From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx145.postini.com [74.125.245.145]) by kanga.kvack.org (Postfix) with SMTP id E34C76B0092 for ; Fri, 16 Mar 2012 10:53:02 -0400 (EDT) Message-Id: <20120316144241.292638290@chello.nl> Date: Fri, 16 Mar 2012 15:40:46 +0100 From: Peter Zijlstra Subject: [RFC][PATCH 18/26] srcu: revert2 References: <20120316144028.036474157@chello.nl> Content-Disposition: inline; filename=srcu-revert-2.patch Sender: owner-linux-mm@kvack.org List-ID: To: Linus Torvalds , Andrew Morton , Thomas Gleixner , Ingo Molnar , Paul Turner , Suresh Siddha , Mike Galbraith , "Paul E. McKenney" , Lai Jiangshan , Dan Smith , Bharata B Rao , Lee Schermerhorn , Andrea Arcangeli , Rik van Riel , Johannes Weiner Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, Peter Zijlstra rcu: Add lockdep-RCU checks for simple self-deadlock It is illegal to have a grace period within a same-flavor RCU read-side critical section, so this commit adds lockdep-RCU checks to splat when such abuse is encountered. This commit does not detect more elaborate RCU deadlock situations. These situations might be a job for lockdep enhancements. Signed-off-by: Paul E. McKenney Signed-off-by: Peter Zijlstra --- kernel/rcutiny.c | 4 ---- kernel/rcutiny_plugin.h | 5 ----- kernel/rcutree.c | 8 -------- kernel/rcutree_plugin.h | 4 ---- kernel/srcu.c | 6 ------ 5 files changed, 27 deletions(-) --- a/kernel/rcutiny.c +++ b/kernel/rcutiny.c @@ -329,10 +329,6 @@ static void rcu_process_callbacks(struct */ void synchronize_sched(void) { - rcu_lockdep_assert(!lock_is_held(&rcu_bh_lock_map) && - !lock_is_held(&rcu_lock_map) && - !lock_is_held(&rcu_sched_lock_map), - "Illegal synchronize_sched() in RCU read-side critical section"); cond_resched(); } EXPORT_SYMBOL_GPL(synchronize_sched); --- a/kernel/rcutiny_plugin.h +++ b/kernel/rcutiny_plugin.h @@ -735,11 +735,6 @@ EXPORT_SYMBOL_GPL(call_rcu); */ void synchronize_rcu(void) { - rcu_lockdep_assert(!lock_is_held(&rcu_bh_lock_map) && - !lock_is_held(&rcu_lock_map) && - !lock_is_held(&rcu_sched_lock_map), - "Illegal synchronize_rcu() in RCU read-side critical section"); - #ifdef CONFIG_DEBUG_LOCK_ALLOC if (!rcu_scheduler_active) return; --- a/kernel/rcutree.c +++ b/kernel/rcutree.c @@ -1919,10 +1919,6 @@ EXPORT_SYMBOL_GPL(call_rcu_bh); */ void synchronize_sched(void) { - rcu_lockdep_assert(!lock_is_held(&rcu_bh_lock_map) && - !lock_is_held(&rcu_lock_map) && - !lock_is_held(&rcu_sched_lock_map), - "Illegal synchronize_sched() in RCU-sched read-side critical section"); if (rcu_blocking_is_gp()) return; wait_rcu_gp(call_rcu_sched); @@ -1940,10 +1936,6 @@ EXPORT_SYMBOL_GPL(synchronize_sched); */ void synchronize_rcu_bh(void) { - rcu_lockdep_assert(!lock_is_held(&rcu_bh_lock_map) && - !lock_is_held(&rcu_lock_map) && - !lock_is_held(&rcu_sched_lock_map), - "Illegal synchronize_rcu_bh() in RCU-bh read-side critical section"); if (rcu_blocking_is_gp()) return; wait_rcu_gp(call_rcu_bh); --- a/kernel/rcutree_plugin.h +++ b/kernel/rcutree_plugin.h @@ -731,10 +731,6 @@ EXPORT_SYMBOL_GPL(kfree_call_rcu); */ void synchronize_rcu(void) { - rcu_lockdep_assert(!lock_is_held(&rcu_bh_lock_map) && - !lock_is_held(&rcu_lock_map) && - !lock_is_held(&rcu_sched_lock_map), - "Illegal synchronize_rcu() in RCU read-side critical section"); if (!rcu_scheduler_active) return; wait_rcu_gp(call_rcu); --- a/kernel/srcu.c +++ b/kernel/srcu.c @@ -172,12 +172,6 @@ static void __synchronize_srcu(struct sr { int idx; - rcu_lockdep_assert(!lock_is_held(&sp->dep_map) && - !lock_is_held(&rcu_bh_lock_map) && - !lock_is_held(&rcu_lock_map) && - !lock_is_held(&rcu_sched_lock_map), - "Illegal synchronize_srcu() in same-type SRCU (or RCU) read-side critical section"); - idx = sp->completed; mutex_lock(&sp->mutex); -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org