From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757474Ab2HPSdP (ORCPT ); Thu, 16 Aug 2012 14:33:15 -0400 Received: from cam-admin0.cambridge.arm.com ([217.140.96.50]:60219 "EHLO cam-admin0.cambridge.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752662Ab2HPSdM (ORCPT ); Thu, 16 Aug 2012 14:33:12 -0400 Date: Thu, 16 Aug 2012 19:32:56 +0100 From: Will Deacon 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" Subject: Re: [PATCH] mm: hugetlb: flush dcache before returning zeroed huge page to userspace Message-ID: <20120816183255.GB19401@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> <20120816182015.GC12578@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20120816182015.GC12578@dhcp22.suse.cz> 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 Thu, Aug 16, 2012 at 07:20:15PM +0100, Michal Hocko wrote: > On Thu 16-08-12 17:09:54, Will Deacon wrote: > > +static inline void arch_clear_hugepage_flags(struct page *page) > > +{ > > + flush_dcache_page(page); > > +} > > + > > Why do we need the hook for ia64? hugetlb_no_page calls clear_huge_page > and that one calls flush_dcache_page (via clear_user_page), right? > The same applies to copy_huge_page for COW. You're right, these are redundant for ppc and ia64 (although ppc does have a comment moaning about the flush). Looks like it's just sh and ARM that need to do anything. Cheers, Will From mboxrd@z Thu Jan 1 00:00:00 1970 From: Will Deacon Subject: Re: [PATCH] mm: hugetlb: flush dcache before returning zeroed huge page to userspace Date: Thu, 16 Aug 2012 19:32:56 +0100 Message-ID: <20120816183255.GB19401@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> <20120816182015.GC12578@dhcp22.suse.cz> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20120816182015.GC12578@dhcp22.suse.cz> Sender: owner-linux-mm@kvack.org 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" List-Id: linux-arch.vger.kernel.org On Thu, Aug 16, 2012 at 07:20:15PM +0100, Michal Hocko wrote: > On Thu 16-08-12 17:09:54, Will Deacon wrote: > > +static inline void arch_clear_hugepage_flags(struct page *page) > > +{ > > + flush_dcache_page(page); > > +} > > + > > Why do we need the hook for ia64? hugetlb_no_page calls clear_huge_page > and that one calls flush_dcache_page (via clear_user_page), right? > The same applies to copy_huge_page for COW. You're right, these are redundant for ppc and ia64 (although ppc does have a comment moaning about the flush). Looks like it's just sh and ARM that need to do anything. Cheers, 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