Messages in this thread | | | Subject | Re: [PATCH] sched/cpufreq: don't trigger cpufreq update w/o real rt/deadline tasks running | From | "Rafael J. Wysocki" <> | Date | Thu, 21 Apr 2016 00:28:35 +0200 |
| |
On 4/21/2016 12:24 AM, Wanpeng Li wrote: > 2016-04-20 22:01 GMT+08:00 Peter Zijlstra <peterz@infradead.org>: >> On Wed, Apr 20, 2016 at 02:32:35AM +0200, Rafael J. Wysocki wrote: >>> On Monday, April 18, 2016 01:51:24 PM Wanpeng Li wrote: >>>> Sometimes update_curr() is called w/o tasks actually running, it is >>>> captured by: >>>> u64 delta_exec = rq_clock_task(rq) - curr->se.exec_start; >>>> We should not trigger cpufreq update in this case for rt/deadline >>>> classes, and this patch fix it. >>>> >>>> Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> >>> The signed-off-by tag should agree with the From: header. One way to achieve >>> that is to add an extra From: line at the start of the changelog. >>> >>> That said, this looks like a good catch that should go into 4.6 to me. >>> >>> Peter, what do you think? >> I'm confused by the Changelog. *what* ? > Sometimes .update_curr hook is called w/o tasks actually running, it is > captured by: > > u64 delta_exec = rq_clock_task(rq) - curr->se.exec_start; > > We should not trigger cpufreq update in this case for rt/deadline > classes, and this patch fix it.
That's what you wrote in the changelog, no need to repeat that.
I guess Peter is asking for more details, though. I actually would like to get some more details here too. Like an example of when the situation in question actually happens.
Thanks, Rafael
| |