Date: Thu, 28 Jan 2010 16:21:56 -0800 (PST)
From: Linus Torvalds <torvalds@linux-foundation.org>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>
cc: Kyle Moffett <kyle@moffetthome.net>, tytso@mit.edu,
       "Frank Ch. Eigler" <fche@redhat.com>, Ingo Molnar <mingo@elte.hu>,
       Oleg Nesterov <oleg@redhat.com>,
       Andrew Morton <akpm@linux-foundation.org>,
       Stephen Rothwell <sfr@canb.auug.org.au>,
       Peter Zijlstra <a.p.zijlstra@chello.nl>,
       Peter Zijlstra <peterz@infradead.org>,
       Fr??d??ric Weisbecker <fweisbec@gmail.com>,
       LKML <linux-kernel@vger.kernel.org>,
       Steven Rostedt <rostedt@goodmis.org>,
       Arnaldo Carvalho de Melo <acme@redhat.com>, linux-next@vger.kernel.org,
       "H. Peter Anvin" <hpa@zytor.com>, utrace-devel@redhat.com,
       Thomas Gleixner <tglx@linutronix.de>
Subject: Re: linux-next: add utrace tree
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On Fri, 29 Jan 2010, Benjamin Herrenschmidt wrote:
> 
> like returning a fd to poll() on ? :-)

Well, there's the possibility of async polling (rather than the 
synchronous wait that ptrace forces now), but there are other advantages 
to having a "connection" model - like not having to look up the child 
process every time like ptrace does now.

Although 'find_task_by_vpid()' is probably cheap enough that nobody really 
cares. We do a fair job at those hash tables.

			Linus
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