diff options
| author | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2009-11-13 19:51:38 -0800 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-11-14 10:31:42 +0100 |
| commit | 560d4bc0df9a5e63b980432282d8c2bd3559ec74 (patch) | |
| tree | 1e44bf34973b217977d0b4d57d2b1ee1d4209f08 | |
| parent | 8e9aa8f067d2dcd9457980ced618e1cffbcfba46 (diff) | |
rcu: Further cleanups of use of lastcomp
Now that a copy of the rsp->completed flag is available in all
rcu_node structures, make full use of it. It is still
legitimate to access rsp->completed while holding the root
rcu_node structure's lock, however.
Also, tighten up force_quiescent_state()'s checks for end of
current grace period.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: laijs@cn.fujitsu.com
Cc: dipankar@in.ibm.com
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: <1258170699933-git-send-email->
Signed-off-by: Ingo Molnar <mingo@elte.hu>
| -rw-r--r-- | kernel/rcutree.c | 13 |
1 files changed, 6 insertions, 7 deletions
diff --git a/kernel/rcutree.c b/kernel/rcutree.c index 3df04381ea3..24bbf2ce060 100644 --- a/kernel/rcutree.c +++ b/kernel/rcutree.c @@ -817,7 +817,7 @@ cpu_quiet(int cpu, struct rcu_state *rsp, struct rcu_data *rdp, long lastcomp) rnp = rdp->mynode; spin_lock_irqsave(&rnp->lock, flags); - if (lastcomp != ACCESS_ONCE(rsp->completed)) { + if (lastcomp != rnp->completed) { /* * Someone beat us to it for this grace period, so leave. @@ -935,7 +935,6 @@ static void rcu_adopt_orphan_cbs(struct rcu_state *rsp) static void __rcu_offline_cpu(int cpu, struct rcu_state *rsp) { unsigned long flags; - long lastcomp; unsigned long mask; struct rcu_data *rdp = rsp->rda[cpu]; struct rcu_node *rnp; @@ -971,7 +970,6 @@ static void __rcu_offline_cpu(int cpu, struct rcu_state *rsp) spin_unlock(&rnp->lock); /* irqs remain disabled. */ rnp = rnp->parent; } while (rnp != NULL); - lastcomp = rsp->completed; spin_unlock_irqrestore(&rsp->onofflock, flags); @@ -1145,7 +1143,7 @@ static int rcu_process_dyntick(struct rcu_state *rsp, long lastcomp, rcu_for_each_leaf_node(rsp, rnp) { mask = 0; spin_lock_irqsave(&rnp->lock, flags); - if (rsp->completed != lastcomp) { + if (rnp->completed != lastcomp) { spin_unlock_irqrestore(&rnp->lock, flags); return 1; } @@ -1159,7 +1157,7 @@ static int rcu_process_dyntick(struct rcu_state *rsp, long lastcomp, if ((rnp->qsmask & bit) != 0 && f(rsp->rda[cpu])) mask |= bit; } - if (mask != 0 && rsp->completed == lastcomp) { + if (mask != 0 && rnp->completed == lastcomp) { /* cpu_quiet_msk() releases rnp->lock. */ cpu_quiet_msk(mask, rsp, rnp, flags); @@ -1196,7 +1194,7 @@ static void force_quiescent_state(struct rcu_state *rsp, int relaxed) lastcomp = rsp->gpnum - 1; signaled = rsp->signaled; rsp->jiffies_force_qs = jiffies + RCU_JIFFIES_TILL_FORCE_QS; - if (lastcomp == rsp->gpnum) { + if(!rcu_gp_in_progress(rsp)) { rsp->n_force_qs_ngp++; spin_unlock(&rnp->lock); goto unlock_ret; /* no GP in progress, time updated. */ @@ -1224,7 +1222,8 @@ static void force_quiescent_state(struct rcu_state *rsp, int relaxed) /* Update state, record completion counter. */ forcenow = 0; spin_lock(&rnp->lock); - if (lastcomp == rsp->completed && + if (lastcomp + 1 == rsp->gpnum && + lastcomp == rsp->completed && rsp->signaled == signaled) { rsp->signaled = RCU_FORCE_QS; rsp->completed_fqs = lastcomp; |