Re: signifanctly slowdown of FreeBSD 8.0-CURRENT/amd64

From: Pierre Guinoiseau <geekounet_at_poildetroll.net>
Date: Sun, 05 Jul 2009 03:02:40 +0200
Hi,

I have some good news: the problem seems to be solved (at least for me)
since I updated to r195011 about 2 weeks ago. I think it may be related
to the MSI fixes (and the drm module may have been the cause, even if
not used?), but I might be wrong. After this update, the permanent
slowdown issue disappeared, but I still had some slowdown on high CPU
load (but it was back to normal soon after coming back to a low load). I
then figured out that it was due to an overheat problem on my laptop,
slowing down the wall machine in some way... I've cleaned it up (there
was a 5mm wall of dust in the fan!), and no more overheat nor slowdown
since then.

I'm sorry I can't reproduce it anymore now. ;)
And I hope Randall's problem is fixed as well. :)

Thanks for your help anyway!

Pierre Guinoiseau


Attilio Rao wrote:
> 2009/6/24 Randall Stewart <rrs_at_lakerest.net>:
>> One thing I have noticed for a while.. and have not
>> been able to track down..
>>
>> If one runs
>>
>> /usr/src/tools/tools/syscall_timing/syscall_timing
>>
>> On a 7.2 kernel and compare it on the same machine to an 8.0 kernel
>> you will see almost a 3x slow down in 8.
> 
> So, as long as I think that for the pressing, next release, it is very
> important to track such regressions down, I hope both Pierre and
> Randall want to lend an hand.
> 
> First thing, Randall, could you recompile your kernel with
> HWPMC_HOOKS, device hwpmc, and do some pmcstat runs in order to see
> where/how the slowdown happens?
> For example you could check if the number of cache misses increases, or similar.
> 
> Both could provide, instead, once the slowdown takes place, verbose
> top, ps and possibly vmstat, just to be sure in case.
> 
> If you are unable to reproduce the slowdown or give an hand, please let me know.
> 
> Thanks,
> Attilio
> 
> 


Received on Sat Jul 04 2009 - 23:02:56 UTC

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