ARM: smp: avoid incrementing mm_users on CPU startup
We should not be incrementing mm_users when we startup a secondary
CPU - doing so results in mm_users incrementing by one each time we
hotplug a CPU, which will eventually wrap, and will cause problems.
Other architectures such as x86 do not increment mm_users, but only
mm_count, so we follow that pattern.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c
index 8c19595..9066473 100644
--- a/arch/arm/kernel/smp.c
+++ b/arch/arm/kernel/smp.c
@@ -310,7 +310,6 @@
* All kernel threads share the same mm context; grab a
* reference and switch to it.
*/
- atomic_inc(&mm->mm_users);
atomic_inc(&mm->mm_count);
current->active_mm = mm;
cpumask_set_cpu(cpu, mm_cpumask(mm));