From mboxrd@z Thu Jan 1 00:00:00 1970 From: Julien Grall Subject: Re: [PATCH v5 7/8] xen: arm: use superpages in p2m when pages are suitably aligned Date: Wed, 09 Jul 2014 17:28:04 +0100 Message-ID: <53BD6D94.7010108@linaro.org> References: <1404907608.16789.18.camel@kazak.uk.xensource.com> <1404907666-8594-7-git-send-email-ian.campbell@citrix.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1404907666-8594-7-git-send-email-ian.campbell@citrix.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Ian Campbell , xen-devel@lists.xen.org Cc: tim@xen.org, stefano.stabellini@eu.citrix.com List-Id: xen-devel@lists.xenproject.org Hi Ian, On 07/09/2014 01:07 PM, Ian Campbell wrote: > diff --git a/xen/arch/arm/p2m.c b/xen/arch/arm/p2m.c > index cb22e9c..642591b 100644 > --- a/xen/arch/arm/p2m.c > +++ b/xen/arch/arm/p2m.c [..] > + case CACHEFLUSH: > + if ( !p2m_valid(orig_pte) ) > + { > + *addr = (*addr + level_size) & level_mask; > + return P2M_ONE_PROGRESS_NOP; > + } > + > + if ( level < 3 && p2m_table(orig_pte) ) > + return P2M_ONE_DESCEND; > + /* > + * could flush up to the next boundary, but would need to be > + * careful about preemption, so just do one page now and loop. At the first glance I though this code didn't handle correctly superpage flush. It took me several minutes to understand that you rely P2M_ONE_PROGRESS{,_NOP} to do the job for you. Can you explain this trick in the commit message? With this changes: Acked-by: Julien Grall Regards, -- Julien Grall