From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-171.mta1.migadu.com (out-171.mta1.migadu.com [95.215.58.171]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id BD4662EA157 for ; Wed, 29 Oct 2025 03:12:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.171 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761707560; cv=none; b=RUB7qd78dve0/PFKMVF7UmSQgsbZoilEeqB8POtoVyZnxQt2+S1YrW3+Ej1O2QOfWar9Hz08S7IcRHOKjD3n+ldrY9uh+mFJKJlDtjfwJzXbTQjO1//1Sij4WL81UHFiNcEEaCsakobph1x7F/zWcoUXvLspWK+z/anOM9vMLCQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761707560; c=relaxed/simple; bh=hytguSx1VQCNNuHx835HgjhxZYkwWh6Hhjo1p4lF9Ig=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=jUMDpFq3QTSQbOvRe6+8VbOKeTPHNsJ+Oxw5zwbgn2hxnHQ2sy+2NYuUz10tlAB1tx9wChhzqJYxPkd0VwuLHsukLPTCUxaBaZjhhXCa/CfYrXkNZZWC3E1y11ad6wDH/1Hv4/pWfvEnY3Tr8Oz7x3cIgbp0tn9qX5FcVMHZsmg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=DruSDcLg; arc=none smtp.client-ip=95.215.58.171 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="DruSDcLg" Message-ID: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1761707555; 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=8U2/SRrzdo4Rwp5cpioI5+15rE47Gvkhsrn4dsdPbQM=; b=DruSDcLgKCqasjSORgvtKLccMIgUgAw9AbnSQzVZDb1mLkpujqTjHHUBMYj1SRcHgLqZN9 a2itK2hbxjSdRqD/XLybZHvtRP3ZIxiDA0D4Mrwv0f5/H4OsJIm8AfJOem4Es5HcY7726o G2rmoLCw0O5hZNmyy2+zlbFzAnWtuFw= Date: Wed, 29 Oct 2025 11:12:24 +0800 Precedence: bulk X-Mailing-List: cgroups@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Subject: Re: [syzbot ci] Re: Eliminate Dying Memory Cgroup To: Harry Yoo , syzbot ci Cc: akpm@linux-foundation.org, axelrasmussen@google.com, cgroups@vger.kernel.org, chengming.zhou@linux.dev, david@redhat.com, hannes@cmpxchg.org, hughd@google.com, imran.f.khan@oracle.com, kamalesh.babulal@oracle.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, lorenzo.stoakes@oracle.com, mhocko@suse.com, muchun.song@linux.dev, nphamcs@gmail.com, roman.gushchin@linux.dev, shakeel.butt@linux.dev, songmuchun@bytedance.com, weixugc@google.com, yuanchu@google.com, zhengqi.arch@bytedance.com, ziy@nvidia.com, syzbot@lists.linux.dev, syzkaller-bugs@googlegroups.com References: <69012e79.050a0220.3344a1.03ee.GAE@google.com> X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Qi Zheng In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Migadu-Flow: FLOW_OUT Hi Harry, On 10/29/25 8:22 AM, Harry Yoo wrote: > On Tue, Oct 28, 2025 at 01:58:33PM -0700, syzbot ci wrote: >> syzbot ci has tested the following series >> >> [v1] Eliminate Dying Memory Cgroup >> https://lore.kernel.org/all/cover.1761658310.git.zhengqi.arch@bytedance.com >> * [PATCH v1 01/26] mm: memcontrol: remove dead code of checking parent memory cgroup >> * [PATCH v1 02/26] mm: workingset: use folio_lruvec() in workingset_refault() >> * [PATCH v1 03/26] mm: rename unlock_page_lruvec_irq and its variants >> * [PATCH v1 04/26] mm: vmscan: refactor move_folios_to_lru() >> * [PATCH v1 05/26] mm: memcontrol: allocate object cgroup for non-kmem case >> * [PATCH v1 06/26] mm: memcontrol: return root object cgroup for root memory cgroup >> * [PATCH v1 07/26] mm: memcontrol: prevent memory cgroup release in get_mem_cgroup_from_folio() >> * [PATCH v1 08/26] buffer: prevent memory cgroup release in folio_alloc_buffers() >> * [PATCH v1 09/26] writeback: prevent memory cgroup release in writeback module >> * [PATCH v1 