From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail190.messagelabs.com (mail190.messagelabs.com [216.82.249.51]) by kanga.kvack.org (Postfix) with SMTP id E9E598D0039 for ; Thu, 10 Mar 2011 12:04:49 -0500 (EST) Date: Thu, 10 Mar 2011 09:03:45 -0800 From: Andi Kleen Subject: Re: [PATCH 0/5] make *_gate_vma accept mm_struct instead of task_struct II Message-ID: <20110310170345.GE20504@alboin.amr.corp.intel.com> References: <1299630721-4337-1-git-send-email-wilsons@start.ca> <20110310160032.GA20504@alboin.amr.corp.intel.com> <20110310163809.GA20675@alboin.amr.corp.intel.com> <20110310165414.GA6431@fibrous.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20110310165414.GA6431@fibrous.localdomain> Sender: owner-linux-mm@kvack.org List-ID: To: Stephen Wilson Cc: x86@kernel.org, Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , Benjamin Herrenschmidt , Paul Mackerras , Martin Schwidefsky , Heiko Carstens , linux390@de.ibm.com, Paul Mundt , Michel Lespinasse , Andrew Morton , Alexander Viro , linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, linux-sh@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org On Thu, Mar 10, 2011 at 11:54:14AM -0500, Stephen Wilson wrote: > > On Thu, Mar 10, 2011 at 08:38:09AM -0800, Andi Kleen wrote: > > On Thu, Mar 10, 2011 at 08:00:32AM -0800, Andi Kleen wrote: > > > On Tue, Mar 08, 2011 at 07:31:56PM -0500, Stephen Wilson wrote: > > > > The only architecture this change impacts in any significant way is x86_64. > > > > The principle change on that architecture is to mirror TIF_IA32 via > > > > a new flag in mm_context_t. > > > > > > The problem is -- you're adding a likely cache miss on mm_struct for > > > every 32bit compat syscall now, even if they don't need mm_struct > > > currently (and a lot of them do not) Unless there's a very good > > > justification to make up for this performance issue elsewhere > > > (including numbers) this seems like a bad idea. > > > > Hmm I see you're only setting it on exec time actually on rereading > > the patches. I thought you were changing TS_COMPAT which is in > > the syscall path. > > > > Never mind. I have no problems with doing such a change on exec > > time. > > OK. Great! Does this mean I have your ACK'ed by or reviewed by? I didn't read it all, but the first two patches looked ok. -Andi -- 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