From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932382AbXGNXwx (ORCPT ); Sat, 14 Jul 2007 19:52:53 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757614AbXGNXwp (ORCPT ); Sat, 14 Jul 2007 19:52:45 -0400 Received: from bc.sympatico.ca ([209.226.175.184]:44693 "EHLO tomts22-srv.bellnexxia.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759411AbXGNXwp (ORCPT ); Sat, 14 Jul 2007 19:52:45 -0400 Date: Sat, 14 Jul 2007 19:52:43 -0400 From: Mathieu Desnoyers To: akpm@linux-foundation.org, linux-kernel@vger.kernel.org Cc: Christoph Hellwig Subject: [PATCH] Immediate Value - Architecture Independent Code Deferred Sync Message-ID: <20070714235243.GA20571@Krystal> References: <20070714012439.285079881@polymtl.ca> <20070714012623.231272637@polymtl.ca> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline In-Reply-To: <20070714012623.231272637@polymtl.ca> X-Editor: vi X-Info: http://krystal.dyndns.org:8080 X-Operating-System: Linux/2.6.21.3-grsec (i686) X-Uptime: 19:50:18 up 7 days, 13:55, 2 users, load average: 0.75, 0.32, 0.24 User-Agent: Mutt/1.5.13 (2006-08-11) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Linux Kernel Markers - Architecture Independent Code Deferred Sync Upon marker probe_unregister, we delay call to synchronize_sched() to accelerate mass unregistration (only when there is no more reference to a give module do we call synchronize_sched()). However, we need to make sure every critical region have ended before we re-arm a marker that has been unregistered and then registered back with a different probe data. Signed-off-by: Mathieu Desnoyers CC: Christoph Hellwig --- kernel/marker.c | 22 ++++++++++++++++++++-- 1 file changed, 20 insertions(+), 2 deletions(-) Index: linux-2.6-lttng/kernel/marker.c =================================================================== --- linux-2.6-lttng.orig/kernel/marker.c 2007-07-14 19:38:11.000000000 -0400 +++ linux-2.6-lttng/kernel/marker.c 2007-07-14 19:46:25.000000000 -0400 @@ -30,11 +30,21 @@ extern struct __mark_marker __stop___mar /* * module_mutex nests inside markers_mutex. Markers mutex protects the builtin - * and module markers, and the hash table. + * and module markers, the hash table and deferred_sync. */ DEFINE_MUTEX(markers_mutex); /* + * Marker deferred synchronization. + * Upon marker probe_unregister, we delay call to synchronize_sched() to + * accelerate mass unregistration (only when there is no more reference to a + * give module do we call synchronize_sched()). However, we need to make sure + * every critical region have ended before we re-arm a marker that has been + * unregistered and then registered back with a different probe data. + */ +static int deferred_sync; + +/* * Marker hash table, containing the active markers. * Protected by module_mutex. */ @@ -303,8 +313,10 @@ static inline void __marker_update_probe __stop___markers, probe_module, &refcount); /* Markers in modules. */ __marker_update_probes_modules(probe_module, &refcount); - if (probe_module && refcount == 0) + if (probe_module && refcount == 0) { synchronize_sched(); + deferred_sync = 0; + } } #ifdef CONFIG_MODULES @@ -353,6 +365,10 @@ int marker_probe_register(const char *na ret = -EBUSY; goto end; } + if (deferred_sync) { + synchronize_sched(); + deferred_sync = 0; + } ret = _add_marker(name, format, probe, pdata); if (ret) goto end; @@ -384,6 +400,7 @@ void *marker_probe_unregister(const char /* In what module is the probe handler ? */ probe_module = __module_text_address((unsigned long)entry->probe); pdata = _remove_marker(name); + deferred_sync = 1; _marker_update_probes(probe_module); end: mutex_unlock(&markers_mutex); @@ -425,6 +442,7 @@ iter_end: /* In what module is the probe handler ? */ probe_module = __module_text_address((unsigned long)entry->probe); pdata = _remove_marker(entry->name); + deferred_sync = 1; _marker_update_probes(probe_module); end: mutex_unlock(&markers_mutex); -- Mathieu Desnoyers Computer Engineering Ph.D. Student, Ecole Polytechnique de Montreal OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F BA06 3F25 A8FE 3BAE 9A68