Commit-ID: c4be9cb4f19cbd534a6c4c334cd48d8bb483e17a Gitweb: http://git.kernel.org/tip/c4be9cb4f19cbd534a6c4c334cd48d8bb483e17a Author: Michel Lespinasse <wal...@google.com> AuthorDate: Mon, 8 Jul 2013 14:23:51 -0700 Committer: Ingo Molnar <mi...@kernel.org> CommitDate: Fri, 12 Jul 2013 13:51:19 +0200
lglock: Update lockdep annotations to report recursive local locks Oleg Nesterov recently noticed that the lockdep annotations in lglock.c are not sufficient to detect some obvious deadlocks, such as lg_local_lock(LOCK) + lg_local_lock(LOCK) or spin_lock(X) + lg_local_lock(Y) vs lg_local_lock(Y) + spin_lock(X). Both issues are easily fixed by indicating to lockdep that lglock's local locks are not recursive. We shouldn't use the rwlock acquire/release functions here, as lglock doesn't share the same semantics. Instead we can base our lockdep annotations on the lock_acquire_shared (for local lglock) and lock_acquire_exclusive (for global lglock) helpers. I am not proposing new lglock specific helpers as I don't see the point of the existing second level of helpers :) Noticed-by: Oleg Nesterov <o...@redhat.com> Signed-off-by: Michel Lespinasse <wal...@google.com> Cc: Lai Jiangshan <la...@cn.fujitsu.com> Cc: "Srivatsa S. Bhat" <srivatsa.b...@linux.vnet.ibm.com> Cc: Rusty Russell <ru...@rustcorp.com.au> Cc: Andi Kleen <a...@linux.intel.com> Cc: "Paul E. McKenney" <paul...@us.ibm.com> Cc: Steven Rostedt <rost...@goodmis.org> Signed-off-by: Andrew Morton <a...@linux-foundation.org> Signed-off-by: Peter Zijlstra <pet...@infradead.org> Link: http://lkml.kernel.org/r/20130708212352.1769031c...@corp2gmr1-1.hot.corp.google.com Signed-off-by: Ingo Molnar <mi...@kernel.org> --- kernel/lglock.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/kernel/lglock.c b/kernel/lglock.c index 6535a66..86ae2ae 100644 --- a/kernel/lglock.c +++ b/kernel/lglock.c @@ -21,7 +21,7 @@ void lg_local_lock(struct lglock *lg) arch_spinlock_t *lock; preempt_disable(); - rwlock_acquire_read(&lg->lock_dep_map, 0, 0, _RET_IP_); + lock_acquire_shared(&lg->lock_dep_map, 0, 0, NULL, _RET_IP_); lock = this_cpu_ptr(lg->lock); arch_spin_lock(lock); } @@ -31,7 +31,7 @@ void lg_local_unlock(struct lglock *lg) { arch_spinlock_t *lock; - rwlock_release(&lg->lock_dep_map, 1, _RET_IP_); + lock_release(&lg->lock_dep_map, 1, _RET_IP_); lock = this_cpu_ptr(lg->lock); arch_spin_unlock(lock); preempt_enable(); @@ -43,7 +43,7 @@ void lg_local_lock_cpu(struct lglock *lg, int cpu) arch_spinlock_t *lock; preempt_disable(); - rwlock_acquire_read(&lg->lock_dep_map, 0, 0, _RET_IP_); + lock_acquire_shared(&lg->lock_dep_map, 0, 0, NULL, _RET_IP_); lock = per_cpu_ptr(lg->lock, cpu); arch_spin_lock(lock); } @@ -53,7 +53,7 @@ void lg_local_unlock_cpu(struct lglock *lg, int cpu) { arch_spinlock_t *lock; - rwlock_release(&lg->lock_dep_map, 1, _RET_IP_); + lock_release(&lg->lock_dep_map, 1, _RET_IP_); lock = per_cpu_ptr(lg->lock, cpu); arch_spin_unlock(lock); preempt_enable(); @@ -65,7 +65,7 @@ void lg_global_lock(struct lglock *lg) int i; preempt_disable(); - rwlock_acquire(&lg->lock_dep_map, 0, 0, _RET_IP_); + lock_acquire_exclusive(&lg->lock_dep_map, 0, 0, NULL, _RET_IP_); for_each_possible_cpu(i) { arch_spinlock_t *lock; lock = per_cpu_ptr(lg->lock, i); @@ -78,7 +78,7 @@ void lg_global_unlock(struct lglock *lg) { int i; - rwlock_release(&lg->lock_dep_map, 1, _RET_IP_); + lock_release(&lg->lock_dep_map, 1, _RET_IP_); for_each_possible_cpu(i) { arch_spinlock_t *lock; lock = per_cpu_ptr(lg->lock, i); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
