From a68db763af9b676590c3fe9ec3f17bf18015eb2f Mon Sep 17 00:00:00 2001
From: Peter Chubb <peterc@gelato.unsw.edu.au>
Date: Thu, 23 Jun 2005 21:14:00 -0700
Subject: [IA64] Fix another IA64 preemption problem
There's another problem shown up by Ingo's recent patch to make
smp_processor_id() complain if it's called with preemption enabled.
local_finish_flush_tlb_mm() calls activate_context() in a situation
where it could be rescheduled to another processor. This patch
disables preemption around the call.
Signed-off-by: Peter Chubb <peterc@gelato.unsw.edu.au>
Signed-off-by: Tony Luck <tony.luck@intel.com>
---
arch/ia64/kernel/smp.c | 3 +++
include/asm-ia64/mmu_context.h | 3 +++
2 files changed, 6 insertions(+)
diff --git a/arch/ia64/kernel/smp.c b/arch/ia64/kernel/smp.c
index b49d4ddaab..0166a98470 100644
--- a/arch/ia64/kernel/smp.c
+++ b/arch/ia64/kernel/smp.c
@@ -231,13 +231,16 @@ smp_flush_tlb_all (void)
void
smp_flush_tlb_mm (struct mm_struct *mm)
{
+ preempt_disable();
/* this happens for the common case of a single-threaded fork(): */
if (likely(mm == current->active_mm && atomic_read(&mm->mm_users) == 1))
{
local_finish_flush_tlb_mm(mm);
+ preempt_enable();
return;
}
+ preempt_enable();
/*
* We could optimize this further by using mm->cpu_vm_mask to track which CPUs
* have been running in the address space. It's not clear that this is worth the
diff --git a/include/asm-ia64/mmu_context.h b/include/asm-ia64/mmu_context.h
index 0096e7e050..e3e5fededb 100644
--- a/include/asm-ia64/mmu_context.h
+++ b/include/asm-ia64/mmu_context.h
@@ -132,6 +132,9 @@ reload_context (mm_context_t context)
ia64_srlz_i(); /* srlz.i implies srlz.d */
}
+/*
+ * Must be called with preemption off
+ */
static inline void
activate_context (struct mm_struct *mm)
{
--
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