From: Peter Zijlstra <peterz@infradead.org>
To: Ricardo Neri <ricardo.neri-calderon@linux.intel.com>
Cc: Juri Lelli <juri.lelli@redhat.com>,
Vincent Guittot <vincent.guittot@linaro.org>,
Ricardo Neri <ricardo.neri@intel.com>,
"Ravi V. Shankar" <ravi.v.shankar@intel.com>,
Ben Segall <bsegall@google.com>,
Daniel Bristot de Oliveira <bristot@redhat.com>,
Dietmar Eggemann <dietmar.eggemann@arm.com>,
Len Brown <len.brown@intel.com>, Mel Gorman <mgorman@suse.de>,
"Rafael J. Wysocki" <rafael.j.wysocki@intel.com>,
Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>,
Steven Rostedt <rostedt@goodmis.org>,
Tim Chen <tim.c.chen@linux.intel.com>,
Valentin Schneider <vschneid@redhat.com>,
x86@kernel.org, linux-kernel@vger.kernel.org,
"Tim C . Chen" <tim.c.chen@intel.com>
Subject: Re: [RFC PATCH 23/23] x86/process: Reset hardware history in context switch
Date: Tue, 27 Sep 2022 14:53:29 +0200 [thread overview]
Message-ID: <YzLySV4545F0MKSl@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <20220909231205.14009-24-ricardo.neri-calderon@linux.intel.com>
On Fri, Sep 09, 2022 at 04:12:05PM -0700, Ricardo Neri wrote:
> Reset the classification history of the current task when switching to
> the next task. Hardware will start anew the classification of the next
> running task.
Please quantify the cost of this HRESET instruction.
> diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c
> index 2f314b170c9f..74d8ad83e0b3 100644
> --- a/arch/x86/kernel/process_32.c
> +++ b/arch/x86/kernel/process_32.c
> @@ -52,6 +52,7 @@
> #include <asm/switch_to.h>
> #include <asm/vm86.h>
> #include <asm/resctrl.h>
> +#include <asm/hreset.h>
> #include <asm/proto.h>
>
> #include "process.h"
> @@ -214,6 +215,8 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p)
> /* Load the Intel cache allocation PQR MSR. */
> resctrl_sched_in();
>
> + reset_hardware_history();
> +
> return prev_p;
> }
>
> diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
> index 1962008fe743..0b175f30f359 100644
> --- a/arch/x86/kernel/process_64.c
> +++ b/arch/x86/kernel/process_64.c
> @@ -53,6 +53,7 @@
> #include <asm/xen/hypervisor.h>
> #include <asm/vdso.h>
> #include <asm/resctrl.h>
> +#include <asm/hreset.h>
> #include <asm/unistd.h>
> #include <asm/fsgsbase.h>
> #ifdef CONFIG_IA32_EMULATION
> @@ -657,6 +658,8 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p)
> /* Load the Intel cache allocation PQR MSR. */
> resctrl_sched_in();
>
> + reset_hardware_history();
> +
> return prev_p;
> }
>
> --
> 2.25.1
>
next prev parent reply other threads:[~2022-09-27 12:53 UTC|newest]
Thread overview: 78+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-09 23:11 [RFC PATCH 00/23] sched: Introduce classes of tasks for load balance Ricardo Neri
2022-09-09 23:11 ` [RFC PATCH 01/23] sched/task_struct: Introduce classes of tasks Ricardo Neri
2022-09-14 13:46 ` Peter Zijlstra
2022-09-16 14:41 ` Ricardo Neri
2022-09-27 13:01 ` Peter Zijlstra
2022-10-02 22:32 ` Ricardo Neri
2022-09-09 23:11 ` [RFC PATCH 02/23] sched: Add interfaces for " Ricardo Neri
2022-09-09 23:11 ` [RFC PATCH 03/23] sched/core: Initialize the class of a new task Ricardo Neri
2022-09-26 14:57 ` Joel Fernandes
2022-09-26 21:53 ` Ricardo Neri
2022-09-27 13:04 ` Peter Zijlstra
2022-09-27 15:48 ` Joel Fernandes
2022-10-01 20:32 ` Ricardo Neri
2022-09-09 23:11 ` [RFC PATCH 04/23] sched/core: Add user_tick as argument to scheduler_tick() Ricardo Neri
2022-09-09 23:11 ` [RFC PATCH 05/23] sched/core: Move is_core_idle() out of fair.c Ricardo Neri
2022-09-09 23:11 ` [RFC PATCH 06/23] sched/core: Update the classification of the current task Ricardo Neri
2022-09-14 13:44 ` Peter Zijlstra
2022-09-16 14:42 ` Ricardo Neri
2022-09-09 23:11 ` [RFC PATCH 07/23] sched/fair: Collect load-balancing stats for task classes Ricardo Neri
2022-09-09 23:11 ` [RFC PATCH 08/23] sched/fair: Compute task-class performance scores for load balancing Ricardo Neri
2022-09-27 9:15 ` Peter Zijlstra
