linux-kernel - Re: [PATCH] x86/alternatives: Add cond_resched() to text_poke_bp

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Message-ID: <20230528232132.14ab3201@rorschach.local.home>
Date:   Sun, 28 May 2023 23:21:32 -0400
From:   Steven Rostedt <rostedt@...dmis.org>
To:     "Masami Hiramatsu (Google)" <mhiramat@...nel.org>
Cc:     LKML <linux-kernel@...r.kernel.org>, x86@...nel.org,
        Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...nel.org>, Borislav Petkov <bp@...en8.de>,
        Peter Zijlstra <peterz@...radead.org>
Subject: Re: [PATCH] x86/alternatives: Add cond_resched() to
 text_poke_bp_batch()

On Mon, 29 May 2023 11:52:46 +0900
Masami Hiramatsu (Google) <mhiramat@...nel.org> wrote:

> > +	/*
> > +	 * Function tracing can enable thousands of places that need to be
> > +	 * updated. This can take quite some time, and with full kernel debugging
> > +	 * enabled, this could cause the softlockup watchdog to trigger.
> > +	 * Add cond_resched() calls to each phase.
> > +	 */
> > +	cond_resched();  
> 
> Hmm, why don't you put this between the first step (put int3) and the
> second step (put other bytes)? I guess those would takes more time.

Ah you're right. I still want this here to clear the 'need resched'
flag before we start the process, but I did miss one after the first
loop.

Thanks for the review!

-- Steve