All of lore.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.