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 X-Spam-Level: X-Spam-Status: No, score=-2.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7D8E3C433B4 for ; Fri, 9 Apr 2021 11:39:52 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id E6C0A6115C for ; Fri, 9 Apr 2021 11:39:51 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E6C0A6115C Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 560776B006C; Fri, 9 Apr 2021 07:39:51 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 5103D6B006E; Fri, 9 Apr 2021 07:39:51 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 389F96B0070; Fri, 9 Apr 2021 07:39:51 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0206.hostedemail.com [216.40.44.206]) by kanga.kvack.org (Postfix) with ESMTP id 18B9B6B006C for ; Fri, 9 Apr 2021 07:39:51 -0400 (EDT) Received: from smtpin22.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id AA5FD12EE for ; Fri, 9 Apr 2021 11:39:50 +0000 (UTC) X-FDA: 78012634140.22.7A3E2E0 Received: from mail-qk1-f172.google.com (mail-qk1-f172.google.com [209.85.222.172]) by imf10.hostedemail.com (Postfix) with ESMTP id 9F0F240002CE for ; Fri, 9 Apr 2021 11:39:46 +0000 (UTC) Received: by mail-qk1-f172.google.com with SMTP id c4so5451799qkg.3 for ; Fri, 09 Apr 2021 04:39:50 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:reply-to:from:date:message-id :subject:to:cc:content-transfer-encoding; bh=n6kG64sSQGZeoJDQwpKXTmXY9H14h1av0i3P5Us6SFs=; b=BXbJ1L5xRQpCGxnEOqFfCnNW2c69wYcmTrGaQebwA38O1n2xim6oQz8szF4jNR2VlX 71oemixjMlVA+oIVN0Oz0H1bKsN+PKXSLATX3kZ6GAB0ZcgWhowC+u6dth96vWAUWDs7 P9VvmJOLwvd0/DXj+66Z80NkDYVdzRM7DXvzKvnuepG30l8Aa6w3tWXs0TxEYySBFAmH xfv6Y1rEn+XVmskEYX4PV6I/1LNf+ptaRjre4kFZXXGycVh0Z2b0Rs4TUDwD7s9CLX+n wuBWsmQtrQyEx98ZNFyrgWLeBZq4dhhnMK2KdGN9FpS+fOXTA30bbYmhaaY50kh/pc54 Up+Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:reply-to :from:date:message-id:subject:to:cc:content-transfer-encoding; bh=n6kG64sSQGZeoJDQwpKXTmXY9H14h1av0i3P5Us6SFs=; b=JXVUGap1i+PgcOLCc2Wu4BO0SXYNQnfhdYtid22zQxTwLfqHIeA26x2ct8BYB3Z3ok YGsb+8S1wxvknkAF7cGqpTQHPKzf16+Mkl6unmdJhx85GOU6+jdGErj1pWbqDb8Ryy83 2iI/G1K5fcAwVlOMXQ1p7LNmq1yDUnBV9ucOI0kwuDoJLwQg28vdJSG+f57w04TZ3A+E 11r6fEkTL3FqZxW9TBpphSh+GD1G4j39sRX/vY+nyeCgf4myRUYL8DOlj820q28pn+WC jeV0mS6o+tf98Hg5a/fm/p2PFt9R7+NTM9YSGoooHNyzPrYSXpKpGiMyad48qGAwBOzl 6xYA== X-Gm-Message-State: AOAM533Eo713LHYwMq4kP9u0RxaFp33Yb7QcjhqwAganLXSAIbZX/t8F tic3szFa63OrKoZhpGO4XuFCXVeL26t+Sk/UNbg= X-Google-Smtp-Source: ABdhPJwg73tSmKXp6M8rcjqNBXtAmIaG1SYy0llAs93aIKkB8GScyNTywIbSeGRgvDHIHLbXp+ctSXoKMt8NJdQg6Lw= X-Received: by 2002:a05:620a:119a:: with SMTP id b26mr13823682qkk.438.1617968389636; Fri, 09 Apr 2021 04:39:49 -0700 (PDT) MIME-Version: 1.0 References: <20210408072800.6C1F.409509F4@e16-tech.com> <20210408171959.2D72.409509F4@e16-tech.com> In-Reply-To: Reply-To: fdmanana@gmail.com From: Filipe Manana Date: Fri, 9 Apr 2021 12:39:38 +0100 Message-ID: Subject: Re: unexpected -ENOMEM from percpu_counter_init() To: Dennis Zhou Cc: Wang Yugui , Vlastimil Babka , linux-mm@kvack.org, linux-btrfs Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: 9F0F240002CE X-Stat-Signature: 3ftrg8wxkeaawu8mr644ywyd3cc1mhid Received-SPF: none (gmail.com>: No applicable sender policy available) receiver=imf10; identity=mailfrom; envelope-from=""; helo=mail-qk1-f172.google.com; client-ip=209.85.222.172 X-HE-DKIM-Result: pass/pass X-HE-Tag: 1617968386-452205 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: On Thu, Apr 8, 2021 at 4:02 PM Dennis Zhou wrote: > > On Thu, Apr 08, 2021 at 03:28:20PM +0100, Filipe Manana wrote: > > On Thu, Apr 8, 2021 at 2:50 PM Dennis Zhou wrote: > > > > > > On Thu, Apr 08, 2021 at 05:20:00PM +0800, Wang Yugui wrote: > > > > Hi, > > > > > > > > > On Thu, Apr 08, 2021 at 07:28:01AM +0800, Wang Yugui wrote: > > > > > > Hi, > > > > > > > > > > > > > > > > upper caller: > > > > > > > > > > nofs_flag =3D memalloc_nofs_save(); > > > > > > > > > > ret =3D btrfs_drew_lock_init(&root->snapshot_lock); > > > > > > > > > > memalloc_nofs_restore(nofs_flag); > > > > > > > > > > > > > > The issue is here. nofs is set which means percpu attempts an= atomic > > > > > > > allocation. If it cannot find anything already allocated it i= sn't happy. > > > > > > > This was done before memalloc_nofs_{save/restore}() were perv= asive. > > > > > > > > > > > > > > Percpu should probably try to allocate some pages if possible= even if > > > > > > > nofs is set. > > > > > > > > > > > > Thanks. > > > > > > > > > > > > I will wait for the patch, and then test it. > > > > > > > > > > > > > > > > I'm currently a bit busy with some other things. Adding support I= don't > > > > > think will be much work, just a little bit tricky. > > > > > > > > > > I recommend carrying what you have minus the change to reserved p= ercpu > > > > > memory for now. If I'm the one to write it, I'll cc you. > > > > > > > > > > Thanks, > > > > > Dennis > > > > > > > > > > > > In the recent test, another problem is triggered too with my extend= ed > > > > percpu buffer size patch. maybe this info is helpful. > > > > > > > > problem: > > > > OS/VGA console is freezed , and no call stace is outputed. > > > > Just some info is outputed to IPMI/dell iDRAC > > > > 2 | 04/03/2021 | 11:35:01 | OS Critical Stop #0x46 | Run-time cr= itical stop () | Asserted > > > > 3 | Linux kernel panic: Fatal excep > > > > 4 | Linux kernel panic: tion > > > > 5 | 04/05/2021 | 19:09:14 | OS Critical Stop #0x46 | Run-time cr= itical stop () | Asserted > > > > 6 | Linux kernel panic: Fatal excep > > > > 7 | Linux kernel panic: tion > > > > 8 | 04/06/2021 | 13:08:42 | OS Critical Stop #0x46 | Run-time cr= itical stop () | Asserted > > > > 9 | Linux kernel panic: Fatal excep > > > > a | Linux kernel panic: tion > > > > b | 04/08/2021 | 02:12:46 | OS Critical Stop #0x46 | Run-time cr= itical stop () | Asserted > > > > c | Linux kernel panic: Fatal excep > > > > d | Linux kernel panic: tion > > > > > > Unfortunately non of the above to me is useful. > > > > > > > kernel: at least 