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-rw-r--r--arch/x86_64/kernel/entry.S15
-rw-r--r--arch/x86_64/kernel/i8259.c20
-rw-r--r--arch/x86_64/kernel/smp.c123
-rw-r--r--include/asm-x86_64/hw_irq.h17
4 files changed, 117 insertions, 58 deletions
diff --git a/arch/x86_64/kernel/entry.S b/arch/x86_64/kernel/entry.S
index 3620508c8bd..873c39d8f81 100644
--- a/arch/x86_64/kernel/entry.S
+++ b/arch/x86_64/kernel/entry.S
@@ -536,8 +536,19 @@ ENTRY(thermal_interrupt)
ENTRY(reschedule_interrupt)
apicinterrupt RESCHEDULE_VECTOR,smp_reschedule_interrupt
-ENTRY(invalidate_interrupt)
- apicinterrupt INVALIDATE_TLB_VECTOR,smp_invalidate_interrupt
+ .macro INVALIDATE_ENTRY num
+ENTRY(invalidate_interrupt\num)
+ apicinterrupt INVALIDATE_TLB_VECTOR_START+\num,smp_invalidate_interrupt
+ .endm
+
+ INVALIDATE_ENTRY 0
+ INVALIDATE_ENTRY 1
+ INVALIDATE_ENTRY 2
+ INVALIDATE_ENTRY 3
+ INVALIDATE_ENTRY 4
+ INVALIDATE_ENTRY 5
+ INVALIDATE_ENTRY 6
+ INVALIDATE_ENTRY 7
ENTRY(call_function_interrupt)
apicinterrupt CALL_FUNCTION_VECTOR,smp_call_function_interrupt
diff --git a/arch/x86_64/kernel/i8259.c b/arch/x86_64/kernel/i8259.c
index a8916909512..909fc63c03b 100644
--- a/arch/x86_64/kernel/i8259.c
+++ b/arch/x86_64/kernel/i8259.c
@@ -486,7 +486,14 @@ void spurious_interrupt(void);
void error_interrupt(void);
void reschedule_interrupt(void);
void call_function_interrupt(void);
-void invalidate_interrupt(void);
+void invalidate_interrupt0(void);
+void invalidate_interrupt1(void);
+void invalidate_interrupt2(void);
+void invalidate_interrupt3(void);
+void invalidate_interrupt4(void);
+void invalidate_interrupt5(void);
+void invalidate_interrupt6(void);
+void invalidate_interrupt7(void);
void thermal_interrupt(void);
void i8254_timer_resume(void);
@@ -562,8 +569,15 @@ void __init init_IRQ(void)
*/
set_intr_gate(RESCHEDULE_VECTOR, reschedule_interrupt);
- /* IPI for invalidation */
- set_intr_gate(INVALIDATE_TLB_VECTOR, invalidate_interrupt);
+ /* IPIs for invalidation */
+ set_intr_gate(INVALIDATE_TLB_VECTOR_START+0, invalidate_interrupt0);
+ set_intr_gate(INVALIDATE_TLB_VECTOR_START+1, invalidate_interrupt1);
+ set_intr_gate(INVALIDATE_TLB_VECTOR_START+2, invalidate_interrupt2);
+ set_intr_gate(INVALIDATE_TLB_VECTOR_START+3, invalidate_interrupt3);
+ set_intr_gate(INVALIDATE_TLB_VECTOR_START+4, invalidate_interrupt4);
+ set_intr_gate(INVALIDATE_TLB_VECTOR_START+5, invalidate_interrupt5);
+ set_intr_gate(INVALIDATE_TLB_VECTOR_START+6, invalidate_interrupt6);
+ set_intr_gate(INVALIDATE_TLB_VECTOR_START+7, invalidate_interrupt7);
/* IPI for generic function call */
set_intr_gate(CALL_FUNCTION_VECTOR, call_function_interrupt);
diff --git a/arch/x86_64/kernel/smp.c b/arch/x86_64/kernel/smp.c
index 82d38f145b4..801db885955 100644
--- a/arch/x86_64/kernel/smp.c
+++ b/arch/x86_64/kernel/smp.c
@@ -29,6 +29,8 @@
#include <asm/proto.h>
#include <asm/apicdef.h>
+#define __cpuinit __init
+
/*
* Smarter SMP flushing macros.