2022-10-26 3:57 ` Ricardo Neri
2022-10-26 8:55 ` Peter Zijlstra
2022-10-27 3:30 ` Ricardo Neri
2022-09-09 23:11 ` [RFC PATCH 09/23] sched/fair: Use task-class performance score to pick the busiest group Ricardo Neri
2022-09-27 11:01 ` Peter Zijlstra
2022-10-05 23:38 ` Ricardo Neri
2022-10-06 8:37 ` Peter Zijlstra
2022-10-06 19:07 ` Ricardo Neri
2022-09-09 23:11 ` [RFC PATCH 10/23] sched/fair: Use classes of tasks when selecting a busiest runqueue Ricardo Neri
2022-09-27 11:25 ` Peter Zijlstra
2022-10-07 23:36 ` Ricardo Neri
2022-09-09 23:11 ` [RFC PATCH 11/23] thermal: intel: hfi: Introduce Hardware Feedback Interface classes Ricardo Neri
2022-09-09 23:11 ` [RFC PATCH 12/23] thermal: intel: hfi: Convert table_lock to use flags-handling variants Ricardo Neri
2022-09-27 11:34 ` Peter Zijlstra
2022-09-27 11:36 ` Peter Zijlstra
2022-10-26 3:59 ` Ricardo Neri
2022-10-26 3:58 ` Ricardo Neri
2022-09-09 23:11 ` [RFC PATCH 13/23] x86/cpufeatures: Add the Intel Thread Director feature definitions Ricardo Neri
2022-09-09 23:11 ` [RFC PATCH 14/23] thermal: intel: hfi: Update the class of the current task Ricardo Neri
2022-09-27 11:46 ` Peter Zijlstra
2022-10-07 20:34 ` Ricardo Neri
2022-09-09 23:11 ` [RFC PATCH 15/23] thermal: intel: hfi: Report per-cpu class-specific performance scores Ricardo Neri
2022-09-27 11:59 ` Peter Zijlstra
2022-10-05 23:59 ` Ricardo Neri
2022-10-06 8:52 ` Peter Zijlstra
2022-10-06 9:14 ` Peter Zijlstra
2022-10-06 15:05 ` Brown, Len
2022-10-06 16:14 ` Peter Zijlstra
2022-10-07 11:20 ` Len Brown
2022-09-09 23:11 ` [RFC PATCH 16/23] thermal: intel: hfi: Define a default classification for unclassified tasks Ricardo Neri
2022-09-09 23:11 ` [RFC PATCH 17/23] thermal: intel: hfi: Enable the Intel Thread Director Ricardo Neri
2022-09-27 12:00 ` Peter Zijlstra
2022-10-06 1:50 ` Ricardo Neri
2022-09-09 23:12 ` [RFC PATCH 18/23] sched/task_struct: Add helpers for task classification Ricardo Neri
2022-09-27 11:52 ` Peter Zijlstra
2022-10-08 0:38 ` Ricardo Neri
2022-09-09 23:12 ` [RFC PATCH 19/23] sched/core: Initialize helpers of " Ricardo Neri
2022-09-09 23:12 ` [RFC PATCH 20/23] thermal: intel: hfi: Implement model-specific checks for " Ricardo Neri
2022-09-09 23:12 ` [RFC PATCH 21/23] x86/cpufeatures: Add feature bit for HRESET Ricardo Neri
2022-09-09 23:12 ` [RFC PATCH 22/23] x86/hreset: Configure history reset Ricardo Neri
2022-09-27 12:03 ` Peter Zijlstra
2022-10-02 22:34 ` Ricardo Neri
2022-09-09 23:12 ` [RFC PATCH 23/23] x86/process: Reset hardware history in context switch Ricardo Neri
2022-09-27 12:52 ` Peter Zijlstra
2022-10-03 23:07 ` Ricardo Neri
2022-10-06 8:35 ` Peter Zijlstra
2022-10-06 22:55 ` Ricardo Neri
2022-09-27 12:53 ` Peter Zijlstra [this message]
2022-10-02 22:02 ` Ricardo Neri
2022-09-27 13:15 ` Borislav Petkov
2022-10-02 22:12 ` Ricardo Neri
2022-10-02 22:15 ` Borislav Petkov
2022-10-03 19:49 ` Ricardo Neri
2022-10-03 19:55 ` Borislav Petkov
[not found] ` <20220910072120.2651-1-hdanton@sina.com>
2022-09-16 14:51 ` [RFC PATCH 06/23] sched/core: Update the classification of the current task Ricardo Neri
2022-10-11 19:12 ` Trying to apply patch set Carlos Bilbao
2022-10-18 2:31 ` Ricardo Neri
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=YzLySV4545F0MKSl@hirez.programming.kicks-ass.net \
--to=peterz@infradead.org \
--cc=bristot@redhat.com \
--cc=bsegall@google.com \
--cc=dietmar.eggemann@arm.com \
--cc=juri.lelli@redhat.com \
--cc=len.brown@intel.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mgorman@suse.de \
--cc=rafael.j.wysocki@intel.com \
--cc=ravi.v.shankar@intel.com \
--cc=ricardo.neri-calderon@linux.intel.com \
--cc=ricardo.neri@intel.com \
--cc=rostedt@goodmis.org \
--cc=srinivas.pandruvada@linux.intel.com \
--cc=tim.c.chen@intel.com \
--cc=tim.c.chen@linux.intel.com \
--cc=vincent.guittot@linaro.org \
--cc=vschneid@redhat.com \
--cc=x86@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).