From fc2219d49ef1606e7fd2c88af2b423b01ff3d319 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Wed, 23 Sep 2009 09:50:41 -0700 Subject: rcu: Clean up code based on review feedback from Josh Triplett These issues identified during an old-fashioned face-to-face code review extended over many hours. o Bury various forms of the "rsp->completed == rsp->gpnum" comparison into an rcu_gp_in_progress() function, which has the beneficial side-effect of forcing consistent use of ACCESS_ONCE(). o Replace hand-coded arithmetic with DIV_ROUND_UP(). o Bury several "!list_empty(&rnp->blocked_tasks[rnp->gpnum & 0x01])" instances into an rcu_preempted_readers() function, as this expression indicates that there are no readers blocked within RCU read-side critical sections blocking the current grace period. (Though there might well be similar readers blocking the next grace period.) o Remove a dangling rcu_restart_cpu() declaration that has been dangling for almost 20 minor releases of the kernel. Signed-off-by: Paul E. McKenney Acked-by: Peter Zijlstra Cc: laijs@cn.fujitsu.com Cc: dipankar@in.ibm.com Cc: akpm@linux-foundation.org Cc: mathieu.desnoyers@polymtl.ca Cc: josh@joshtriplett.org Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: rostedt@goodmis.org Cc: Valdis.Kletnieks@vt.edu Cc: dhowells@redhat.com LKML-Reference: <12537246442687-git-send-email-> Signed-off-by: Ingo Molnar --- include/linux/rcutree.h | 1 - 1 file changed, 1 deletion(-) (limited to 'include') diff --git a/include/linux/rcutree.h b/include/linux/rcutree.h index 37682770e9d2..88109c87f29c 100644 --- a/include/linux/rcutree.h +++ b/include/linux/rcutree.h @@ -85,7 +85,6 @@ static inline void synchronize_rcu_bh_expedited(void) extern void __rcu_init(void); extern void rcu_check_callbacks(int cpu, int user); -extern void rcu_restart_cpu(int cpu); extern long rcu_batches_completed(void); extern long rcu_batches_completed_bh(void); -- cgit v1.2.3 From 1eba8f84380bede3c602bd7758dea96925cead01 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Wed, 23 Sep 2009 09:50:42 -0700 Subject: rcu: Clean up code based on review feedback from Josh Triplett, part 2 These issues identified during an old-fashioned face-to-face code review extending over many hours. o Add comments for tricky parts of code, and correct comments that have passed their sell-by date. o Get rid of the vestiges of rcu_init_sched(), which is no longer needed now that PREEMPT_RCU is gone. o Move the #include of rcutree_plugin.h to the end of rcutree.c, which means that, rather than having a random collection of forward declarations, the new set of forward declarations document the set of plugins. The new home for this #include also allows __rcu_init_preempt() to move into rcutree_plugin.h. o Fix rcu_preempt_check_callbacks() to be static. Suggested-by: Josh Triplett Signed-off-by: Paul E. McKenney Cc: laijs@cn.fujitsu.com Cc: dipankar@in.ibm.com Cc: akpm@linux-foundation.org Cc: mathieu.desnoyers@polymtl.ca Cc: josh@joshtriplett.org Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org Cc: rostedt@goodmis.org Cc: Valdis.Kletnieks@vt.edu Cc: dhowells@redhat.com LKML-Reference: <12537246443924-git-send-email-> Signed-off-by: Ingo Molnar Peter Zijlstra --- include/linux/rcupdate.h | 4 ++++ include/linux/rcutree.h | 6 +----- 2 files