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From: Arjan van de Ven <arjan@linux.intel.com>
To: Peter Zijlstra <peterz@infradead.org>, Andi Kleen <ak@linux.intel.com>
Cc: "Li, Aubrey" <aubrey.li@linux.intel.com>,
	Frederic Weisbecker <fweisbec@gmail.com>,
	Christoph Lameter <cl@linux.com>, Aubrey Li <aubrey.li@intel.com>,
	tglx@linutronix.de, len.brown@intel.com, rjw@rjwysocki.net,
	tim.c.chen@linux.intel.com, paulmck@linux.vnet.ibm.com,
	yang.zhang.wz@gmail.com, x86@kernel.org,
	linux-kernel@vger.kernel.org, daniel.lezcano@linaro.org
Subject: Re: [RFC PATCH v1 00/11] Create fast idle path for short idle periods
Date: Mon, 17 Jul 2017 12:27:56 -0700	[thread overview]
Message-ID: <91d02dce-7a3c-371c-a247-55fce1e7124a@linux.intel.com> (raw)
In-Reply-To: <20170717192309.ubn5muvc3u7htuaw@hirez.programming.kicks-ass.net>

On 7/17/2017 12:23 PM, Peter Zijlstra wrote:
> Now I think the problem is that the current predictor goes for an
> average idle duration. This means that we, on average, get it wrong 50%
> of the time. For performance that's bad.

that's not really what it does; it looks at next tick
and then discounts that based on history;
(with different discounts for different order of magnitude)

  reply	other threads:[~2017-07-17 19:28 UTC|newest]

