linux-kernel - Re: [PATCH] blk-mq: add module parameter to not run block kworker on isolated CPUs

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: <ZSkpUFlw8FINofLG@lothringen>
Date:   Fri, 13 Oct 2023 13:26:08 +0200
From:   Frederic Weisbecker <frederic@...nel.org>
To:     Tejun Heo <tj@...nel.org>
Cc:     Ming Lei <ming.lei@...hat.com>, Jens Axboe <axboe@...nel.dk>,
        linux-block@...r.kernel.org, linux-kernel@...r.kernel.org,
        Juri Lelli <juri.lelli@...hat.com>,
        Andrew Theurer <atheurer@...hat.com>,
        Joe Mario <jmario@...hat.com>, Sebastian Jug <sejug@...hat.com>
Subject: Re: [PATCH] blk-mq: add module parameter to not run block kworker on
 isolated CPUs

On Tue, Oct 10, 2023 at 08:45:44AM -1000, Tejun Heo wrote:
> > +static bool respect_cpu_isolation;
> > +module_param(respect_cpu_isolation, bool, 0444);
> > +MODULE_PARM_DESC(respect_cpu_isolation,
> > +		"Don't schedule blk-mq worker on isolated CPUs passed in "
> > +		"isolcpus= or nohz_full=. User need to guarantee to not run "
> > +		"block IO on isolated CPUs (default: false)");
> 
> Any chance we can centralize these? It's no fun to try to hunt down module
> params to opt in different subsystems and the housekeeping interface does
> have some provisions for selecting different parts. I'd much prefer to see
> these settings to be collected into a central place.

Do we need this parameter in the first place? Shouldn't we avoid scheduling
blk-mq worker on isolated CPUs in any case?

Thanks.

> 
> Thanks.
> 
> -- 
> tejun