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Date: Wed, 19 May 2010 11:51:36 -0400
From: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Subject: Re: Unexpected splice "always copy" behavior observed
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To: Steven Rostedt <rostedt@goodmis.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>, Nick Piggin <npiggin@suse.de>, Peter Zijlstra <peterz@infradead.org>, Frederic Weisbecker <fweisbec@gmail.com>, Pierre Tardy <tardyp@gmail.com>, Ingo Molnar <mingo@elte.hu>, Arnaldo Carvalho de Melo <acme@redhat.com>, Tom Zanussi <tzanussi@gmail.com>, Paul Mackerras <paulus@samba.org>, linux-kernel@vger.kernel.org, arjan@infradead.org, ziga.mahkovec@gmail.com, davem <davem@davemloft.net>, linux-mm@kvack.org, Andrew Morton <akpm@linux-foundation.org>, KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>, Christoph Lameter <cl@linux-foundation.org>, Tejun Heo <tj@kernel.org>, Jens Axboe <jens.axboe@oracle.com>
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* Steven Rostedt (rostedt@goodmis.org) wrote:
> On Wed, 2010-05-19 at 07:59 -0700, Linus Torvalds wrote:
> > 
> 
> > Btw, since you apparently have a real case - is the "splice to file" 
> > always just an append? IOW, if I'm not right in assuming that the only 
> > sane thing people would reasonable care about is "append to a file", then 
> > holler now.
> 
> My use case is just to move the data from the ring buffer into a file
> (or network) as fast as possible. It creates a new file and all
> additions are "append to a file".
> 
> I believe Mathieu does the same.
> 
> With me, you are correct.

Same here. My ring buffer only ever use splice() to append at the end of a file
or to the network, and always outputs data in multiples of the page size.

Thanks,

Mathieu

> 
> -- Steve
> 
> 

-- 
Mathieu Desnoyers
Operating System Efficiency R&D Consultant
EfficiOS Inc.
http://www.efficios.com

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