From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754549Ab2JZSsc (ORCPT ); Fri, 26 Oct 2012 14:48:32 -0400 Received: from mx1.redhat.com ([209.132.183.28]:40645 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753766Ab2JZSsb (ORCPT ); Fri, 26 Oct 2012 14:48:31 -0400 Date: Fri, 26 Oct 2012 14:44:19 -0400 From: Rik van Riel To: Ingo Molnar Cc: Andi Kleen , Michel Lespinasse , Linus Torvalds , Peter Zijlstra , Andrea Arcangeli , Mel Gorman , Johannes Weiner , Thomas Gleixner , Andrew Morton , linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: [PATCH 1/3] x86/mm: only do a local TLB flush in ptep_set_access_flags() Message-ID: <20121026144419.7e666023@dull> In-Reply-To: <20121026132601.GC9886@gmail.com> References: <20121025121617.617683848@chello.nl> <20121025124832.840241082@chello.nl> <5089F5B5.1050206@redhat.com> <508A0A0D.4090001@redhat.com> <508A8D31.9000106@redhat.com> <20121026132601.GC9886@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Here are the TLB patches as requested: ---8<--- The function ptep_set_access_flags() is only ever invoked to upgrade access permissions on a PTE. That makes it safe to skip flushing the TLBs on remote TLBs. The worst that can happen is a spurious page fault on other CPUs, which would flush that TLB entry. Lazily letting another CPU incur a spurious page fault occasionally is (much!) cheaper than aggressively flushing everybody else's TLB. Signed-off-by: Rik van Riel Cc: Linus Torvalds Cc: Andrew Morton Cc: Peter Zijlstra Cc: Michel Lespinasse Cc: Ingo Molnar --- arch/x86/mm/pgtable.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/mm/pgtable.c b/arch/x86/mm/pgtable.c index 8573b83..b3b852c 100644 --- a/arch/x86/mm/pgtable.c +++ b/arch/x86/mm/pgtable.c @@ -310,7 +310,7 @@ int ptep_set_access_flags(struct vm_area_struct *vma, if (changed && dirty) { *ptep = entry; pte_update_defer(vma->vm_mm, address, ptep); - flush_tlb_page(vma, address); + __flush_tlb_one(address); } return changed; From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx187.postini.com [74.125.245.187]) by kanga.kvack.org (Postfix) with SMTP id 3D1CA6B007B for ; Fri, 26 Oct 2012 14:48:26 -0400 (EDT) Date: Fri, 26 Oct 2012 14:44:19 -0400 From: Rik van Riel Subject: [PATCH 1/3] x86/mm: only do a local TLB flush in ptep_set_access_flags() Message-ID: <20121026144419.7e666023@dull> In-Reply-To: <20121026132601.GC9886@gmail.com> References: <20121025121617.617683848@chello.nl> <20121025124832.840241082@chello.nl> <5089F5B5.1050206@redhat.com> <508A0A0D.4090001@redhat.com> <508A8D31.9000106@redhat.com> <20121026132601.GC9886@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Ingo Molnar Cc: Andi Kleen , Michel Lespinasse , Linus Torvalds , Peter Zijlstra , Andrea Arcangeli , Mel Gorman , Johannes Weiner , Thomas Gleixner , Andrew Morton , linux-kernel@vger.kernel.org, linux-mm@kvack.org Here are the TLB patches as requested: ---8<--- The function ptep_set_access_flags() is only ever invoked to upgrade access permissions on a PTE. That makes it safe to skip flushing the TLBs on remote TLBs. The worst that can happen is a spurious page fault on other CPUs, which would flush that TLB entry. Lazily letting another CPU incur a spurious page fault occasionally is (much!) cheaper than aggressively flushing everybody else's TLB. Signed-off-by: Rik van Riel Cc: Linus Torvalds Cc: Andrew Morton Cc: Peter Zijlstra Cc: Michel Lespinasse Cc: Ingo Molnar --- arch/x86/mm/pgtable.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/mm/pgtable.c b/arch/x86/mm/pgtable.c index 8573b83..b3b852c 100644 --- a/arch/x86/mm/pgtable.c +++ b/arch/x86/mm/pgtable.c @@ -310,7 +310,7 @@ int ptep_set_access_flags(struct vm_area_struct *vma, if (changed && dirty) { *ptep = entry; pte_update_defer(vma->vm_mm, address, ptep); - flush_tlb_page(vma, address); + __flush_tlb_one(address); } return changed; -- 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