From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932529AbXGOBdM (ORCPT ); Sat, 14 Jul 2007 21:33:12 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1758711AbXGOBc6 (ORCPT ); Sat, 14 Jul 2007 21:32:58 -0400 Received: from tomts25-srv.bellnexxia.net ([209.226.175.188]:39841 "EHLO tomts25-srv.bellnexxia.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755584AbXGOBc6 (ORCPT ); Sat, 14 Jul 2007 21:32:58 -0400 Date: Sat, 14 Jul 2007 21:32:56 -0400 From: Mathieu Desnoyers To: akpm@linux-foundation.org, linux-kernel@vger.kernel.org Cc: Christoph Hellwig Subject: Re: [PATCH] Immediate Value - Architecture Independent Code Deferred Sync Message-ID: <20070715013256.GD23209@Krystal> References: <20070714012439.285079881@polymtl.ca> <20070714012623.231272637@polymtl.ca> <20070714235243.GA20571@Krystal> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline In-Reply-To: <20070714235243.GA20571@Krystal> X-Editor: vi X-Info: http://krystal.dyndns.org:8080 X-Operating-System: Linux/2.6.21.3-grsec (i686) X-Uptime: 21:32:19 up 7 days, 15:37, 2 users, load average: 0.35, 0.21, 0.14 User-Agent: Mutt/1.5.13 (2006-08-11) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Please drop, wrong thread. Will repost in the right one. * Mathieu Desnoyers (mathieu.desnoyers@polymtl.ca) wrote: > 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 > - > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ > -- Mathieu Desnoyers Computer Engineering Ph.D. Student, Ecole Polytechnique de Montreal OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F BA06 3F25 A8FE 3BAE 9A68