poor performance on big machine
Roman Divacky
rdivacky at FreeBSD.org
Mon Jul 30 09:35:47 PDT 2007
On Mon, Jul 30, 2007 at 05:54:11PM +0200, Simon 'corecode' Schubert wrote:
> Simon 'corecode' Schubert wrote:
> >more data:
> >
> >- irq21 seems to always carry about half of the number of interrupts
> >atapci1 is carrying.
> >
> >- over large periods, the % busy of ad6 is at 100%, servicing maybe 350
> >or even 800 requests/sec. I/O speed then is around 3-10 MB/sec. this
> >is with 1.10 and SMP. I'll try compiling a old-ata kernel now.
>
> Okay, old ata kernel does not help. I'd even be inclined to say "looks
> even worse", but that might be subjective. We definitely need an I/O
> scheduler and a low level disk scheduler.
there's an implementation of anticipatory io scheduler for freebsd 4.3
it might be quite easily portable to dfly
http://www.cs.rice.edu/~ssiyer/r/antsched/
roman
More information about the Kernel
mailing list