On Tue, Jul 30, 2019 at 12:25:28PM -0400, Qian Cai wrote: > OOM workloads with swapping is unable to recover with linux-next since next- > 20190729 due to the commit "mm: account nr_isolated_xxx in > [isolate|putback]_lru_page" breaks OOM with swap" [1] > > [1] https://lore.kernel.org/linux-mm/20190726023435.214162-4-minchan@xxxxxxxxxx/ > T/#mdcd03bcb4746f2f23e6f508c205943726aee8355 > > For example, LTP oom01 test case is stuck for hours, while it finishes in a few > minutes here after reverted the above commit. Sometimes, it prints those message > while hanging. > > [ 509.983393][ T711] INFO: task oom01:5331 blocked for more than 122 seconds. > [ 509.983431][ T711] Not tainted 5.3.0-rc2-next-20190730 #7 > [ 509.983447][ T711] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" > disables this message. > [ 509.983477][ T711] oom01 D24656 5331 5157 0x00040000 > [ 509.983513][ T711] Call Trace: > [ 509.983538][ T711] [c00020037d00f880] [0000000000000008] 0x8 (unreliable) > [ 509.983583][ T711] [c00020037d00fa60] [c000000000023724] > __switch_to+0x3a4/0x520 > [ 509.983615][ T711] [c00020037d00fad0] [c0000000008d17bc] > __schedule+0x2fc/0x950 > [ 509.983647][ T711] [c00020037d00fba0] [c0000000008d1e68] schedule+0x58/0x150 > [ 509.983684][ T711] [c00020037d00fbd0] [c0000000008d7614] > rwsem_down_read_slowpath+0x4b4/0x630 > [ 509.983727][ T711] [c00020037d00fc90] [c0000000008d7dfc] > down_read+0x12c/0x240 > [ 509.983758][ T711] [c00020037d00fd20] [c00000000005fb28] > __do_page_fault+0x6f8/0xee0 > [ 509.983801][ T711] [c00020037d00fe20] [c00000000000a364] > handle_page_fault+0x18/0x38 Thanks for the testing! No surprise the patch make some bugs because it's rather tricky. Could you test this patch? >From b31667210dd747f4d8aeb7bdc1f5c14f1f00bff5 Mon Sep 17 00:00:00 2001 From: Minchan Kim <minchan@xxxxxxxxxx> Date: Wed, 31 Jul 2019 14:18:01 +0900 Subject: [PATCH] mm: decrease NR_ISOALTED count at succesful migration If migration fails, it should go back to LRU list so putback_lru_page could handle NR_ISOLATED count in pair with isolate_lru_page. However, if migration is successful, the page will be freed so no need to add the page back to LRU list. Thus, NR_ISOLATED count should be done in manually. Signed-off-by: Minchan Kim <minchan@xxxxxxxxxx> --- mm/migrate.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) diff --git a/mm/migrate.c b/mm/migrate.c index 84b89d2d69065..96ae0c3cada8d 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -1166,6 +1166,7 @@ static ICE_noinline int unmap_and_move(new_page_t get_new_page, { int rc = MIGRATEPAGE_SUCCESS; struct page *newpage; + bool is_lru = __PageMovable(page); if (!thp_migration_supported() && PageTransHuge(page)) return -ENOMEM; @@ -1175,17 +1176,10 @@ static ICE_noinline int unmap_and_move(new_page_t get_new_page, return -ENOMEM; if (page_count(page) == 1) { - bool is_lru = !__PageMovable(page); - /* page was freed from under us. So we are done. */ ClearPageActive(page); ClearPageUnevictable(page); - if (likely(is_lru)) - mod_node_page_state(page_pgdat(page), - NR_ISOLATED_ANON + - page_is_file_cache(page), - -hpage_nr_pages(page)); - else { + if (unlikely(!is_lru)) { lock_page(page); if (!PageMovable(page)) __ClearPageIsolated(page); @@ -1229,6 +1223,12 @@ static ICE_noinline int unmap_and_move(new_page_t get_new_page, if (set_hwpoison_free_buddy_page(page)) num_poisoned_pages_inc(); } + + if (likely(is_lru)) + mod_node_page_state(page_pgdat(page), + NR_ISOLATED_ANON + + page_is_file_cache(page), + -hpage_nr_pages(page)); } else { if (rc != -EAGAIN) { if (likely(!__PageMovable(page))) { -- 2.22.0.709.g102302147b-goog
