From: Kim Phillips <kim.phillips@freescale.com>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: linuxppc-dev@ozlabs.org, Csdncannon <csdncannon@gmail.com>,
zhouminggang@hotmail.com
Subject: Re: Continual reading from the PowerPc time base register is not stable
Date: Thu, 22 Apr 2010 18:27:14 -0500 [thread overview]
Message-ID: <20100422182714.b591f3e2.kim.phillips@freescale.com> (raw)
In-Reply-To: <1271897416.2330.186.camel@pasglop>
On Thu, 22 Apr 2010 10:50:16 +1000
Benjamin Herrenschmidt <benh@kernel.crashing.org> wrote:
> On Wed, 2010-04-21 at 19:44 -0500, Kim Phillips wrote:
> > I took an 8377 rdb board, and let it run timebase.c (with the isync &
> > long long casts) all weekend, and have failed to reproduce the issue.
> > That was on linux 2.6.33, and I've got another machine running the
> > same
> > thing under 2.6.28 for the last couple of hours, still unable to
> > reproduce the issue.
>
> Do we need to add an isync to the vdso and kernel gettimeofday() ?
don't see why: I put two gettimeofday calls in a tight loop, checking
if (t2.tv_sec < t1.tv_sec) || (t2.tv_sec > t1.tv_sec + 1), and the
condition was never met. I also removed all {i,}sync instructions from
timebase.c (but left the long long casts in), and no failures were
reported.
Kim
next prev parent reply other threads:[~2010-04-22 23:15 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-03-25 2:41 Continual reading from the PowerPc time base register is not stable Csdncannon
2010-03-25 8:21 ` Benjamin Herrenschmidt
2010-03-25 10:05 ` Arnd Bergmann
2010-03-25 15:00 ` Csdncannon
2010-03-25 20:38 ` Benjamin Herrenschmidt
2010-03-26 1:11 ` Csdncannon
2010-03-26 1:22 ` Segher Boessenkool
2010-03-26 2:01 ` Csdncannon
2010-03-26 8:52 ` Segher Boessenkool
2010-03-26 9:01 ` Segher Boessenkool
2010-03-26 12:14 ` Csdncannon
2010-04-06 8:02 ` Csdncannon
2010-03-26 1:55 ` Benjamin Herrenschmidt
2010-03-26 2:04 ` Csdncannon
2010-03-25 22:00 ` Chris Friesen
2010-03-25 22:57 ` Benjamin Herrenschmidt
2010-03-25 23:37 ` Kumar Gala
2010-03-25 21:37 ` Segher Boessenkool
2010-04-10 3:14 ` Csdncannon
2010-04-22 0:44 ` Kim Phillips
2010-04-22 0:50 ` Benjamin Herrenschmidt
2010-04-22 23:27 ` Kim Phillips [this message]
2010-04-23 10:57 ` Csdncannon
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