From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932323AbVHKR54 (ORCPT ); Thu, 11 Aug 2005 13:57:56 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932334AbVHKR54 (ORCPT ); Thu, 11 Aug 2005 13:57:56 -0400 Received: from mx1.redhat.com ([66.187.233.31]:48839 "EHLO mx1.redhat.com") by vger.kernel.org with ESMTP id S932323AbVHKR5z (ORCPT ); Thu, 11 Aug 2005 13:57:55 -0400 From: David Howells In-Reply-To: <20050811172312.GA10202@lst.de> References: <20050811172312.GA10202@lst.de> To: Christoph Hellwig Cc: dhowells@redhat.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH, RFC] kill odd mm context pinning hack in frv X-Mailer: MH-E 7.82; nmh 1.0.4; GNU Emacs 22.0.50.4 Date: Thu, 11 Aug 2005 18:57:43 +0100 Message-ID: <6466.1123783063@warthog.cambridge.redhat.com> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Christoph Hellwig wrote: > David, is that more than a debugging aid? I'm trying to get rid of > tasklist_lock users and this one looks really suspicios.. Yes. The FR451 CPU (the only one with an MMU at the moment) has accounting and profiling aids that are enabled by the context number set in the CXNR register. This context number also selectively enables TLB entries on a per-mm context basis. So to profile a process you pin a context number to that process, and then the profiling h/w is only active for that process. David