This is the mail archive of the
systemtap@sourceware.org
mailing list for the systemtap project.
[Bug runtime/3916] improve timing monotony
- From: "fche at redhat dot com" <sourceware-bugzilla at sourceware dot org>
- To: systemtap at sources dot redhat dot com
- Date: 24 Jan 2007 19:32:24 -0000
- Subject: [Bug runtime/3916] improve timing monotony
- References: <20070124160955.3916.fche@redhat.com>
- Reply-to: sourceware-bugzilla at sourceware dot org
------- Additional Comments From fche at redhat dot com 2007-01-24 19:32 -------
(In reply to comment #1)
> Possible solutions:
> * Find a better estimate of the cpu freq
> * Use a clock that's independent of cpu freq (e.g., a motherboard/chipset timer)
> * Get the kernel to provide a lockless gettimeofday
> * Others?
One simple thing is to keep the per-cpu counts from ever decreasing during
the resynchronization phase. This could let them drift ahead of real time,
but so be it. If it gets too bad, the runtime could emit a warning.
Also, the resync phase may not be necessary so frequently on stable_tsc
processors.
--
http://sourceware.org/bugzilla/show_bug.cgi?id=3916
------- You are receiving this mail because: -------
You are the assignee for the bug, or are watching the assignee.