From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758956AbYCZT12 (ORCPT ); Wed, 26 Mar 2008 15:27:28 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754883AbYCZT1T (ORCPT ); Wed, 26 Mar 2008 15:27:19 -0400 Received: from netops-testserver-3-out.sgi.com ([192.48.171.28]:54954 "EHLO relay.sgi.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1754729AbYCZT1T (ORCPT ); Wed, 26 Mar 2008 15:27:19 -0400 Date: Wed, 26 Mar 2008 12:25:21 -0700 (PDT) From: Christoph Lameter X-X-Sender: clameter@schroedinger.engr.sgi.com To: "Luck, Tony" cc: linux-arch@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: What if a TLB flush needed to sleep? In-Reply-To: <1FE6DD409037234FAB833C420AA843ECE9DF60@orsmsx424.amr.corp.intel.com> Message-ID: References: <1FE6DD409037234FAB833C420AA843ECE9DF60@orsmsx424.amr.corp.intel.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 25 Mar 2008, Luck, Tony wrote: > 2) Is it feasible to rearrange the MM code so that we don't > hold any locks while doing a TLB flush? Or should I implement > some sort of spin_only_semaphore? The EMM notifier V2 patchset contains two patches that convert the immap_lock and the anon_vma lock to semaphores. After that much of the TLB flushing is (tlb_finish_mmu, tlb_gather etc) is running without holding any spinlocks. There would need to be additional measures for flushing inherent in macros (like ptep_clear_flush). Currently the pte functions are called under pte lock.