From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from relay.yourmailgateway.de (relay.yourmailgateway.de [194.59.206.189]) (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 8686D3E3D81 for ; Tue, 17 Mar 2026 14:52:53 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=194.59.206.189 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773759175; cv=none; b=uEKbHAip0wAwqRw98AiABBVkl0i6HYnMx/NT+SRWZnLC9gne7e43APMcQ4n9wuyP3zIUzd7z1J3kgQrWfTkEBULSDE5GkMr8Sq2T7m9CAtGwdDGWKBEc9XXoDdh2bicHFpnU8NBFmcfGY5cpnum+l4y5j6lmn+F05xC5FK48do8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773759175; c=relaxed/simple; bh=hU7Ja8MxE/dZQQrcMBR1UXNehBbNM13GFFWz7ogHftw=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=ClIAv9gqgohgdED/tTMEGq5N5XjIEZQdlNEhbYkao4++ghmJleOdWYekJpAzMGtsP++rOWf6Ayk3jlID5lzuaWSHAKBf78KDvlns2rZfnadKz7Q8fv7y/JJ2tj03UbYZcmEJnJ0lDonYbRHJEjHlxiWToY+u/A9joUl7P4bh7HI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=leemhuis.info; spf=pass smtp.mailfrom=leemhuis.info; dkim=pass (2048-bit key) header.d=leemhuis.info header.i=@leemhuis.info header.b=iZQaMoUL; arc=none smtp.client-ip=194.59.206.189 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=leemhuis.info Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=leemhuis.info Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=leemhuis.info header.i=@leemhuis.info header.b="iZQaMoUL" Received: from relay02-mors.netcup.net (localhost [127.0.0.1]) by relay02-mors.netcup.net (Postfix) with ESMTPS id 4fZvsW4vvzz4DtN; Tue, 17 Mar 2026 15:46:07 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=leemhuis.info; s=key2; t=1773758767; bh=hU7Ja8MxE/dZQQrcMBR1UXNehBbNM13GFFWz7ogHftw=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=iZQaMoUL+oEc/38KhuA8S8+7E2NC0J9rVIUVZT1JJx77OS2j03vgj/xPlEfi1f+0P 2E/ZAkpooyMSNVCR4T3TYQVQ3+OwddXBwg7Y+3xoXtRP3DFc5KNG8fP+yXV9/cfZSV 3EzJwd34x2jmlmbejI6WdW8jHuCLwJzCDBWEuh9Tg+wuceQFsDh4WaGmC5hJKDTA3r 67oSp6nLaKx47Ueixr32DUPLT7p9+kllIMM41Exr1T0pZI4f5i0pEXrMQ4KobMEtEc k3qh4fDeKdkqz9s+0mbTL/7yXh+BO/eRgcFgbfyzO6w375znWGq2hZ3OEUqDAkKer6 F/Pt2AlX37nsQ== Received: from policy02-mors.netcup.net (unknown [46.38.225.35]) by relay02-mors.netcup.net (Postfix) with ESMTPS id 4fZvsW4Bygz7wZR; Tue, 17 Mar 2026 15:46:07 +0100 (CET) Received: from mxe9fb.netcup.net (unknown [10.243.12.53]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-256) server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by policy02-mors.netcup.net (Postfix) with ESMTPS id 4fZvsW0drvz8svF; Tue, 17 Mar 2026 15:46:07 +0100 (CET) Received: from [IPV6:2a02:8108:8984:1d00:a0cf:1912:4be:477f] (unknown [IPv6:2a02:8108:8984:1d00:a0cf:1912:4be:477f]) by mxe9fb.netcup.net (Postfix) with ESMTPSA id 7C11D632D3; Tue, 17 Mar 2026 15:46:06 +0100 (CET) Authentication-Results: mxe9fb; spf=pass (sender IP is 2a02:8108:8984:1d00:a0cf:1912:4be:477f) smtp.mailfrom=regressions@leemhuis.info smtp.helo=[IPV6:2a02:8108:8984:1d00:a0cf:1912:4be:477f] Received-SPF: pass (mxe9fb: connection is authenticated) Message-ID: Date: Tue, 17 Mar 2026 15:46:06 +0100 Precedence: bulk X-Mailing-List: rcu@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: [regression] Re: RCU stall in unmap_page_range during exit_mmap (6.19 regression) To: Benjamin Eikel , linux-mm@kvack.org Cc: rcu@vger.kernel.org, Linux kernel regressions list References: <6261958.lOV4Wx5bFT@thinkpad-benjamin> From: Thorsten Leemhuis Content-Language: de-DE, en-US In-Reply-To: <6261958.lOV4Wx5bFT@thinkpad-benjamin> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-PPP-Message-ID: <177375876673.4092997.3395963888020776942@mxe9fb.netcup.net> X-Rspamd-Server: rspamd-worker-8404 X-Rspamd-Queue-Id: 7C11D632D3 X-NC-CID: VI8GR9lw6G18Uo1yXINFhZklGUWTm/u/WkVDAqWoHVKv1JU15aY= [ccing the regression list] Lo! On 3/16/26 09:18, Benjamin Eikel wrote: > > I have reported this issue as Debian bug #1130138 [1], which has been marked > “upstream”. I am therefore also reaching out here to make you aware of it. > Please let me know if you need additional information. FWIW, if no developer soon shows up to look into this, you likely need to perform a git bisection to identify the change that causes this; you might also want to check if mainline is affected: https://docs.kernel.org/admin-guide/verify-bugs-and-bisect-regressions.html https://docs.kernel.org/admin-guide/bug-bisect.html Ciao, Thorsten > After upgrading from linux-image-6.18.15+deb14-amd64, I see this error several > times and the system shortly freezes. It seems related to Zoom crashing first, > but the freezes were not noticable with older Linux kernels. > Currently booted into 6.18.15+deb14-amd64 which does not exhibit this issue. > The stalls occurred when running 6.19.6+deb14-amd64. More information about my > system can be found in the Debian bug report. > > Mär 09 09:13:48 thinkpad-benjamin kernel: rcu: INFO: rcu_preempt detected > stalls on CPUs/tasks: > Mär 09 09:13:48 thinkpad-benjamin kernel: rcu: Tasks blocked on > level-0 rcu_node (CPUs 0-15): P10008/1:b..l > Mär 09 09:13:48 thinkpad-benjamin kernel: rcu: (detected by 5, t=5252 > jiffies, g=177537, q=28067 ncpus=16) > Mär 09 09:13:48 thinkpad-benjamin kernel: task:zoom state:R > running task stack:0 pid:10008 tgid:10008 ppid:2089 > task_flags:0x40040c flags:0x00080802 > Mär 09 09:13:48 thinkpad-benjamin kernel: Call Trace: > Mär 09 09:13:48 thinkpad-benjamin kernel: > Mär 09 09:13:48 thinkpad-benjamin kernel: __schedule+0x48a/0xfc0 > Mär 09 09:13:48 thinkpad-benjamin kernel: preempt_schedule+0x32/0x50 > Mär 09 09:13:48 thinkpad-benjamin kernel: preempt_schedule_thunk+0x16/0x30 > Mär 09 09:13:48 thinkpad-benjamin kernel: _raw_spin_unlock+0x22/0x30 > Mär 09 09:13:48 thinkpad-benjamin kernel: unmap_page_range+0xbcb/0x1700 > Mär 09 09:13:48 thinkpad-benjamin kernel: unmap_vmas+0xa1/0x180 > Mär 09 09:13:48 thinkpad-benjamin kernel: exit_mmap+0xe1/0x3b0 > Mär 09 09:13:48 thinkpad-benjamin kernel: __mmput+0x41/0x150 > Mär 09 09:13:48 thinkpad-benjamin kernel: do_exit+0x251/0xa70 > Mär 09 09:13:48 thinkpad-benjamin kernel: do_group_exit+0x2d/0xc0 > Mär 09 09:13:48 thinkpad-benjamin kernel: ? > srso_alias_return_thunk+0x5/0xfbef5 > Mär 09 09:13:48 thinkpad-benjamin kernel: get_signal+0x8a4/0x920 > Mär 09 09:13:48 thinkpad-benjamin kernel: > arch_do_signal_or_restart+0x40/0x250 > Mär 09 09:13:48 thinkpad-benjamin kernel: exit_to_user_mode_loop+0x8e/0x480 > Mär 09 09:13:48 thinkpad-benjamin kernel: ? __x64_sys_sched_setaffinity+0x6a/ > 0xb0 > Mär 09 09:13:48 thinkpad-benjamin kernel: do_syscall_64+0x20b/0x600 > Mär 09 09:13:48 thinkpad-benjamin kernel: ? > srso_alias_return_thunk+0x5/0xfbef5 > Mär 09 09:13:48 thinkpad-benjamin kernel: ? ksys_read+0xcd/0xf0 > Mär 09 09:13:48 thinkpad-benjamin kernel: ? > srso_alias_return_thunk+0x5/0xfbef5 > Mär 09 09:13:48 thinkpad-benjamin kernel: ? do_syscall_64+0xbe/0x600 > Mär 09 09:13:48 thinkpad-benjamin kernel: ? > srso_alias_return_thunk+0x5/0xfbef5 > Mär 09 09:13:48 thinkpad-benjamin kernel: ? do_syscall_64+0xbe/0x600 > Mär 09 09:13:48 thinkpad-benjamin kernel: ? __x64_sys_close+0x3d/0x80 > Mär 09 09:13:48 thinkpad-benjamin kernel: ? > srso_alias_return_thunk+0x5/0xfbef5 > Mär 09 09:13:48 thinkpad-benjamin kernel: ? do_syscall_64+0xbe/0x600 > Mär 09 09:13:48 thinkpad-benjamin kernel: ? > srso_alias_return_thunk+0x5/0xfbef5 > Mär 09 09:13:48 thinkpad-benjamin kernel: ? exc_page_fault+0x7e/0x1a0 > Mär 09 09:13:48 thinkpad-benjamin kernel: > entry_SYSCALL_64_after_hwframe+0x76/0x7e > Mär 09 09:13:48 thinkpad-benjamin kernel: RIP: 0033:0x7f2876359e2d > Mär 09 09:13:48 thinkpad-benjamin kernel: RSP: 002b:00007ffc91243ad8 EFLAGS: > 00000246 ORIG_RAX: 00000000000000cb > Mär 09 09:13:48 thinkpad-benjamin kernel: RAX: 0000000000000000 RBX: > 00007f2875207700 RCX: 00007f2876359e2d > Mär 09 09:13:48 thinkpad-benjamin kernel: RDX: 00007ffc91243ae0 RSI: > 0000000000000080 RDI: 0000000000002718 > Mär 09 09:13:48 thinkpad-benjamin kernel: RBP: 0000000000000020 R08: > 0000000000000001 R09: 00007f2875206de8 > Mär 09 09:13:48 thinkpad-benjamin kernel: R10: 0000000000000000 R11: > 0000000000000246 R12: 00007ffc91243ae0 > Mär 09 09:13:48 thinkpad-benjamin kernel: R13: 00007ffc91243c80 R14: > 0000000000000000 R15: 0000000000000020 > Mär 09 09:13:48 thinkpad-benjamin kernel: > Mär 09 09:13:48 thinkpad-benjamin kernel: rcu: INFO: rcu_preempt detected > expedited stalls on CPUs/tasks: { P10008 } 5361 jiffies s: 1609 root: 0x0/T > Mär 09 09:13:48 thinkpad-benjamin kernel: rcu: blocking rcu_node structures > (internal RCU debug): > > Another one: > > Mär 09 09:14:51 thinkpad-benjamin kernel: rcu: INFO: rcu_preempt detected > stalls on CPUs/tasks: > Mär 09 09:14:51 thinkpad-benjamin kernel: rcu: Tasks blocked on > level-0 rcu_node (CPUs 0-15): P10008/1:b..l > Mär 09 09:14:51 thinkpad-benjamin kernel: rcu: (detected by 5, t=21007 > jiffies, g=177537, q=87903 ncpus=16) > Mär 09 09:14:51 thinkpad-benjamin kernel: task:zoom state:R > running task stack:0 pid:10008 tgid:10008 ppid:2089 > task_flags:0x40040c flags:0x00080802 > Mär 09 09:14:51 thinkpad-benjamin kernel: Call Trace: > Mär 09 09:14:51 thinkpad-benjamin kernel: > Mär 09 09:14:51 thinkpad-benjamin kernel: __schedule+0x48a/0xfc0 > Mär 09 09:14:51 thinkpad-benjamin kernel: preempt_schedule+0x32/0x50 > Mär 09 09:14:51 thinkpad-benjamin kernel: preempt_schedule_thunk+0x16/0x30 > Mär 09 09:14:51 thinkpad-benjamin kernel: _raw_spin_unlock+0x22/0x30 > Mär 09 09:14:51 