changed, 5 insertions(+), 5 deletions(-) (limited to 'include') diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h index 6fe0363724e9..70331218e4b4 100644 --- a/include/linux/rcupdate.h +++ b/include/linux/rcupdate.h @@ -196,6 +196,8 @@ static inline void rcu_read_lock_sched(void) __acquire(RCU_SCHED); rcu_read_acquire(); } + +/* Used by lockdep and tracing: cannot be traced, cannot call lockdep. */ static inline notrace void rcu_read_lock_sched_notrace(void) { preempt_disable_notrace(); @@ -213,6 +215,8 @@ static inline void rcu_read_unlock_sched(void) __release(RCU_SCHED); preempt_enable(); } + +/* Used by lockdep and tracing: cannot be traced, cannot call lockdep. */ static inline notrace void rcu_read_unlock_sched_notrace(void) { __release(RCU_SCHED); diff --git a/include/linux/rcutree.h b/include/linux/rcutree.h index 88109c87f29c..19a3b06943e0 100644 --- a/include/linux/rcutree.h +++ b/include/linux/rcutree.h @@ -90,10 +90,6 @@ extern long rcu_batches_completed(void); extern long rcu_batches_completed_bh(void); extern long rcu_batches_completed_sched(void); -static inline void rcu_init_sched(void) -{ -} - #ifdef CONFIG_NO_HZ void rcu_enter_nohz(void); void rcu_exit_nohz(void); @@ -106,7 +102,7 @@ static inline void rcu_exit_nohz(void) } #endif /* CONFIG_NO_HZ */ -/* A context switch is a grace period for rcutree. */ +/* A context switch is a grace period for RCU-sched and RCU-bh. */ static inline int rcu_blocking_is_gp(void) { return num_online_cpus() == 1; -- cgit v1.2.3 From 9b2619aff0332e95ea5eb7a0d75b0208818d871c Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Wed, 23 Sep 2009 09:50:43 -0700 Subject: rcu: Clean up code to address Ingo's checkpatch feedback Move declarations and update storage classes to make checkpatch happy. Signed-off-by: Paul E. McKenney Cc: laijs@cn.fujitsu.com Cc: dipankar@in.ibm.com Cc: akpm@linux-foundation.org Cc: mathieu.desnoyers@polymtl.ca Cc: josh@joshtriplett.org Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org Cc: rostedt@goodmis.org Cc: Valdis.Kletnieks@vt.edu Cc: dhowells@redhat.com LKML-Reference: <12537246441701-git-send-email-> Signed-off-by: Ingo Molnar --- include/linux/rcutree.h | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) (limited to 'include') diff --git a/include/linux/rcutree.h b/include/linux/rcutree.h index 19a3b06943e0..46e9ab3ee6e1 100644 --- a/include/linux/rcutree.h +++ b/include/linux/rcutree.h @@ -30,10 +30,14 @@ #ifndef __LINUX_RCUTREE_H #define __LINUX_RCUTREE_H +struct notifier_block; + extern void rcu_sched_qs(int cpu); extern void rcu_bh_qs(int cpu); - +extern int rcu_cpu_notify(struct notifier_block *self, + unsigned long action, void *hcpu); extern int rcu_needs_cpu(int cpu); +extern int rcu_expedited_torture_stats(char *page); #ifdef CONFIG_TREE_PREEMPT_RCU -- cgit v1.2.3 From 3d76c082907e8f83c5d5c4572f38d53ad8f00c4b Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Mon, 28 Sep 2009 07:46:32 -0700 Subject: rcu: Clean up code based on review feedback from Josh Triplett, part 3 Whitespace fixes, updated comments, and trivial code movement. o Fix whitespace error in RCU_HEAD_INIT() o Move "So where is rcu_write_lock()" comment so that it does not come between the rcu_read_unlock() header comment and the rcu_read_unlock() definition. o Move the module_param