linux-kernel - Re: [PATCH 1/5] sched/deadline: Initialize dl

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-next>] [day] [month] [year] [list]

Message-ID: <aGJlDGR1Wud0LOG5@jlelli-thinkpadt14gen4.remote.csb>
Date: Mon, 30 Jun 2025 11:21:00 +0100
From: Juri Lelli <juri.lelli@...hat.com>
To: Waiman Long <llong@...hat.com>
Cc: Ingo Molnar <mingo@...hat.com>, Peter Zijlstra <peterz@...radead.org>,
	Vincent Guittot <vincent.guittot@...aro.org>,
	Dietmar Eggemann <dietmar.eggemann@....com>,
	Steven Rostedt <rostedt@...dmis.org>,
	Ben Segall <bsegall@...gle.com>, Mel Gorman <mgorman@...e.de>,
	Valentin Schneider <vschneid@...hat.com>,
	linux-kernel@...r.kernel.org,
	Marcel Ziswiler <marcel.ziswiler@...ethink.co.uk>,
	Luca Abeni <luca.abeni@...tannapisa.it>
Subject: Re: [PATCH 1/5] sched/deadline: Initialize dl_servers after SMP

On 29/06/25 18:48, Waiman Long wrote:
> On 6/27/25 7:51 AM, Juri Lelli wrote:

...

> > @@ -1652,6 +1664,8 @@ int dl_server_apply_params(struct sched_dl_entity *dl_se, u64 runtime, u64 perio
> >   	int retval = 0;
> >   	int cpus;
> > +	guard(rcu)();
> > +
> 
> Your patch doesn't explain why a RCU guard is needed here?
> sched_init_dl_servers() is the changed caller, but it is called with
> rq_lock_irq held which should implies a RCU read critical section as IRQ is
> disabled.

Yeah, looks like it's not required. Will remove. Thanks for spotting it!

Best,
Juri