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 <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Acked-by: Michal Suchanek <msuchanek@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/powerpc/kernel/setup-common.c b/arch/powerpc/kernel/setup-common.c
index 1362cd62b3fa5c32fdcc27d3ba3e5ee0e21fd974..d4c368b09415be12a3f28d37c301db7ae6b1395f 100644 (file)
--- a/arch/powerpc/kernel/setup-common.c
+++ b/arch/powerpc/kernel/setup-common.c
@@ -217,14 +217,6 @@ 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
@@ -329,9 +321,6 @@ 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);