zswap_frontswap_store() is called during memory reclaim, therefore it can't use __GFP_FS, otherwise we may renter into fs code and deadlock. zswap_frontswap_store() also shouldn't do __GFP_IO, to avoid reentering into zswap code itself.
WARNING: at mm/slub.c:1250 slab_pre_alloc_hook.isra.42.part.43+0x15/0x17() ... Call Trace: [<ffffffff8163413f>] dump_stack+0x19/0x1b [<ffffffff8107b620>] warn_slowpath_common+0x70/0xb0 [<ffffffff8107b76a>] warn_slowpath_null+0x1a/0x20 [<ffffffff816311c8>] slab_pre_alloc_hook.isra.42.part.43+0x15/0x17 [<ffffffff811d7235>] kmem_cache_alloc+0x55/0x220 [<ffffffff811c4a09>] zswap_frontswap_store+0xe9/0x320 [<ffffffff811c3d5b>] __frontswap_store+0x7b/0x110 [<ffffffff811bf6a3>] swap_writepage+0x23/0x80 [<ffffffff8118fff2>] shrink_page_list+0x4b2/0xa80 [<ffffffff81190c1b>] shrink_inactive_list+0x1fb/0x6c0 [<ffffffff811918b5>] shrink_lruvec+0x395/0x800 [<ffffffff81191e0f>] shrink_zone+0xef/0x2d0 [<ffffffff81192390>] do_try_to_free_pages+0x170/0x530 [<ffffffff81192825>] try_to_free_pages+0xd5/0x160 [<ffffffff81185aa5>] __alloc_pages_nodemask+0x8a5/0xc10 [<ffffffff811cb1da>] alloc_pages_current+0xaa/0x170 [<ffffffff811803de>] __get_free_pages+0xe/0x50 [<ffffffffa029a5aa>] jbd2_alloc+0x8a/0x90 [jbd2] [<ffffffffa028fab4>] do_get_write_access+0x1d4/0x4d0 [jbd2] [<ffffffffa028fdd7>] jbd2_journal_get_write_access+0x27/0x40 [jbd2] [<ffffffffa02e8e0b>] __ext4_journal_get_write_access+0x3b/0x80 [ext4] [<ffffffffa02efccd>] ext4_mb_mark_diskspace_used+0x7d/0x4f0 [ext4] [<ffffffffa02f156d>] ext4_mb_new_blocks+0x36d/0x620 [ext4] [<ffffffffa02e601d>] ext4_ext_map_blocks+0x49d/0xed0 [ext4] [<ffffffffa02b2689>] ext4_map_blocks+0x179/0x590 [ext4] [<ffffffffa02b5bc2>] ext4_writepages+0x692/0xd60 [ext4] [<ffffffff8118828e>] do_writepages+0x1e/0x40 [<ffffffff812249da>] __writeback_single_inode+0x7a/0x410 [<ffffffff812257d7>] writeback_sb_inodes+0x2c7/0x540 [<ffffffff81225aef>] __writeback_inodes_wb+0x9f/0xd0 [<ffffffff81225d83>] wb_writeback+0x263/0x320 [<ffffffff8122821d>] bdi_writeback_workfn+0x11d/0x420 [<ffffffff8109ef4b>] process_one_work+0x17b/0x470 [<ffffffff8109fd1b>] worker_thread+0x11b/0x400 [<ffffffff810a779f>] kthread+0xcf/0xe0 [<ffffffff81644918>] ret_from_fork+0x58/0x90 ---[ end trace 892c68052e9c3d3f ]--- Also add __GFP_NOWARN as failures here is fine. https://jira.sw.ru/browse/PSBM-58279 Signed-off-by: Andrey Ryabinin <aryabi...@virtuozzo.com> --- mm/zswap.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/zswap.c b/mm/zswap.c index e2f8c7e..c582024 100644 --- a/mm/zswap.c +++ b/mm/zswap.c @@ -665,7 +665,7 @@ static int zswap_frontswap_store(unsigned type, pgoff_t offset, } /* allocate entry */ - entry = zswap_entry_cache_alloc(GFP_KERNEL); + entry = zswap_entry_cache_alloc(GFP_NOIO | __GFP_NOWARN); if (!entry) { zswap_reject_kmemcache_fail++; ret = -ENOMEM; -- 2.10.2 _______________________________________________ Devel mailing list Devel@openvz.org https://lists.openvz.org/mailman/listinfo/devel
