Messages in this thread | | | Subject | Re: [PATCH] fix granularity of task_u/stime(), v2 | From | Peter Zijlstra <> | Date | Thu, 12 Nov 2009 15:15:58 +0100 |
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On Thu, 2009-11-12 at 13:33 +0900, Hidetoshi Seto wrote: > Originally task_s/utime() were designed to return clock_t but later > changed to return cputime_t by following commit: > > commit efe567fc8281661524ffa75477a7c4ca9b466c63 > Author: Christian Borntraeger <borntraeger@de.ibm.com> > Date: Thu Aug 23 15:18:02 2007 +0200 > > It only changed the type of return value, but not the implementation. > As the result the granularity of task_s/utime() is still that of > clock_t, not that of cputime_t. > > So using task_s/utime() in __exit_signal() makes values accumulated > to the signal struct to be rounded and coarse grained. > > This patch removes casts to clock_t in task_u/stime(), to keep > granularity of cputime_t over the calculation. > > v2: > Use div_u64() to avoid error "undefined reference to `__udivdi3`" > on some 32bit systems. > > Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
/me hates all the cputime_t and clock_t mess.. but I guess the patch is good.
Thanks.
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