From: "Rafael J. Wysocki" <rjw@rjwysocki.net>
To: Frederic Weisbecker <frederic@kernel.org>
Cc: Linux PM <linux-pm@vger.kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Frederic Weisbecker <fweisbec@gmail.com>,
Thomas Gleixner <tglx@linutronix.de>,
Paul McKenney <paulmck@linux.vnet.ibm.com>,
Thomas Ilsche <thomas.ilsche@tu-dresden.de>,
Doug Smythies <dsmythies@telus.net>,
Rik van Riel <riel@surriel.com>,
Aubrey Li <aubrey.li@linux.intel.com>,
Mike Galbraith <mgalbraith@suse.de>,
LKML <linux-kernel@vger.kernel.org>,
Len Brown <len.brown@intel.com>
Subject: Re: [PATCH v9 05/10] cpuidle: Return nohz hint from cpuidle_select()
Date: Fri, 06 Apr 2018 09:24:42 +0200 [thread overview]
Message-ID: <1694033.ykrRIB27yN@aspire.rjw.lan> (raw)
In-Reply-To: <20180406024413.GB4400@lerouge>
On Friday, April 6, 2018 4:44:14 AM CEST Frederic Weisbecker wrote:
> On Wed, Apr 04, 2018 at 10:39:50AM +0200, Rafael J. Wysocki wrote:
> > From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> > Index: linux-pm/kernel/time/tick-sched.c
> > ===================================================================
> > --- linux-pm.orig/kernel/time/tick-sched.c
> > +++ linux-pm/kernel/time/tick-sched.c
> > @@ -991,6 +991,20 @@ void tick_nohz_irq_exit(void)
> > }
> >
> > /**
> > + * tick_nohz_idle_got_tick - Check whether or not the tick handler has run
> > + */
> > +bool tick_nohz_idle_got_tick(void)
> > +{
> > + struct tick_sched *ts = this_cpu_ptr(&tick_cpu_sched);
> > +
> > + if (ts->inidle > 1) {
> > + ts->inidle = 1;
> > + return true;
> > + }
> > + return false;
> > +}
> > +
> > +/**
> > * tick_nohz_get_sleep_length - return the length of the current sleep
> > *
> > * Called from power state control code with interrupts disabled
> > @@ -1101,6 +1115,9 @@ static void tick_nohz_handler(struct clo
> > struct pt_regs *regs = get_irq_regs();
> > ktime_t now = ktime_get();
> >
> > + if (ts->inidle)
> > + ts->inidle = 2;
> > +
>
> You can move that to tick_sched_do_timer() to avoid code duplication.
Right.
> Also these constants are very opaque. And even with proper symbols it wouldn't look
> right to extend ts->inidle that way.
Well, this was a Peter's idea. :-)
> Perhaps you should add a field such as ts->got_idle_tick under the boolean fields
> after the below patch:
OK, but at this point I'd prefer to make such changes on top of the existing
set, because that's got quite some testing coverage already and honestly this
is cosmetics in my view (albeit important).
> --
> From c7b2ca5a4c512517ddfeb9f922d5999f82542ced Mon Sep 17 00:00:00 2001
> From: Frederic Weisbecker <frederic@kernel.org>
> Date: Fri, 6 Apr 2018 04:32:37 +0200
> Subject: [PATCH] nohz: Gather tick_sched booleans under a common flag field
>
> This optimize the space and leave plenty of room for further flags.
