Re: Heavy I/O blocks FreeBSD box for several seconds

On 07/06/11 23:49, Oliver Pinter wrote:
> On 7/6/11, Hartmann, O.<ohartman_at_zedat.fu-berlin.de>  wrote:
>> On 07/06/11 21:36, Steve Kargl wrote:
>>> On Wed, Jul 06, 2011 at 03:18:35PM -0400, Arnaud Lacombe wrote:
>>>> Hi,
>>>>
>>>> On Wed, Jul 6, 2011 at 12:28 PM, Steve Kargl
>>>> <sgk_at_troutmask.apl.washington.edu>   wrote:
>>>>> On Wed, Jul 06, 2011 at 05:29:24PM +0200, O. Hartmann wrote:
>>>>>> I use SCHED_ULE on all machines, since it is supposed to be performing
>>>>>> better on multicore boxes, but there are lots of suggestions switching
>>>>>> back to the old SCHED_4BSD scheduler.
>>>>>>
>>>>> If you are using MPI in numerical codes, then you want
>>>>> to use SCHED_4BSD. ?I've posted numerous times about ULE
>>>>> and its very poor performance when using MPI.
>>>>>
>>>>> http://lists.freebsd.org/pipermail/freebsd-hackers/2008-October/026375.html
>>>>>
>>>> [sarcasm]
>>>> It is rather funny to see that the post you point out has generated
>>>> exactly 0 meaningful follow-up then and as you mention later in this
>>>> thread, the issue still remains today :-)
>>>> [/sarcasm]
>>>>
>>> Apparently, you are privy to my private email exchanges
>>> with jeffr.
>>>
>>> I'm also not sure why you're being sarcastic here.  The
>>> issue was and AFAIK still is a problem for anyone using
>>> FreeBSD in a HPC cluster.  ULE simply performs worse than
>>> 4BSD.
>>>
>> Well, I know only very little people using FreeBSD within a HPC cluster
>> or even for scientific purposes, except myself and some people around here.
>> _______________________________________________
>> freebsd-current_at_freebsd.org mailing list
>> http://lists.freebsd.org/mailman/listinfo/freebsd-current
>> To unsubscribe, send any mail to "freebsd-current-unsubscribe_at_freebsd.org"
>>
>
> http://lists.freebsd.org/pipermail/freebsd-stable/2010-September/thread.html#58537

The problem is not only related to desktop boxes, it involves servers 
with "big" hardware as well.