From: "Jack Harvard" <jack.harvard@googlemail.com>
To: linux-kernel@vger.kernel.org
Subject: gettimeofday() resolution in Linux?
Date: Thu, 10 Apr 2008 15:40:59 +0100 [thread overview]
Message-ID: <a72f6a3c0804100740s687beacbh80653107f4a7b702@mail.gmail.com> (raw)
Hi,
I would like to ask a few questions about how Linux keeps time.
As far as I understand,
1. Linux's time resolution is 10ms, as defined by HZ=100.
2. gettimeofday() can get time in microseconds, but I'm not sure about
the accuracy of the time finer than 10ms. Sometimes gettimeofday( )
can even give me microseconds results rolled backwards in time, which
I suspect could be caused by its accuracy. My question here is "how
accurate is the time from gettimeofday()"
3. If I want to increase the time resolution to 1ms, I can possibly
change HZ=1000, but if I want 1usec resolution, how can I do that? It
would be too busy for the processor to handle so frequent timer
interrupts if I just increase HZ=1000000.
Many thanks/muchas gracias/Danke vielmals!
next reply other threads:[~2008-04-10 14:41 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-04-10 14:40 Jack Harvard [this message]
2008-04-10 15:04 ` Lennart Sorensen
2008-04-10 15:35 ` Andi Kleen
2008-04-10 15:59 ` Jack Harvard
2008-04-10 17:41 ` Bart Van Assche
[not found] ` <a72f6a3c0804101057i10c572bak1dd09f0c7fd75d30@mail.gmail.com>
2008-04-10 18:02 ` Bart Van Assche
2008-04-10 15:49 ` Chris Friesen
2008-04-10 16:07 ` Bart Van Assche
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