From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754892Ab1GNNUk (ORCPT ); Thu, 14 Jul 2011 09:20:40 -0400 Received: from mx1.redhat.com ([209.132.183.28]:44239 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754585Ab1GNNUi (ORCPT ); Thu, 14 Jul 2011 09:20:38 -0400 Date: Thu, 14 Jul 2011 15:18:22 +0200 From: Oleg Nesterov To: Frantisek Hrbata Cc: linux-kernel@vger.kernel.org, matt.fleming@linux.intel.com, hughd@google.com Subject: Re: [PATCH] exec: remove page_table_lock for mm counters in acct_arg_size() Message-ID: <20110714131821.GA3177@redhat.com> References: <1310649380-13492-1-git-send-email-fhrbata@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1310649380-13492-1-git-send-email-fhrbata@redhat.com> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 07/14, Frantisek Hrbata wrote: > > Commit 172703b mm: delete non-atomic mm counter implementation > removed non-atomic mm counters implementation. I think there is no need to hold > page_table_lock for add_mm_counter() when the splitted page table locks are not > used. This patch removes the locking. > > Signed-off-by: Frantisek Hrbata > --- > fs/exec.c | 6 ------ > 1 files changed, 0 insertions(+), 6 deletions(-) > > diff --git a/fs/exec.c b/fs/exec.c > index 6075a1e..e6fc5e1 100644 > --- a/fs/exec.c > +++ b/fs/exec.c > @@ -182,13 +182,7 @@ static void acct_arg_size(struct linux_binprm *bprm, unsigned long pages) > > bprm->vma_pages = pages; > > -#ifdef SPLIT_RSS_COUNTING > add_mm_counter(mm, MM_ANONPAGES, diff); > -#else > - spin_lock(&mm->page_table_lock); > - add_mm_counter(mm, MM_ANONPAGES, diff); > - spin_unlock(&mm->page_table_lock); > -#endif Heh. Thanks Frantisek, you are right. But this patch is already in mm-tree, fs-execc-acct_arg_size-ptl-is-no-longer-needed-for-add_mm_counter.patch Oleg.