[lkml]   [2006]   [Nov]   [14]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
    SubjectRe: UDP packets loss
    Thanks for the commets.
    I actually use UDP because I am seeking for ways to improve the
    performance of IPOIB and I wanted to avoid TCP's flow control. I am really
    up to making anaysis. Can you tell me more about irqbalnced? Where can I
    find more info how to control it? I would like my interrupts serviced by
    all CPUs in a somehow equal manner. I mentioned MSIX - the driver already
    make use of MSIX and I thought this is relevant to interrupts affinity.

    > On Wed, 15 Nov 2006 00:15:47 +0200 (IST)
    > wrote:
    >> Hi,
    >> I am running a client/server test app over IPOIB in which the client
    >> sends
    >> a certain amount of data to the server. When the transmittion ends, the
    >> server prints the bandwidth and how much data it received. I can see
    >> that
    >> the server reports it received about 60% that the client sent. However,
    >> when I look at the server's interface counters before and after the
    >> transmittion, I see that it actually received all the data that the
    >> client
    >> sent. This leads me to suspect that the networking layer somehow dropped
    >> some of the data. One thing to not - the CPU is 100% busy at the
    >> receiver.
    >> Could this be the reason (the machine I am using is 2 dual cores - 4
    >> CPUs).
    > If receiver application can't keep up UDP drops packets. The counter
    > receive buffer errors (UDP_MIB_RCVBUFERRORS) is incremented.
    > Don't expect flow control or reliable delivery; it's a datagram service!
    >> The secod question is how do I make the interrupts be srviced by all
    >> CPUs?
    >> I tried through the procfs as described by IRQ-affinity.txt but I can
    >> set
    >> the mask to 0F bu then I read back and see it is indeed 0f but after a
    >> few
    >> seconds I see it back to 02 (which means only CPU1).
    > Most likely, the user level irq balance daemon (irqbalanced) is adjusting
    > it?
    >> One more thing - the device I am using is capable of generating MSIX
    >> interrupts.
    > Look at device capabilities with:
    > lspci -vv
    > --
    > Stephen Hemminger <>

    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to
    More majordomo info at
    Please read the FAQ at

     \ /
      Last update: 2006-11-15 00:23    [W:0.024 / U:23.232 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site