From: Viresh Kumar <viresh.kumar@linaro.org>
To: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Peter Zijlstra <peterz@infradead.org>,
Julia Lawall <julia.lawall@inria.fr>,
Mel Gorman <mgorman@suse.de>, Ingo Molnar <mingo@redhat.com>,
kernel-janitors@vger.kernel.org,
Juri Lelli <juri.lelli@redhat.com>,
Vincent Guittot <vincent.guittot@linaro.org>,
Dietmar Eggemann <dietmar.eggemann@arm.com>,
Steven Rostedt <rostedt@goodmis.org>,
Ben Segall <bsegall@google.com>,
Daniel Bristot de Oliveira <bristot@redhat.com>,
linux-kernel@vger.kernel.org,
Valentin Schneider <valentin.schneider@arm.com>,
Gilles Muller <Gilles.Muller@inria.fr>,
srinivas.pandruvada@linux.intel.com
Subject: Re: [PATCH] sched/fair: check for idle core
Date: Thu, 22 Oct 2020 04:53:46 +0000 [thread overview]
Message-ID: <20201022044146.4n2jl6jzyycfhfzg@vireshk-i7> (raw)
In-Reply-To: <6145907.dAfbsivgMF@kreacher>
On 21-10-20, 20:11, Rafael J. Wysocki wrote:
> On Wednesday, October 21, 2020 3:10:26 PM CEST Peter Zijlstra wrote:
> > On Wed, Oct 21, 2020 at 02:19:50PM +0200, Peter Zijlstra wrote:
> > > On Wed, Oct 21, 2020 at 01:56:55PM +0200, Julia Lawall wrote:
> > > > Prior to 5.8, my machine was using intel_pstate and had few background
> > > > tasks. Thus the problem wasn't visible in practice. Starting with 5.8
> > > > the kernel decided that intel_cpufreq would be more appropriate, which
> > > > introduced kworkers every 0.004 seconds on all cores.
> > >
> > > That still doesn't make any sense. Are you running the legacy on-demand
> > > thing or something?
> > >
> > > Rafael, Srinivas, Viresh, how come it defaults to that?
> >
> > Does we want something like this?
> >
> > ---
> > arch/x86/configs/i386_defconfig | 3 +--
> > arch/x86/configs/x86_64_defconfig | 3 +--
> > drivers/cpufreq/Kconfig | 7 +++++--
> > 3 files changed, 7 insertions(+), 6 deletions(-)
> >
> > diff --git a/arch/x86/configs/i386_defconfig b/arch/x86/configs/i386_defconfig
> > index 78210793d357..c343ad459737 100644
> > --- a/arch/x86/configs/i386_defconfig
> > +++ b/arch/x86/configs/i386_defconfig
> > @@ -41,8 +41,7 @@ CONFIG_PM_DEBUG=y
> > CONFIG_PM_TRACE_RTC=y
> > CONFIG_ACPI_DOCK=y
> > CONFIG_ACPI_BGRT=y
> > -CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE=y
> > -CONFIG_CPU_FREQ_GOV_ONDEMAND=y
> > +CONFIG_CPU_FREQ_DEFAULT_GOV_SCHEDUTIL=y
> > CONFIG_X86_ACPI_CPUFREQ=y
> > CONFIG_EFI_VARS=y
> > CONFIG_KPROBES=y
> > diff --git a/arch/x86/configs/x86_64_defconfig b/arch/x86/configs/x86_64_defconfig
> > index 9936528e1939..23e1ea85c1ec 100644
> > --- a/arch/x86/configs/x86_64_defconfig
> > +++ b/arch/x86/configs/x86_64_defconfig
> > @@ -38,8 +38,7 @@ CONFIG_PM_DEBUG=y
> > CONFIG_PM_TRACE_RTC=y
> > CONFIG_ACPI_DOCK=y
> > CONFIG_ACPI_BGRT=y
> > -CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE=y
> > -CONFIG_CPU_FREQ_GOV_ONDEMAND=y
> > +CONFIG_CPU_FREQ_DEFAULT_GOV_SCHEDUTIL=y
> > CONFIG_X86_ACPI_CPUFREQ=y
> > CONFIG_IA32_EMULATION=y
> > CONFIG_EFI_VARS=y
> > diff --git a/drivers/cpufreq/Kconfig b/drivers/cpufreq/Kconfig
> > index 2c7171e0b001..8dfca6e9b836 100644
> > --- a/drivers/cpufreq/Kconfig
> > +++ b/drivers/cpufreq/Kconfig
> > @@ -37,8 +37,7 @@ config CPU_FREQ_STAT
> > choice
> > prompt "Default CPUFreq governor"
> > default CPU_FREQ_DEFAULT_GOV_USERSPACE if ARM_SA1100_CPUFREQ || ARM_SA1110_CPUFREQ
> > - default CPU_FREQ_DEFAULT_GOV_SCHEDUTIL if ARM64 || ARM
> > - default CPU_FREQ_DEFAULT_GOV_SCHEDUTIL if X86_INTEL_PSTATE && SMP
> > + default CPU_FREQ_DEFAULT_GOV_SCHEDUTIL if SMP
> > default CPU_FREQ_DEFAULT_GOV_PERFORMANCE
> > help
> > This option sets which CPUFreq governor shall be loaded at
> > @@ -71,6 +70,7 @@ config CPU_FREQ_DEFAULT_GOV_USERSPACE
> >
> > config CPU_FREQ_DEFAULT_GOV_ONDEMAND
> > bool "ondemand"
> > + depends on !SMP
> > select CPU_FREQ_GOV_ONDEMAND
> > select CPU_FREQ_GOV_PERFORMANCE
> > help
> > @@ -83,6 +83,7 @@ config CPU_FREQ_DEFAULT_GOV_ONDEMAND
> >
> > config CPU_FREQ_DEFAULT_GOV_CONSERVATIVE
> > bool "conservative"
> > + depends on !SMP
> > select CPU_FREQ_GOV_CONSERVATIVE
> > select CPU_FREQ_GOV_PERFORMANCE
> > help
>
> The changes above should work.
