Re: [Bugme-new] [Bug 8479] New: gettimeofday returning 1000000 in tv_usec on core2duo

[Andrew Morton <akpm@linux-foundation.org>]

On Tue, 15 May 2007 08:06:52 +0200 Eric Dumazet <dada1@cosmosbay.com> wrote:

> Andrew Morton a écrit :
> > On Mon, 14 May 2007 21:17:47 -0700 bugme-daemon@bugzilla.kernel.org wrote:
> > 
> >> http://bugzilla.kernel.org/show_bug.cgi?id=8479
> >>
> >>            Summary: gettimeofday returning 1000000 in tv_usec on core2duo
> >>     Kernel Version: 2.6.21
> >>             Status: NEW
> >>           Severity: normal
> >>              Owner: ak@suse.de
> >>          Submitter: dang@gentoo.org
> >>
> >>
> >> Most recent kernel where this bug did *NOT* occur: 2.6.20
> >> Distribution: Gentoo
> >> Hardware Environment: core2duo T7200 (all reporters had this same CPU)
> >> Software Environment: Linux 2.6.21, glibc 2.5
> >> Problem Description:
> >>
> >> gettimeofday returns 1 - 1000000 in tv_usec, not 0 - 999999 
> >> This does not happen on any of my AMD-based 32 or 64 bit boxes, only on my
> >> core2duo; I have 2 other reports of this problem, all on T7200's
> >>
> >> Steps to reproduce:
> >>
> >> call gettimeofday a lot.  Eventually, you'll get 1000000 returned in tv_usec. My
> >> average is ~1 in 1000000 calls.  I've attached my test program, with output from
> >> various boxes.  One of the other reporters tried the test program too, and got
> >> similar output.  .config will be attached too.
> > 
> > err, whoops.
> 
> I remember I already hit this and corrected it
> 
> http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=blobdiff;f=arch/x86_64/kernel/vsyscall.c;h=dc32cef961950915fbaa185e36ab802d5f7cea3b;hp=ba330f87067996a17495f7d03466d646c718b52c;hb=c8118c6c07f2edfd697aaa0b93e08c3b65a5a675;hpb=272a3713bb9e302e0455c894c41180a482d2c8a3

Oh, OK.

> Maybe a stable push is necessary ?

yup.  Please always think of -stable when preparing fixes.  I'm sure many
useful fixes are slipping past simply because those who _are_ looking out
for backportable fixes are missing things.

Greg, Chris: please consider c8118c6c07f2edfd697aaa0b93e08c3b65a5a675
for -stable, if it isn't already there.