From: Zhenzhong Duan <zhenzhong.duan@oracle.com>
Date: Thu, 17 Jan 2019 10:10:59 +0000 (-0800)
Subject: x86/speculation: Remove redundant arch_smt_update() invocation
X-Git-Tag: v4.19.116~52
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=6209e0981bc4c1a022d09a64a47e9109a85c4cd6;p=thirdparty%2Fkernel%2Fstable.git

x86/speculation: Remove redundant arch_smt_update() invocation

commit 34d66caf251df91ff27b24a3a786810d29989eca upstream.

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 <zhenzhong.duan@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: <konrad.wilk@oracle.com>
Cc: <dwmw@amazon.co.uk>
Cc: <bp@suse.de>
Cc: <srinivas.eeda@oracle.com>
Cc: <peterz@infradead.org>
Cc: <hpa@zytor.com>
Link: https://lkml.kernel.org/r/e2e064f2-e8ef-42ca-bf4f-76b612964752@default
Cc: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/kernel/cpu.c b/kernel/cpu.c
index 2d850eaaf82e3..6d6c106a495c7 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -2070,10 +2070,8 @@ 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;
 }
@@ -2084,7 +2082,6 @@ 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)))