3c905C: very high system/interrupt CPU usage

From: Peter Schuller (peter.schuller_at_infidyne.com)
Date: 10/15/05

  • Next message: Gerard Seibert: "Re: bizar problem with a Dell latitude D600's onboard nic" 
    Date: Sat, 15 Oct 2005 17:30:47 +0200
To: freebsd-questions@freebsd.org

    Hello,

    I have a machine here with a couple of 3c905C:s in it. For some
    reason, network activity causes very high amounts of system and
    interrupt CPU usage. By "very high" i mean more than 50% interrupt,
    and more than 25% system usage.

    It is not just a measuring issue either, because the whole reason I
    looked into it was that file transfers have been slow for as long as I
    can remember. Especially with ssh, everything is extremely slow given
    that only a small fraction of the available CPU resources are left
    over for userspace.

    Any ideas on what would cause this? I am not experiencing any other
    issues with the NIC or anything else, its just the high CPU
    usage. Could it be that the xl driver has fallen back to not using DMA
    (is that even supported with 3c905c?)? If this is the case, is there a
    way to find out whether it is currently using DMA? (I see nothing in
    particular in the kernel log).

    Also: The CPU usage problem occurrs on both outgoing and incoming
    traffic, and on both NIC:s. 

    -- 
/ Peter Schuller, InfiDyne Technologies HB
PGP userID: 0xE9758B7D or 'Peter Schuller <peter.schuller@infidyne.com>'
Key retrieval: Send an E-Mail to getpgpkey@scode.org
E-Mail: peter.schuller@infidyne.com Web: http://www.scode.org
_______________________________________________
freebsd-questions@freebsd.org mailing list
http://lists.freebsd.org/mailman/listinfo/freebsd-questions
To unsubscribe, send any mail to "freebsd-questions-unsubscribe@freebsd.org"
  • Next message: Gerard Seibert: "Re: bizar problem with a Dell latitude D600's onboard nic"

    Relevant Pages