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Date: Thu, 25 Sep 2025 07:15:45 -0400
From: Steven Rostedt <rostedt@kernel.org>
To: Peter Zijlstra <peterz@infradead.org>
Cc: linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, Masami
 Hiramatsu <mhiramat@kernel.org>, Mark Rutland <mark.rutland@arm.com>,
 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>, Andrew Morton
 <akpm@linux-foundation.org>, Namhyung Kim <namhyung@kernel.org>, Takaya
 Saeki <takayas@google.com>, Tom Zanussi <zanussi@kernel.org>, Thomas
 Gleixner <tglx@linutronix.de>, Ian Rogers <irogers@google.com>, Douglas
 Raillard <douglas.raillard@arm.com>
Subject: Re: [PATCH v2 3/8] tracing: Have syscall trace events read user
 space string
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In-Reply-To: <20250925072609.GU4067720@noisy.programming.kicks-ass.net>
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On Thu, 25 Sep 2025 09:26:09 +0200
Peter Zijlstra <peterz@infradead.org> wrote:

> And you can't just allocate memory and not bother with the
> migrate_disable() and retry stuff because?

Because tracing is supposed to be as non-intrusive as possible. I
rather not call into the allocation system from a trace point. I'm not
sure what side effects that may cause either.

I have yet to cause the retry path under stress tests. I had to insert
a msleep() for testing purposes to make sure it worked.

-- Steve