Messages in this thread | | | Subject | Re: Ques: [kernel/time/*] Is there any disadvantage in using usleep_range for more than 20ms delay ? | From | Clemens Ladisch <> | Date | Tue, 8 Dec 2015 10:03:59 +0100 |
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Aniroop Mathur wrote: > As in the kernel documentation, it is mentioned to use msleep for > 10ms+ delay, I am confused whether there would be any disadvantage in > using usleep_range for higher delays values because normally drivers > have variety of delays used (2, 10, 20, 40, 100, 500 ms). > > So, could you please help to confirm that if we use usleep_range for > inserting delays greater than 20 ms, would it be harmful or beneficial > or does not make any difference at all ?
As the documentation told you, usleep_range() is likely to require a separate interrupt, while msleep() is likely to round to some other, already-scheduled interrupt. The former is possibly harmful regarding CPU and power usage; you have to balance it against your need for accuracy.
(And usleep_range() has a 32-bit nanosecond limit on 32-bit architectures.)
Regards, Clemens
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