From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754256Ab2C0One (ORCPT ); Tue, 27 Mar 2012 10:43:34 -0400 Received: from acsinet15.oracle.com ([141.146.126.227]:18546 "EHLO acsinet15.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750977Ab2C0On3 (ORCPT ); Tue, 27 Mar 2012 10:43:29 -0400 Date: Tue, 27 Mar 2012 10:26:55 -0400 From: Konrad Rzeszutek Wilk To: Stefano Stabellini Cc: linux-kernel@vger.kernel.org, xen-devel@lists.xensource.com Subject: Re: [PATCH 2/2] m2p_find_override: use list_for_each_entry_safe Message-ID: <20120327142654.GA30655@phenom.dumpdata.com> References: <1332856364-29995-1-git-send-email-stefano.stabellini@eu.citrix.com> <1332856364-29995-2-git-send-email-stefano.stabellini@eu.citrix.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1332856364-29995-2-git-send-email-stefano.stabellini@eu.citrix.com> User-Agent: Mutt/1.5.21 (2010-09-15) X-Source-IP: acsinet21.oracle.com [141.146.126.237] X-Auth-Type: Internal IP X-CT-RefId: str=0001.0A090208.4F71D20C.00B7,ss=1,re=0.000,fgs=0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Mar 27, 2012 at 02:52:44PM +0100, Stefano Stabellini wrote: > Use list_for_each_entry_safe and remove the spin_lock acquisition in > m2p_find_override. So this would allow us to get stale entries. Is that OK? > > Signed-off-by: Stefano Stabellini > --- > arch/x86/xen/p2m.c | 8 ++------ > 1 files changed, 2 insertions(+), 6 deletions(-) > > diff --git a/arch/x86/xen/p2m.c b/arch/x86/xen/p2m.c > index 1b267e7..7ed8cc3 100644 > --- a/arch/x86/xen/p2m.c > +++ b/arch/x86/xen/p2m.c > @@ -809,21 +809,17 @@ struct page *m2p_find_override(unsigned long mfn) > { > unsigned long flags; > struct list_head *bucket = &m2p_overrides[mfn_hash(mfn)]; > - struct page *p, *ret; > + struct page *p, *t, *ret; > > ret = NULL; > > - spin_lock_irqsave(&m2p_override_lock, flags); > - > - list_for_each_entry(p, bucket, lru) { > + list_for_each_entry_safe(p, t, bucket, lru) { > if (page_private(p) == mfn) { > ret = p; > break; > } > } > > - spin_unlock_irqrestore(&m2p_override_lock, flags); > - > return ret; > } > > -- > 1.7.2.5