>
> Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
> ---
> kernel/time/tick-sched.h | 10 ++++++----
> 1 file changed, 6 insertions(+), 4 deletions(-)
>
> diff --git a/kernel/time/tick-sched.h b/kernel/time/tick-sched.h
> index 954b43d..38f24dc 100644
> --- a/kernel/time/tick-sched.h
> +++ b/kernel/time/tick-sched.h
> @@ -45,14 +45,17 @@ struct tick_sched {
> struct hrtimer sched_timer;
> unsigned long check_clocks;
> enum tick_nohz_mode nohz_mode;
> +
> + unsigned int inidle : 1;
> + unsigned int tick_stopped : 1;
> + unsigned int idle_active : 1;
> + unsigned int do_timer_last : 1;
> +
> ktime_t last_tick;
> ktime_t next_tick;
> - int inidle;
> - int tick_stopped;
> unsigned long idle_jiffies;
> unsigned long idle_calls;
> unsigned long idle_sleeps;
> - int idle_active;
> ktime_t idle_entrytime;
> ktime_t idle_waketime;
> ktime_t idle_exittime;
> @@ -62,7 +65,6 @@ struct tick_sched {
> unsigned long last_jiffies;
> u64 next_timer;
> ktime_t idle_expires;
> - int do_timer_last;
> atomic_t tick_dep_mask;
> };
>
>
next prev parent reply other threads:[~2018-04-06 7:24 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-04-04 8:32 [PATCH v9 00/10] sched/cpuidle: Idle loop rework Rafael J. Wysocki
2018-04-04 8:33 ` [PATCH v9 01/10] time: tick-sched: Reorganize idle tick management code Rafael J. Wysocki
2018-04-04 8:34 ` [PATCH v9 02/10] sched: idle: Do not stop the tick upfront in the idle loop Rafael J. Wysocki
2018-04-04 8:36 ` [PATCH v9 03/10] sched: idle: Do not stop the tick before cpuidle_idle_call() Rafael J. Wysocki
2018-04-04 8:38 ` [PATCH v9 04/10] jiffies: Introduce USER_TICK_USEC and redefine TICK_USEC Rafael J. Wysocki
2018-04-06 1:09 ` Frederic Weisbecker
2018-04-06 7:20 ` Rafael J. Wysocki
2018-04-04 8:39 ` [PATCH v9 05/10] cpuidle: Return nohz hint from cpuidle_select() Rafael J. Wysocki
2018-04-06 2:44 ` Frederic Weisbecker
2018-04-06 7:24 ` Rafael J. Wysocki [this message]
2018-04-06 14:19 ` Frederic Weisbecker
2018-04-06 7:58 ` Peter Zijlstra
2018-04-06 14:23 ` Frederic Weisbecker
2018-04-06 8:11 ` Rafael J. Wysocki
2018-04-06 12:56 ` Rafael J. Wysocki
2018-04-06 15:28 ` Frederic Weisbecker
2018-04-06 14:28 ` Frederic Weisbecker
2018-04-04 8:41 ` [PATCH v9 06/10] time: tick-sched: Split tick_nohz_stop_sched_tick() Rafael J. Wysocki
2018-04-07 2:36 ` Frederic Weisbecker
2018-04-07 16:36 ` Rafael J. Wysocki
2018-04-04 8:45 ` [PATCH v9 07/10] time: hrtimer: Introduce hrtimer_next_event_without() Rafael J. Wysocki
2018-04-07 14:46 ` Frederic Weisbecker
2018-04-08 8:20 ` Rafael J. Wysocki
2018-04-08 17:58 ` Frederic Weisbecker
2018-04-04 8:47 ` [PATCH v9 08/10] sched: idle: Select idle state before stopping the tick Rafael J. Wysocki
2018-04-09 2:41 ` Frederic Weisbecker
2018-04-04 8:49 ` [PATCH v9 09/10] cpuidle: menu: Refine idle state selection for running tick Rafael J. Wysocki
2018-04-05 12:27 ` Peter Zijlstra
2018-04-05 13:51 ` Rafael J. Wysocki
2018-04-05 12:32 ` Peter Zijlstra
2018-04-05 13:52 ` Rafael J. Wysocki
2018-04-04 8:50 ` [PATCH v9 10/10] cpuidle: menu: Avoid selecting shallow states with stopped tick Rafael J. Wysocki
2018-04-05 12:47 ` Peter Zijlstra
2018-04-05 13:49 ` Rafael J. Wysocki
2018-04-05 14:11 ` Peter Zijlstra
2018-04-05 14:13 ` Peter Zijlstra
2018-04-05 14:29 ` Rafael J. Wysocki
2018-04-08 16:32 ` [PATCH v9 00/10] sched/cpuidle: Idle loop rework Rafael J. Wysocki
2018-04-09 15:58 ` Thomas Ilsche
2018-04-10 7:03 ` Rafael J. Wysocki
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=1694033.ykrRIB27yN@aspire.rjw.lan \
--to=rjw@rjwysocki.net \
--cc=aubrey.li@linux.intel.com \
--cc=dsmythies@telus.net \
--cc=frederic@kernel.org \
--cc=fweisbec@gmail.com \
--cc=len.brown@intel.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-pm@vger.kernel.org \
--cc=mgalbraith@suse.de \
--cc=paulmck@linux.vnet.ibm.com \
--cc=peterz@infradead.org \
--cc=riel@surriel.com \
--cc=tglx@linutronix.de \
--cc=thomas.ilsche@tu-dresden.de \
/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).