john stultz wrote: > On Mon, 2005-12-12 at 19:31 +0000, Shailabh Nagar wrote: > >>Christoph Lameter wrote: >> >>>On Wed, 7 Dec 2005, Shailabh Nagar wrote: >>> >>> >>> >>>>+void getnstimestamp(struct timespec *ts) >>> >>> >>>There is already getnstimeofday in the kernel. >>> >> >>Yes, and that function is being used within the getnstimestamp() being >>proposed. >>However, John Stultz had advised that getnstimeofday could get affected by >>calls to >>settimeofday and had recommended adjusting the getnstimeofday value with >>wall_to_monotonic. >> >>John, could you elaborate ? > > > I think you pretty well have it covered. > > getnstimeofday + wall_to_monotonic should be higher-res and more > reliable (then TSC based sched_clock(), for example) for getting a > timestamp. > > There may be performance concerns as you have to access the clock > hardware in getnstimeofday(), but there really is no other way for > reliable finely grained monotonically increasing timestamps. > > thanks > -john
Thanks, that clarifies. I guess the other underlying concern here would be whether these improvements (in resolution and reliability) should be going into getnstimeofday() itself (rather than creating a new func for the same) ? Or is it better to leave getnstimeofday as it is ? Thanks, Shailabh ------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Do you grep through log files for problems? Stop! Download the new AJAX search engine that makes searching your log files as easy as surfing the web. DOWNLOAD SPLUNK! http://ads.osdn.com/?ad_id=7637&alloc_id=16865&op=click _______________________________________________ ckrm-tech mailing list https://lists.sourceforge.net/lists/listinfo/ckrm-tech
