bad network performance in 2.4.0-test1

From: Justin (jguyett@andrew.cmu.edu)
Date: Sat Jun 03 2000 - 07:35:40 EDT

  • Next message: Andrew Sharp: "Re: Hot pluggable CPUs ( was Linux 2.5 / 2.6 TODO (preliminary) )"

    I've looked through /proc/sys/net/ipv4 and I don't see anything terribly
    wrong in 2.4.0-test1, yet there seems to be a serious performance
    difference.

    Both kernels were compiled with equivalent networking options, memory
    mapped io, no packet filtering. Identical hardware. 2.2.15 is running
    kpiod, but otherwise the process names in ps auxww are identical)

    2.2.15:
    # time ping -c 100000 -s 3500 -f 127.0.0.1 > /dev/null
    2.50user 2.38system 0:04.88elapsed 99%CPU (0avgtext+0avgdata
    0maxresident)k
    0inputs+0outputs (106major+15minor)pagefaults 0swaps

    2.4.0-test1
    # time ping -c 100000 -s 3500 -f 127.0.0.1 > /dev/null
    1.64user 8.12system 0:09.75elapsed 100%CPU (0avgtext+0avgdata
    0maxresident)k
    0inputs+0outputs (106major+17minor)pagefaults 0swaps

    -

    Linux test1 2.2.15 #1 Wed May 31 18:52:44 UTC 2000 i686 unknown
    TCP REQUEST/RESPONSE TEST to localhost
    Local /Remote
    Socket Size Request Resp. Elapsed Trans.
    Send Recv Size Size Time Rate
    bytes Bytes bytes bytes secs. per sec

    65535 65535 1 1 9.99 40920.28
    65535 65535

    Linux test2 2.4.0-test1 #5 Tue May 30 04:53:02 UTC 2000 i686 unknown
    TCP REQUEST/RESPONSE TEST to localhost
    Local /Remote
    Socket Size Request Resp. Elapsed Trans.
    Send Recv Size Size Time Rate
    bytes Bytes bytes bytes secs. per sec

    65535 65535 1 1 9.99 4361.66
    65535 65535

    -

    Linux test1 2.2.15 #1 Wed May 31 18:52:44 UTC 2000 i686 unknown
    TCP STREAM TEST to localhost
    Recv Send Send
    Socket Socket Message Elapsed
    Size Size Size Time Throughput
    bytes bytes bytes secs. 10^6bits/sec

     65535 65535 65535 9.99 1048.07

    Linux test2 2.4.0-test1 #5 Tue May 30 04:53:02 UTC 2000 i686 unknown
    TCP STREAM TEST to localhost
    Recv Send Send
    Socket Socket Message Elapsed
    Size Size Size Time Throughput
    bytes bytes bytes secs. 10^6bits/sec

     65535 65535 65535 9.99 732.44

    This cannot be good.

    Justin

    -
    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to majordomo@vger.rutgers.edu
    Please read the FAQ at http://www.tux.org/lkml/

    This archive was generated by hypermail 2b29 : Sat Jun 03 2000 - 07:48:56 EDT