public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
From: Pawel Moll <pawel.moll@arm.com>
To: John Stultz <john.stultz@linaro.org>
Cc: Steven Rostedt <rostedt@goodmis.org>,
	Ingo Molnar <mingo@redhat.com>,
	Peter Zijlstra <peterz@infradead.org>,
	Oleg Nesterov <oleg@redhat.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	Mel Gorman <mgorman@suse.de>,
	Andy Lutomirski <luto@amacapital.net>,
	Stephen Boyd <sboyd@codeaurora.org>,
	Baruch Siach <baruch@tkos.co.il>,
	Thomas Gleixner <tglx@linutronix.de>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [RFC] sched_clock: Track monotonic raw clock
Date: Tue, 22 Jul 2014 17:17:11 +0100	[thread overview]
Message-ID: <1406045831.25343.69.camel@hornet> (raw)
In-Reply-To: <53C95E97.2020805@linaro.org>

On Fri, 2014-07-18 at 18:51 +0100, John Stultz wrote:
> Very cool work! 

Glad that it doesn't sound too ridiculous :-)

> I've not been able to review it carefully, but one good
> stress test would be to pick a system where the hardware used for
> sched_clock is different from the hardware used for timekeeping.

Actually I've got exactly this situation on my board. I've got two
sources, and actually the worse (narrower and more expensive) one is
getting eventually used (because it's registered later - separate patch
to follow).

> Although, looking again, this looks like it only works on the "generic"
> sched_clock (so ARM/ARM64?)...

... and microblaze and xtensa right now, yes. This was just the simplest
thing for me to start with, but I appreciate it doesn't cover all
possible cases. Thus the debugfs attribute to tell userspace what can it
expect from the sched_clock. A hack it is, yes.

Pawel


  parent reply	other threads:[~2014-07-22 16:17 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-07-18 17:43 [RFC] sched_clock: Track monotonic raw clock Pawel Moll
2014-07-18 17:51 ` John Stultz
2014-07-18 19:06   ` Peter Zijlstra
2014-07-22 16:17   ` Pawel Moll [this message]
2014-07-18 19:13 ` Peter Zijlstra
2014-07-18 19:25   ` John Stultz
2014-07-18 19:34     ` Peter Zijlstra
2014-07-18 19:46       ` John Stultz
2014-07-18 20:22         ` Peter Zijlstra
2014-07-18 22:41           ` Peter Zijlstra
2014-07-22 16:17             ` Pawel Moll
2014-07-22 16:29               ` Peter Zijlstra
2014-07-22 16:17       ` Pawel Moll
2014-07-19  5:02 ` Richard Cochran
2014-07-22 16:17   ` Pawel Moll
2014-07-22 16:34     ` Peter Zijlstra
2014-07-22 16:48       ` Pawel Moll
2014-07-22 19:39     ` Richard Cochran
2014-09-12 11:45       ` Pawel Moll

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=1406045831.25343.69.camel@hornet \
    --to=pawel.moll@arm.com \
    --cc=akpm@linux-foundation.org \
    --cc=baruch@tkos.co.il \
    --cc=john.stultz@linaro.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=luto@amacapital.net \
    --cc=mgorman@suse.de \
    --cc=mingo@redhat.com \
    --cc=oleg@redhat.com \
    --cc=peterz@infradead.org \
    --cc=rostedt@goodmis.org \
    --cc=sboyd@codeaurora.org \
    --cc=tglx@linutronix.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