linux-kernel - [tip:smp/urgent] x86/speculation: Remove redundant arch_smt

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Date:   Tue, 29 Jan 2019 13:24:58 -0800
From:   tip-bot for Zhenzhong Duan <tipbot@...or.com>
To:     linux-tip-commits@...r.kernel.org
Cc:     peterz@...radead.org, srinivas.eeda@...cle.com, tglx@...utronix.de,
        dwmw@...zon.co.uk, zhenzhong.duan@...cle.com,
        linux-kernel@...r.kernel.org, mingo@...nel.org,
        konrad.wilk@...cle.com, hpa@...or.com, bp@...e.de
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 <zhenzhong.duan@...cle.com>
AuthorDate: Thu, 17 Jan 2019 02:10:59 -0800
Committer:  Thomas Gleixner <tglx@...utronix.de>
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 <zhenzhong.duan@...cle.com>
Signed-off-by: Thomas Gleixner <tglx@...utronix.de>
Cc: <konrad.wilk@...cle.com>
Cc: <dwmw@...zon.co.uk>
Cc: <bp@...e.de>
Cc: <srinivas.eeda@...cle.com>
Cc: <peterz@...radead.org>
Cc: <hpa@...or.com>
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)))