Messages in this thread | | | Date | Fri, 30 May 2014 13:58:02 +0100 | Subject | Re: [PATCH] staging: nokia_h4: nokia_core.c: use usleep_range() instead of msleep() | From | Miguel Oliveira <> |
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Not on my prespective. Its says "~20 ms actual sleep for any value given in the 1~20ms range", so from my point of view it will sleep for 20ms, so I will save between 5 to 10ms. But maybe I'm seeing it the wrong way.
Regards
2014-05-30 13:35 GMT+01:00 Pavel Machek <pavel@ucw.cz>: > Hi! > >> So the /Documentation/timers/timers-howto.txt stats: >> >> SLEEPING FOR ~USECS OR SMALL MSECS ( 10us - 20ms): >> * Use usleep_range >> >> - Why not msleep for (1ms - 20ms)? >> Explained originally here: >> http://lkml.org/lkml/2007/8/3/250 >> msleep(1~20) may not do what the caller intends, and >> will often sleep longer (~20 ms actual sleep for any >> value given in the 1~20ms range). In many cases this >> is not the desired behavior. > ... >> Should the documentation should be ignored? > > Caller wants to sleep for 10ms; docs said it may sleep for 10-20msec; > that sounds reasonable. You replaced it with busy-loop for 10-15msec. > > That does not sound like improvement. > > Thanks, > Pavel > > -- > (english) http://www.livejournal.com/~pavelmachek > (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
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