From: Rasmus Villemoes <linux@rasmusvillemoes•dk>
To: mtk.manpages@gmail•com
Cc: linux-man@vger•kernel.org, linuxppc-dev@lists•ozlabs.org
Subject: clock_gettime.2: _COARSE clocks are not always faster...
Date: Sat, 09 Apr 2016 18:50:47 +0200 [thread overview]
Message-ID: <87k2k67ml4.fsf@rasmusvillemoes.dk> (raw)
Hi Michael
The other day, I was curious how the vdso was implemented on ppc, and I
noted that neither ppc32 or ppc64 handle the _COARSE versions of
CLOCK_{REALTIME,MONOTONIC} in the vdso, so they fall back to an actual
syscall. And sure enough, measuring CLOCK_MONOTONIC
vs. CLOCK_MONOTONIC_COARSE shows that the latter has three times as much
overhead as the former.
Whether it's worth adding a note to the man page is up to you.
Best,
Rasmus
next reply other threads:[~2016-04-09 16:50 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-04-09 16:50 Rasmus Villemoes [this message]
2016-04-18 15:12 ` clock_gettime.2: _COARSE clocks are not always faster Michael Kerrisk (man-pages)
2016-04-18 15:23 ` Michael Kerrisk (man-pages)
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