statements for blimit, qhimark, and qlowmark to immediately follow the corresponding definitions. o In __rcu_offline_cpu(), move the assignment to rdp_me inside the "if" statement, given that rdp_me is not used outside of that "if" statement. Signed-off-by: Paul E. McKenney Cc: laijs@cn.fujitsu.com Cc: dipankar@in.ibm.com Cc: akpm@linux-foundation.org Cc: mathieu.desnoyers@polymtl.ca Cc: josh@joshtriplett.org Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org Cc: rostedt@goodmis.org Cc: Valdis.Kletnieks@vt.edu Cc: dhowells@redhat.com LKML-Reference: <12541491931164-git-send-email-> Signed-off-by: Ingo Molnar --- include/linux/rcupdate.h | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) (limited to 'include') diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h index 70331218e4b4..3ebd0b7bcb08 100644 --- a/include/linux/rcupdate.h +++ b/include/linux/rcupdate.h @@ -77,7 +77,7 @@ extern int rcu_scheduler_active; #error "Unknown RCU implementation specified to kernel configuration" #endif -#define RCU_HEAD_INIT { .next = NULL, .func = NULL } +#define RCU_HEAD_INIT { .next = NULL, .func = NULL } #define RCU_HEAD(head) struct rcu_head head = RCU_HEAD_INIT #define INIT_RCU_HEAD(ptr) do { \ (ptr)->next = NULL; (ptr)->func = NULL; \ @@ -129,12 +129,6 @@ static inline void rcu_read_lock(void) rcu_read_acquire(); } -/** - * rcu_read_unlock - marks the end of an RCU read-side critical section. - * - * See rcu_read_lock() for more information. - */ - /* * So where is rcu_write_lock()? It does not exist, as there is no * way for writers to lock out RCU readers. This is a feature, not @@ -144,6 +138,12 @@ static inline void rcu_read_lock(void) * used as well. RCU does not care how the writers keep out of each * others' way, as long as they do so. */ + +/** + * rcu_read_unlock - marks the end of an RCU read-side critical section. + * + * See rcu_read_lock() for more information. + */ static inline void rcu_read_unlock(void) { rcu_read_release(); -- cgit v1.2.3 From f8d1e548931cfa5ea9a082e020c2a47d27e5d793 Mon Sep 17 00:00:00 2001 From: Anton Blanchard Date: Wed, 7 Oct 2009 11:13:58 +1100 Subject: futex: Fix typo in FUTEX_WAIT/WAKE_BITSET_PRIVATE definitions Looks like a typo, FUTEX_WAKE_BITS should be FUTEX_WAIT_BITSET. Signed-off-by: Anton Blanchard LKML-Reference: <20091007001358.GE16073@kryten> Signed-off-by: Thomas Gleixner --- include/linux/futex.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'include') diff --git a/include/linux/futex.h b/include/linux/futex.h index 34956c8fdebf..78b92ec9edbd 100644 --- a/include/linux/futex.h +++ b/include/linux/futex.h @@ -38,8 +38,8 @@ union ktime; #define FUTEX_LOCK_PI_PRIVATE (FUTEX_LOCK_PI | FUTEX_PRIVATE_FLAG) #define FUTEX_UNLOCK_PI_PRIVATE (FUTEX_UNLOCK_PI | FUTEX_PRIVATE_FLAG) #define FUTEX_TRYLOCK_PI_PRIVATE (FUTEX_TRYLOCK_PI | FUTEX_PRIVATE_FLAG) -#define FUTEX_WAIT_BITSET_PRIVATE (FUTEX_WAIT_BITS | FUTEX_PRIVATE_FLAG) -#define FUTEX_WAKE_BITSET_PRIVATE (FUTEX_WAKE_BITS | FUTEX_PRIVATE_FLAG) +#define FUTEX_WAIT_BITSET_PRIVATE (FUTEX_WAIT_BITSET | FUTEX_PRIVATE_FLAG) +#define FUTEX_WAKE_BITSET_PRIVATE (FUTEX_WAKE_BITSET | FUTEX_PRIVATE_FLAG) #define FUTEX_WAIT_REQUEUE_PI_PRIVATE (FUTEX_WAIT_REQUEUE_PI | \ FUTEX_PRIVATE_FLAG) #define FUTEX_CMP_REQUEUE_PI_PRIVATE (FUTEX_CMP_REQUEUE_PI | \ -- cgit v1.2.3