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From: Avi Kivity <avi-atKUWr5tajBWk0Htik3J/w@public.gmane.org>
To: Aurelien Jarno <aurelien-rXXEIb44qovR7s880joybQ@public.gmane.org>
Cc: kvm-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org
Subject: Re: Network performance regression between kvm-29 and kvm-31
Date: Sun, 22 Jul 2007 13:30:14 +0300	[thread overview]
Message-ID: <46A331B6.7020306@qumranet.com> (raw)
In-Reply-To: <46A1BA2D.30800-rXXEIb44qovR7s880joybQ@public.gmane.org>

Aurelien Jarno wrote:
>>>
>>> I finally didn't resist to run git bisect before going to bed...
>>>
>>> The patch that causes the regression is:
>>>
>>> commit 7d2e674835492040c9baddf0989a95abea9a8d0f
>>> Author: Avi Kivity <avi-atKUWr5tajBWk0Htik3J/w@public.gmane.org>
>>> Date:   Sun Jul 15 15:08:23 2007 +0300
>>>
>>>     kvm: qemu: synchronous signal handling
>>>     
>>>     in order to ensure that signals are handled with the global lock held, we
>>>     block them, and dequeue them with sigtimedwait().  we can then call the
>>>     handlers directly.
>>>     
>>>     this ensures that the device model and internal qemu data structures are not
>>>     corrupted by cpu 0 thread handling a signal while cpu 1 is servicing a pio
>>>     or mmio request.
>>>
>>>   
>>>       
>> Is this with -net user or -net tap?
>>
>>     
>
> With -net tap.
>
>   

I pushed a commit which fixes a latency issue with that commit.  However 
with my test (ping -f against the host) I only get a x2 performance 
increase.  Can you test kvm-userspace.git?  And can you detail your 
benchmark?

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


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  parent reply	other threads:[~2007-07-22 10:30 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-07-20 22:25 Network performance regression between kvm-29 and kvm-31 Aurelien Jarno
     [not found] ` <20070720222545.GB22656-OqXK5JiLQY5aJl8KAwiEcA@public.gmane.org>
2007-07-20 22:58   ` Aurelien Jarno
     [not found]     ` <20070720225813.GA24368-OqXK5JiLQY5aJl8KAwiEcA@public.gmane.org>
2007-07-21  6:22       ` Avi Kivity
     [not found]         ` <46A1A610.2050603-atKUWr5tajBWk0Htik3J/w@public.gmane.org>
2007-07-21  7:47           ` Aurelien Jarno
     [not found]             ` <46A1BA2D.30800-rXXEIb44qovR7s880joybQ@public.gmane.org>
2007-07-22 10:30               ` Avi Kivity [this message]
     [not found]                 ` <46A331B6.7020306-atKUWr5tajBWk0Htik3J/w@public.gmane.org>
2007-07-22 13:29                   ` Aurelien Jarno

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