public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
From: Xose Vazquez Perez <xose@wanadoo.es>
To: linux-kernel@vger.kernel.org
Subject: Re: bad performance on 2.4.23
Date: Wed, 10 Dec 2003 03:51:00 +0100	[thread overview]
Message-ID: <3FD68A14.90500@wanadoo.es> (raw)
In-Reply-To: Pine.LNX.4.44.0312081101030.1289-100000@logos.cnet

Marcelo Tosatti wrote:

> About the high numbers on -ac and -aa:
> 
> -ac includes rmap and the drop_behind() logic (I just posted the patch
> against 2.4.23 to lkml). I believe its the reason for the read slowdowns
> reported on lkml.
> 
> -aa includes this patch which will increase the max readahead 
> significantly. Mind trying it?

Sorry. I don't have any free machine to do this kind of tests. :(

>>In 'Sequential Reads' and 'Sequential Writes', 'Maximum Latency' is _too much high_
>>
>>2.4.23-pre4                   8192  4096  256    5.10  6.83%   430.551  1602091.53  0.35501  0.31585     75
>>2.4.23-rc1                    8192  4096  256    5.04  6.94%   432.486  1937701.66  0.33408  0.29884     73

> Now this is really odd. When did it started happening?

It looks like between .20 and .23, included.

Test was done by Randy Hron <rwhron@earthlink.net> over a OSDL server:
4x700 mhz Pentium III Xeons with 1MB cache 3.75 GB RAM
DAC960 Fiber channel to SCSI disks in RAID5 configuration
more details at http://home.earthlink.net/~rwhron/kernel/bigbox.html

what is very strange is that in two different tests and kernels
(2.4.23-pre4 and2.4.23-rc1) 'Maximum Latency' is very high with
256 threads.


      reply	other threads:[~2003-12-10  2:51 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <3FD2FDE3.9060909@wanadoo.es>
2003-12-08 13:22 ` bad performance on 2.4.23 Marcelo Tosatti
2003-12-10  2:51   ` Xose Vazquez Perez [this message]

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=3FD68A14.90500@wanadoo.es \
    --to=xose@wanadoo.es \
    --cc=linux-kernel@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox