All of lore.kernel.org
 help / color / mirror / Atom feed
From: Thomas Gleixner <tglx@linutronix.de>
To: Zhaoyang Huang <zhaoyang.huang@linaro.org>
Cc: linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org,
	mingo@redhat.com, peterz@infradead.org,
	"Zhaoyang Huang (黄朝阳)" <zhaoyang.huang@spreadtrum.com>
Subject: Re: [RESEND PATCH v2 2/2] power/idle: enhance the precision of sleep_length
Date: Fri, 17 Jun 2016 13:50:50 +0200 (CEST)	[thread overview]
Message-ID: <alpine.DEB.2.11.1606171346540.5839@nanos> (raw)
In-Reply-To: <CAN2waFuETjxzRwST_EGY4GhxFUZZsOPkysrcBsKCSmcp5hV+UQ@mail.gmail.com>

On Fri, 17 Jun 2016, Zhaoyang Huang wrote:
> On 17 June 2016 at 17:27, Thomas Gleixner <tglx@linutronix.de> wrote:
> > On Fri, 17 Jun 2016, Zhaoyang Huang wrote:
> >> There should be a gap between tick_nohz_idle_enter and
> >> tick_nohz_get_sleep_length when idle, which will cause the
> >> sleep_length is not very precised. Change it in this patch.
> >
> > What kind of imprecision are we talking about? Seconds, nanoseconds or
> > lightyears?
> >
> > Your changelog lacks any form of useful information.
> >
> sorry for the confusion. The imprecision can be caused by, for
> example, the callback function registered for CPU_PM_ENTER, which may
> consume a period of time within the 'idle' time. Besides, I also
> wonder why not calc the 'sleep_length' in the
> tick_nohz_get_sleep_length?  This value is calculated at very
> beginning of the idle in current approach.

You still are not explaining the amount of imprecision. What are you talking
about and is it really relevant in any way or are you just trying to solve an
acedemic issue?

Thanks,

	tglx

  reply	other threads:[~2016-06-17 11:53 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-06-17  9:13 [RESEND PATCH v2 1/2] power/cpuidle: enhance the precision of state select Zhaoyang Huang
2016-06-17  9:13 ` [RESEND PATCH v2 2/2] power/idle: enhance the precision of sleep_length Zhaoyang Huang
2016-06-17  9:27   ` Thomas Gleixner
2016-06-17 11:18     ` Zhaoyang Huang
2016-06-17 11:50       ` Thomas Gleixner [this message]
2016-06-20  1:14         ` Zhaoyang Huang
2016-06-22  3:01           ` Zhaoyang Huang
2016-06-23  7:01             ` Thomas Gleixner
2016-06-23  7:26               ` Zhaoyang Huang
2016-06-23  8:18                 ` Thomas Gleixner
2016-06-23  8:34                   ` Zhaoyang Huang
2016-06-23  8:35                     ` Thomas Gleixner
2016-06-23  8:45                       ` Zhaoyang Huang
2016-06-23 10:16                         ` Thomas Gleixner
2016-06-25  1:09 ` [RESEND PATCH v2 1/2] power/cpuidle: enhance the precision of state select Rafael J. Wysocki
2016-06-27  1:13   ` Zhaoyang Huang

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=alpine.DEB.2.11.1606171346540.5839@nanos \
    --to=tglx@linutronix.de \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-pm@vger.kernel.org \
    --cc=mingo@redhat.com \
    --cc=peterz@infradead.org \
    --cc=zhaoyang.huang@linaro.org \
    --cc=zhaoyang.huang@spreadtrum.com \
    /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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.