From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx151.postini.com [74.125.245.151]) by kanga.kvack.org (Postfix) with SMTP id 157B36B0072 for ; Thu, 16 Aug 2012 13:35:10 -0400 (EDT) Date: Thu, 16 Aug 2012 18:34:59 +0100 From: Will Deacon Subject: Re: [PATCH] mm: hugetlb: flush dcache before returning zeroed huge page to userspace Message-ID: <20120816173459.GB7203@mudshark.cambridge.arm.com> References: <20120710094513.GB9108@mudshark.cambridge.arm.com> <20120710104234.GI9108@mudshark.cambridge.arm.com> <20120711174802.GG13498@mudshark.cambridge.arm.com> <20120712111659.GF21013@tiehlicka.suse.cz> <20120712112645.GG2816@mudshark.cambridge.arm.com> <20120712115708.GG21013@tiehlicka.suse.cz> <20120807160337.GC16877@mudshark.cambridge.arm.com> <20120808162607.GA7885@dhcp22.suse.cz> <20120816160954.GA4330@mudshark.cambridge.arm.com> <20120816172527.GA12578@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20120816172527.GA12578@dhcp22.suse.cz> Sender: owner-linux-mm@kvack.org List-ID: To: Michal Hocko Cc: Hugh Dickins , Andrew Morton , Hillf Danton , Russell King , "linux-arch@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "linux-mm@kvack.org" On Thu, Aug 16, 2012 at 06:25:27PM +0100, Michal Hocko wrote: > On Thu 16-08-12 17:09:54, Will Deacon wrote: > > On Wed, Aug 08, 2012 at 05:26:07PM +0100, Michal Hocko wrote: > > > I guess the cleanest way is to hook into dequeue_huge_page_node and add > > > something like arch_clear_hugepage_flags. > > > > I hooked into enqueue_huge_page instead, but how about something like this?: > > Do you have any specific reason for that? enqueue_huge_page is called on > pages which potentially never get used so isn't that wasting a bit? > Not that it would be wrong I was just thinking why shouldn't we do it > when the page is actualy going to be used for sure. I just did it that way to match the flag clearing for normal pages. I can move it into dequeue if you think it's worthwhile but in the worst case it just adds a clear_bit call, so I doubt it's measurable. Will -- 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/ . Don't email: email@kvack.org