From: Sasha Levin <sashal@kernel.org>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: patches@lists.linux.dev, stable@vger.kernel.org,
Vladimir Riabchun <ferr.lambarginio@gmail.com>,
mhiramat@kernel.org, linux-kernel@vger.kernel.org,
linux-trace-kernel@vger.kernel.org
Subject: Re: [PATCH AUTOSEL 6.17-6.1] ftrace: Fix softlockup in ftrace_module_enable
Date: Tue, 28 Oct 2025 13:48:58 -0400 [thread overview]
Message-ID: <aQECCjH3rMiUSj-f@laps> (raw)
In-Reply-To: <20251025152545.534cb450@batman.local.home>
On Sat, Oct 25, 2025 at 03:25:45PM -0400, Steven Rostedt wrote:
>On Sat, 25 Oct 2025 12:00:16 -0400
>Sasha Levin <sashal@kernel.org> wrote:
>
>> - The change inserts `cond_resched()` inside the inner iteration over
>> every ftrace record (`kernel/trace/ftrace.c:7538`). That loop holds
>> the ftrace mutex and, for each record, invokes heavy helpers like
>> `test_for_valid_rec()` which in turn calls `kallsyms_lookup()`
>> (`kernel/trace/ftrace.c:4289`). On huge modules (e.g. amdgpu) this can
>> run for tens of milliseconds with preemption disabled, triggering the
>
>It got the "preemption disabled" wrong. Well maybe when running
>PREEMPT_NONE it is, but the description doesn't imply that.
Thanks for the review! I've been trying a new LLM for part of this series, and
it seems to underperform the one I was previously using.
--
Thanks,
Sasha
prev parent reply other threads:[~2025-10-28 17:48 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20251025160905.3857885-1-sashal@kernel.org>
2025-10-25 16:00 ` [PATCH AUTOSEL 6.17-6.1] ftrace: Fix softlockup in ftrace_module_enable Sasha Levin
2025-10-25 19:25 ` Steven Rostedt
2025-10-28 17:48 ` Sasha Levin [this message]
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