsolated(page); unlock_page(page); - return true; + return 0; out_no_isolated: unlock_page(page); out_putpage: put_page(page); out: - return false; + return -EBUSY; } /* It should be called on page which is PG_movable */ _ -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html