5.10.26/5.10.27/5.10.28 > > > > > > > > This problem is triggered by our application, NOT xfstests. > > > > But our applicaiton have some heavy write load just like xfstest/ge= neric/476. > > > > Our application use at most 75% of memory, if still not enough, > > > > it will write out all buffer info to filesystem. > > > > > > Do you use cgroups at all? If yes can you describe the workload patte= rn > > > a bit. > > > > > > > This problem is happen in linux kernel 5.10.x, but not happen in li= nux > > > > kernel 5.4.x. It have high frequency to repduce too. > > > > > > Ah. Can you try the following patch? > > > https://lore.kernel.org/lkml/20210408035736.883861-4-guro@fb.com/ > > > > Btw, this has been happening since 5.9. > > I never managed to find the time to bisect it, but it might be more > > obvious to you or anyone else with deep experience of mm/percpu of > > what changed. > > > > Ah I'm sorry about that. It wasn't brought to my attention and I don't > frequent the btrfs slack anymore. I can try and pop in more frequently > if that would help with these things. No worries, I don't think anyone reported it before. > > > It's triggered very frequently with long runs of fsstress on btrfs, > > such as with test cases btrfs/078 and generic/476 from fstests. > > It produces a trace like the following: > > > > [128063.794597] ------------[ cut here ]------------ > > [128063.795305] BTRFS: Transaction aborted (error -12) > > [128063.795831] WARNING: CPU: 0 PID: 1131545 at > > fs/btrfs/transaction.c:1683 create_pending_snapshot+0xa2a/0xfd0 > > [btrfs] > > [128063.796235] Modules linked in: dm_snapshot btrfs dm_thin_pool > > dm_persistent_data dm_bio_prison dm_bufio dm_log_writes dm_dust > > dm_flakey dm_mod loop xfs blake2b_generic xor raid6_pq libcrc32c > > intel_rapl_msr intel_rapl_common kvm_intel kvm irqbypass > > crct10dif_pclmul g> > > [128063.798521] CPU: 0 PID: 1131545 Comm: fsstress Tainted: G W > > 5.10.0-rc2-btrfs-next-71 #1 > > [128063.799102] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), > > BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014 > > [128063.800150] RIP: 0010:create_pending_snapshot+0xa2a/0xfd0 [btrfs] > > [128063.800748] Code: 02 72 30 83 f8 fb 0f 84 38 03 00 00 83 f8 e2 0f > > 84 2f 03 00 00 89 c6 48 c7 c7 e8 af c5 c0 48 89 85 78 ff ff ff e8 6d > > 29 6b ca <0f> 0b 48 8b 85 78 ff ff ff 89 c1 ba 93 06 00 00 48 c7 c6 90 > > a6 c4 > > [128063.801886] RSP: 0018:ffffaad1444cfd50 EFLAGS: 00010282 > > [128063.802529] RAX: 0000000000000000 RBX: ffff99c4c0d0b500 RCX: > > 0000000000000000 > > [128063.803175] RDX: 0000000000000001 RSI: 0000000000000027 RDI: > > 00000000ffffffff > > [128063.803829] RBP: ffffaad1444cfe20 R08: 0000000000000000 R09: > > 0000000000000000 > > [128063.804478] R10: 0000000000000000 R11: 0000000000000000 R12: > > ffff99c70a1a4c10 > > [128063.805134] R13: ffff99c59e3d0e00 R14: ffff99c70e935d08 R15: > > 00000000fffffff4 > > [128063.805816] FS: 00007f0fdd733240(0000) GS:ffff99c7ebe00000(0000) > > knlGS:0000000000000000 > > [128063.806547] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > > [128063.807264] CR2: 00007f0fdd731000 CR3: 00000001ee3b6003 CR4: > > 00000000003706f0 > > [128063.807998] DR0: 0000000000000000 DR1: 0000000000000000 DR2: > > 0000000000000000 > > [128063.808707] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: > > 0000000000000400 > > [128063.809415] Call Trace: > > [128063.810172] ? create_pending_snapshots+0xaa/0xd0 [btrfs] > > [128063.810921] create_pending_snapshots+0xaa/0xd0 [btrfs] > > [128063.811680] btrfs_commit_transaction+0x2b6/0xb80 [btrfs] > > [128063.812429] ? finish_wait+0x90/0x90 > > [128063.813176] ? __ia32_sys_fdatasync+0x20/0x20 > > [128063.813898] iterate_supers+0x87/0xf0 > > [128063.814562] ksys_sync+0x60/0xb0 > > [128063.815214] __do_sys_sync+0xa/0x10 > > [128063.815879] do_syscall_64+0x33/0x80 > > [128063.816539] entry_SYSCALL_64_after_hwframe+0x44/0xa9 > > [128063.817191] RIP: 0033:0x7f0fdd829bd7 > > [128063.817907] Code: ff ff ff ff c3 66 0f 1f 44 00 00 48 8b 15 b1 82 > > 0c 00 f7 d8 64 89 02 b8 ff ff ff ff eb b8 0f 1f 44 00 00 b8 a2 00 00 > > 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 89 82 0c 00 f7 d8 64 89 > > 01 48 > > [128063.819411] RSP: 002b:00007fff356b8968 EFLAGS: 00000206 ORIG_RAX: > > 00000000000000a2 > > [128063.820233] RAX: ffffffffffffffda RBX: 000055acc4127560 RCX: > > 00007f0fdd829bd7 > > [128063.821028] RDX: 00000000ffffffff RSI: 000000002ecb3555 RDI: > > 00000000000069f4 > > [128063.821808] RBP: 000000000000c350 R08: 0000000000000014 R09: > > 00007fff356b893c > > [128063.822632] R10: 00007fff356b8565 R11: 0000000000000206 R12: > > 00000000000069f4 > > [128063.823416] R13: 00007fff356b89d0 R14: 00007fff356b8986 R15: > > 000055acc4115350 > > [128063.824249] CPU: 5 PID: 1131545 Comm: fsstress Tainted: G W > > 5.10.0-rc2-btrfs-next-71 #1 > > [128063.824931] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), > > BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014 > > [128063.826439] Call Trace: > > [128063.827119] dump_stack+0x8d/0xb5 > > [128063.827804] ? create_pending_snapshot+0xa2a/0xfd0 [btrfs] > > [128063.828456] __warn.cold+0x24/0x4b > > [128063.829100] ? create_pending_snapshot+0xa2a/0xfd0 [btrfs] > > [128063.829724] report_bug+0xd1/0x100 > > [128063.830327] handle_bug+0x35/0x80 > > [128063.830910] exc_invalid_op+0x14/0x70 > > [128063.831476] asm_exc_invalid_op+0x12/0x20 > > [128063.832042] RIP: 0010:create_pending_snapshot+0xa2a/0xfd0 [btrfs] > > > > With 5.8 and older, I never got such failures on my test boxes. > > > > Ah. Roman's cgroup percpu changes went in for 5.9. Can you please patch: > https://lore.kernel.org/lkml/20210408035736.883861-4-guro@fb.com/ > > That most likely will have to be cced to stable for 5.9+. With that patch applied, +12 hours runs of heavy fsstress and fstests did not trigger the issue anymore here. Thanks Dennis. > > Thanks, > Dennis --=20 Filipe David Manana, =E2=80=9CWhether you think you can, or you think you can't =E2=80=94 you're= right.=E2=80=9D