Re: major network performance difference between 2.4 and 2.6.2-rc2

From: Andrew Morton (akpm_at_osdl.org)
Date: 02/04/04

  • Next message: Pedro Larroy: "Re: Promise PDC20269 (Ultra133 TX2) + Software RAID" 
    Date:	Wed, 4 Feb 2004 12:54:44 -0800
To: Jim Faulkner <jfaulkne@ccs.neu.edu>

    Jim Faulkner <jfaulkne@ccs.neu.edu> wrote:
    >
    >
    > I am still experiencing severely degraded network performance under
    > 2.6.2-rc3 and 2.6.2-rc3-mm1.

    A kernel profile is needed.

    > Based on some kernel output, I think this
    > problem may be related to Gerd Knorr's input patches, so I am CCing him on
    > this e-mail.

    Sounds unlikely.

    > Additionally, while large network transfers are going on, both ksoftirqd/0
    > and events/0 start going crazy, putting a huge load on my system:
    >
    > PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
    > 3 root 35 19 0 0 0 S 45.9 0.0 0:46.98 ksoftirqd/0
    > 6 root 5 -10 0 0 0 S 43.3 0.0 1:56.63 events/0
    > 12008 dogshu 15 0 4800 2356 3828 S 5.3 0.2 0:05.98 proftpd
    > 12 root 15 0 0 0 0 S 0.3 0.0 0:00.41 pdflush
    > 9778 root 16 0 5888 1724 5516 R 0.3 0.2 0:00.12 sshd
    >
    > the load before that network transfer was 0.01, and the load after the
    > network transfer was 1.45.

    Could be a networking problem, but boy that's a lot of CPU time.

    Please, do this:

    - Boot with `profile=1' on the kernel command line

    sudo readprofile -r
    sudo readprofile -M10
    time <whatever command it is that is causing the problem>
    readprofile -n -v -m /boot/System.map | sort -n +2 | tail -40 | tee ~/log

    Making very sure that /boot/System.map is the correct map file for the
    currently-running kernel.

    Thanks.
    -
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  • Next message: Pedro Larroy: "Re: Promise PDC20269 (Ultra133 TX2) + Software RAID"

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