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Date: Wed, 12 May 2010 14:04:38 -0400
From: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>,
       Steven Rostedt <rostedt@goodmis.org>, Pierre Tardy <tardyp@gmail.com>,
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       linux-kernel@vger.kernel.org, arjan@infradead.org,
       ziga.mahkovec@gmail.com, davem <davem@davemloft.net>
Subject: Re: Perf and ftrace [was Re: PyTimechart]
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* Peter Zijlstra (peterz@infradead.org) wrote:
> On Wed, 2010-05-12 at 13:53 -0400, Mathieu Desnoyers wrote:
> > 
> > Would you be fine with an alternative implementation and API that support both
> > mmap() and splice(), without any need to swap pages ? 
> 
> Sure, what did you have in mind?
> 
> You basically give you page to splice, never to see it again, you'd need
> to fill that hole in your buffer again.
> 

Can't we keep multiple references to each page ? (shared page) so it's still in
the buffer, also accessed by mmap(), and in addition accessed by splice.

Mathieu


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