Subject: Re: Is the current more slowly?
To: HEO SeonMeyong <seirios@Matrix.IRI.Co.Jp>
From: Manuel Bouyer <email@example.com>
Date: 06/24/1999 18:21:59
On Fri, Jun 25, 1999 at 01:12:11AM +0900, HEO SeonMeyong wrote:
> Hi. I'm HEO SeonMeyong.
> I'm very sorry for late reply.
> > Now that I'm thinking on it, are you *sure* it is IDE-related ?
> > I'm sitting in fron of a SCSI-only box rigth now, and it feels slow as well
> > when doing a I/O (a 'make depend' in /usr/src in my case).
> > Could someone confirm the same behavior with a scsi box ?
> Now I think this probrem (NetBSD becomes more slowly) is not
> related IDE, because my other SCSI-only machine becomes more
> This week I'm very busy, then I cannot run bonnie on
> 1.4-Release/1.3I installed machine.
> I will test bonnie, and other benchmarks at next week or next next
I actually think this is I/O related, maybe something to do with the
buffer cache and I/O queues. My 'make depend' doesn't eat much CPU
(apps are still responsive as before when they need CPU), but an I/O
takes a long time. So anything that needs to read or write a file on
disk gets blocked, although top says there's a lot of CPU idle.
My theory is that the requests stay in the I/O queue for too long, because
resquest from 'make depend' gets prepended and not appended. Or maybe it's
that buffers we just read are recycled immediatly, discarding effect of
Does someone remember of a change that affected the way the I/O queue is
managed ? Maybe something in disksort() ?
Manuel Bouyer, LIP6, Universite Paris VI. Manuel.Bouyer@lip6.fr