Re: more profiling

On 19 Sep 2006 at 13:17, Adrian Chadd wrote:

> Here's the hourly snapshot.
>
> Adrian
>
> Last 1 hour averages: (Cumulated time: 25411206816740, 2782.06 sec)
>
> Probe Name Events cumulated time best case average worst case Rate / sec % in int
>
> PROF_UNACCOUNTED 105984696 1728110104996 0 16305 424549192 38095.75 6.801
> PROF_OVERHEAD 115170 18666044 0 162 212816 41.40 0.000
> HttpStateData_readReply 6748802 20584289534326 0 3050065 23144291000 2425.83 81.005
> StoreEntry_write 82448181 19892984791130 0 241278 23142919280 29635.65 78.284
> storeGetMemSpace 82448181 18827597315536 0 228356 23142884908 29635.65 74.092
> comm_check_incoming 1746752 1530441372606 0 876164 92138904 627.86 6.023
> comm_handle_ready_fd 1652867 1265826211860 0 765836 233867732 594.12 4.981
> HttpStateData_processReplyBody 6747441 1252785308450 0 185668 9434162500 2425.34 4.930
> MemObject_write 82448181 1023697835718 0 12416 87664104 29635.65 4.029
> storeWriteComplete 82448181 684813646988 0 8305 46559868 29635.65 2.695
>

Is that all? or did you paste only part of probes?
When I used it on my prod caches, I enabled quite alot
more probes. When the profiling feature was included,
there were other concurrent changes (eg chunked mempools)
and in submitted patch many probes got left out.

Since then quite alot of changes have happened, so I'd
suggest to look at the gprof stats to decide what funcs
to probe with hires prof and add them.

Also review the probes already there - you'd want to make
sure a probe isn't left "running" at any function exit
point - this would lead to accounting to a probe sections
of code incorrectly.

There's something fishy with "best case" timers. They
shouldn't be zero, ever. Ditto "worst case" - they *can*
get high due to task switches, but your worst cases look
way too high, on P4 2.6G there should be 2.6G ticks per
second. Your worst case looks like probes have been
running for 8.9secs straight, seems unlikely.
So there seems to be a need to get hires profiling
uptodate with current squid code base.

Unfortunately, I can't participate for now, my company
has been restructured and caching has been thrown out, so
I don't have any suitable platform at the moment.. ;(

------------------------------------
 Andres Kroonmaa
 Elion
Received on Tue Sep 19 2006 - 05:15:40 MDT