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authorEric Dumazet <eric.dumazet@gmail.com>2011-01-13 15:45:38 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2011-01-13 17:32:31 -0800
commit6c9ae009b298753a3baf71298d676a68b5a10c8f (patch)
tree95a7e4ca54fe8e96c95cedd4e8d6450659015212 /include/linux/kernel_stat.h
parent558bbb2fc75fd9676e07e347c021865e326c56db (diff)
downloadblackbird-op-linux-6c9ae009b298753a3baf71298d676a68b5a10c8f.tar.gz
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irq: use per_cpu kstat_irqs
Use modern per_cpu API to increment {soft|hard}irq counters, and use per_cpu allocation for (struct irq_desc)->kstats_irq instead of an array. This gives better SMP/NUMA locality and saves few instructions per irq. With small nr_cpuids values (8 for example), kstats_irq was a small array (less than L1_CACHE_BYTES), potentially source of false sharing. In the !CONFIG_SPARSE_IRQ case, remove the huge, NUMA/cache unfriendly kstat_irqs_all[NR_IRQS][NR_CPUS] array. Note: we still populate kstats_irq for all possible irqs in early_irq_init(). We probably could use on-demand allocations. (Code included in alloc_descs()). Problem is not all IRQS are used with a prior alloc_descs() call. kstat_irqs_this_cpu() is not used anymore, remove it. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Reviewed-by: Christoph Lameter <cl@linux.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Andi Kleen <andi@firstfloor.org> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux/kernel_stat.h')
-rw-r--r--include/linux/kernel_stat.h19
1 files changed, 9 insertions, 10 deletions
diff --git a/include/linux/kernel_stat.h b/include/linux/kernel_stat.h
index 44e83ba12b5b..0cce2db580c3 100644
--- a/include/linux/kernel_stat.h
+++ b/include/linux/kernel_stat.h
@@ -46,16 +46,14 @@ DECLARE_PER_CPU(struct kernel_stat, kstat);
extern unsigned long long nr_context_switches(void);
#ifndef CONFIG_GENERIC_HARDIRQS
-#define kstat_irqs_this_cpu(irq) \
- (this_cpu_read(kstat.irqs[irq])
struct irq_desc;
static inline void kstat_incr_irqs_this_cpu(unsigned int irq,
struct irq_desc *desc)
{
- kstat_this_cpu.irqs[irq]++;
- kstat_this_cpu.irqs_sum++;
+ __this_cpu_inc(kstat.irqs[irq]);
+ __this_cpu_inc(kstat.irqs_sum);
}
static inline unsigned int kstat_irqs_cpu(unsigned int irq, int cpu)
@@ -65,17 +63,18 @@ static inline unsigned int kstat_irqs_cpu(unsigned int irq, int cpu)
#else
#include <linux/irq.h>
extern unsigned int kstat_irqs_cpu(unsigned int irq, int cpu);
-#define kstat_irqs_this_cpu(DESC) \
- ((DESC)->kstat_irqs[smp_processor_id()])
-#define kstat_incr_irqs_this_cpu(irqno, DESC) do {\
- ((DESC)->kstat_irqs[smp_processor_id()]++);\
- kstat_this_cpu.irqs_sum++; } while (0)
+
+#define kstat_incr_irqs_this_cpu(irqno, DESC) \
+do { \
+ __this_cpu_inc(*(DESC)->kstat_irqs); \
+ __this_cpu_inc(kstat.irqs_sum); \
+} while (0)
#endif
static inline void kstat_incr_softirqs_this_cpu(unsigned int irq)
{
- kstat_this_cpu.softirqs[irq]++;
+ __this_cpu_inc(kstat.softirqs[irq]);
}
static inline unsigned int kstat_softirqs_cpu(unsigned int irq, int cpu)
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