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| author | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2016-01-12 17:33:37 +0100 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2016-03-31 22:34:03 +0200 |
| commit | 28728dd310d48834cd486dac3cac9ae96b9deb96 (patch) | |
| tree | 507e605d6e89567f62d8148b779a45d6f369d52e /kernel | |
| parent | rcu: Consolidate dumping of ftrace buffer (diff) | |
| download | linux-28728dd310d48834cd486dac3cac9ae96b9deb96.tar.xz linux-28728dd310d48834cd486dac3cac9ae96b9deb96.zip | |
rcu: Make expedited RCU-sched grace period immediately detect idle
Currently, sync_sched_exp_handler() will force a reschedule unless
this CPU has already checked in or unless a reschedule has already
been called for. This is clearly wasteful if sync_sched_exp_handler()
interrupted an idle CPU, so this commit immediately reports the
quiescent state in that case.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/rcu/tree.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index 531a328076bd..5f4336fadc28 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -3649,6 +3649,11 @@ static void sync_sched_exp_handler(void *data) if (!(READ_ONCE(rnp->expmask) & rdp->grpmask) || __this_cpu_read(rcu_sched_data.cpu_no_qs.b.exp)) return; + if (rcu_is_cpu_rrupt_from_idle()) { + rcu_report_exp_rdp(&rcu_sched_state, + this_cpu_ptr(&rcu_sched_data), true); + return; + } __this_cpu_write(rcu_sched_data.cpu_no_qs.b.exp, true); resched_cpu(smp_processor_id()); } |