Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758718Ab1FVXpF (ORCPT ); Wed, 22 Jun 2011 19:45:05 -0400 Received: from mx1.redhat.com ([209.132.183.28]:18155 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757743Ab1FVXpD (ORCPT ); Wed, 22 Jun 2011 19:45:03 -0400 Date: Thu, 23 Jun 2011 01:44:50 +0200 From: Andrea Arcangeli To: Nai Xia Cc: Andrew Morton , Izik Eidus , Hugh Dickins , Chris Wright , Rik van Riel , linux-mm , Johannes Weiner , linux-kernel , kvm Subject: Re: [PATCH] mmu_notifier, kvm: Introduce dirty bit tracking in spte and mmu notifier to help KSM dirty bit tracking Message-ID: <20110622234450.GB20843@redhat.com> References: <201106212055.25400.nai.xia@gmail.com> <201106212132.39311.nai.xia@gmail.com> <20110622150350.GX20843@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1088 Lines: 28 On Thu, Jun 23, 2011 at 07:19:06AM +0800, Nai Xia wrote: > OK, I'll have a try over other workarounds. > I am not feeling good about need_pte_unmap myself. :-) The usual way is to check VM_HUGETLB in the caller and to call another function that doesn't kmap. Casting pmd_t to pte_t isn't really nice (but hey we're also doing that exceptionally in smaps_pte_range for THP, but it safe there because we're casting the value of the pmd, not the pointer to the pmd, so the kmap is done by the pte version of the caller and not done by the pmd version of the caller). Is it done for migrate? Surely it's not for swapout ;). > Thanks for viewing! You're welcome! JFYI I'll be offline on vacation for a week, starting tomorrow, so if I don't answer in the next few days that's the reason but I'll follow the progress in a week. Thanks! Andrea -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/