thinkpad-benjamin kernel: unmap_page_range+0xbcb/0x1700 > Mär 09 09:14:51 thinkpad-benjamin kernel: unmap_vmas+0xa1/0x180 > Mär 09 09:14:51 thinkpad-benjamin kernel: exit_mmap+0xe1/0x3b0 > Mär 09 09:14:51 thinkpad-benjamin kernel: __mmput+0x41/0x150 > Mär 09 09:14:51 thinkpad-benjamin kernel: do_exit+0x251/0xa70 > Mär 09 09:14:51 thinkpad-benjamin kernel: do_group_exit+0x2d/0xc0 > Mär 09 09:14:51 thinkpad-benjamin kernel: ? > srso_alias_return_thunk+0x5/0xfbef5 > Mär 09 09:14:51 thinkpad-benjamin kernel: get_signal+0x8a4/0x920 > Mär 09 09:14:51 thinkpad-benjamin kernel: > arch_do_signal_or_restart+0x40/0x250 > Mär 09 09:14:51 thinkpad-benjamin kernel: exit_to_user_mode_loop+0x8e/0x480 > Mär 09 09:14:51 thinkpad-benjamin kernel: ? __x64_sys_sched_setaffinity+0x6a/ > 0xb0 > Mär 09 09:14:51 thinkpad-benjamin kernel: do_syscall_64+0x20b/0x600 > Mär 09 09:14:51 thinkpad-benjamin kernel: ? > srso_alias_return_thunk+0x5/0xfbef5 > Mär 09 09:14:51 thinkpad-benjamin kernel: ? ksys_read+0xcd/0xf0 > Mär 09 09:14:51 thinkpad-benjamin kernel: ? > srso_alias_return_thunk+0x5/0xfbef5 > Mär 09 09:14:51 thinkpad-benjamin kernel: ? do_syscall_64+0xbe/0x600 > Mär 09 09:14:51 thinkpad-benjamin kernel: ? > srso_alias_return_thunk+0x5/0xfbef5 > Mär 09 09:14:51 thinkpad-benjamin kernel: ? do_syscall_64+0xbe/0x600 > Mär 09 09:14:51 thinkpad-benjamin kernel: ? __x64_sys_close+0x3d/0x80 > Mär 09 09:14:51 thinkpad-benjamin kernel: ? > srso_alias_return_thunk+0x5/0xfbef5 > Mär 09 09:14:51 thinkpad-benjamin kernel: ? do_syscall_64+0xbe/0x600 > Mär 09 09:14:51 thinkpad-benjamin kernel: ? > srso_alias_return_thunk+0x5/0xfbef5 > Mär 09 09:14:51 thinkpad-benjamin kernel: ? exc_page_fault+0x7e/0x1a0 > Mär 09 09:14:51 thinkpad-benjamin kernel: > entry_SYSCALL_64_after_hwframe+0x76/0x7e > Mär 09 09:14:51 thinkpad-benjamin kernel: RIP: 0033:0x7f2876359e2d > Mär 09 09:14:51 thinkpad-benjamin kernel: RSP: 002b:00007ffc91243ad8 EFLAGS: > 00000246 ORIG_RAX: 00000000000000cb > Mär 09 09:14:51 thinkpad-benjamin kernel: RAX: 0000000000000000 RBX: > 00007f2875207700 RCX: 00007f2876359e2d > Mär 09 09:14:51 thinkpad-benjamin kernel: RDX: 00007ffc91243ae0 RSI: > 0000000000000080 RDI: 0000000000002718 > Mär 09 09:14:51 thinkpad-benjamin kernel: RBP: 0000000000000020 R08: > 0000000000000001 R09: 00007f2875206de8 > Mär 09 09:14:51 thinkpad-benjamin kernel: R10: 0000000000000000 R11: > 0000000000000246 R12: 00007ffc91243ae0 > Mär 09 09:14:51 thinkpad-benjamin kernel: R13: 00007ffc91243c80 R14: > 0000000000000000 R15: 0000000000000020 > Mär 09 09:14:51 thinkpad-benjamin kernel: > Mär 09 09:14:52 thinkpad-benjamin kernel: rcu: INFO: rcu_preempt detected > expedited stalls on CPUs/tasks: { P10008 } 21233 jiffies s: 1609 root: 0x0/T > Mär 09 09:14:52 thinkpad-benjamin kernel: rcu: blocking rcu_node structures > (internal RCU debug): > > Note the stall duration escalating from t=5252 jiffies (~5s) to t=21007 jiffies > (~21s), with the same grace period (g=177537), indicating the unmap_page_range > operation blocked for over a minute. > > Kind regards > Benjamin > > [1] https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1130138 > >