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charset="us-ascii" X-Rspamd-Server: rspam09 X-Rspamd-Queue-Id: 5384940014 X-Stat-Signature: 6b7en3x7y13o5h41pwn9mqokye7j9oba X-Rspam-User: X-HE-Tag: 1711046217-313817 X-HE-Meta: U2FsdGVkX19/jud6vCvwy3OfyjgmCqyo9hMAMBgwWH3hw88Sxv6fLQs6Tu8cCEBA6/Abmx4Qjw5tZKepcZHr7/p3f8UMeJQN3n7yBfbkFH3nIRy0RD55Q9B8tA7fph72wjeIaMNW/JLr5QNeZUWhBcVT/AJH8krQATZ1xTN5jAqF3WUjfuyPbaO7JfPtUDgOxPQHBwbJb3MUR/hKqNL6QoCtKNzvIbL/JuVV42WPxruMrGHxWVQTJ1j6F3lNg2xpALx7F7CxDCj1EYgC7Gy/oUG6RSZx+vQ4ce2r+ezMd7XyY/0U65APXXOpUu6tIX8p8NtwQzUu6XZmIwS3V8liilROBHh9JR5wyIwoY9jjZl4U9NhmDTys+u1zs8EVzMcQ5yqk+48SJK6y0m3DEdWl2yr3Es73ekdV+rSrvxjfCrg12nSQFInCWRL/DdvHM6YPjdkRr+TVYUcFtsKn2aikyFUpkaN20vAZHw/fTvnjgoWrgInfjjB9NQZIB2tddxzRKdvMwkDRrPQP02ntvLCRpIcpI/+E5497LBZ5RAUTdWxWkPwEa0zjD5cv6Zyiz00hb6522b/zbE4m/eJ2vpWY546louTC+fqWk3r/BHTZTGcRT5D1UpnuQhhHyhH9VJ2whLn5BncMoBu5nBj6cU3Lou7eCQpqnM8Nx4JHYlhMx/IXjen5GdN/Fur+CxPxtValskGct+sLmqXJavR0YLYxUwIjsxWVbJW9J+uYigoywcM+g52DuzMCqs0dqxU3HpRaG2s4Up2lkdEo73emDxLCkjZtV+ZcISAVDgASSaSYfHvQBefhwPTIcwOdgH17DlWDNGM6ymwZY7gWYCk17MbE6fX5kW4n9OxasmJ4TRQGRVslH+z0KPcAJpPuhr+JE2zxXFkl8dXernsuEIZyOTqIqxBlP92BXqvfg0F9h40jsEh6N9AJnWqC/nvRm8b/rojW6IPaGBFpGtn7XaQKsQE ch04EWXM 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 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000026, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Thu, Mar 21, 2024 at 02:25:32PM -0400, Johannes Weiner wrote: > Kent forwards this bug report of zswap re-entering the block layer > from an IO request allocation and locking up: > > [10264.128242] sysrq: Show Blocked State > [10264.128268] task:kworker/20:0H state:D stack:0 pid:143 tgid:143 ppid:2 flags:0x00004000 > [10264.128271] Workqueue: bcachefs_io btree_write_submit [bcachefs] > [10264.128295] Call Trace: > [10264.128295] > [10264.128297] __schedule+0x3e6/0x1520 > [10264.128303] schedule+0x32/0xd0 > [10264.128304] schedule_timeout+0x98/0x160 > [10264.128308] io_schedule_timeout+0x50/0x80 > [10264.128309] wait_for_completion_io_timeout+0x7f/0x180 > [10264.128310] submit_bio_wait+0x78/0xb0 > [10264.128313] swap_writepage_bdev_sync+0xf6/0x150 > [10264.128317] zswap_writeback_entry+0xf2/0x180 > [10264.128319] shrink_memcg_cb+0xe7/0x2f0 > [10264.128322] __list_lru_walk_one+0xb9/0x1d0 > [10264.128325] list_lru_walk_one+0x5d/0x90 > [10264.128326] zswap_shrinker_scan+0xc4/0x130 > [10264.128327] do_shrink_slab+0x13f/0x360 > [10264.128328] shrink_slab+0x28e/0x3c0 > [10264.128329] shrink_one+0x123/0x1b0 > [10264.128331] shrink_node+0x97e/0xbc0 > [10264.128332] do_try_to_free_pages+0xe7/0x5b0 > [10264.128333] try_to_free_pages+0xe1/0x200 > [10264.128334] __alloc_pages_slowpath.constprop.0+0x343/0xde0 > [10264.128337] __alloc_pages+0x32d/0x350 > [10264.128338] allocate_slab+0x400/0x460 > [10264.128339] ___slab_alloc+0x40d/0xa40 > [10264.128345] kmem_cache_alloc+0x2e7/0x330 > [10264.128348] mempool_alloc+0x86/0x1b0 > [10264.128349] bio_alloc_bioset+0x200/0x4f0 > [10264.128352] bio_alloc_clone+0x23/0x60 > [10264.128354] alloc_io+0x26/0xf0 [dm_mod 7e9e6b44df4927f93fb3e4b5c782767396f58382] > [10264.128361] dm_submit_bio+0xb8/0x580 [dm_mod 7e9e6b44df4927f93fb3e4b5c782767396f58382] > [10264.128366] __submit_bio+0xb0/0x170 > [10264.128367] submit_bio_noacct_nocheck+0x159/0x370 > [10264.128368] bch2_submit_wbio_replicas+0x21c/0x3a0 [bcachefs 85f1b9a7a824f272eff794653a06dde1a94439f2] > [10264.128391] btree_write_submit+0x1cf/0x220 [bcachefs 85f1b9a7a824f272eff794653a06dde1a94439f2] > [10264.128406] process_one_work+0x178/0x350 > [10264.128408] worker_thread+0x30f/0x450 > [10264.128409] kthread+0xe5/0x120 > > The zswap shrinker resumes the swap_writepage()s that were intercepted > by the zswap store. This will enter the block layer, and may even > enter the filesystem depending on the swap backing file. > > Make it respect GFP_NOIO and GFP_NOFS. > > Link: https://lore.kernel.org/linux-mm/rc4pk2r42oyvjo4dc62z6sovquyllq56i5cdgcaqbd7wy3hfzr@n4nbxido3fme/ > Reported-by: Kent Overstreet > Fixes: b5ba474f3f51 ("zswap: shrink zswap pool based on memory pressure") > Cc: stable@vger.kernel.org [v6.8] > Signed-off-by: Johannes Weiner Acked-by: Yosry Ahmed Thanks for the quick fix. > --- > mm/zswap.c | 8 ++++++++ > 1 file changed, 8 insertions(+) > > diff --git a/mm/zswap.c b/mm/zswap.c > index b31c977f53e9..535c907345e0 100644 > --- a/mm/zswap.c > +++ b/mm/zswap.c > @@ -1303,6 +1303,14 @@ static unsigned long zswap_shrinker_count(struct shrinker *shrinker, > if (!zswap_shrinker_enabled || !mem_cgroup_zswap_writeback_enabled(memcg)) > return 0; > > + /* > + * The shrinker resumes swap writeback, which will enter block > + * and may enter fs. XXX: Harmonize with vmscan.c __GFP_FS > + * rules (may_enter_fs()), which apply on a per-folio basis. > + */ > + if (!gfp_has_io_fs(sc->gfp_mask)) > + return 0; > + > #ifdef CONFIG_MEMCG_KMEM > mem_cgroup_flush_stats(memcg); > nr_backing = memcg_page_state(memcg, MEMCG_ZSWAP_B) >> PAGE_SHIFT; > -- > 2.44.0 >