From: linux@arm.linux.org.uk (Russell King - ARM Linux)
To: linux-arm-kernel@lists.infradead.org
Subject: sched_clock always 0 and no process time accounting with 3.11-rc1
Date: Wed, 17 Jul 2013 10:15:19 +0100 [thread overview]
Message-ID: <20130717091519.GL24642@n2100.arm.linux.org.uk> (raw)
In-Reply-To: <20130717091209.GL6950@tarshish>
On Wed, Jul 17, 2013 at 12:12:09PM +0300, Baruch Siach wrote:
> Hi Russell,
>
> On Wed, Jul 17, 2013 at 10:03:55AM +0100, Russell King - ARM Linux wrote:
> > On Wed, Jul 17, 2013 at 09:19:25AM +0300, Baruch Siach wrote:
> > > Apparently the expression '(1 << 32)' evaluates to 1 on xtensa cross gcc, and
> > > x86_84 native gcc. According to my limited understanding, the C compiler is
> > > allowed to do so. This caused sched_clock_32() to return constant 0. I wonder
> > > how it didn't bite the ARM people who are using this code from quite some time
> > > (added LAKL to CC).
> >
> > It (a) used to be only 32-bit, and (b) <<32 on ARM evaluates to zero in
> > a 32-bit context (it's not a rotate).
> >
> > Patch looks fine.
>
> Thanks for the confirmation, I'll take it as an ack if you don't mind.
If you want it as an ack, use rmk+kernel at arm.linux.org.uk as the email
address please.
next prev parent reply other threads:[~2013-07-17 9:15 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CAMo8BfLO31GgMMA_hENr0xm=qaUz3EVLtaQ8hewiQHdbV+s6sA@mail.gmail.com>
2013-07-17 6:19 ` sched_clock always 0 and no process time accounting with 3.11-rc1 Baruch Siach
2013-07-17 6:39 ` Max Filippov
2013-07-17 6:47 ` [Linux-Xtensa] " Baruch Siach
2013-07-17 7:02 ` Chris Zankel
2013-07-17 7:14 ` Baruch Siach
2013-07-17 9:03 ` Russell King - ARM Linux
2013-07-17 9:12 ` Baruch Siach
2013-07-17 9:15 ` Russell King - ARM Linux [this message]
2013-07-17 15:15 ` [Linux-Xtensa] " Marc Gauthier
2013-07-17 15:24 ` Russell King - ARM Linux
2013-07-17 16:17 ` Marc Gauthier
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