Date: Tue, 06 Feb 2007 22:46:25 +0100
From: Eric Dumazet <dada1@cosmosbay.com>
Subject: Re: [PATCH 2 of 4] Introduce i386 fibril scheduling
In-reply-to: <20070206.133140.91442326.davem@davemloft.net>
To: David Miller <davem@davemloft.net>
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       davidel@xmailserver.org, zach.brown@oracle.com, mingo@elte.hu,
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David Miller a ?crit :
> From: Linus Torvalds <torvalds@linux-foundation.org>
> Date: Tue, 6 Feb 2007 13:28:34 -0800 (PST)
> 
>> Yeah, in 1% of all cases it will block, and you'll want to wait for them. 
>> Maybe the kevent queue works then, but if it needs any more setup than the 
>> nonblocking case, that's a big no.
> 
> So the idea is to just run it to completion if it won't block and use
> a fibril if it would?
> 
> kevent could support something like that too.

It seems to me that kevent was designed to handle many events sources on a 
single endpoint, like epoll (but with different internals). Typical load of 
thousand of sockets/pipes providers glued into one queue.

In the fibril case, I guess a thread wont have many fibrils lying around...

Also, kevent needs a fd lookup/fput to retrieve some queued events, and that 
may be a performance hit for the AIO case, (fget/fput in a multi-threaded 
program cost some atomic ops)

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