From: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
To: lkp@lists.01.org
Subject: Re: [rcu] 00f5159aeb6: +55.3% will-it-scale.time.involuntary_context_switches
Date: Wed, 21 Jan 2015 00:54:32 -0800 [thread overview]
Message-ID: <20150121085432.GD9719@linux.vnet.ibm.com> (raw)
In-Reply-To: <1421827607.5772.19.camel@marge.simpson.net>
[-- Attachment #1: Type: text/plain, Size: 851 bytes --]
On Wed, Jan 21, 2015 at 09:06:47AM +0100, Mike Galbraith wrote:
> On Tue, 2015-01-20 at 23:52 -0800, Paul E. McKenney wrote:
> > On Wed, Jan 21, 2015 at 03:32:44PM +0800, Huang Ying wrote:
> > > FYI, we noticed the below changes on
> > >
> > > git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git stall.2015.01.06a
> > > commit 00f5159aeb68f08ce29597be86be87d6db0c1ba1 ("rcu: Run grace-period kthreads at real-time priority")
> >
> > Glad this helps!
>
> The way I read it, it's hurting by increasing context switches... but if
> you'll need a boot param to turn it on in the future, this is moot :)
Heh! I guess I should read it more carefully. Anyway, the commit does
help in some heavy-load situations, but something more deft is clearly
required if it is to be enabled more generally.
Thanx, Paul
WARNING: multiple messages have this Message-ID (diff)
From: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
To: Mike Galbraith <umgwanakikbuti@gmail.com>
Cc: Huang Ying <ying.huang@intel.com>,
LKML <linux-kernel@vger.kernel.org>, LKP ML <lkp@01.org>
Subject: Re: [LKP] [rcu] 00f5159aeb6: +55.3% will-it-scale.time.involuntary_context_switches
Date: Wed, 21 Jan 2015 00:54:32 -0800 [thread overview]
Message-ID: <20150121085432.GD9719@linux.vnet.ibm.com> (raw)
In-Reply-To: <1421827607.5772.19.camel@marge.simpson.net>
On Wed, Jan 21, 2015 at 09:06:47AM +0100, Mike Galbraith wrote:
> On Tue, 2015-01-20 at 23:52 -0800, Paul E. McKenney wrote:
> > On Wed, Jan 21, 2015 at 03:32:44PM +0800, Huang Ying wrote:
> > > FYI, we noticed the below changes on
> > >
> > > git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git stall.2015.01.06a
> > > commit 00f5159aeb68f08ce29597be86be87d6db0c1ba1 ("rcu: Run grace-period kthreads at real-time priority")
> >
> > Glad this helps!
>
> The way I read it, it's hurting by increasing context switches... but if
> you'll need a boot param to turn it on in the future, this is moot :)
Heh! I guess I should read it more carefully. Anyway, the commit does
help in some heavy-load situations, but something more deft is clearly
required if it is to be enabled more generally.
Thanx, Paul
next prev parent reply other threads:[~2015-01-21 8:54 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-01-21 7:32 [rcu] 00f5159aeb6: +55.3% will-it-scale.time.involuntary_context_switches Huang Ying
2015-01-21 7:32 ` [LKP] " Huang Ying
2015-01-21 7:52 ` Paul E. McKenney
2015-01-21 7:52 ` [LKP] " Paul E. McKenney
2015-01-21 8:06 ` Mike Galbraith
2015-01-21 8:06 ` [LKP] " Mike Galbraith
2015-01-21 8:54 ` Paul E. McKenney [this message]
2015-01-21 8:54 ` Paul E. McKenney
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