Thread overview: 114+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-07-10  1:38 [RFC PATCH v1 00/11] Create fast idle path for short idle periods Aubrey Li
2017-07-10  1:38 ` [RFC PATCH v1 01/11] sched/idle: create a fast " Aubrey Li
2017-07-10  1:38 ` [RFC PATCH v1 02/11] cpuidle: attach cpuidle governor statistics to the per-CPU device Aubrey Li
2017-07-10  1:38 ` [RFC PATCH v1 03/11] cpuidle: introduce cpuidle governor for idle prediction Aubrey Li
2017-07-12 12:16   ` Peter Zijlstra
2017-07-10  1:38 ` [RFC PATCH v1 04/11] sched/idle: make the fast idle path for short idle periods Aubrey Li
2017-07-11 12:58   ` Paul E. McKenney
2017-07-11 16:33     ` Frederic Weisbecker
2017-07-11 18:11       ` Paul E. McKenney
2017-07-12  3:19         ` Li, Aubrey
2017-07-12  5:03           ` Paul E. McKenney
2017-07-12  5:22             ` Li, Aubrey
2017-07-12 12:19       ` Peter Zijlstra
2017-07-10  1:38 ` [RFC PATCH v1 05/11] cpuidle: update idle statistics before cpuidle governor Aubrey Li
2017-07-10  1:38 ` [RFC PATCH v1 06/11] timers: keep sleep length updated as needed Aubrey Li
2017-07-10  1:38 ` [RFC PATCH v1 07/11] cpuidle: make idle residency update more generic Aubrey Li
2017-07-10  1:38 ` [RFC PATCH v1 08/11] cpuidle: menu: remove reduplicative implementation Aubrey Li
2017-07-10  1:38 ` [RFC PATCH v1 09/11] cpuidle: menu: feed cpuidle prediction to menu governor Aubrey Li
2017-07-10  1:38 ` [RFC PATCH v1 10/11] cpuidle: update cpuidle governor when needed Aubrey Li
2017-07-10  1:38 ` [RFC PATCH v1 11/11] sched/idle: Add a tuning knob to allow changing fast idle threshold Aubrey Li
2017-07-10  8:46 ` [RFC PATCH v1 00/11] Create fast idle path for short idle periods Peter Zijlstra
2017-07-10  9:29   ` Wanpeng Li
2017-07-10 13:59   ` Li, Aubrey
2017-07-10 14:46   ` Andi Kleen
2017-07-10 16:42     ` Peter Zijlstra
2017-07-10 17:27       ` Andi Kleen
2017-07-11  4:40         ` Li, Aubrey
2017-07-11  9:41           ` Peter Zijlstra
2017-07-11 16:09             ` Frederic Weisbecker
2017-07-11 16:34               ` Peter Zijlstra
2017-07-11 18:09                 ` Paul E. McKenney
2017-07-12 11:54                   ` Peter Zijlstra
2017-07-12 15:56                     ` Paul E. McKenney
2017-07-12 17:46                       ` Peter Zijlstra
2017-07-12 18:53                         ` Paul E. McKenney
2017-07-12 19:00                           ` Paul E. McKenney
2017-07-19 13:43                       ` Frederic Weisbecker
2017-07-19 14:51                         ` Paul E. McKenney
2017-07-12 12:22                   ` Peter Zijlstra
2017-07-12 15:54                     ` Paul E. McKenney
2017-07-12 17:17                       ` Peter Zijlstra
2017-07-12 17:57                         ` Peter Zijlstra
2017-07-12 18:50                           ` Paul E. McKenney
2017-07-12 18:46                         ` Paul E. McKenney
2017-07-13  8:34                           ` Peter Zijlstra
2017-07-12  4:15                 ` Li, Aubrey
2017-07-12  8:34                   ` Peter Zijlstra
2017-07-12 21:32                     ` Andi Kleen
2017-07-13  8:36                       ` Peter Zijlstra
2017-07-13 14:48                         ` Li, Aubrey
2017-07-13 14:53                           ` Peter Zijlstra
2017-07-13 15:13                             ` Li, Aubrey
2017-07-13 18:28                               ` Peter Zijlstra
2017-07-14  3:56                                 ` Li, Aubrey
2017-07-14 15:38                                   ` Peter Zijlstra
2017-07-14 15:52                                     ` Arjan van de Ven
2017-07-14 15:58                                       ` Peter Zijlstra
2017-07-14 16:03                                         ` Andi Kleen
2017-07-17  9:21                                           ` Peter Zijlstra
2017-07-17 13:41                                             ` Li, Aubrey
2017-07-14 15:53                                     ` Andi Kleen
2017-07-14 16:06                                       ` Peter Zijlstra
2017-07-14 16:26                                         ` Andi Kleen
2017-07-17 19:23                                           ` Peter Zijlstra
2017-07-17 19:27                                             ` Arjan van de Ven [this message]
2017-07-17 19:46                                               ` Thomas Gleixner
2017-07-17 19:51                                                 ` Arjan van de Ven
2017-07-17 19:59                                                   ` Thomas Gleixner
2017-07-17 19:48                                             ` Arjan van de Ven
2017-07-17 19:53                                               ` Thomas Gleixner
2017-07-17 19:55                                                 ` Arjan van de Ven
2017-07-18  3:23                                               ` Li, Aubrey
2017-07-18 18:55                                               ` Peter Zijlstra
2017-07-18  3:14                                             ` Li, Aubrey
2017-07-18  4:45                                               ` Andi Kleen
2017-07-18  6:43                                                 ` Thomas Gleixner
2017-07-18  6:56                                                   ` Li, Aubrey
2017-07-18 15:20                                                     ` Paul E. McKenney
2017-07-18 15:29                                                       ` Arjan van de Ven
2017-07-18 16:36                                                         ` Peter Zijlstra
2017-07-18 16:37                                                           ` Arjan van de Ven
2017-07-18 17:05                                                             ` Peter Zijlstra
2017-07-19  5:44                                                       ` Li, Aubrey
2017-07-19 14:48                                                         ` Paul E. McKenney
2017-07-19 15:03                                                           ` Christopher Lameter
2017-07-19 16:54                                                             ` Paul E. McKenney
2017-07-20  1:40                                                           ` Li, Aubrey
2017-07-20 12:50                                                             ` Paul E. McKenney
2017-07-20 13:45                                                               ` Arjan van de Ven
2017-07-20 14:19                                                               ` Peter Zijlstra
2017-07-20 16:02                                                                 ` Paul E. McKenney
2017-07-18 16:45                                                     ` Peter Zijlstra
2017-07-18  6:59                                                   ` Andi Kleen
2017-07-18  7:19                                                     ` Thomas Gleixner
2017-07-19  6:12                                                       ` Li, Aubrey
2017-07-19  7:55                                                         ` Thomas Gleixner
2017-07-20  1:56                                                           ` Li, Aubrey
2017-07-20  8:11                                                             ` Thomas Gleixner
2017-07-20 13:48                                                               ` Arjan van de Ven
2017-07-18  7:24                                                     ` Thomas Gleixner
2017-07-18 13:23                                               ` Peter Zijlstra
2017-07-19 13:43                                               ` Peter Zijlstra
2017-07-13 15:20                             ` Paul E. McKenney
2017-07-14  3:47                               ` Li, Aubrey
2017-07-14  4:05                                 ` Paul E. McKenney
2017-07-17 13:24                                   ` Li, Aubrey
2017-07-17 13:58                                     ` Peter Zijlstra
2017-07-17 14:02                                       ` Li, Aubrey
2017-07-12 12:14                   ` Peter Zijlstra
2017-07-11 17:58               ` Christoph Lameter
2017-07-12  2:07                 ` Li, Aubrey
2017-07-12  2:35               ` Li, Aubrey
2017-07-12 18:10               ` Peter Zijlstra
2017-07-11  9:02         ` Peter Zijlstra

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