Re: Possible spin-problem in nanosleep()

From: Richard B. Johnson
Date: Thu Jun 23 2005 - 07:48:02 EST

On Thu, 23 Jun 2005, Andreas Schwab wrote:

"Richard B. Johnson" <linux-os@xxxxxxxxxxxx> writes:

nanosleep() appears to have a problem. It may be just an
'accounting' problem, but it isn't pretty. Code that used
to use usleep() to spend most of it's time sleeping, used
little or no CPU time as shown by `top`. The same code,
converted to nanosleep() appears to spend a lot of CPU
cycles spinning. The result is that `top` or similar
programs show lots of wasted CPU time.

usleep() is just a wrapper around nanosleep(). Are you sure you got the
units right?


Yeah nano is -9 micro is -6, three more zeros when using nano.
I note that the actual syscall is __NR_nanosleep = 162. I don't
understand the discrepancy either.

Andreas Schwab, SuSE Labs, schwab@xxxxxxx
SuSE Linux Products GmbH, Maxfeldstraße 5, 90409 Nürnberg, Germany
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