linux-kernel - Re: [PATCH] ftrace: Prevent RCU stall on PREEMPT

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <d32e7b3d-31f3-9699-1eee-c1e3b2839fe2@igalia.com>
Date:   Tue, 22 Nov 2022 10:16:41 -0300
From:   "Guilherme G. Piccoli" <gpiccoli@...lia.com>
To:     rostedt@...dmis.org
Cc:     "Masami Hiramatsu (Google)" <mhiramat@...nel.org>,
        linux-kernel@...r.kernel.org, rcu@...r.kernel.org,
        kernel-dev@...lia.com, kernel@...ccoli.net,
        "Paul E . McKenney" <paulmck@...nel.org>,
        Mark Rutland <mark.rutland@....com>
Subject: Re: [PATCH] ftrace: Prevent RCU stall on PREEMPT_VOLUNTARY kernels

On 16/11/2022 03:36, Masami Hiramatsu (Google) wrote:
> On Tue, 15 Nov 2022 17:48:47 -0300
> "Guilherme G. Piccoli" <gpiccoli@...lia.com> wrote:
> 
>> The function match_records() may take a while due to a large
>> number of string comparisons, so when in PREEMPT_VOLUNTARY
>> kernels we could face RCU stalls due to that.
>>
>> Add a cond_resched() to prevent that.
>>
>> Suggested-by: Steven Rostedt <rostedt@...dmis.org>
>> Acked-by: Paul E. McKenney <paulmck@...nel.org> # from RCU CPU stall warning perspective
>> Cc: Masami Hiramatsu <mhiramat@...nel.org>
>> Cc: Mark Rutland <mark.rutland@....com>
>> Signed-off-by: Guilherme G. Piccoli <gpiccoli@...lia.com>
> 
> This looks good to me.
> 
> Acked-by: Masami Hiramatsu (Google) <mhiramat@...nel.org>
> 
> Thanks!
> 

Hi Steve, apologies for the ping, just want to ask you if you plan to
take this one or should I change something? Thanks in advance,


Guilherme