From 0c8b8d37c85805ebc47a3e6a5f799bad4de8328e Mon Sep 17 00:00:00 2001 From: Benjamin Herrenschmidt Date: Wed, 10 Jan 2018 17:10:12 +1100 Subject: [PATCH] powerpc: Don't preempt_disable() in show_cpuinfo() commit 349524bc0da698ec77f2057cf4a4948eb6349265 upstream. This causes warnings from cpufreq mutex code. This is also rather unnecessary and ineffective. If we really want to prevent concurrent unplug, we could take the unplug read lock but I don't see this being critical. Fixes: cd77b5ce208c ("powerpc/powernv/cpufreq: Fix the frequency read by /proc/cpuinfo") Signed-off-by: Benjamin Herrenschmidt Signed-off-by: Michael Ellerman Acked-by: Michal Suchanek Signed-off-by: Greg Kroah-Hartman --- arch/powerpc/kernel/setup-common.c | 11 ----------- 1 file changed, 11 deletions(-) diff --git a/arch/powerpc/kernel/setup-common.c b/arch/powerpc/kernel/setup-common.c index f516ac508ae3..bf0f712ac0e0 100644 --- a/arch/powerpc/kernel/setup-common.c +++ b/arch/powerpc/kernel/setup-common.c @@ -228,14 +228,6 @@ static int show_cpuinfo(struct seq_file *m, void *v) unsigned short maj; unsigned short min; - /* We only show online cpus: disable preempt (overzealous, I - * knew) to prevent cpu going down. */ - preempt_disable(); - if (!cpu_online(cpu_id)) { - preempt_enable(); - return 0; - } - #ifdef CONFIG_SMP pvr = per_cpu(cpu_pvr, cpu_id); #else @@ -340,9 +332,6 @@ static int show_cpuinfo(struct seq_file *m, void *v) #ifdef CONFIG_SMP seq_printf(m, "\n"); #endif - - preempt_enable(); - /* If this is the last cpu, print the summary */ if (cpumask_next(cpu_id, cpu_online_mask) >= nr_cpu_ids) show_cpuinfo_summary(m);