average user comments on 2.5.1-pre5

average user comments on 2.5.1-pre5

[Zwane Mwaikambo]

Hi,
	I've just tried running 2.5.1-pre5 on my desktop machine and
noticed the following, when untarring medium sized files (kernel tarballs)
even from disk to disk (different channels) or moving large files around i
get mouse lag in X and after its done, and the flushing to disk begins the
interactive performance of the box takes a dive for the duration of that
disk activity. The last kernel i had before this was 2.4.13-ac7-preempt
which didn't exhibit this. 2.5.1-pre1 has the same problem.

The box is a P3-550/512M with disks doing UDMA33 on a PIIX4, the source
filesystem (where the tarballs are) is an ext3 one and destination is
ReiserFS (different disks/channels). The lag doesn't seem attributed to
CPU usage because the disk i/o barely hits the CPU (also checked via
xosview). VM performance on the other hand is quite nice, it does the
right thing a good majority of the time (unused stuff getting paged out,
proper cache/buffer usage) Main memory usage is a mixture of large
datasets and disk cache (multiple 500+ page PDFs being searched, whilst
doing various background compiles).

Regards,
	Zwane Mwaikambo

Re: average user comments on 2.5.1-pre5

[Robert Love]

On Sun, 2001-12-02 at 07:06, Zwane Mwaikambo wrote:

> 	I've just tried running 2.5.1-pre5 on my desktop machine and
> noticed the following, when untarring medium sized files (kernel tarballs)
> even from disk to disk (different channels) or moving large files around i
> get mouse lag in X and after its done, and the flushing to disk begins the
> interactive performance of the box takes a dive for the duration of that
> disk activity. The last kernel i had before this was 2.4.13-ac7-preempt
> which didn't exhibit this. 2.5.1-pre1 has the same problem.

Maybe you ought to try the preempt-kernel patch on your current kernel,
since it may of been responsible for your interactivity improvements.

Although I don't make explicit 2.5 patches available yet, the
2.4.17-pre1 or 2.4.16 patches should apply.  Conversely, 2.4.17-pre2 has
some changes that may improve latency.  You want to try it, or, even
better, it with the preemptive kernel patch.

The preempt-kernel patches can be found at:
	ftp://ftp.kernel.org/pub/linux/kernel/people/rml/preempt-kernel

	Robert Love

Re: average user comments on 2.5.1-pre5

[Zwane Mwaikambo]

I just tried 2.5.1-pre1-preempt with the same results, i'll try
-pre5-preempt as well soon.

Thanks for the suggestion,
	Zwane Mwaikambo

Re: average user comments on 2.5.1-pre5

[Zwane Mwaikambo]

On Mon, 3 Dec 2001, Zwane Mwaikambo wrote:

> I just tried 2.5.1-pre1-preempt with the same results, i'll try
> -pre5-preempt as well soon.
>
-pre5-preempt was the same, i've got 2.4.17-pre2-preempt now and that
works great, no more lag after disk i/o that is.

Cheers,
	Zwane Mwaikambo