Re: [patch] voluntary-preempt-2.6.9-rc1-bk4-Q7

From: Ingo Molnar (mingo_at_elte.hu)
Date: 09/02/04

  • Next message: David S. Miller: "Re: [RFC] Use RCU for tcp_ehash lookup"
    Date:	Thu, 2 Sep 2004 07:37:19 +0200
    To: "K.R. Foley" <kr@cybsft.com>
    
    

    * K.R. Foley <kr@cybsft.com> wrote:

    > This is an interesting one. ~3.9ms generated here by amlat in do_IRQ:

    the overhead is not in do_IRQ():

    > 00000001 0.000ms (+0.000ms): n_tty_receive_buf (pty_write)
    > 00010001 3.992ms (+3.992ms): do_IRQ (n_tty_receive_buf)

    the overhead is always relative to the previous entry - so the overhead
    was in n_tty_receive_buf() [that is the function that was interrupted by
    do_IRQ()]. But it's a bit weird - you should have gotten timer IRQs
    every 1 msec. Does n_tty_receive_buf() run with irqs disabled perhaps?

            Ingo
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  • Next message: David S. Miller: "Re: [RFC] Use RCU for tcp_ehash lookup"

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