From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759564AbZBMAfl (ORCPT ); Thu, 12 Feb 2009 19:35:41 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753904AbZBMAfd (ORCPT ); Thu, 12 Feb 2009 19:35:33 -0500 Received: from gw.goop.org ([64.81.55.164]:58114 "EHLO mail.goop.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750802AbZBMAfd (ORCPT ); Thu, 12 Feb 2009 19:35:33 -0500 Message-ID: <4994C052.9060907@goop.org> Date: Thu, 12 Feb 2009 16:35:30 -0800 From: Jeremy Fitzhardinge User-Agent: Thunderbird 2.0.0.19 (X11/20090105) MIME-Version: 1.0 To: Andrew Morton CC: Linux Kernel Mailing List Subject: Re: [PATCH] mm: disable preemption in apply_to_pte_range References: <4994BCF0.30005@goop.org> In-Reply-To: <4994BCF0.30005@goop.org> X-Enigmail-Version: 0.95.6 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Jeremy Fitzhardinge wrote: > commit 79d9c90453a7bc9e7613ae889a97ff6b44ab8380 Scratch that. This instead. J mm: disable preemption in apply_to_pte_range Lazy mmu mode needs preemption disabled, so if we're apply to init_mm (which doesn't require any pte locks), then explicitly disable preemption. (Do it unconditionally after checking we've successfully done the allocation to simplify the error handling.) Signed-off-by: Jeremy Fitzhardinge diff --git a/mm/memory.c b/mm/memory.c index baa999e..b80cc31 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -1718,6 +1718,7 @@ static int apply_to_pte_range(struct mm_struct *mm, pmd_t *pmd, BUG_ON(pmd_huge(*pmd)); + preempt_disable(); arch_enter_lazy_mmu_mode(); token = pmd_pgtable(*pmd); @@ -1729,6 +1730,7 @@ static int apply_to_pte_range(struct mm_struct *mm, pmd_t *pmd, } while (pte++, addr += PAGE_SIZE, addr != end); arch_leave_lazy_mmu_mode(); + preempt_enable(); if (mm != &init_mm) pte_unmap_unlock(pte-1, ptl);