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 SMTP id 1BB646005A4 for ; Tue, 5 Jan 2010 01:12:56 -0500 (EST) Received: from m2.gw.fujitsu.co.jp ([10.0.50.72]) by fgwmail6.fujitsu.co.jp (Fujitsu Gateway) with ESMTP id o056CqOh027101 for (envelope-from kamezawa.hiroyu@jp.fujitsu.com); Tue, 5 Jan 2010 15:12:52 +0900 Received: from smail (m2 [127.0.0.1]) by outgoing.m2.gw.fujitsu.co.jp (Postfix) with ESMTP id 2C2CA45DE66 for ; Tue, 5 Jan 2010 15:12:52 +0900 (JST) Received: from s2.gw.fujitsu.co.jp (s2.gw.fujitsu.co.jp [10.0.50.92]) by m2.gw.fujitsu.co.jp (Postfix) with ESMTP id F3F2745DE63 for ; Tue, 5 Jan 2010 15:12:51 +0900 (JST) Received: from s2.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s2.gw.fujitsu.co.jp (Postfix) with ESMTP id C8A791DF8001 for ; Tue, 5 Jan 2010 15:12:51 +0900 (JST) Received: from ml14.s.css.fujitsu.com (ml14.s.css.fujitsu.com [10.249.87.104]) by s2.gw.fujitsu.co.jp (Postfix) with ESMTP id 725C3EF8005 for ; Tue, 5 Jan 2010 15:12:51 +0900 (JST) Date: Tue, 5 Jan 2010 15:09:32 +0900 From: KAMEZAWA Hiroyuki Subject: Re: [RFC][PATCH 6/8] mm: handle_speculative_fault() Message-Id: <20100105150932.ab2e6820.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: <28c262361001042209k7241dd38l3d51d230e7b68a5@mail.gmail.com> References: <20100104182429.833180340@chello.nl> <20100104182813.753545361@chello.nl> <20100105092559.1de8b613.kamezawa.hiroyu@jp.fujitsu.com> <28c262361001042029w4b95f226lf54a3ed6a4291a3b@mail.gmail.com> <28c262361001042209k7241dd38l3d51d230e7b68a5@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org To: Minchan Kim Cc: Linus Torvalds , Peter Zijlstra , "Paul E. McKenney" , Peter Zijlstra , "linux-kernel@vger.kernel.org" , "linux-mm@kvack.org" , cl@linux-foundation.org, "hugh.dickins" , Nick Piggin , Ingo Molnar List-ID: On Tue, 5 Jan 2010 15:09:47 +0900 Minchan Kim wrote: > My humble opinion is following as. > > Couldn't we synchronize rcu in that cases(munmap, exit and so on)? > It can delay munap and exit but it would be better than handling them by more > complicated things, I think. And both cases aren't often cases so we > can achieve advantage than disadvantage? > In most case, a program is single threaded. And sychronize_rcu() in unmap path just adds very big overhead. Thanks, -Kame -- 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/ . Don't email: email@kvack.org