Commit-ID: a5d6d3a1b00a0ad88f07c3a727c79b27915278e3 Gitweb: http://git.kernel.org/tip/a5d6d3a1b00a0ad88f07c3a727c79b27915278e3 Author: Eric Dumazet <edumazet@xxxxxxxxxx> AuthorDate: Wed, 16 Apr 2014 09:06:24 -0700 Committer: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx> CommitDate: Tue, 29 Apr 2014 08:45:40 -0700 softirq: A single rcu_bh_qs() call per softirq set is enough Calling rcu_bh_qs() after every softirq action is not really needed. What RCU needs is at least one rcu_bh_qs() per softirq round to note a quiescent state was passed for rcu_bh. Note for Paul and myself : this could be inlined as a single instruction and avoid smp_processor_id() (sone this_cpu_write(rcu_bh_data.passed_quiesce, 1)) Signed-off-by: Eric Dumazet <edumazet@xxxxxxxxxx> Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx> Reviewed-by: Josh Triplett <josh@xxxxxxxxxxxxxxxx> --- kernel/softirq.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/kernel/softirq.c b/kernel/softirq.c index b50990a..b9b2d49 100644 --- a/kernel/softirq.c +++ b/kernel/softirq.c @@ -232,7 +232,6 @@ asmlinkage void __do_softirq(void) bool in_hardirq; __u32 pending; int softirq_bit; - int cpu; /* * Mask out PF_MEMALLOC s current task context is borrowed for the @@ -247,7 +246,6 @@ asmlinkage void __do_softirq(void) __local_bh_disable_ip(_RET_IP_, SOFTIRQ_OFFSET); in_hardirq = lockdep_softirq_start(); - cpu = smp_processor_id(); restart: /* Reset the pending bitmask before enabling irqs */ set_softirq_pending(0); @@ -276,11 +274,11 @@ restart: prev_count, preempt_count()); preempt_count_set(prev_count); } - rcu_bh_qs(cpu); h++; pending >>= softirq_bit; } + rcu_bh_qs(smp_processor_id()); local_irq_disable(); pending = local_softirq_pending(); -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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