2019-01-17 12:42:44

by Zhenzhong Duan

Subject: [PATCH] x86/speculation: Remove redundant arch_smt_update() call in sysfs SMT control

With commit a74cfffb03b7 ("x86/speculation: Rework SMT state change"),
arch_smt_update() is invoked from each individual CPU hotplug function.
Then the extra arch_smt_update() call in the sysfs SMT control is
redundant.

Signed-off-by: Zhenzhong Duan <[email protected]>
---
kernel/cpu.c | 5 +----
1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/kernel/cpu.c b/kernel/cpu.c
index 91d5c38..c0c7f64 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -2090,10 +2090,8 @@ static int cpuhp_smt_disable(enum cpuhp_smt_control ctrlval)
*/
cpuhp_offline_cpu_device(cpu);
}
- if (!ret) {
+ if (!ret)
cpu_smt_control = ctrlval;
- arch_smt_update();
- }
cpu_maps_update_done();
return ret;
}
@@ -2104,7 +2102,6 @@ static int cpuhp_smt_enable(void)

cpu_maps_update_begin();
cpu_smt_control = CPU_SMT_ENABLED;
- arch_smt_update();
for_each_present_cpu(cpu) {
/* Skip online CPUs and CPUs on offline nodes */
if (cpu_online(cpu) || !node_online(cpu_to_node(cpu)))
--
1.8.3.1

2019-01-29 21:26:18

by tip-bot for Vasyl Gomonovych

Subject: [tip:smp/urgent] x86/speculation: Remove redundant arch_smt_update() invocation

Commit-ID: 34d66caf251df91ff27b24a3a786810d29989eca
Gitweb: https://git.kernel.org/tip/34d66caf251df91ff27b24a3a786810d29989eca
Author: Zhenzhong Duan <[email protected]>
AuthorDate: Thu, 17 Jan 2019 02:10:59 -0800
Committer: Thomas Gleixner <[email protected]>
CommitDate: Tue, 29 Jan 2019 22:20:24 +0100

x86/speculation: Remove redundant arch_smt_update() invocation

With commit a74cfffb03b7 ("x86/speculation: Rework SMT state change"),
arch_smt_update() is invoked from each individual CPU hotplug function.

Therefore the extra arch_smt_update() call in the sysfs SMT control is
redundant.

Fixes: a74cfffb03b7 ("x86/speculation: Rework SMT state change")
Signed-off-by: Zhenzhong Duan <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Cc: <[email protected]>
Cc: <[email protected]>
Cc: <[email protected]>
Cc: <[email protected]>
Cc: <[email protected]>
Cc: <[email protected]>
Link: https://lkml.kernel.org/r/e2e064f2-e8ef-42ca-bf4f-76b612964752@default

---
kernel/cpu.c | 5 +----
1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/kernel/cpu.c b/kernel/cpu.c
index 91d5c38eb7e5..c0c7f64573ed 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -2090,10 +2090,8 @@ static int cpuhp_smt_disable(enum cpuhp_smt_control ctrlval)
*/
cpuhp_offline_cpu_device(cpu);
}
- if (!ret) {
+ if (!ret)
cpu_smt_control = ctrlval;
- arch_smt_update();
- }
cpu_maps_update_done();
return ret;
}
@@ -2104,7 +2102,6 @@ static int cpuhp_smt_enable(void)

cpu_maps_update_begin();
cpu_smt_control = CPU_SMT_ENABLED;
- arch_smt_update();
for_each_present_cpu(cpu) {
/* Skip online CPUs and CPUs on offline nodes */
if (cpu_online(cpu) || !node_online(cpu_to_node(cpu)))