| Message ID | 1339794370-28119-8-git-send-email-paulmck@linux.vnet.ibm.com |
|---|---|
| State | New |
| Headers | show |
On Fri, Jun 15, 2012 at 02:06:03PM -0700, Paul E. McKenney wrote: > From: "Paul E. McKenney" <paul.mckenney@linaro.org> > > In order to allow each RCU flavor to concurrently execute its > rcu_barrier() function, it is necessary to move the relevant > state to the rcu_state structure. This commit therefore moves the > rcu_barrier_mutex global variable to a new ->barrier_mutex field > in the rcu_state structure. > > Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> > Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> > --- > kernel/rcutree.c | 11 +++-------- > kernel/rcutree.h | 1 + > 2 files changed, 4 insertions(+), 8 deletions(-) > > diff --git a/kernel/rcutree.c b/kernel/rcutree.c > index a946437..93358d4 100644 > --- a/kernel/rcutree.c > +++ b/kernel/rcutree.c > @@ -71,9 +71,8 @@ static struct lock_class_key rcu_node_class[RCU_NUM_LVLS]; > .onofflock = __RAW_SPIN_LOCK_UNLOCKED(&sname##_state.onofflock), \ > .orphan_nxttail = &sname##_state.orphan_nxtlist, \ > .orphan_donetail = &sname##_state.orphan_donelist, \ > + .barrier_mutex = __MUTEX_INITIALIZER(sname##_state.barrier_mutex), \ > .fqslock = __RAW_SPIN_LOCK_UNLOCKED(&sname##_state.fqslock), \ > - .n_force_qs = 0, \ > - .n_force_qs_ngp = 0, \ The removal of these two fields seems unrelated to the rest of this commit. I assume you've removed them because the use of "static" makes initializations to 0 unnecessary? The rest of this commit seems fine to me. > .name = #sname, \ > } > > @@ -155,10 +154,6 @@ static void invoke_rcu_callbacks(struct rcu_state *rsp, struct rcu_data *rdp); > unsigned long rcutorture_testseq; > unsigned long rcutorture_vernum; > > -/* State information for rcu_barrier() and friends. */ > - > -static DEFINE_MUTEX(rcu_barrier_mutex); > - > /* > * Return true if an RCU grace period is in progress. The ACCESS_ONCE()s > * permit this function to be invoked without holding the root rcu_node > @@ -2300,7 +2295,7 @@ static void _rcu_barrier(struct rcu_state *rsp) > init_rcu_head_on_stack(&rd.barrier_head); > > /* Take mutex to serialize concurrent rcu_barrier() requests. */ > - mutex_lock(&rcu_barrier_mutex); > + mutex_lock(&rsp->barrier_mutex); > > smp_mb(); /* Prevent any prior operations from leaking in. */ > > @@ -2377,7 +2372,7 @@ static void _rcu_barrier(struct rcu_state *rsp) > wait_for_completion(&rsp->barrier_completion); > > /* Other rcu_barrier() invocations can now safely proceed. */ > - mutex_unlock(&rcu_barrier_mutex); > + mutex_unlock(&rsp->barrier_mutex); > > destroy_rcu_head_on_stack(&rd.barrier_head); > } > diff --git a/kernel/rcutree.h b/kernel/rcutree.h > index 56fb8d4..d9ac82f 100644 > --- a/kernel/rcutree.h > +++ b/kernel/rcutree.h > @@ -386,6 +386,7 @@ struct rcu_state { > struct task_struct *rcu_barrier_in_progress; > /* Task doing rcu_barrier(), */ > /* or NULL if no barrier. */ > + struct mutex barrier_mutex; /* Guards barrier fields. */ > atomic_t barrier_cpu_count; /* # CPUs waiting on. */ > struct completion barrier_completion; /* Wake at barrier end. */ > raw_spinlock_t fqslock; /* Only one task forcing */ > -- > 1.7.8 >
diff --git a/kernel/rcutree.c b/kernel/rcutree.c index a946437..93358d4 100644 --- a/kernel/rcutree.c +++ b/kernel/rcutree.c @@ -71,9 +71,8 @@ static struct lock_class_key rcu_node_class[RCU_NUM_LVLS]; .onofflock = __RAW_SPIN_LOCK_UNLOCKED(&sname##_state.onofflock), \ .orphan_nxttail = &sname##_state.orphan_nxtlist, \ .orphan_donetail = &sname##_state.orphan_donelist, \ + .barrier_mutex = __MUTEX_INITIALIZER(sname##_state.barrier_mutex), \ .fqslock = __RAW_SPIN_LOCK_UNLOCKED(&sname##_state.fqslock), \ - .n_force_qs = 0, \ - .n_force_qs_ngp = 0, \ .name = #sname, \ } @@ -155,10 +154,6 @@ static void invoke_rcu_callbacks(struct rcu_state *rsp, struct rcu_data *rdp); unsigned long rcutorture_testseq; unsigned long rcutorture_vernum; -/* State information for rcu_barrier() and friends. */ - -static DEFINE_MUTEX(rcu_barrier_mutex); - /* * Return true if an RCU grace period is in progress. The ACCESS_ONCE()s * permit this function to be invoked without holding the root rcu_node @@ -2300,7 +2295,7 @@ static void _rcu_barrier(struct rcu_state *rsp) init_rcu_head_on_stack(&rd.barrier_head); /* Take mutex to serialize concurrent rcu_barrier() requests. */ - mutex_lock(&rcu_barrier_mutex); + mutex_lock(&rsp->barrier_mutex); smp_mb(); /* Prevent any prior operations from leaking in. */ @@ -2377,7 +2372,7 @@ static void _rcu_barrier(struct rcu_state *rsp) wait_for_completion(&rsp->barrier_completion); /* Other rcu_barrier() invocations can now safely proceed. */ - mutex_unlock(&rcu_barrier_mutex); + mutex_unlock(&rsp->barrier_mutex); destroy_rcu_head_on_stack(&rd.barrier_head); } diff --git a/kernel/rcutree.h b/kernel/rcutree.h index 56fb8d4..d9ac82f 100644 --- a/kernel/rcutree.h +++ b/kernel/rcutree.h @@ -386,6 +386,7 @@ struct rcu_state { struct task_struct *rcu_barrier_in_progress; /* Task doing rcu_barrier(), */ /* or NULL if no barrier. */ + struct mutex barrier_mutex; /* Guards barrier fields. */ atomic_t barrier_cpu_count; /* # CPUs waiting on. */ struct completion barrier_completion; /* Wake at barrier end. */ raw_spinlock_t fqslock; /* Only one task forcing */