From: Peter Zijlstra <peterz@infradead.org>
To: Mike Snitzer <snitzer@redhat.com>
Cc: Mike Galbraith <umgwanakikbuti@gmail.com>,
Thomas Gleixner <tglx@linutronix.de>,
Mikulas Patocka <mpatocka@redhat.com>,
Alasdair Kergon <agk@redhat.com>, Ingo Molnar <mingo@kernel.org>,
linux-kernel@vger.kernel.org, dm-devel@redhat.com,
Joe Thornber <ejt@redhat.com>
Subject: Re: [RFC][PATCH] dm: Remove dm_bufio_cond_resched()
Date: Fri, 23 Sep 2016 14:46:24 +0200 [thread overview]
Message-ID: <20160923124624.GL5008@twins.programming.kicks-ass.net> (raw)
In-Reply-To: <20160923124251.GA22428@redhat.com>
On Fri, Sep 23, 2016 at 08:42:51AM -0400, Mike Snitzer wrote:
> On Fri, Sep 23 2016 at 8:26am -0400,
> Peter Zijlstra <peterz@infradead.org> wrote:
>
> > On Fri, Sep 23, 2016 at 02:17:10PM +0200, Mike Galbraith wrote:
> > > On Fri, 2016-09-23 at 10:00 +0200, Thomas Gleixner wrote:
> > > > On Fri, 23 Sep 2016, Peter Zijlstra wrote:
> > >
> > > > > Is anybody still using PREEMPT_NONE? Most workloads also care about
> > > > > latency to some extend. Lots of code has explicit cond_resched() and
> > > > > doesn't worry.
> > > >
> > > > Dunno. But I bet there are workloads which love it.
> > >
> > > SUSE definitely uses it. I had presumed that was enterprise standard.
> >
> > Hmm, I thought most distros defaulted to PREEMPT_VOLUNTARY.
>
> So what is the concensus on this? Switch dm-bufio's cond_resched calls
> (in peter's patch) to might_sleep()? Or continue using cond_resched but
> fix cond_resched to do the might_sleep() equivalent if PREEMPT_NONE?
I'd go with the one I posted and look again if ever a performance issue
shows up.
next prev parent reply other threads:[~2016-09-23 12:46 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-09-13 8:45 [RFC][PATCH] dm: Remove dm_bufio_cond_resched() Peter Zijlstra
2016-09-13 12:49 ` Thomas Gleixner
2016-09-13 13:39 ` Mike Snitzer
2016-09-19 10:53 ` Peter Zijlstra
2016-09-22 20:53 ` Mikulas Patocka
2016-09-22 20:59 ` Thomas Gleixner
2016-09-23 7:34 ` Peter Zijlstra
2016-09-23 8:00 ` Thomas Gleixner
2016-09-23 9:05 ` Peter Zijlstra
2016-09-23 9:13 ` Thomas Gleixner
2016-09-23 9:26 ` Ingo Molnar
2016-09-23 12:17 ` Mike Galbraith
2016-09-23 12:26 ` Peter Zijlstra
2016-09-23 12:39 ` Mike Galbraith
2016-09-23 12:42 ` Mike Snitzer
2016-09-23 12:46 ` Peter Zijlstra [this message]
2016-09-23 14:32 ` [dm-devel] " Bart Van Assche
2016-09-19 9:49 ` Mikulas Patocka
2016-09-19 10:47 ` Peter Zijlstra
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