From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 23FD4C54E58 for ; Fri, 22 Mar 2024 02:45:17 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 9F7526B0088; Thu, 21 Mar 2024 22:45:16 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 9A63B6B0089; Thu, 21 Mar 2024 22:45:16 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 8BC366B008A; Thu, 21 Mar 2024 22:45:16 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0015.hostedemail.com [216.40.44.15]) by kanga.kvack.org (Postfix) with ESMTP id 7CC4A6B0088 for ; Thu, 21 Mar 2024 22:45:16 -0400 (EDT) Received: from smtpin16.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay08.hostedemail.com (Postfix) with ESMTP id 3428B1406A3 for ; Fri, 22 Mar 2024 02:45:16 +0000 (UTC) X-FDA: 81923133432.16.AA69710 Received: from out-172.mta1.migadu.com (out-172.mta1.migadu.com [95.215.58.172]) by imf16.hostedemail.com (Postfix) with ESMTP id 44E6E18000A for ; Fri, 22 Mar 2024 02:45:14 +0000 (UTC) Authentication-Results: imf16.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=kORYnHy1; spf=pass (imf16.hostedemail.com: domain of chengming.zhou@linux.dev designates 95.215.58.172 as permitted sender) smtp.mailfrom=chengming.zhou@linux.dev; dmarc=pass (policy=none) header.from=linux.dev ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1711075514; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=OCTXhEVfRcod0gk2uJbigtkgzM1uKiNOmgoxZlYoNnY=; b=CsWS2v9deNFtOcyhtM0HMk5ewCC6bF323+qurulcAAqw7tiZkJer8TRli/p+t04CfbNLk8 ib56gwsuX69VUD2LgYDyunsJwENLz6KDFfg3F+w7fkbnJFRbJIpe9Ky+aPwHDr2wbKE8Mi QuM/18odJyOerAREcwIM5bhFhfw62W0= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1711075514; a=rsa-sha256; cv=none; b=2gvhyu1xAjJnptvI/3rzcpaM4xveWfG06tmTaS3pp326fcPkEww1iV4+PWq4CRrgHru7YG NhYX5SIOGzbnQh9gA6z2L5Espg1NCmb0/1g1DqNb0t40M4aRoMxNL7VLYy3nhVfYHaTEJc hhJYsak7LIXoaFYPFP32OMaKZSLc3AM= ARC-Authentication-Results: i=1; imf16.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=kORYnHy1; spf=pass (imf16.hostedemail.com: domain of chengming.zhou@linux.dev designates 95.215.58.172 as permitted sender) smtp.mailfrom=chengming.zhou@linux.dev; dmarc=pass (policy=none) header.from=linux.dev Message-ID: <8a0a3987-bc38-4069-9005-f8097a4d934e@linux.dev> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1711075511; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=OCTXhEVfRcod0gk2uJbigtkgzM1uKiNOmgoxZlYoNnY=; b=kORYnHy1Szf5D8ha4QPHKPsmDUutFpu7FQa1h4gf/O3FrGTgI5ZqhROoEewX027jJhjfoC 9Xod03XHmavPou4crSHL+p3zUxS9w1UoF7ChrXg/NDEYbOVwYivtMI4PVaxg/vVqTS6olf tNzVLSbrM1ZxI1CiPTuDv2U1Ug5CwoE= Date: Fri, 22 Mar 2024 10:45:05 +0800 MIME-Version: 1.0 Subject: Re: [PATCH] mm: zswap: fix writeback shinker GFP_NOIO/GFP_NOFS recursion Content-Language: en-US To: Johannes Weiner , Andrew Morton Cc: Kent Overstreet , Chengming Zhou , Nhat Pham , Yosry Ahmed , linux-mm@kvack.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org References: <20240321182532.60000-1-hannes@cmpxchg.org> X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Chengming Zhou In-Reply-To: <20240321182532.60000-1-hannes@cmpxchg.org> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Migadu-Flow: FLOW_OUT X-Rspamd-Queue-Id: 44E6E18000A X-Rspam-User: X-Rspamd-Server: rspam11 X-Stat-Signature: juj5zoeub4zwx7oreo6i1ok1rj7q7qjk X-HE-Tag: 1711075514-91651 X-HE-Meta: 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 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, 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 2024/3/22 02:25, 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 Reviewed-by: Chengming Zhou Thanks. > --- > 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;