From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx193.postini.com [74.125.245.193]) by kanga.kvack.org (Postfix) with SMTP id 72B646B004F for ; Sun, 15 Jan 2012 07:06:18 -0500 (EST) Date: Sun, 15 Jan 2012 13:06:05 +0100 From: Andrea Arcangeli Subject: Re: [PATCH 1/6] pagemap: avoid splitting thp when reading /proc/pid/pagemap Message-ID: <20120115120605.GI3236@redhat.com> References: <1326396898-5579-1-git-send-email-n-horiguchi@ah.jp.nec.com> <1326396898-5579-2-git-send-email-n-horiguchi@ah.jp.nec.com> <20120114170026.GF3236@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20120114170026.GF3236@redhat.com> Sender: owner-linux-mm@kvack.org List-ID: To: Naoya Horiguchi Cc: linux-mm@kvack.org, Andrew Morton , David Rientjes , Andi Kleen , Wu Fengguang , KOSAKI Motohiro , KAMEZAWA Hiroyuki , linux-kernel@vger.kernel.org On Sat, Jan 14, 2012 at 06:00:26PM +0100, Andrea Arcangeli wrote: > Why don't you pass the pmd and then do "if (pmd_present(pmd)) > page_to_pfn(pmd_page(pmd)) ? What's the argument for the cast. I'm Of course I meant pmd_pfn above... in short as a replacement of the pte_pfn in your patch. About the _stable function, I was now thinking maybe _lock suffix is more appropriate than _stable, because that function effectively has the objective of taking the page_table_lock in the most efficient way, and not much else other than taking the lock. Adding a comment that it's only safe to call with the mmap_sem held in the inline version in the .h file (the one that then would call the __ version in the .c file). -- 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 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751271Ab2AOMGV (ORCPT ); Sun, 15 Jan 2012 07:06:21 -0500 Received: from mx1.redhat.com ([209.132.183.28]:56587 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750761Ab2AOMGU (ORCPT ); Sun, 15 Jan 2012 07:06:20 -0500 Date: Sun, 15 Jan 2012 13:06:05 +0100 From: Andrea Arcangeli To: Naoya Horiguchi Cc: linux-mm@kvack.org, Andrew Morton , David Rientjes , Andi Kleen , Wu Fengguang , KOSAKI Motohiro , KAMEZAWA Hiroyuki , linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/6] pagemap: avoid splitting thp when reading /proc/pid/pagemap Message-ID: <20120115120605.GI3236@redhat.com> References: <1326396898-5579-1-git-send-email-n-horiguchi@ah.jp.nec.com> <1326396898-5579-2-git-send-email-n-horiguchi@ah.jp.nec.com> <20120114170026.GF3236@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20120114170026.GF3236@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Jan 14, 2012 at 06:00:26PM +0100, Andrea Arcangeli wrote: > Why don't you pass the pmd and then do "if (pmd_present(pmd)) > page_to_pfn(pmd_page(pmd)) ? What's the argument for the cast. I'm Of course I meant pmd_pfn above... in short as a replacement of the pte_pfn in your patch. About the _stable function, I was now thinking maybe _lock suffix is more appropriate than _stable, because that function effectively has the objective of taking the page_table_lock in the most efficient way, and not much else other than taking the lock. Adding a comment that it's only safe to call with the mmap_sem held in the inline version in the .h file (the one that then would call the __ version in the .c file).