Date: Fri, 3 Nov 2000 13:01:17 -0500 (EST) From: Zhiui Zhang <zzhang@cs.binghamton.edu> To: Poul-Henning Kamp <phk@critter.freebsd.dk> Cc: freebsd-hackers@FreeBSD.ORG Subject: Re: granularity of gettimeofday() Message-ID: <Pine.SOL.4.21.0011031255360.118-100000@jade> In-Reply-To: <920.973271386@critter>
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On Fri, 3 Nov 2000, Poul-Henning Kamp wrote: > In message <Pine.SOL.4.21.0011031156050.29568-100000@jade>, Zhiui Zhang writes: > > > >The manual says the granularity of gettimeofday() is hardware dependent. > >The time may be updated continuously or in clock ticks. Can anyone > >explain for me the two different ways of updating the time? What kind of > >hardware can help? > > You probably need to tell me what you need first... This is actually a question from the book "Kernel Project for Linux" and I am a TA for an operating system course that uses this textbook. I know a little bit of NTP and Intel Time stamp counter. I need an authoritive answer for this question because I do not have the time to go through the FreeBSD code to find out myself in a short time. My impression is that if the time is updated by an interrupt handler per tick, it can not get a microsecond granularity. -Zhihui To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
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