* c/o Linus Torvalds.
@@ -37,19 +39,41 @@
* writing to user space from interrupts. (Its not allowed anyway).
*
* Optimizations Manfred Spraul <manfred@colorfullife.com>
+ *
+ * More scalable flush, from Andi Kleen
+ *
+ * To avoid global state use 8 different call vectors.
+ * Each CPU uses a specific vector to trigger flushes on other
+ * CPUs. Depending on the received vector the target CPUs look into
+ * the right per cpu variable for the flush data.
+ *
+ * With more than 8 CPUs they are hashed to the 8 available
+ * vectors. The limited global vector space forces us to this right now.
+ * In future when interrupts are split into per CPU domains this could be
+ * fixed, at the cost of triggering multiple IPIs in some cases.
*/
-static cpumask_t flush_cpumask;
-static struct mm_struct * flush_mm;
-static unsigned long flush_va;
-static DEFINE_SPINLOCK(tlbstate_lock);
+union smp_flush_state {
+ struct {
+ cpumask_t flush_cpumask;
+ struct mm_struct *flush_mm;
+ unsigned long flush_va;
#define FLUSH_ALL -1ULL
+ spinlock_t tlbstate_lock;
+ };
+ char pad[SMP_CACHE_BYTES];
+} ____cacheline_aligned;
+
+/* State is put into the per CPU data section, but padded
+ to a full cache line because other CPUs can access it and we don't
+ want false sharing in the per cpu data segment. */
+static DEFINE_PER_CPU(union smp_flush_state, flush_state);
/*
* We cannot call mmdrop() because we are in interrupt context,
* instead update mm->cpu_vm_mask.
*/
-static inline void leave_mm (unsigned long cpu)
+static inline void leave_mm(int cpu)
{
if (read_pda(mmu_state) == TLBSTATE_OK)
BUG();
@@ -101,15 +125,25 @@ static inline void leave_mm (unsigned long cpu)
*
* 1) Flush the tlb entries if the cpu uses the mm that's being flushed.
* 2) Leave the mm if we are in the lazy tlb mode.
+ *
+ * Interrupts are disabled.
*/
-asmlinkage void smp_invalidate_interrupt (void)
+asmlinkage void smp_invalidate_interrupt(struct pt_regs *regs)
{
- unsigned long cpu;
+ int cpu;
+ int sender;
+ union smp_flush_state *f;
- cpu = get_cpu();
+ cpu = smp_processor_id();
+ /*
+ * orig_rax contains the interrupt vector - 256.
+ * Use that to determine where the sender put the data.
+ */
+ sender = regs->orig_rax + 256 - INVALIDATE_TLB_VECTOR_START;
+ f = &per_cpu(flush_state, sender);
- if (!cpu_isset(cpu, flush_cpumask))
+ if (!cpu_isset(cpu, f->flush_cpumask))
goto out;
/*
* This was a BUG() but until someone can quote me the
@@ -120,64 +154,63 @@ asmlinkage void smp_invalidate_interrupt (void)
* BUG();
*/
- if (flush_mm == read_pda(active_mm)) {
+ if (f->flush_mm == read_pda(active_mm)) {
if (read_pda(mmu_state) == TLBSTATE_OK) {
- if (flush_va == FLUSH_ALL)
+ if (f->flush_va == FLUSH_ALL)
local_flush_tlb();
else
- __flush_tlb_one(flush_va);
+ __flush_tlb_one(f->flush_va);
} else
leave_mm(cpu);
}
out:
ack_APIC_irq();
- cpu_clear(cpu, flush_cpumask);
- put_cpu_no_resched();
+ cpu_clear(cpu, f->flush_cpumask);
}
static void flush_tlb_others(cpumask_t cpumask, struct mm_struct *mm,
unsigned long va)
{
- cpumask_t tmp;
- /*
- * A couple of (to be removed) sanity checks:
- *
- * - we do not send IPIs to not-yet booted CPUs.
