Messages in this thread | | | Date | Mon, 25 Jan 2016 12:26:06 +0100 | From | Peter Zijlstra <> | Subject | Re: [PATCH] sched: Make schedstats a runtime tunable that is disabled by default |
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On Mon, Jan 25, 2016 at 10:05:31AM +0000, Mel Gorman wrote: > schedstats is very useful during debugging and performance tuning but it > incurs overhead. As such, even though it can be disabled at build time, > it is often enabled as the information is useful. This patch adds a > kernel command-line and sysctl tunable to enable or disable schedstats on > demand. It is disabled by default as someone who knows they need it can > also learn to enable it when necessary.
So the reason its often enabled in distro configs is (IIRC) that it enables trace_sched_stat_{wait,sleep,iowait,blocked}().
I've not looked at the details of this patch, but I suspect this patch would make these tracepoints available but non-functional unless you poke the magic button.
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