[haiku-bugs] Re: [Haiku] #10454: New scheduler: substantial performance drop
- From: "stippi" <trac@xxxxxxxxxxxx>
- Date: Tue, 21 Jan 2014 08:30:52 -0000
#10454: New scheduler: substantial performance drop
-----------------------------+----------------------------
Reporter: stippi | Owner: pdziepak
Type: task | Status: new
Priority: high | Milestone: R1
Component: System/Kernel | Version: R1/Development
Resolution: | Keywords:
Blocked By: | Blocking:
Has a Patch: 0 | Platform: All
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Description changed by stippi:
Old description:
> I've already made Pawel aware of it, but wanted it logged, that the new
> scheduler comes with a substantial drop in performance for certain work
> loads. I've timed the Haiku revision before the merge building HaikuDepot
> (after jam clean). These are my timings:
>
> {{{
> jam -q -j4 HaikuDepot
>
> Haiku old scheduler:
> real 0m58.340s
> user 2m25.305s
> sys 0m52.408s
>
> real 0m57.608s
> user 2m25.175s
> sys 0m52.455s
>
> Haiku, new scheduler:
> real 1m40.426s
> user 2m23.923s
> sys 0m42.496s
>
> real 1m40.283s
> user 2m23.842s
> sys 0m42.488s
>
> Linux 12.04:
> real 0m24.603s
> user 1m5.592s
> sys 0m5.376s
>
> real 0m24.620s
> user 1m5.720s
> sys 0m5.268s
> }}}
>
> The system time actually improved, but the overall time for the
> concurrent jobs is much worse than before. Looing at ActivityMonitor, the
> thread migration between cores seems to be the problem, because each core
> peaks only for short times, while with the old scheduler, the cores stay
> peaked.
New description:
I've already made Pawel aware of it, but wanted it logged, that the new
scheduler comes with a substantial drop in performance for certain work
loads. I've timed the Haiku revision before the merge building HaikuDepot
(after jam clean). These are my timings:
{{{
jam -q -j4 HaikuDepot
Haiku old scheduler:
real 0m58.340s
user 2m25.305s
sys 0m52.408s
real 0m57.608s
user 2m25.175s
sys 0m52.455s
Haiku, new scheduler:
real 1m40.426s
user 2m23.923s
sys 0m42.496s
real 1m40.283s
user 2m23.842s
sys 0m42.488s
Linux 12.04:
real 0m24.603s
user 1m5.592s
sys 0m5.376s
real 0m24.620s
user 1m5.720s
sys 0m5.268s
}}}
The system time actually improved, but the overall time for the concurrent
jobs is much worse than before. Looing at ActivityMonitor, the thread
migration between cores seems to be the problem, because each core peaks
only for short times, while with the old scheduler, the cores stay peaked.
Both Haiku images had been compiled with KDEBUG_LEVEL = 0 and the code was
compiled on a BFS partition that has query support.
--
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Ticket URL: <https://dev.haiku-os.org/ticket/10454#comment:1>
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