Currently we allocate the stale_map for a cpu when it comes online,
this leaves open a small window where a process can be scheduled
on the cpu before the stale_map is allocated. Instead allocate
the stale_map at CPU_UP_PREPARE time, that way it will be always
available before tasks start running.
It is possible the cpu fails to come up, in which case we should free
the stale_map, so add a CPU_UP_CANCELED case to do that.
Signed-off-by: Michael Ellerman <mich...@ellerman.id.au>
---
arch/powerpc/mm/mmu_context_nohash.c | 6 ++++--
1 files changed, 4 insertions(+), 2 deletions(-)
diff --git a/arch/powerpc/mm/mmu_context_nohash.c
b/arch/powerpc/mm/mmu_context_nohash.c
index c0aab52..4d8fa91 100644
--- a/arch/powerpc/mm/mmu_context_nohash.c
+++ b/arch/powerpc/mm/mmu_context_nohash.c
@@ -338,12 +338,14 @@ static int __cpuinit mmu_context_cpu_notify(struct
notifier_block *self,
return NOTIFY_OK;
switch (action) {
- case CPU_ONLINE:
- case CPU_ONLINE_FROZEN:
+ case CPU_UP_PREPARE:
+ case CPU_UP_PREPARE_FROZEN:
pr_devel("MMU: Allocating stale context map for CPU %d\n", cpu);
stale_map[cpu] = kzalloc(CTX_MAP_SIZE, GFP_KERNEL);
break;
#ifdef CONFIG_HOTPLUG_CPU
+ case CPU_UP_CANCELED:
+ case CPU_UP_CANCELED_FROZEN:
case CPU_DEAD:
case CPU_DEAD_FROZEN:
pr_devel("MMU: Freeing stale context map for CPU %d\n", cpu);
--
1.7.1
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