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* virtio_net missing interrupts?
@ 2008-01-07 18:56 Anthony Liguori
       [not found] ` <478275F2.5030507-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org>
  0 siblings, 1 reply; 2+ messages in thread
From: Anthony Liguori @ 2008-01-07 18:56 UTC (permalink / raw)
  To: Rusty Russell; +Cc: kvm-devel, Avi Kivity

Avi noticed that when using the virtio_net driver, ping responses stop 
coming in after 12 packets.  ping will then throw an "sendmsg: no buffer 
space available" error.

This occurs on all kernel versions (even 2.6.24).

Regards,

Anthony Liguori

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* Re: virtio_net missing interrupts?
       [not found] ` <478275F2.5030507-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org>
@ 2008-01-07 19:29   ` Avi Kivity
  0 siblings, 0 replies; 2+ messages in thread
From: Avi Kivity @ 2008-01-07 19:29 UTC (permalink / raw)
  To: Anthony Liguori; +Cc: kvm-devel

Anthony Liguori wrote:
> Avi noticed that when using the virtio_net driver, ping responses stop 
> coming in after 12 packets.  ping will then throw an "sendmsg: no 
> buffer space available" error.
>
> This occurs on all kernel versions (even 2.6.24).
>

Latencies are high at around 4ms when the packets do arrive.

Further speculation yielded the following:  a non hrtimer kernel will 
delay all packets by one jiffie due to the tx timer.  For an unknown 
reason, an arp packet is lost, so further echo requests are queued up 
until the buffer is exhausted.

-- 
error compiling committee.c: too many arguments to function


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^ permalink raw reply	[flat|nested] 2+ messages in thread

end of thread, other threads:[~2008-01-07 19:29 UTC | newest]

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2008-01-07 18:56 virtio_net missing interrupts? Anthony Liguori
     [not found] ` <478275F2.5030507-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org>
2008-01-07 19:29   ` Avi Kivity

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