diff mbox

[08/14] powerpc/64s: idle set polling before enabling irqs

Message ID 20170602073946.8983-9-npiggin@gmail.com (mailing list archive)
State Superseded
Headers show

Commit Message

Nicholas Piggin June 2, 2017, 7:39 a.m. UTC 
local_irq_enable can cause interrupts to be taken which could
take significant amount of processing time. The idle process
should set its polling flag before this, so another process that
wakes it during this time will not have to send an IPI.

Expand the TIF_POLLING_NRFLAG coverage to as large as possible.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 drivers/cpuidle/cpuidle-powernv.c | 4 +++-
 drivers/cpuidle/cpuidle-pseries.c | 3 ++-
 2 files changed, 5 insertions(+), 2 deletions(-)
diff mbox

Patch

diff --git a/drivers/cpuidle/cpuidle-powernv.c b/drivers/cpuidle/cpuidle-powernv.c
index 150b971c303b..0ee4660efb5f 100644
--- a/drivers/cpuidle/cpuidle-powernv.c
+++ b/drivers/cpuidle/cpuidle-powernv.c
@@ -51,9 +51,10 @@  static int snooze_loop(struct cpuidle_device *dev,
 {
 	u64 snooze_exit_time;
 
-	local_irq_enable();
 	set_thread_flag(TIF_POLLING_NRFLAG);
 
+	local_irq_enable();
+
 	snooze_exit_time = get_tb() + snooze_timeout;
 	ppc64_runlatch_off();
 	HMT_very_low();
@@ -66,6 +67,7 @@  static int snooze_loop(struct cpuidle_device *dev,
 	ppc64_runlatch_on();
 	clear_thread_flag(TIF_POLLING_NRFLAG);
 	smp_mb();
+
 	return index;
 }
 
diff --git a/drivers/cpuidle/cpuidle-pseries.c b/drivers/cpuidle/cpuidle-pseries.c
index 166ccd711ec9..7b12bb2ea70f 100644
--- a/drivers/cpuidle/cpuidle-pseries.c
+++ b/drivers/cpuidle/cpuidle-pseries.c
@@ -62,9 +62,10 @@  static int snooze_loop(struct cpuidle_device *dev,
 	unsigned long in_purr;
 	u64 snooze_exit_time;
 
+	set_thread_flag(TIF_POLLING_NRFLAG);
+
 	idle_loop_prolog(&in_purr);
 	local_irq_enable();
-	set_thread_flag(TIF_POLLING_NRFLAG);
 	snooze_exit_time = get_tb() + snooze_timeout;
 
 	while (!need_resched()) {