From: Yosry Ahmed <yosryahmed@google.com>
To: Shakeel Butt <shakeel.butt@linux.dev>
Cc: syzbot <syzbot+9319a4268a640e26b72b@syzkaller.appspotmail.com>,
akpm@linux-foundation.org, cgroups@vger.kernel.org,
hannes@cmpxchg.org, linux-kernel@vger.kernel.org,
linux-mm@kvack.org, mhocko@kernel.org, muchun.song@linux.dev,
roman.gushchin@linux.dev, syzkaller-bugs@googlegroups.com,
yuzhao@google.com
Subject: Re: [syzbot] [mm?] [cgroups?] WARNING in __mod_memcg_lruvec_state
Date: Mon, 6 May 2024 09:12:53 -0700 [thread overview]
Message-ID: <CAJD7tkYVa5WQ=rSWYbm6EwAVJFjQE4iGsue8aOA80j6OHO6iQQ@mail.gmail.com> (raw)
In-Reply-To: <gbsy4rpt3fbcspuepstk6tzzwd3mrosuba7ufm7phopwor4pyb@ucxrvdw6nly3>
On Mon, May 6, 2024 at 8:59 AM Shakeel Butt <shakeel.butt@linux.dev> wrote:
>
> On Mon, May 06, 2024 at 02:11:57PM +0000, Yosry Ahmed wrote:
> > On Mon, May 06, 2024 at 06:03:29AM -0700, syzbot wrote:
> > > syzbot has found a reproducer for the following issue on:
> > >
> > > HEAD commit: 2b84edefcad1 Add linux-next specific files for 20240506
> > > git tree: linux-next
> > > console+strace: https://syzkaller.appspot.com/x/log.txt?x=1164931f180000
> > > kernel config: https://syzkaller.appspot.com/x/.config?x=b499929e4aaba1af
> > > dashboard link: https://syzkaller.appspot.com/bug?extid=9319a4268a640e26b72b
> > > compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
> > > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=123d5d1f180000
> > > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=16527450980000
> > >
> > > Downloadable assets:
> > > disk image: https://storage.googleapis.com/syzbot-assets/6a22cf95ee14/disk-2b84edef.raw.xz
> > > vmlinux: https://storage.googleapis.com/syzbot-assets/f5c45b515282/vmlinux-2b84edef.xz
> > > kernel image: https://storage.googleapis.com/syzbot-assets/9bf98258a662/bzImage-2b84edef.xz
> > >
> > > IMPORTANT: if you fix the issue, please add the following tag to the commit:
> > > Reported-by: syzbot+9319a4268a640e26b72b@syzkaller.appspotmail.com
> > >
> > > ------------[ cut here ]------------
> > > __mod_memcg_lruvec_state: missing stat item 25
> > > WARNING: CPU: 0 PID: 5091 at mm/memcontrol.c:999 __mod_memcg_lruvec_state+0x18c/0x430 mm/memcontrol.c:999
> >
> > This doesn't seem to be the same issue as the original one syzbot
> > reported. It's the same function but a different warning. I am not sure
> > how to tell syzbot that.
> >
> > Anyway, this warning is the one newly introduced by Shakeel. It is
> > firing because NR_SHMEM_PMDMAPPED and/or NR_FILE_PMDMAPPED are being
> > updated using __lruvec_stat_mod_folio(), which also updates the memcg
> > stats. However, these stats are not exported per-memcg.
> >
> > I think the following should fix it.
> >
>
> Hey Yosry, can you please post your patch with the signoff? The patch
> looks good and you can put my ack on it.
Will do. I noticed we also update these stats from
__folio_remove_rmap(). I will send a patch fixing these as well, so
I'll not include your Ack for that as it will be different.
next prev parent reply other threads:[~2024-05-06 16:13 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-02 8:03 [syzbot] [cgroups?] [mm?] WARNING in __mod_memcg_lruvec_state syzbot
2024-04-04 1:07 ` Andrew Morton
2024-04-04 23:36 ` Yosry Ahmed
2024-04-05 1:44 ` Yu Zhao
2024-04-05 4:47 ` Yosry Ahmed
2024-04-14 4:43 ` Shakeel Butt
2024-05-06 13:03 ` [syzbot] [mm?] [cgroups?] " syzbot
2024-05-06 14:11 ` Yosry Ahmed
2024-05-06 15:59 ` Shakeel Butt
2024-05-06 16:12 ` Yosry Ahmed [this message]
2024-05-06 16:13 ` syzbot
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