On Fri, 19 Aug 2005, Amos Shapira wrote: > On 8/19/05, guy keren <[EMAIL PROTECTED]> wrote: > > actually, it _looks_ like gettimeofday() sometimes takes less then a > > micro-second to execute. i tested it a few years ago on redhat 7.3, on a > > pentium 1.8MHz and an AMD athlon 2200+, and on both ofthem running > > gettimeofday in a tight loop very often yielded the same time (and > > gettimeofday returns the time in microsecond resolution). > > I'm not sure this is a correct way to measure - gettimeofday(2)'s *interface > definition* is to count nanoseconds, but that doesn't mean that the system's > clock can measure at this resolution.
on redhat 7.3 (that's where i made the tests, as i wrote), gettimeofday returns the time in a 'struct timeval', which has the time in seconds and micro-seconds. for the gory details - arch/XXX/kernel/time.c - do_gettimeofday(). the fact is, that i kept getting very close values - closer then the 'clock ticks' you get when using nanosleep in normal priority (i.e. the sleeps on the arch mentioned previously are 10ms or higher). you want to argue - argue with the numbers, not with me. ;) i'm not taking sides. -- guy "For world domination - press 1, or dial 0, and please hold, for the creator." -- nob o. dy ================================================================= To unsubscribe, send mail to [EMAIL PROTECTED] with the word "unsubscribe" in the message body, e.g., run the command echo unsubscribe | mail [EMAIL PROTECTED]
