There seem to be two issues with nanosleep. The first is a lack of information in the man page. It would be useful to know that the minimum sleep time is limited to one tick of the system clock and that it varies with the architecture.
Second, given the above, there seems to be an initialization or end point count problem. The minimum time seems to be two ticks, not one and the sleep time is one more tick than is requested. -----Original Message----- From: owner-...@openbsd.org <owner-...@openbsd.org> On Behalf Of Philip Guenther Sent: May 21, 2018 7:29 PM To: Stephen Graf <s_g...@telus.net> Cc: arm@openbsd.org; Artturi Alm <artturi....@gmail.com> Subject: Re: nanosleep issue On Mon, May 21, 2018 at 11:30 AM, <s_g...@telus.net> wrote: > Thank you for the patch. I applied it and am now able to get times > less than 20 ms. However the time is now off by 1 ms instead of 10. A > sleep of > 10 ms goes 11 ms and a 1 ms sleep goes 2ms. See attached. > OpenBSD is not a tickless kernel. If you need nanosleep precision that's much higher than what you're seeing, then OpenBSD is not currently able to meet your requirements. Would it be better to be tickless? Sure, but no one has sat down and figured out how to do that _and_ continue to support the range of hardware we support. Is it on peoples' lists? Sure, but so is a lot of other stuff which is higher priority. Some day? Philip Guenther
