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RE: S390 _stp_gettimeofday_ns() change
- From: "Stone, Joshua I" <joshua dot i dot stone at intel dot com>
- To: "David Wilder" <dwilder at us dot ibm dot com>
- Cc: <systemtap at sources dot redhat dot com>
- Date: Mon, 9 Oct 2006 12:39:21 -0700
- Subject: RE: S390 _stp_gettimeofday_ns() change
On Monday, October 09, 2006 12:33 PM, David Wilder wrote:
> While investigating a possible compiler bug on the s390 affecting
> __stp_estimate_cpufreq(), I came to the conclusion that this function
> made little sense on the s390. Both get_cycles() and udelay() use the
> TOD clock. On the s390 the TOD is always at a known frequency on all
> models. The following patch to _stp_gettimeofday_ns() simply
> converts get_cycles()'s return value into nanoseconds and it has the
> side effect of avoiding the gcc bug :)
>
> The per-cpu timer values are also not needed on the s390 as all cpus
> use the same TOD clock. However, I did not remove this code for ease
> of maintenance.
Committed. I don't have an s390 to test, so I'll have to assume you
know what you're talking about. ;)
Josh