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Message-ID: <1334692418.28150.88.camel@twins>
Subject: Re: [PATCH 2/6] uprobes: introduce is_swbp_at_addr_fast()
From: Peter Zijlstra <peterz@infradead.org>
To: Oleg Nesterov <oleg@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>, Srikar Dronamraju <srikar@linux.vnet.ibm.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Ananth N Mavinakayanahalli <ananth@in.ibm.com>,
        Jim Keniston <jkenisto@linux.vnet.ibm.com>,
        LKML <linux-kernel@vger.kernel.org>, Linux-mm <linux-mm@kvack.org>,
        Andi Kleen <andi@firstfloor.org>,
        Christoph Hellwig <hch@infradead.org>,
        Steven Rostedt <rostedt@goodmis.org>,
        Arnaldo Carvalho de Melo <acme@infradead.org>,
        Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>,
        Thomas Gleixner <tglx@linutronix.de>, Anton Arapov <anton@redhat.com>
Date: Tue, 17 Apr 2012 21:53:38 +0200
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On Tue, 2012-04-17 at 19:09 +0200, Oleg Nesterov wrote:
> 
> This reminds me. Why read_opcode() does lock_page? I was going
> to send the cleanup which removes it, but I need to recheck.
> 
> Perhaps you can explain the reason? 

I can't seem to recall, I suspect its to serialize against
__replace_page(). I can't say if that's strictly needed though.