From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757340Ab2BICVM (ORCPT ); Wed, 8 Feb 2012 21:21:12 -0500 Received: from fgwmail5.fujitsu.co.jp ([192.51.44.35]:59211 "EHLO fgwmail5.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751706Ab2BICVL (ORCPT ); Wed, 8 Feb 2012 21:21:11 -0500 X-SecurityPolicyCheck-FJ: OK by FujitsuOutboundMailChecker v1.3.1 Date: Thu, 9 Feb 2012 11:19:50 +0900 From: KAMEZAWA Hiroyuki To: Naoya Horiguchi Cc: linux-mm@kvack.org, Andrew Morton , David Rientjes , Andi Kleen , Wu Fengguang , Andrea Arcangeli , KOSAKI Motohiro , linux-kernel@vger.kernel.org Subject: Re: [PATCH 2/6] thp: optimize away unnecessary page table locking Message-Id: <20120209111950.b3e626d1.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: <1328716302-16871-3-git-send-email-n-horiguchi@ah.jp.nec.com> References: <1328716302-16871-1-git-send-email-n-horiguchi@ah.jp.nec.com> <1328716302-16871-3-git-send-email-n-horiguchi@ah.jp.nec.com> Organization: FUJITSU Co. LTD. X-Mailer: Sylpheed 3.1.1 (GTK+ 2.10.14; i686-pc-mingw32) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 8 Feb 2012 10:51:38 -0500 Naoya Horiguchi wrote: > Currently when we check if we can handle thp as it is or we need to > split it into regular sized pages, we hold page table lock prior to > check whether a given pmd is mapping thp or not. Because of this, > when it's not "huge pmd" we suffer from unnecessary lock/unlock overhead. > To remove it, this patch introduces a optimized check function and > replace several similar logics with it. > > Signed-off-by: Naoya Horiguchi > Cc: David Rientjes > I prefer 'bool' for return type..but seems much better. Thank you. I think this clean up is very good. Reviewed-by: KAMEZAWA Hiroyuki