Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753838Ab1DNVx6 (ORCPT ); Thu, 14 Apr 2011 17:53:58 -0400 Received: from gir.skynet.ie ([193.1.99.77]:53142 "EHLO gir.skynet.ie" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751192Ab1DNVxz (ORCPT ); Thu, 14 Apr 2011 17:53:55 -0400 Date: Thu, 14 Apr 2011 22:53:27 +0100 From: Mel Gorman To: raz ben yehuda Cc: Andrea Arcangeli , lkml , riel@redhat.com, kosaki.motohiro@jp.fujitsu.com, akpm@linux-foundation.org Subject: Re: 2.6.38 page_test regression Message-ID: <20110414215327.GI11871@csn.ul.ie> References: <1302692638.15225.14.camel@raz.scalemp.com> <20110413125146.GR29444@random.random> <1302703579.17536.1.camel@raz.scalemp.com> <20110413172127.GB5734@random.random> <1302781754.5098.13.camel@raz.scalemp.com> <20110414150925.GD15707@random.random> <1302811643.10051.8.camel@raz.scalemp.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <1302811643.10051.8.camel@raz.scalemp.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1401 Lines: 33 On Thu, Apr 14, 2011 at 11:07:23PM +0300, raz ben yehuda wrote: > bah. Mel is correct. I did mean page_test ( in my defense it is in the > msg ). > Here some more information: > 1. I manage to lower the regression to 2 sha1's: > 32dba98e085f8b2b4345887df9abf5e0e93bfc12 to > 71e3aac0724ffe8918992d76acfe3aad7d8724a5. > though I had to remark wait_split_huge_page for the sake of > compilation. up to 32dba98e085f8b2b4345887df9abf5e0e93bfc12 there is no > regression. > > 2. I booted 2.6.37-rc5 you gave me. same regression is there. Extremely long shot - try this patch. diff --git a/mm/memory.c b/mm/memory.c index c50a195..a39baaf 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -3317,7 +3317,7 @@ int handle_mm_fault(struct mm_struct *mm, struct vm_area_struct *vma, * run pte_offset_map on the pmd, if an huge pmd could * materialize from under us from a different thread. */ - if (unlikely(__pte_alloc(mm, vma, pmd, address))) + if (unlikely(!pmd_present(*(pmd))) && __pte_alloc(mm, vma, pmd, address)) return VM_FAULT_OOM; /* if an huge pmd materialized from under us just retry later */ if (unlikely(pmd_trans_huge(*pmd))) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/