From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756993AbZA1OEa (ORCPT ); Wed, 28 Jan 2009 09:04:30 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755405AbZA1N5n (ORCPT ); Wed, 28 Jan 2009 08:57:43 -0500 Received: from bombadil.infradead.org ([18.85.46.34]:60386 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755279AbZA1N5c (ORCPT ); Wed, 28 Jan 2009 08:57:32 -0500 Message-Id: <20090128135459.332648902@chello.nl> References: <20090128135352.679025549@chello.nl> User-Agent: quilt/0.46-1 Date: Wed, 28 Jan 2009 14:54:12 +0100 From: Peter Zijlstra To: mingo@elte.hu Cc: linux-kernel@vger.kernel.org, npiggin@suse.de, Peter Zijlstra Subject: [PATCH 20/21] lockdep: get_user_chars() redo Content-Disposition: inline; filename=lockdep-get_usage_chars2.patch X-Bad-Reply: References but no 'Re:' in Subject. Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Generic, states independent, get_user_chars(). Signed-off-by: Peter Zijlstra --- Documentation/lockdep-design.txt | 30 +++++++++++++++++------------- kernel/lockdep.c | 26 +++++++++++++------------- kernel/lockdep_internals.h | 7 ++++--- kernel/lockdep_proc.c | 6 +++--- 4 files changed, 37 insertions(+), 32 deletions(-) Index: linux-2.6/kernel/lockdep.c =================================================================== --- linux-2.6.orig/kernel/lockdep.c +++ linux-2.6/kernel/lockdep.c @@ -487,25 +487,25 @@ static char get_usage_char(struct lock_c return c; } -void -get_usage_chars(struct lock_class *class, char *c1, char *c2, char *c3, - char *c4, char *c5, char *c6) -{ - *c1 = get_usage_char(class, LOCK_USED_IN_HARDIRQ); - *c2 = get_usage_char(class, LOCK_USED_IN_SOFTITQ); - *c3 = get_usage_char(class, LOCK_USED_IN_HARDIRQ_READ); - *c4 = get_usage_char(class, LOCK_USED_IN_SOFTITQ_READ); +void get_usage_chars(struct lock_class *class, char usage[LOCK_USAGE_CHARS]) +{ + int i = 0; + +#define LOCKDEP_STATE(__STATE) \ + usage[i++] = get_usage_char(class, LOCK_USED_IN_##__STATE); \ + usage[i++] = get_usage_char(class, LOCK_USED_IN_##__STATE##_READ); +#include "lockdep_states.h" +#undef LOCKDEP_STATE - *c5 = get_usage_char(class, LOCK_USED_IN_RECLAIM_FS); - *c6 = get_usage_char(class, LOCK_USED_IN_RECLAIM_FS_READ); + usage[i] = '\0'; } static void print_lock_name(struct lock_class *class) { - char str[KSYM_NAME_LEN], c1, c2, c3, c4, c5, c6; + char str[KSYM_NAME_LEN], usage[LOCK_USAGE_CHARS]; const char *name; - get_usage_chars(class, &c1, &c2, &c3, &c4, &c5, &c6); + get_usage_chars(class, usage); name = class->name; if (!name) { @@ -518,7 +518,7 @@ static void print_lock_name(struct lock_ if (class->subclass) printk("/%d", class->subclass); } - printk("){%c%c%c%c%c%c}", c1, c2, c3, c4, c5, c6); + printk("){%s}", usage); } static void print_lockdep_cache(struct lockdep_map *lock) Index: linux-2.6/kernel/lockdep_internals.h =================================================================== --- linux-2.6.orig/kernel/lockdep_internals.h +++ linux-2.6/kernel/lockdep_internals.h @@ -70,9 +70,10 @@ enum { extern struct list_head all_lock_classes; extern struct lock_chain lock_chains[]; -extern void -get_usage_chars(struct lock_class *class, char *c1, char *c2, char *c3, - char *c4, char *c5, char *c6); +#define LOCK_USAGE_CHARS (1+LOCK_USAGE_STATES/2) + +extern void get_usage_chars(struct lock_class *class, + char usage[LOCK_USAGE_CHARS]); extern const char * __get_key_name(struct lockdep_subclass_key *key, char *str); Index: linux-2.6/kernel/lockdep_proc.c =================================================================== --- linux-2.6.orig/kernel/lockdep_proc.c +++ linux-2.6/kernel/lockdep_proc.c @@ -84,7 +84,7 @@ static int l_show(struct seq_file *m, vo { struct lock_class *class = v; struct lock_list *entry; - char c1, c2, c3, c4, c5, c6; + char usage[LOCK_USAGE_CHARS]; if (v == SEQ_START_TOKEN) { seq_printf(m, "all lock classes:\n"); @@ -100,8 +100,8 @@ static int l_show(struct seq_file *m, vo seq_printf(m, " BD:%5ld", lockdep_count_backward_deps(class)); #endif - get_usage_chars(class, &c1, &c2, &c3, &c4, &c5, &c6); - seq_printf(m, " %c%c%c%c%c%c", c1, c2, c3, c4, c5, c6); + get_usage_chars(class, usage); + seq_printf(m, " %s", usage); seq_printf(m, ": "); print_name(m, class); Index: linux-2.6/Documentation/lockdep-design.txt =================================================================== --- linux-2.6.orig/Documentation/lockdep-design.txt +++ linux-2.6/Documentation/lockdep-design.txt @@ -27,33 +27,37 @@ lock-class. State ----- -The validator tracks lock-class usage history into 5 separate state bits: +The validator tracks lock-class usage history into 4n + 1 separate state bits: -- 'ever held in hardirq context' [ == hardirq-safe ] -- 'ever held in softirq context' [ == softirq-safe ] -- 'ever held with hardirqs enabled' [ == hardirq-unsafe ] -- 'ever held with softirqs and hardirqs enabled' [ == softirq-unsafe ] +- 'ever held in STATE context' +- 'ever head as readlock in STATE context' +- 'ever head with STATE enabled' +- 'ever head as readlock with STATE enabled' + +Where STATE can be either one of (kernel/lockdep_states.h) + - hardirq + - softirq + - reclaim_fs - 'ever used' [ == !unused ] -When locking rules are violated, these 4 state bits are presented in the -locking error messages, inside curlies. A contrived example: +When locking rules are violated, these state bits are presented in the +locking error messages, inside curlies. A contrived example: modprobe/2287 is trying to acquire lock: - (&sio_locks[i].lock){--..}, at: [] mutex_lock+0x21/0x24 + (&sio_locks[i].lock){-.-...}, at: [] mutex_lock+0x21/0x24 but task is already holding lock: - (&sio_locks[i].lock){--..}, at: [] mutex_lock+0x21/0x24 + (&sio_locks[i].lock){-.-...}, at: [] mutex_lock+0x21/0x24 -The bit position indicates hardirq, softirq, hardirq-read, -softirq-read respectively, and the character displayed in each -indicates: +The bit position indicates STATE, STATE-read, for each of the states listed +above, and the character displayed in each indicates: '.' acquired while irqs disabled '+' acquired in irq context '-' acquired with irqs enabled - '?' read acquired in irq context with irqs enabled. + '?' acquired in irq context with irqs enabled. Unused mutexes cannot be part of the cause of an error. --