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author | Steven Rostedt <rostedt@goodmis.org> | 2008-07-07 14:16:51 -0400 |
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committer | Ingo Molnar <mingo@elte.hu> | 2008-07-11 15:53:25 +0200 |
commit | f7cce27f5605b9e137b829a47949cb2d3c7e1cab (patch) | |
tree | fbe270ccfb5cee3d055a52b6351ade2d34c5d74b /kernel/time | |
parent | 62c43dd9864dbd52ff158922d1d08c75f20335af (diff) | |
download | kernel_samsung_smdk4412-f7cce27f5605b9e137b829a47949cb2d3c7e1cab.zip kernel_samsung_smdk4412-f7cce27f5605b9e137b829a47949cb2d3c7e1cab.tar.gz kernel_samsung_smdk4412-f7cce27f5605b9e137b829a47949cb2d3c7e1cab.tar.bz2 |
sched_clock: widen the max and min time
With keeping the max and min sched time within one jiffy of the gtod clock
was too tight. Just before a schedule tick the max could easily be hit, as
well as just after a schedule_tick the min could be hit. This caused the
clock to jump around by a jiffy.
This patch widens the minimum to
last gtod + (delta_jiffies ? delta_jiffies - 1 : 0) * TICK_NSECS
and the maximum to
last gtod + (2 + delta_jiffies) * TICK_NSECS
This keeps the minum to gtod or if one jiffy less than delta jiffies
and the maxim 2 jiffies ahead of gtod. This may cause unstable TSCs to be
a bit more sporadic, but it helps keep a clock with a stable TSC working well.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Cc: Steven Rostedt <srostedt@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/time')
0 files changed, 0 insertions, 0 deletions