From patchwork Sat Feb 4 01:45:17 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Paul E. 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McKenney" To: linux-kernel@vger.kernel.org Cc: mingo@elte.hu, laijs@cn.fujitsu.com, dipankar@in.ibm.com, akpm@linux-foundation.org, mathieu.desnoyers@polymtl.ca, josh@joshtriplett.org, niv@us.ibm.com, tglx@linutronix.de, peterz@infradead.org, rostedt@goodmis.org, Valdis.Kletnieks@vt.edu, dhowells@redhat.com, eric.dumazet@gmail.com, darren@dvhart.com, fweisbec@gmail.com, patches@linaro.org, Heiko Carstens , "Paul E. McKenney" Subject: [PATCH tip/core/rcu 42/47] rcu: Convert WARN_ON_ONCE() in rcu_lock_acquire() to lockdep Date: Fri, 3 Feb 2012 17:45:17 -0800 Message-Id: <1328319922-30828-42-git-send-email-paulmck@linux.vnet.ibm.com> X-Mailer: git-send-email 1.7.8 In-Reply-To: <1328319922-30828-1-git-send-email-paulmck@linux.vnet.ibm.com> References: <20120204014452.GA29811@linux.vnet.ibm.com> <1328319922-30828-1-git-send-email-paulmck@linux.vnet.ibm.com> X-Content-Scanned: Fidelis XPS MAILER x-cbid: 12020401-5518-0000-0000-000001FD8B1F From: Heiko Carstens The WARN_ON_ONCE() in rcu_lock_acquire() results in infinite recursion on S390, and also doesn't print very much information. Remove this. Updated patch to add lockdep-RCU assertions to RCU's read-side primitives. Signed-off-by: Heiko Carstens Signed-off-by: Paul E. McKenney --- include/linux/rcupdate.h | 14 ++++++++++++-- include/linux/srcu.h | 4 ++++ 2 files changed, 16 insertions(+), 2 deletions(-) diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h index 146d37d..6ee663c 100644 --- a/include/linux/rcupdate.h +++ b/include/linux/rcupdate.h @@ -248,13 +248,11 @@ static inline int rcu_is_cpu_idle(void) static inline void rcu_lock_acquire(struct lockdep_map *map) { - WARN_ON_ONCE(rcu_is_cpu_idle()); lock_acquire(map, 0, 0, 2, 1, NULL, _THIS_IP_); } static inline void rcu_lock_release(struct lockdep_map *map) { - WARN_ON_ONCE(rcu_is_cpu_idle()); lock_release(map, 1, _THIS_IP_); } @@ -699,6 +697,8 @@ static inline void rcu_read_lock(void) __rcu_read_lock(); __acquire(RCU); rcu_lock_acquire(&rcu_lock_map); + rcu_lockdep_assert(!rcu_is_cpu_idle(), + "rcu_read_lock() used illegally while idle"); } /* @@ -718,6 +718,8 @@ static inline void rcu_read_lock(void) */ static inline void rcu_read_unlock(void) { + rcu_lockdep_assert(!rcu_is_cpu_idle(), + "rcu_read_unlock() used illegally while idle"); rcu_lock_release(&rcu_lock_map); __release(RCU); __rcu_read_unlock(); @@ -745,6 +747,8 @@ static inline void rcu_read_lock_bh(void) local_bh_disable(); __acquire(RCU_BH); rcu_lock_acquire(&rcu_bh_lock_map); + rcu_lockdep_assert(!rcu_is_cpu_idle(), + "rcu_read_lock_bh() used illegally while idle"); } /* @@ -754,6 +758,8 @@ static inline void rcu_read_lock_bh(void) */ static inline void rcu_read_unlock_bh(void) { + rcu_lockdep_assert(!rcu_is_cpu_idle(), + "rcu_read_unlock_bh() used illegally while idle"); rcu_lock_release(&rcu_bh_lock_map); __release(RCU_BH); local_bh_enable(); @@ -777,6 +783,8 @@ static inline void rcu_read_lock_sched(void) preempt_disable(); __acquire(RCU_SCHED); rcu_lock_acquire(&rcu_sched_lock_map); + rcu_lockdep_assert(!rcu_is_cpu_idle(), + "rcu_read_lock_sched() used illegally while idle"); } /* Used by lockdep and tracing: cannot be traced, cannot call lockdep. */ @@ -793,6 +801,8 @@ static inline notrace void rcu_read_lock_sched_notrace(void) */ static inline void rcu_read_unlock_sched(void) { + rcu_lockdep_assert(!rcu_is_cpu_idle(), + "rcu_read_unlock_sched() used illegally while idle"); rcu_lock_release(&rcu_sched_lock_map); __release(RCU_SCHED); preempt_enable(); diff --git a/include/linux/srcu.h b/include/linux/srcu.h index 9a32372..d3d5fa5 100644 --- a/include/linux/srcu.h +++ b/include/linux/srcu.h @@ -172,6 +172,8 @@ static inline int srcu_read_lock(struct srcu_struct *sp) __acquires(sp) int retval = __srcu_read_lock(sp); rcu_lock_acquire(&(sp)->dep_map); + rcu_lockdep_assert(!rcu_is_cpu_idle(), + "srcu_read_lock() used illegally while idle"); return retval; } @@ -185,6 +187,8 @@ static inline int srcu_read_lock(struct srcu_struct *sp) __acquires(sp) static inline void srcu_read_unlock(struct srcu_struct *sp, int idx) __releases(sp) { + rcu_lockdep_assert(!rcu_is_cpu_idle(), + "srcu_read_unlock() used illegally while idle"); rcu_lock_release(&(sp)->dep_map); __srcu_read_unlock(sp, idx); }