From: Preeti U Murthy <preeti@linux.vnet.ibm.com>
To: Frederic Weisbecker <fweisbec@gmail.com>,
LKML <linux-kernel@vger.kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>,
Thomas Gleixner <tglx@linutronix.de>,
Christoph Lameter <cl@linux.com>, Ingo Molnar <mingo@kernel.org>,
Viresh Kumar <viresh.kumar@linaro.org>,
Rik van Riel <riel@redhat.com>
Subject: Re: [PATCH 5/8] nohz: Restart the tick from irq exit
Date: Sun, 14 Jun 2015 14:49:16 +0530 [thread overview]
Message-ID: <557D4714.1090600@linux.vnet.ibm.com> (raw)
In-Reply-To: <1434044168-23173-6-git-send-email-fweisbec@gmail.com>
On 06/11/2015 11:06 PM, Frederic Weisbecker wrote:
> Restart the tick when necessary from the irq exit path. It makes nohz
> full more flexible and allow it to piggyback the tick restart on the
> scheduler IPI in the future instead of sending a dedicated IPI that
> often doubles the scheduler IPI on task wakeup. This will require
You can piggy back on the scheduler ipi when you add a timer/hrtimer and
add a new task to the runqueue of the nohz_full cpus, since we call
resched_curr() in these code paths. But what about the calls to kick
nohz_full cpus by perf events and posix cpu timers ? These call sites
seem to be concerned about specifically waking up nohz_full cpus as far
as I can see. IOW there is no scheduling ipi that we can fall back on in
these paths.
> careful review of resched_curr() callers.
>
Regards
Preeti U Murthy
next prev parent reply other threads:[~2015-06-14 9:19 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-06-11 17:36 [PATCH 0/8] tick/nohz: Tick dependency quick check + cleanups Frederic Weisbecker
2015-06-11 17:36 ` [PATCH 1/8] jiffies: Remove HZ > USEC_PER_SEC special case Frederic Weisbecker
2015-06-11 20:46 ` Rik van Riel
2015-06-11 17:36 ` [PATCH 2/8] apm32: Fix cputime == jiffies assumption Frederic Weisbecker
2015-06-11 20:47 ` Rik van Riel
2015-06-11 17:36 ` [PATCH 3/8] alpha: Fix jiffies based cputime assumption Frederic Weisbecker
2015-06-11 20:47 ` Rik van Riel
2015-06-11 17:36 ` [PATCH 4/8] nohz: Remove idle task special case Frederic Weisbecker
2015-06-11 20:47 ` Rik van Riel
2015-06-14 1:44 ` Preeti U Murthy
2015-07-07 14:45 ` Frederic Weisbecker
2015-06-11 17:36 ` [PATCH 5/8] nohz: Restart the tick from irq exit Frederic Weisbecker
2015-06-11 20:48 ` Rik van Riel
2015-06-12 7:32 ` Peter Zijlstra
2015-06-12 12:38 ` Frederic Weisbecker
2015-06-12 12:59 ` Peter Zijlstra
2015-06-12 13:06 ` Frederic Weisbecker
2015-06-14 9:30 ` Preeti U Murthy
2015-07-07 14:23 ` Frederic Weisbecker
2015-06-14 9:18 ` Preeti U Murthy
2015-06-14 9:19 ` Preeti U Murthy [this message]
2015-07-07 14:20 ` Frederic Weisbecker
2015-06-11 17:36 ` [PATCH 6/8] nohz: Move tick_nohz_restart_sched_tick() above its users Frederic Weisbecker
2015-06-11 20:48 ` Rik van Riel
2015-06-11 17:36 ` [PATCH 7/8] nohz: Evaluate tick dependency once on context switch Frederic Weisbecker
2015-06-11 20:46 ` Rik van Riel
2015-06-17 5:59 ` Preeti U Murthy
2015-07-07 14:30 ` Frederic Weisbecker
2015-06-12 7:36 ` Peter Zijlstra
2015-07-06 16:14 ` Frederic Weisbecker
2015-06-11 17:36 ` [PATCH 8/8] nohz: Remove useless argument on tick_nohz_task_switch() Frederic Weisbecker
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=557D4714.1090600@linux.vnet.ibm.com \
--to=preeti@linux.vnet.ibm.com \
--cc=cl@linux.com \
--cc=fweisbec@gmail.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@kernel.org \
--cc=peterz@infradead.org \
--cc=riel@redhat.com \
--cc=tglx@linutronix.de \
--cc=viresh.kumar@linaro.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