10/26] mm: memcontrol: prevent memory cgroup release in count_memcg_folio_events() >> * [PATCH v1 11/26] mm: page_io: prevent memory cgroup release in page_io module >> * [PATCH v1 12/26] mm: migrate: prevent memory cgroup release in folio_migrate_mapping() >> * [PATCH v1 13/26] mm: mglru: prevent memory cgroup release in mglru >> * [PATCH v1 14/26] mm: memcontrol: prevent memory cgroup release in mem_cgroup_swap_full() >> * [PATCH v1 15/26] mm: workingset: prevent memory cgroup release in lru_gen_eviction() >> * [PATCH v1 16/26] mm: thp: prevent memory cgroup release in folio_split_queue_lock{_irqsave}() >> * [PATCH v1 17/26] mm: workingset: prevent lruvec release in workingset_refault() >> * [PATCH v1 18/26] mm: zswap: prevent lruvec release in zswap_folio_swapin() >> * [PATCH v1 19/26] mm: swap: prevent lruvec release in swap module >> * [PATCH v1 20/26] mm: workingset: prevent lruvec release in workingset_activation() >> * [PATCH v1 21/26] mm: memcontrol: prepare for reparenting LRU pages for lruvec lock >> * [PATCH v1 22/26] mm: vmscan: prepare for reparenting traditional LRU folios >> * [PATCH v1 23/26] mm: vmscan: prepare for reparenting MGLRU folios >> * [PATCH v1 24/26] mm: memcontrol: refactor memcg_reparent_objcgs() >> * [PATCH v1 25/26] mm: memcontrol: eliminate the problem of dying memory cgroup for LRU folios >> * [PATCH v1 26/26] mm: lru: add VM_WARN_ON_ONCE_FOLIO to lru maintenance helpers >> >> and found the following issue: >> WARNING in folio_memcg >> >> Full report is available here: >> https://ci.syzbot.org/series/0d48a77a-fb4f-485d-9fd6-086afd6fb650 >> >> *** >> >> WARNING in folio_memcg >> >> tree: mm-new >> URL: https://kernel.googlesource.com/pub/scm/linux/kernel/git/akpm/mm.git >> base: b227c04932039bccc21a0a89cd6df50fa57e4716 >> arch: amd64 >> compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8 >> config: https://ci.syzbot.org/builds/503d7034-ae99-44d1-8fb2-62e7ef5e1c7c/config >> C repro: https://ci.syzbot.org/findings/880c374a-1b49-436e-9be2-63d5e2c6b6ab/c_repro >> syz repro: https://ci.syzbot.org/findings/880c374a-1b49-436e-9be2-63d5e2c6b6ab/syz_repro >> >> exFAT-fs (loop0): failed to load upcase table (idx : 0x00010000, chksum : 0xe5674ec2, utbl_chksum : 0xe619d30d) >> exFAT-fs (loop0): failed to load alloc-bitmap >> exFAT-fs (loop0): failed to recognize exfat type >> ------------[ cut here ]------------ >> WARNING: CPU: 1 PID: 5965 at ./include/linux/memcontrol.h:380 obj_cgroup_memcg include/linux/memcontrol.h:380 [inline] >> WARNING: CPU: 1 PID: 5965 at ./include/linux/memcontrol.h:380 folio_memcg+0x148/0x1c0 include/linux/memcontrol.h:434 > > This is understandable as the code snippet was added fairly recently > and is easy to miss during rebasing. My mistake, I should recheck it. > > #syz test > > diff --git a/mm/zswap.c b/mm/zswap.c > index a341814468b9..738d914e5354 100644 > --- a/mm/zswap.c > +++ b/mm/zswap.c > @@ -896,11 +896,14 @@ static bool zswap_compress(struct page *page, struct zswap_entry *entry, > * to the active LRU list in the case. > */ > if (comp_ret || !dlen || dlen >= PAGE_SIZE) { > + rcu_read_lock(); > if (!mem_cgroup_zswap_writeback_enabled( > folio_memcg(page_folio(page)))) { > + rcu_read_unlock(); > comp_ret = comp_ret ? comp_ret : -EINVAL; > goto unlock; > } > + rcu_read_unlock(); > comp_ret = 0; > dlen = PAGE_SIZE; > dst = kmap_local_page(page); LGTM, will do in the next version. Thanks! >