On 12/08/08 08:34, Rafael Vanoni wrote: > Li, Aubrey wrote: >> Li, Aubrey wrote: >> >>> Hi Rafael, >>> >>> Rafael.Vanoni wrote: >>> >>>> Here's a patch to identify the function causing a xcall. Here's an >>>> example output of the change this introduces: >>>> >>>> from >>>> >>>> sched : <cross calls> >>>> >>>> to >>>> >>>> sched : <cross call> unix`dtrace_xcall_func >>>> >>>> >>>> I'm not sure whether this should be the default option or only for >>>> -v. So please let me know what you think. >>>> >>>> Thanks, >>>> Rafael >>> I saw this patch in the powertop repo. >>> Previously, the cross call number on my idle system is: ============= >>> Wakeups-from-idle per second: 1621.6 interval: 5.0s >>> Top causes for wakeups: >>> 76.1% (1234.3) sched :<cross calls> >>> >>> --------snip-------- >>> 0.9% ( 14.0) dtrace :<cross calls> >>> ============ >>> >>> with this patch, the number decreased too much, see below: >>> ============== Wakeups-from-idle per second: 1592.7 interval: 5.0s >>> Top causes for wakeups: >>> 11.2% (178.8) sched :<cross call> >>> unix`dtrace_xcall_func >>> ----snip---- >>> 1.0% ( 16.0) dtrace :<cross call> unix`dtrace_xcall_func >>> ============== >>> >>> I believe the actual cross call shouldn't vary too much in idle. >>> Any thoughts? >>> >> hmm..., on x86, the patch missed xc_capture_cpus() function. >> on sparc, it missed too much. >> It looks like "sysinfo:::xcalls" is far more than "fbt::xc_common:entry". >> >> If we want to implement 6781149, we probably need to improve the probe. >> >> Thanks, >> -Aubrey >
Hi Aubrey Could you test this patch on your system? I've added firings of fbt::send_dirint that were not accounted for by fbt::xc_common. Unfortunately, I don't see a way of getting the function causing the xcalls in this situation. I chose to use send_dirint because it relates to a patch I'm sending in a few minutes to run PowerTOP on a specific cpu. Thanks, Rafael -------------- next part -------------- An embedded and charset-unspecified text was scrubbed... Name: more-xcalls.diff URL: <http://mail.opensolaris.org/pipermail/tesla-dev/attachments/20081208/fe8e518e/attachment.ksh>
