Messages in this thread | | | Date | Fri, 31 Oct 2008 08:46:06 -0500 | From | Dimitri Sivanich <> | Subject | Re: [PATCH] small optimization to update_curr_rt |
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On Fri, Oct 31, 2008 at 06:10:13AM -0700, Steven Noonan wrote: > On Fri, Oct 31, 2008 at 6:03 AM, Dimitri Sivanich <sivanich@sgi.com> wrote: > > A very minor improvement, but might it be better to check sched_rt_runtime(rt_rq) > > before taking the rt_runtime_lock? > > Is it possible that the attribute sched_rt_runtime is checking could > change by the time it acquires the lock? If not, should be fine, I > think. >
Steve,
While it might be possible for it to change in that instant, I don't know if it matters.
If the runtime value should change to RUNTIME_INF in that instant, it will be caught in sched_rt_runtime_exceeded(). If it changed from RUNTIME_INF to a lower value, I doubt it would matter much, as at most one more rt_rq value wouldn't be checked. Either way some rt_rq values would have been checked during the loop and some would not.
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