>
> > @@ -144,6 +145,7 @@ config CPU_FREQ_GOV_USERSPACE
> >
> > config CPU_FREQ_GOV_ONDEMAND
> > tristate "'ondemand' cpufreq policy governor"
> > + depends on !SMP
>
> But I don't think that we can do this and the one below.
I have exactly the same comments.
> > select CPU_FREQ_GOV_COMMON
> > help
> > 'ondemand' - This driver adds a dynamic cpufreq policy governor.
> > @@ -163,6 +165,7 @@ config CPU_FREQ_GOV_ONDEMAND
> > config CPU_FREQ_GOV_CONSERVATIVE
> > tristate "'conservative' cpufreq governor"
> > depends on CPU_FREQ
> > + depends on !SMP
> > select CPU_FREQ_GOV_COMMON
> > help
> > 'conservative' - this driver is rather similar to the 'ondemand'
> >
>
>
>
--
viresh
next prev parent reply other threads:[~2020-10-22 4:53 UTC|newest]
Thread overview: 68+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-20 16:37 [PATCH] sched/fair: check for idle core Julia Lawall
2020-10-21 7:29 ` Vincent Guittot
2020-10-21 11:13 ` Peter Zijlstra
2020-10-21 12:27 ` Vincent Guittot
2020-10-21 11:20 ` Mel Gorman
2020-10-21 11:56 ` Julia Lawall
2020-10-21 12:19 ` Peter Zijlstra
2020-10-21 12:42 ` Julia Lawall
2020-10-21 12:52 ` Peter Zijlstra
2020-10-21 18:18 ` Rafael J. Wysocki
2020-10-21 18:15 ` Rafael J. Wysocki
2020-10-21 19:47 ` Julia Lawall
2020-10-21 20:25 ` Rafael J. Wysocki
2020-10-21 13:10 ` Peter Zijlstra
2020-10-21 18:11 ` Rafael J. Wysocki
2020-10-22 4:53 ` Viresh Kumar [this message]
2020-10-22 7:11 ` Peter Zijlstra
2020-10-22 10:59 ` Viresh Kumar
2020-10-22 11:45 ` Rafael J. Wysocki
2020-10-22 12:02 ` default cpufreq gov, was: " Peter Zijlstra
2020-10-22 12:19 ` Rafael J. Wysocki
2020-10-22 12:29 ` Peter Zijlstra
2020-10-22 14:52 ` Mel Gorman
2020-10-22 14:58 ` Colin Ian King
2020-10-22 15:12 ` Phil Auld
2020-10-22 16:35 ` Mel Gorman
2020-10-22 17:59 ` Rafael J. Wysocki
2020-10-22 20:32 ` Mel Gorman
2020-10-22 20:39 ` Phil Auld
2020-10-22 15:25 ` Peter Zijlstra
2020-10-22 15:55 ` Rafael J. Wysocki
2020-10-22 16:29 ` Mel Gorman
2020-10-22 20:10 ` Giovanni Gherdovich
2020-10-22 20:16 ` Giovanni Gherdovich
2020-10-23 7:03 ` Peter Zijlstra
2020-10-23 17:46 ` Tom Lendacky
2020-10-26 19:52 ` Fontenot, Nathan
2020-10-22 15:45 ` A L
2020-10-22 15:55 ` Vincent Guittot
2020-10-23 5:23 ` Viresh Kumar
2020-10-22 16:23 ` [PATCH] cpufreq: Avoid configuring old governors as default with intel_pstate Rafael J. Wysocki
2020-10-23 6:29 ` Viresh Kumar
2020-10-23 11:59 ` Rafael J. Wysocki
2020-10-23 15:15 ` [PATCH v2] " Rafael J. Wysocki
2020-10-27 3:13 ` Viresh Kumar
2020-10-27 11:11 ` default cpufreq gov, was: [PATCH] sched/fair: check for idle core Qais Yousef
2020-10-27 11:26 ` Valentin Schneider
2020-10-27 11:42 ` Qais Yousef
2020-10-27 11:48 ` Viresh Kumar
2020-10-23 6:24 ` Viresh Kumar
2020-10-23 15:06 ` Rafael J. Wysocki
2020-10-27 3:13 ` Viresh Kumar
2020-10-22 11:21 ` AW: " Walter Harms
2020-10-21 12:28 ` Mel Gorman
2020-10-21 12:25 ` Vincent Guittot
2020-10-21 12:47 ` Mel Gorman
2020-10-21 12:56 ` Julia Lawall
2020-10-21 13:18 ` Mel Gorman
2020-10-21 13:24 ` Julia Lawall
2020-10-21 15:08 ` Mel Gorman
2020-10-21 15:18 ` Julia Lawall
2020-10-21 15:23 ` Vincent Guittot
2020-10-21 15:33 ` Julia Lawall
2020-10-21 15:19 ` Vincent Guittot
2020-10-21 17:00 ` Mel Gorman
2020-10-21 17:39 ` Julia Lawall
2020-10-21 13:48 ` Julia Lawall
2020-10-21 15:26 ` Mel Gorman
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