public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
From: john stultz <johnstul@us.ibm.com>
To: Salman Qazi <sqazi@google.com>
Cc: Ingo Molnar <mingo@elte.hu>, Paul Turner <pjt@google.com>,
	Peter Zijlstra <a.p.zijlstra@chello.nl>,
	LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] sched, x86: fix overflow in cyc2ns_offset
Date: Fri, 09 Mar 2012 16:35:14 -0800	[thread overview]
Message-ID: <1331339714.26253.139.camel@work-vm> (raw)
In-Reply-To: <CAKUOC8Wo6-YgrX7POQ2fukNcVre7K_f4n1+gXNk5s3gsbF-s+Q@mail.gmail.com>

On Fri, 2012-03-09 at 16:28 -0800, Salman Qazi wrote:
> On Fri, Mar 9, 2012 at 4:25 PM, john stultz <johnstul@us.ibm.com> wrote:
> > So... Sorry, why did you change it from the shifted logic?
> >
> 
> It's more generally applicable.  The compiler is smart enough to do
> the right thing in the power-of-two
> constant case.
>
> >
> > Is the compiler really smart enough to avoid the divides?
> 
> Yes, it is.  I verified that.

Ok, great! Thanks again! (Although I probably need to put rewriting the
the big x86/include/asm/timer.h comment on my TODO, since its not as
relevant anymore)

Acked-by: John Stultz <john.stultz@linaro.org>

Ingo/Thomas, this should probably go tip/timers/urgent & be marked for
stable. I can queue it and send you a pull request, but it might be just
easier to just pick up the patch.

thanks
-john


  reply	other threads:[~2012-03-10  0:35 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-03-08 23:23 [PATCH] sched, x86: fix overflow in cyc2ns_offset Salman Qazi
2012-03-09 19:23 ` john stultz
2012-03-09 23:58   ` Salman Qazi
2012-03-10  0:00     ` Salman Qazi
2012-03-10  0:22       ` Paul Turner
2012-03-10  0:29         ` Salman Qazi
2012-03-10  0:25       ` john stultz
2012-03-10  0:28         ` Salman Qazi
2012-03-10  0:35           ` john stultz [this message]
  -- strict thread matches above, loose matches on Subject: below --
2012-03-10  0:41 Salman Qazi

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=1331339714.26253.139.camel@work-vm \
    --to=johnstul@us.ibm.com \
    --cc=a.p.zijlstra@chello.nl \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mingo@elte.hu \
    --cc=pjt@google.com \
    --cc=sqazi@google.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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox