Re: [PATCH] tmpfs time granularity fix for [acm]time moving backwards.

["Robin H. Johnson" <robbat2@gentoo.org>]

On Sun, Jun 11, 2006 at 12:12:41PM +0200, Jan Engelhardt wrote:
> >Test output from a filesystem supporting sub-second timestamps (jfs,xfs,ramfs):
> >creat:   m=1149891452.928796249 c=1149891452.928796249 a=1149891452.928796249
> >futimes: m=1149891452.928796249 c=1149891452.928796249 a=1149891452.928796249
> >
> >Test output from the tmpfs filesystem with the patch below:
> >creat:   m=1149892086.382150894 c=1149892086.382150894 a=1149892075.473249075
> >futimes: m=1149892086.383150885 c=1149892086.383150885 a=1149892086.383150885
> >
> Is it normal that creat and futimes match for jfs/xfs?
My testcase just seemed to run nice and fast there, if I do some work in the
middle or sleep, the numbers will be different more, but otherwise I think it
implies that both operations are taking place during the same time instance (I
have HZ=1000 as you may be able to deduce by the 1ms differences in some of the
pairs).

I ran it a few more times on ramfs for good measure.
creat: m=1150025153.933532153 c=1150025153.933532153 a=1150025151.29558289
futimes: m=1150025153.933532153 c=1150025153.933532153 a=1150025153.933532153
...
creat: m=1150025156.860505810 c=1150025156.860505810 a=1150025153.933532153
futimes: m=1150025156.861505801 c=1150025156.861505801 a=1150025156.861505801
...
creat: m=1150025247.906686387 c=1150025247.906686387 a=1150025247.459690410
futimes: m=1150025247.907686378 c=1150025247.907686378 a=1150025247.907686378

> >Signed-off-by: Robin H. Johnson <robbat2@gentoo.org>
> Hint: Cc it to the shmem.c maintainer, or it may get missed :)
Will do, thanks.

-- 
Robin Hugh Johnson
E-Mail     : robbat2@gentoo.org
GnuPG FP   : 11AC BA4F 4778 E3F6 E4ED  F38E B27B 944E 3488 4E85

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