From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail137.messagelabs.com (mail137.messagelabs.com [216.82.249.19]) by kanga.kvack.org (Postfix) with ESMTP id 521A88D003A for ; Tue, 15 Mar 2011 14:13:48 -0400 (EDT) Received: from d01dlp02.pok.ibm.com (d01dlp02.pok.ibm.com [9.56.224.85]) by e8.ny.us.ibm.com (8.14.4/8.13.1) with ESMTP id p2FDsWc5026907 for ; Tue, 15 Mar 2011 09:54:33 -0400 Received: from d01relay07.pok.ibm.com (d01relay07.pok.ibm.com [9.56.227.147]) by d01dlp02.pok.ibm.com (Postfix) with ESMTP id 2F1FC6E803E for ; Tue, 15 Mar 2011 14:13:46 -0400 (EDT) Received: from d01av02.pok.ibm.com (d01av02.pok.ibm.com [9.56.224.216]) by d01relay07.pok.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id p2FIDjLd2314484 for ; Tue, 15 Mar 2011 14:13:45 -0400 Received: from d01av02.pok.ibm.com (loopback [127.0.0.1]) by d01av02.pok.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id p2FIDh0G031969 for ; Tue, 15 Mar 2011 15:13:45 -0300 Date: Tue, 15 Mar 2011 23:37:43 +0530 From: Srikar Dronamraju Subject: Re: [PATCH v2 2.6.38-rc8-tip 3/20] 3: uprobes: Breakground page replacement. Message-ID: <20110315180743.GD24254@linux.vnet.ibm.com> Reply-To: Srikar Dronamraju References: <20110314133403.27435.7901.sendpatchset@localhost6.localdomain6> <20110314133433.27435.49566.sendpatchset@localhost6.localdomain6> <20110315175048.GC24254@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline In-Reply-To: Sender: owner-linux-mm@kvack.org List-ID: To: Thomas Gleixner Cc: Peter Zijlstra , Ingo Molnar , Steven Rostedt , Linux-mm , Arnaldo Carvalho de Melo , Linus Torvalds , Ananth N Mavinakayanahalli , Christoph Hellwig , Andi Kleen , Masami Hiramatsu , Oleg Nesterov , LKML , Jim Keniston , Roland McGrath , SystemTap , Andrew Morton , "Paul E. McKenney" * Thomas Gleixner [2011-03-15 19:03:44]: > On Tue, 15 Mar 2011, Srikar Dronamraju wrote: > > > * Thomas Gleixner [2011-03-15 14:22:09]: > > > > > On Mon, 14 Mar 2011, Srikar Dronamraju wrote: > > > > +/* > > > > + * Called with tsk->mm->mmap_sem held (either for read or write and > > > > + * with a reference to tsk->mm > > > > > > Hmm, why is holding it for read sufficient? > > > > We are not adding a new vma to the mm; but just replacing a page with > > another after holding the locks for the pages. Existing routines > > doing close to similar things like the > > access_process_vm/get_user_pages seem to be taking the read_lock. Do > > you see a resaon why readlock wouldnt suffice? > > No, I just was confused by the comment. Probably should have asked why > you want to call it write locked. We no more call it write locked. So we can drop the reference to write lock. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org