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From: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
To: Peter Zijlstra <peterz@infradead.org>,
	"Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Mel Gorman <mgorman@techsingularity.net>,
	Mike Galbraith <efault@gmx.de>,
	Matt Fleming <matt@codeblueprint.co.uk>,
	LKML <linux-kernel@vger.kernel.org>, Len Brown <lenb@kernel.org>
Subject: Re: [PATCH 4/4] sched/fair: Use a recently used CPU as an idle candidate and the basis for SIS
Date: Sat, 03 Feb 2018 08:30:48 -0800	[thread overview]
Message-ID: <1517675448.21379.2.camel@linux.intel.com> (raw)
In-Reply-To: <20180202140817.GP2295@hirez.programming.kicks-ass.net>

On Fri, 2018-02-02 at 15:08 +0100, Peter Zijlstra wrote:
> On Fri, Feb 02, 2018 at 01:46:47PM +0100, Peter Zijlstra wrote:
> 
> > +static void __intel_pstate_hwp_set_desired(int val)
> > +{
> > +	u64 value;
> > +
> > +	value = rdmsrl(MSR_HWP_REQUEST);
> > +	value &= ~GENMASK_ULL(23, 16);
> > +	value |= (val & 0xff) << 16;
> > +	wrmsrl(MSR_HWP_REQUEST, val);
> > +}
> 
> Also, if we keep a software shadow of that MSR, we can avoid the
> rdmsr, which might also help.
The reason we don't keep a software shadow as users can use x86-energy-
perf utility or via BMC to adjust.  CCed  to Len. 

  reply	other threads:[~2018-02-03 16:30 UTC|newest]

Thread overview: 48+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-01-30 10:45 [PATCH 0/4] Reduce migrations and unnecessary spreading of load to multiple CPUs Mel Gorman
2018-01-30 10:45 ` [PATCH 1/4] sched/fair: Remove unnecessary parameters from wake_affine_idle Mel Gorman
2018-02-06 11:55   ` [tip:sched/urgent] sched/fair: Remove unnecessary parameters from wake_affine_idle() tip-bot for Mel Gorman
2018-01-30 10:45 ` [PATCH 2/4] sched/fair: Restructure wake_affine to return a CPU id Mel Gorman
2018-02-06 11:56   ` [tip:sched/urgent] sched/fair: Restructure wake_affine*() " tip-bot for Mel Gorman
2018-01-30 10:45 ` [PATCH 3/4] sched/fair: Do not migrate if the prev_cpu is idle Mel Gorman
2018-02-06 11:56   ` [tip:sched/urgent] " tip-bot for Mel Gorman
2018-01-30 10:45 ` [PATCH 4/4] sched/fair: Use a recently used CPU as an idle candidate and the basis for SIS Mel Gorman
2018-01-30 11:50   ` Peter Zijlstra
2018-01-30 12:57     ` Mel Gorman
2018-01-30 13:15       ` Peter Zijlstra
2018-01-30 13:25         ` Mel Gorman
2018-01-30 13:40           ` Peter Zijlstra
2018-01-30 14:06             ` Mel Gorman
2018-01-31  9:22         ` Rafael J. Wysocki
2018-01-31 10:17           ` Peter Zijlstra
2018-01-31 11:54             ` Mel Gorman
2018-01-31 17:44             ` Srinivas Pandruvada
2018-02-01  9:11               ` Peter Zijlstra
2018-02-01  7:50             ` Rafael J. Wysocki
2018-02-01  9:11               ` Peter Zijlstra
2018-02-01 13:18                 ` Srinivas Pandruvada
2018-02-02 11:00                   ` Rafael J. Wysocki
2018-02-02 14:54                     ` Srinivas Pandruvada
2018-02-02 19:48                       ` Mel Gorman
2018-02-02 20:01                         ` Srinivas Pandruvada
2018-02-05 11:10                           ` Mel Gorman
2018-02-05 17:04                             ` Srinivas Pandruvada
2018-02-05 17:50                               ` Mel Gorman
2018-02-04  8:42                         ` Rafael J. Wysocki
2018-02-04  8:38                       ` Rafael J. Wysocki
2018-02-02 11:42                 ` Rafael J. Wysocki
2018-02-02 12:46                   ` Peter Zijlstra
2018-02-02 12:55                     ` Peter Zijlstra
2018-02-02 14:08                     ` Peter Zijlstra
2018-02-03 16:30                       ` Srinivas Pandruvada [this message]
2018-02-05 10:44                         ` Peter Zijlstra
2018-02-05 10:58                           ` Ingo Molnar
2018-02-02 12:58                   ` Peter Zijlstra
2018-02-02 13:27                   ` Mel Gorman
2018-01-30 13:15       ` Mike Galbraith
2018-01-30 13:25         ` Peter Zijlstra
2018-01-30 13:35           ` Mike Galbraith
2018-01-30 11:53   ` Peter Zijlstra
2018-01-30 12:59     ` Mel Gorman
2018-01-30 13:06     ` Peter Zijlstra
2018-01-30 13:18       ` Mel Gorman
2018-02-06 11:56   ` [tip:sched/urgent] " tip-bot for Mel Gorman

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