Heavy I/O blocks FreeBSD box for several seconds

[Arnaud Lacombe]

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]

 - Arnaud