From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 BDE4D1C84AB for ; Thu, 1 Jan 2026 02:48:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767235713; cv=none; b=ZZ98PAlo//9cBr92Wk1RfEg9ANBsYylENg9XZzoP+AIOt8RpYLlPeKgNiuV82y0jxrnK38WcfRjiWxlDCYR6CRcvlXwApC3XSsEfHlKx0xNUktA08heCPnCSo2QXQOuvfFB587yVXEA9dbcwH8SB4cyzRmVEJR93lFV1P969ZJA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767235713; c=relaxed/simple; bh=y4AaWjLvfA+pKiWJ2xMU+1Ggn01e7HqjvghsPMr0bAM=; h=Date:To:From:Subject:Message-Id; b=ogQBE3tpv4BoDgXeoJc+CuLh7EBHtJpxjfloc5liT/ty0QiG8gGrJYcrY7GdOSUExTDS/T9T92ium3HVwMFd9Eq9ad7gvkslmq6wrqRQep6YtgXj6Gx+KluHqEEaBNBiPnbWIXwSnLUBWR+ebB/ZrmWus7/0+G5OJAPpm5aM+YM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=kvIs2Umn; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="kvIs2Umn" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 232C0C113D0; Thu, 1 Jan 2026 02:48:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1767235713; bh=y4AaWjLvfA+pKiWJ2xMU+1Ggn01e7HqjvghsPMr0bAM=; h=Date:To:From:Subject:From; b=kvIs2Umn2SzAbp7pZlzPr2LqKuVtbFjH/GDNz4BH/jEdCKXl5LPqaUNe3Pvpj/FdS vXa73Uhd+kBFtBtk8XoyMaUPYcTEmkehG7zHRZG4jWYpTPh/AU6O+d+M9E6uDbwL/O pbOkp2XxY9B/QIYZolR13ggB381EdKnTyqaeGYeg= Date: Wed, 31 Dec 2025 18:48:32 +9900 To: mm-commits@vger.kernel.org,pmladek@suse.com,mhiramat@kernel.org,lance.yang@linux.dev,joel.granados@kernel.org,gregkh@linuxfoundation.org,feng.tang@linux.alibaba.com,atomlin@atomlin.com,akpm@linux-foundation.org From: Andrew Morton Subject: + hung_task-introduce-helper-for-hung-task-warning.patch added to mm-nonmm-unstable branch Message-Id: <20260101024833.232C0C113D0@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The patch titled Subject: hung_task: introduce helper for hung task warning has been added to the -mm mm-nonmm-unstable branch. Its filename is hung_task-introduce-helper-for-hung-task-warning.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/hung_task-introduce-helper-for-hung-task-warning.patch This patch will later appear in the mm-nonmm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via various branches at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there most days ------------------------------------------------------ From: Aaron Tomlin Subject: hung_task: introduce helper for hung task warning Date: Tue, 30 Dec 2025 19:41:24 -0500 Patch series "hung_task: Provide runtime reset interface for hung task detector", v5. This series introduces the ability to reset /proc/sys/kernel/hung_task_detect_count. Writing a zero value to this file atomically resets the counter of detected hung tasks. This functionality provides system administrators with the means to clear the cumulative diagnostic history following incident resolution, thereby simplifying subsequent monitoring without necessitating a system restart. The implementation uses atomic acquire/release semantics to ensure that diagnostic metadata published by one CPU is correctly observed by the monitoring thread on another CPU. This patch (of 2): Consolidate the multi-line console output block for reporting a hung task into a new helper function, hung_task_diagnostics(). This improves readability in the main check_hung_task() loop and makes the diagnostic output structure easier to maintain and update in the future. Link: https://lkml.kernel.org/r/20251231004125.2380105-1-atomlin@atomlin.com Link: https://lkml.kernel.org/r/20251231004125.2380105-2-atomlin@atomlin.com Signed-off-by: Aaron Tomlin Cc: Greg Kroah-Hartman Cc: Joel Granados Cc: Lance Yang Cc: "Masami Hiramatsu (Google)" Cc: Petr Mladek Cc: Feng Tang Cc: Masami Hiramatsu (Google) Signed-off-by: Andrew Morton --- kernel/hung_task.c | 33 +++++++++++++++++++++++---------- 1 file changed, 23 insertions(+), 10 deletions(-) --- a/kernel/hung_task.c~hung_task-introduce-helper-for-hung-task-warning +++ a/kernel/hung_task.c @@ -223,6 +223,28 @@ static inline void debug_show_blocker(st } #endif +/** + * hung_task_diagnostics - Print structured diagnostic info for a hung task. + * @t: Pointer to the detected hung task. + * + * This function consolidates the printing of core diagnostic information + * for a task found to be blocked. + */ +static inline void hung_task_diagnostics(struct task_struct *t) +{ + unsigned long blocked_secs = (jiffies - t->last_switch_time) / HZ; + + pr_err("INFO: task %s:%d blocked for more than %ld seconds.\n", + t->comm, t->pid, blocked_secs); + pr_err(" %s %s %.*s\n", + print_tainted(), init_utsname()->release, + (int)strcspn(init_utsname()->version, " "), + init_utsname()->version); + if (t->flags & PF_POSTCOREDUMP) + pr_err(" Blocked by coredump.\n"); + pr_err("\"echo 0 > /proc/sys/kernel/hung_task_timeout_secs\" disables this message.\n"); +} + static void check_hung_task(struct task_struct *t, unsigned long timeout, unsigned long prev_detect_count) { @@ -252,16 +274,7 @@ static void check_hung_task(struct task_ if (sysctl_hung_task_warnings || hung_task_call_panic) { if (sysctl_hung_task_warnings > 0) sysctl_hung_task_warnings--; - pr_err("INFO: task %s:%d blocked for more than %ld seconds.\n", - t->comm, t->pid, (jiffies - t->last_switch_time) / HZ); - pr_err(" %s %s %.*s\n", - print_tainted(), init_utsname()->release, - (int)strcspn(init_utsname()->version, " "), - init_utsname()->version); - if (t->flags & PF_POSTCOREDUMP) - pr_err(" Blocked by coredump.\n"); - pr_err("\"echo 0 > /proc/sys/kernel/hung_task_timeout_secs\"" - " disables this message.\n"); + hung_task_diagnostics(t); sched_show_task(t); debug_show_blocker(t, timeout); _ Patches currently in -mm which might be from atomlin@atomlin.com are fs-proc-expose-mm_cpumask-in-proc-status.patch hung_task-introduce-helper-for-hung-task-warning.patch hung_task-enable-runtime-reset-of-hung_task_detect_count.patch hung_task-provide-runtime-reset-interface-for-hung-task-detector.patch