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Message-ID: <4A1BA111.9060801@codemonkey.ws>
Date: Tue, 26 May 2009 02:58:09 -0500
From: Anthony Liguori <anthony@codemonkey.ws>
MIME-Version: 1.0
Subject: Re: [Qemu-devel] Do we need CONFIG_AIO?
References: <20090525082151.GA4107@lst.de> <4A1A85B4.3060200@eu.citrix.com>
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To: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Cc: Christoph Hellwig <hch@lst.de>, "qemu-devel@nongnu.org" <qemu-devel@nongnu.org>

Stefano Stabellini wrote:
> Christoph Hellwig wrote:
>
>   
>> Currently all aio code in the raw-posix block driver depends on a
>> CONFIG_AIO symbol that gets set based on the availability of the
>> pthreads library.  Beeing able to rely on unconditional aio support
>> means we could remove the whole code for plain bdrv_read/bdrv_write
>> in raw-posix.c which is about 300 lines of code and a duplicated code
>> path.  Is there any Posix-ish platform qemu supports that does not
>> have pthreads support?
>>
>>     
>
> MiniOS.
> I would appreciate if you keep that flag.
>   

Threads are not going to be able to remain an optional dependency 
forever.  I would be willing to merge something to remove CONFIG_AIO 
although I expect that there will be some fall out.  Some people are 
using --disable-aio today for either historic reasons or because there 
are weird bugs with AIO enabled.

Regards,

Anthony Liguori