summaryrefslogtreecommitdiffstats
path: root/arch/x86/mm/tlb.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/x86/mm/tlb.c')
-rw-r--r--arch/x86/mm/tlb.c48
1 files changed, 47 insertions, 1 deletions
diff --git a/arch/x86/mm/tlb.c b/arch/x86/mm/tlb.c
index c03f14ab6667..49358481c733 100644
--- a/arch/x86/mm/tlb.c
+++ b/arch/x86/mm/tlb.c
@@ -5,6 +5,7 @@
#include <linux/smp.h>
#include <linux/interrupt.h>
#include <linux/module.h>
+#include <linux/cpu.h>
#include <asm/tlbflush.h>
#include <asm/mmu_context.h>
@@ -52,6 +53,8 @@ union smp_flush_state {
want false sharing in the per cpu data segment. */
static union smp_flush_state flush_state[NUM_INVALIDATE_TLB_VECTORS];
+static DEFINE_PER_CPU_READ_MOSTLY(int, tlb_vector_offset);
+
/*
* We cannot call mmdrop() because we are in interrupt context,
* instead update mm->cpu_vm_mask.
@@ -173,7 +176,7 @@ static void flush_tlb_others_ipi(const struct cpumask *cpumask,
union smp_flush_state *f;
/* Caller has disabled preemption */
- sender = smp_processor_id() % NUM_INVALIDATE_TLB_VECTORS;
+ sender = this_cpu_read(tlb_vector_offset);
f = &flush_state[sender];
/*
@@ -218,6 +221,47 @@ void native_flush_tlb_others(const struct cpumask *cpumask,
flush_tlb_others_ipi(cpumask, mm, va);
}
+static void __cpuinit calculate_tlb_offset(void)
+{
+ int cpu, node, nr_node_vecs;
+ /*
+ * we are changing tlb_vector_offset for each CPU in runtime, but this
+ * will not cause inconsistency, as the write is atomic under X86. we
+ * might see more lock contentions in a short time, but after all CPU's
+ * tlb_vector_offset are changed, everything should go normal
+ *
+ * Note: if NUM_INVALIDATE_TLB_VECTORS % nr_online_nodes !=0, we might
+ * waste some vectors.
+ **/
+ if (nr_online_nodes > NUM_INVALIDATE_TLB_VECTORS)
+ nr_node_vecs = 1;
+ else
+ nr_node_vecs = NUM_INVALIDATE_TLB_VECTORS/nr_online_nodes;
+
+ for_each_online_node(node) {
+ int node_offset = (node % NUM_INVALIDATE_TLB_VECTORS) *
+ nr_node_vecs;
+ int cpu_offset = 0;
+ for_each_cpu(cpu, cpumask_of_node(node)) {
+ per_cpu(tlb_vector_offset, cpu) = node_offset +
+ cpu_offset;
+ cpu_offset++;
+ cpu_offset = cpu_offset % nr_node_vecs;
+ }
+ }
+}
+
+static int tlb_cpuhp_notify(struct notifier_block *n,
+ unsigned long action, void *hcpu)
+{
+ switch (action & 0xf) {
+ case CPU_ONLINE:
+ case CPU_DEAD:
+ calculate_tlb_offset();
+ }
+ return NOTIFY_OK;
+}
+
static int __cpuinit init_smp_flush(void)
{
int i;
@@ -225,6 +269,8 @@ static int __cpuinit init_smp_flush(void)
for (i = 0; i < ARRAY_SIZE(flush_state); i++)
raw_spin_lock_init(&flush_state[i].tlbstate_lock);
+ calculate_tlb_offset();
+ hotcpu_notifier(tlb_cpuhp_notify, 0);
return 0;
}
core_initcall(init_smp_flush);