Re: clock_gettime.2: _COARSE clocks are not always faster...

2016-04-18 Thread Michael Kerrisk (man-pages)
On 04/18/2016 04:12 PM, Michael Kerrisk (man-pages) wrote: > Hello Rasmus, > > On 04/09/2016 05:50 PM, Rasmus Villemoes wrote: >> 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_{R

Re: clock_gettime.2: _COARSE clocks are not always faster...

2016-04-18 Thread Michael Kerrisk (man-pages)
Hello Rasmus, On 04/09/2016 05:50 PM, Rasmus Villemoes wrote: > 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 > sysc

clock_gettime.2: _COARSE clocks are not always faster...

2016-04-09 Thread Rasmus Villemoes
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