From: Mike Galbraith <bitbucket@online.de>
To: John Stultz <john.stultz@linaro.org>
Cc: LKML <linux-kernel@vger.kernel.org>,
"Cc: Salman Qazi" <sqazi@google.com>
Subject: Re: [RFC][PATCH] clocksource: avoid unnecessary overflow in cyclecounter_cyc2ns()
Date: Tue, 04 Mar 2014 08:10:11 +0100 [thread overview]
Message-ID: <1393917011.5419.12.camel@marge.simpson.net> (raw)
In-Reply-To: <CALAqxLUeb2GuPyULnHL+FHgbdanVxz2JsvD2O0bJWKyN=CJ3UQ@mail.gmail.com>
On Tue, 2014-03-04 at 14:40 +0800, John Stultz wrote:
> On Tue, Mar 4, 2014 at 1:38 PM, Mike Galbraith <bitbucket@online.de> wrote:
> > (crap crap crap... M.A.I.N.T.A.I.N.E.R.S _dummy_)
> >
> > clocksource: avoid unnecessary overflow in cyclecounter_cyc2ns()
> >
> > As per 4cecf6d401a "sched, x86: Avoid unnecessary overflow in sched_clock",
> > cycles * mult >> shift is overflow prone. so give it the same treatment.
> >
> > Cc: Salman Qazi <sqazi@google.com>
> > Cc: John Stultz <john.stultz@linaro.org>,
> > Signed-off-by: Mike Galbraith <bitbucket@online.de>
>
> Thanks for sending this in! Curious exactly how the issue was being
> triggered?
Dunno that it is. This is the result of me rummaging around, looking
for any excuse what-so-ever for a small and identical group of weird a$$
boxen running old 2.6.32 kernels (w. 208 day fix!) to manage to hop back
and forth in time by exactly 208 days. Grep showed me that function, so
I scurried off and swiped the fix.
-Mike
next prev parent reply other threads:[~2014-03-04 7:10 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-03-04 5:38 [RFC][PATCH] clocksource: avoid unnecessary overflow in cyclecounter_cyc2ns() Mike Galbraith
2014-03-04 6:40 ` John Stultz
2014-03-04 7:10 ` Mike Galbraith [this message]
2014-03-05 0:58 ` John Stultz
2014-03-05 2:56 ` Mike Galbraith
-- strict thread matches above, loose matches on Subject: below --
2014-03-04 5:20 Mike Galbraith
2014-03-04 7:20 ` Henrik Austad
2014-03-04 7:31 ` Mike Galbraith
2014-03-04 7:36 ` Mike Galbraith
2014-03-04 8:02 ` Henrik Austad
2014-03-04 8:24 ` Mike Galbraith
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