From 6c9ae009b298753a3baf71298d676a68b5a10c8f Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Thu, 13 Jan 2011 15:45:38 -0800 Subject: 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 Reviewed-by: Christoph Lameter Cc: Ingo Molnar Cc: Andi Kleen Cc: Tejun Heo Cc: Thomas Gleixner Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/kernel_stat.h | 19 +++++++++---------- 1 file changed, 9 insertions(+), 10 deletions(-) (limited to 'include/linux/kernel_stat.h') 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 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) -- cgit v1.2.3-59-g8ed1b