linux-kernel - Re: [PATCH v2] sched/core: Preempt current task in favour of bound kthread

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]

Date:   Tue, 10 Dec 2019 15:48:46 +0530
From:   Srikar Dronamraju <srikar@...ux.vnet.ibm.com>
To:     Peter Zijlstra <peterz@...radead.org>
Cc:     Dave Chinner <david@...morbit.com>, Phil Auld <pauld@...hat.com>,
        Ming Lei <ming.lei@...hat.com>, linux-block@...r.kernel.org,
        linux-fsdevel@...r.kernel.org, linux-xfs@...r.kernel.org,
        linux-kernel@...r.kernel.org, Jeff Moyer <jmoyer@...hat.com>,
        Dave Chinner <dchinner@...hat.com>,
        Eric Sandeen <sandeen@...hat.com>,
        Christoph Hellwig <hch@....de>, Jens Axboe <axboe@...nel.dk>,
        Ingo Molnar <mingo@...hat.com>, Tejun Heo <tj@...nel.org>,
        Vincent Guittot <vincent.guittot@...aro.org>
Subject: Re: [PATCH v2] sched/core: Preempt current task in favour of bound
 kthread

* Peter Zijlstra <peterz@...radead.org> [2019-12-10 10:33:38]:

> On Tue, Dec 10, 2019 at 10:26:01AM +0100, Peter Zijlstra wrote:
> 
> > > @@ -6716,7 +6737,7 @@ static void check_preempt_wakeup(struct rq *rq, struct task_struct *p, int wake_
> > >  	find_matching_se(&se, &pse);
> > >  	update_curr(cfs_rq_of(se));
> > >  	BUG_ON(!pse);
> > > -	if (wakeup_preempt_entity(se, pse) == 1) {
> > > +	if (wakeup_preempt_entity(se, pse) == 1 || kthread_wakeup_preempt(rq, p, wake_flags)) {
> > >  		/*
> > >  		 * Bias pick_next to pick the sched entity that is
> > >  		 * triggering this preemption.
> > 
> > How about something like:
> > 
> 	if (wakeup_preempt_entity(se, pse) >= !(wake_flags & WF_KTHREAD))
>
> That's a slightly less convoluted expression for the same value :-)	

Yes, this should work, let me try and get back to you.

-- 
Thanks and Regards
Srikar Dronamraju