- * - current CPU must not be in mask
- * - mask must exist :)
- */
- BUG_ON(cpus_empty(cpumask));
- cpus_and(tmp, cpumask, cpu_online_map);
- BUG_ON(!cpus_equal(tmp, cpumask));
- BUG_ON(cpu_isset(smp_processor_id(), cpumask));
- if (!mm)
- BUG();
+ int sender;
+ union smp_flush_state *f;
- /*
- * I'm not happy about this global shared spinlock in the
- * MM hot path, but we'll see how contended it is.
- * Temporarily this turns IRQs off, so that lockups are
- * detected by the NMI watchdog.
- */
- spin_lock(&tlbstate_lock);
-
- flush_mm = mm;
- flush_va = va;
- cpus_or(flush_cpumask, cpumask, flush_cpumask);
+ /* Caller has disabled preemption */
+ sender = smp_processor_id() % NUM_INVALIDATE_TLB_VECTORS;
+ f = &per_cpu(flush_state, sender);
+
+ /* Could avoid this lock when
+ num_online_cpus() <= NUM_INVALIDATE_TLB_VECTORS, but it is
+ probably not worth checking this for a cache-hot lock. */
+ spin_lock(&f->tlbstate_lock);
+
+ f->flush_mm = mm;
+ f->flush_va = va;
+ cpus_or(f->flush_cpumask, cpumask, f->flush_cpumask);
/*
* We have to send the IPI only to
* CPUs affected.
*/
- send_IPI_mask(cpumask, INVALIDATE_TLB_VECTOR);
+ send_IPI_mask(cpumask, INVALIDATE_TLB_VECTOR_START + sender);
- while (!cpus_empty(flush_cpumask))
- mb(); /* nothing. lockup detection does not belong here */;
+ while (!cpus_empty(f->flush_cpumask))
+ cpu_relax();
- flush_mm = NULL;
- flush_va = 0;
- spin_unlock(&tlbstate_lock);
+ f->flush_mm = NULL;
+ f->flush_va = 0;
+ spin_unlock(&f->tlbstate_lock);
}
+
+int __cpuinit init_smp_flush(void)
+{
+ int i;
+ for_each_cpu_mask(i, cpu_possible_map) {
+ spin_lock_init(&per_cpu(flush_state.tlbstate_lock, i));
+ }
+ return 0;
+}
+
+core_initcall(init_smp_flush);
void flush_tlb_current_task(void)
{
diff --git a/include/asm-x86_64/hw_irq.h b/include/asm-x86_64/hw_irq.h
index 2b5cb2865d2..d9212eb4e89 100644
--- a/include/asm-x86_64/hw_irq.h
+++ b/include/asm-x86_64/hw_irq.h
@@ -50,14 +50,15 @@ struct hw_interrupt_type;
*/
#define SPURIOUS_APIC_VECTOR 0xff
#define ERROR_APIC_VECTOR 0xfe
-#define INVALIDATE_TLB_VECTOR 0xfd
-#define RESCHEDULE_VECTOR 0xfc
-#define TASK_MIGRATION_VECTOR 0xfb
-#define CALL_FUNCTION_VECTOR 0xfa
-#define KDB_VECTOR 0xf9
-
-#define THERMAL_APIC_VECTOR 0xf0
-
+#define RESCHEDULE_VECTOR 0xfd
+#define CALL_FUNCTION_VECTOR 0xfc
+#define KDB_VECTOR 0xfb /* reserved for KDB */
+#define THERMAL_APIC_VECTOR 0xfa
+/* 0xf9 free */
+#define INVALIDATE_TLB_VECTOR_END 0xf8
+#define INVALIDATE_TLB_VECTOR_START 0xf0 /* f0-f8 used for TLB flush */
+
+#define NUM_INVALIDATE_TLB_VECTORS 8
/*
* Local APIC timer IRQ vector is on a different priority level,