2018-10-09 15:46:05

by Peng Hao

Subject: [PATCH] tick/sched : remove redundancy cpu_online check

From: Peng Hao <[email protected]>

in can_stop_idle_tick cpu_online() was called earlier and if cpu
offline it will return. so it don't need to call cpu_online()
again.

Signed-off-by: Peng Hao <[email protected]>
---
kernel/time/tick-sched.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index 5b33e2f..69e673b 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -885,7 +885,7 @@ static bool can_stop_idle_tick(int cpu, struct tick_sched *ts)
if (need_resched())
return false;

- if (unlikely(local_softirq_pending() && cpu_online(cpu))) {
+ if (unlikely(local_softirq_pending())) {
static int ratelimit;

if (ratelimit < 10 &&
--
1.8.3.1

2018-10-10 09:52:36

by tip-bot for Vasyl Gomonovych

Subject: [tip:timers/core] tick/sched : Remove redundant cpu_online() check

Commit-ID: d59e0ba19481c0046d2ea2bd0e5344eeaf45aace
Gitweb: https://git.kernel.org/tip/d59e0ba19481c0046d2ea2bd0e5344eeaf45aace
Author: Peng Hao <[email protected]>
AuthorDate: Tue, 9 Oct 2018 11:43:35 -0400
Committer: Thomas Gleixner <[email protected]>
CommitDate: Wed, 10 Oct 2018 11:47:20 +0200

tick/sched : Remove redundant cpu_online() check

can_stop_idle_tick() checks cpu_online() twice. The first check leaves the
function when the CPU is not online, so the second check it
redundant. Remove it.

Signed-off-by: Peng Hao <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Cc: [email protected]
Link: https://lkml.kernel.org/r/[email protected]
---
kernel/time/tick-sched.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index 5b33e2f5c0ed..69e673b88474 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -885,7 +885,7 @@ static bool can_stop_idle_tick(int cpu, struct tick_sched *ts)
if (need_resched())
return false;

- if (unlikely(local_softirq_pending() && cpu_online(cpu))) {
+ if (unlikely(local_softirq_pending())) {
static int ratelimit;

if (ratelimit < 10 &&