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| author |   Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2013-12-16 05:57:10 -0800 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2014-02-25 12:39:00 -0800 |
| commit | d550e81dc0ddc04f1b417c179c214103a28e0ee8 (patch) | |
| tree | a873c6b1a980500c59af7b194374d604e3dba1eb /tools/perf/scripts/python/export-to-postgresql.py | |
| parent | timers: Track total number of timers in list (diff) | |
| download | linux-dev-d550e81dc0ddc04f1b417c179c214103a28e0ee8.tar.xz linux-dev-d550e81dc0ddc04f1b417c179c214103a28e0ee8.zip | |
timers: Reduce __run_timers() latency for empty list
The __run_timers() function currently steps through the list one jiffy at
a time in order to update the timer wheel. However, if the timer wheel
is empty, no adjustment is needed other than updating ->timer_jiffies.
In this case, which is likely to be common for NO_HZ_FULL kernels, the
kernel currently incurs a large latency for no good reason. This commit
therefore short-circuits this case.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
Tested-by: Mike Galbraith <bitbucket@online.de>
Diffstat (limited to 'tools/perf/scripts/python/export-to-postgresql.py')
0 files changed, 0 insertions, 0 deletions