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authorSuresh Siddha <suresh.b.siddha@intel.com>2008-11-04 13:53:04 -0800
committerIngo Molnar <mingo@elte.hu>2008-11-06 09:41:49 +0100
commitd6f0f39b7d05e62b347c4352d070e4afb3ade4b5 (patch)
treef5f2e844e5674b1d572be2b6e54fb36e5540cbe3
parent7db282fa67b58daff8a57f9e1c93d4474b5908ff (diff)
x86: add smp_mb() before sending INVALIDATE_TLB_VECTOR
Impact: fix rare x2apic hang On x86, x2apic mode accesses for sending IPI's don't have serializing semantics. If the IPI receivner refers(in lock-free fashion) to some memory setup by the sender, the need for smp_mb() before sending the IPI becomes critical in x2apic mode. Add the smp_mb() in native_flush_tlb_others() before sending the IPI. Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
-rw-r--r--arch/x86/kernel/tlb_32.c6
-rw-r--r--arch/x86/kernel/tlb_64.c5
2 files changed, 11 insertions, 0 deletions
diff --git a/arch/x86/kernel/tlb_32.c b/arch/x86/kernel/tlb_32.c
index e00534b33534..f4049f3513b6 100644
--- a/arch/x86/kernel/tlb_32.c
+++ b/arch/x86/kernel/tlb_32.c
@@ -154,6 +154,12 @@ void native_flush_tlb_others(const cpumask_t *cpumaskp, struct mm_struct *mm,
flush_mm = mm;
flush_va = va;
cpus_or(flush_cpumask, cpumask, flush_cpumask);
+
+ /*
+ * Make the above memory operations globally visible before
+ * sending the IPI.
+ */
+ smp_mb();
/*
* We have to send the IPI only to
* CPUs affected.
diff --git a/arch/x86/kernel/tlb_64.c b/arch/x86/kernel/tlb_64.c
index dcbf7a1159ea..8f919ca69494 100644
--- a/arch/x86/kernel/tlb_64.c
+++ b/arch/x86/kernel/tlb_64.c
@@ -183,6 +183,11 @@ void native_flush_tlb_others(const cpumask_t *cpumaskp, struct mm_struct *mm,
cpus_or(f->flush_cpumask, cpumask, f->flush_cpumask);
/*
+ * Make the above memory operations globally visible before
+ * sending the IPI.
+ */
+ smp_mb();
+ /*
* We have to send the IPI only to
* CPUs affected.
*/