diff options
Diffstat (limited to 'arch/x86/mm/tlb.c')
| -rw-r--r-- | arch/x86/mm/tlb.c | 48 |
1 files changed, 47 insertions, 1 deletions
diff --git a/arch/x86/mm/tlb.c b/arch/x86/mm/tlb.c index c03f14ab666..49358481c73 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); |