From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753725Ab1L0Mso (ORCPT ); Tue, 27 Dec 2011 07:48:44 -0500 Received: from cantor2.suse.de ([195.135.220.15]:42234 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753054Ab1L0Msm (ORCPT ); Tue, 27 Dec 2011 07:48:42 -0500 Date: Tue, 27 Dec 2011 13:48:37 +0100 From: Michal Hocko To: Hillf Danton Cc: linux-mm@kvack.org, LKML , Andrew Morton , KAMEZAWA Hiroyuki Subject: Re: [PATCH] mm: hugetlb: fix non-atomic enqueue of huge page Message-ID: <20111227124837.GF5344@tiehlicka.suse.cz> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: 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 On Fri 23-12-11 21:35:25, Hillf Danton wrote: > From: Hillf Danton > Subject: [PATCH] mm: hugetlb: fix non-atomic enqueue of huge page > > If huge page is enqueued under the protection of hugetlb_lock, then > the operation is atomic and safe. > > Cc: Michal Hocko > Cc: KAMEZAWA Hiroyuki > Cc: Andrew Morton > Signed-off-by: Hillf Danton Yes, looks correct even though the changelog could be more verbose. The code is broken since .37 Reviewed-by: Michal Hocko Thanks > --- > > --- a/mm/hugetlb.c Tue Dec 20 21:26:30 2011 > +++ b/mm/hugetlb.c Fri Dec 23 21:16:28 2011 > @@ -901,7 +901,6 @@ retry: > h->resv_huge_pages += delta; > ret = 0; > > - spin_unlock(&hugetlb_lock); > /* Free the needed pages to the hugetlb pool */ > list_for_each_entry_safe(page, tmp, &surplus_list, lru) { > if ((--needed) < 0) > @@ -915,6 +914,7 @@ retry: > VM_BUG_ON(page_count(page)); > enqueue_huge_page(h, page); > } > + spin_unlock(&hugetlb_lock); > > /* Free unnecessary surplus pages to the buddy allocator */ > free: -- Michal Hocko SUSE Labs SUSE LINUX s.r.o. Lihovarska 1060/12 190 00 Praha 9 Czech Republic