diff options
| author | Eric Dumazet <eric.dumazet@gmail.com> | 2011-01-13 15:45:38 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2011-01-13 17:32:31 -0800 |
| commit | 6c9ae009b298753a3baf71298d676a68b5a10c8f (patch) | |
| tree | 95a7e4ca54fe8e96c95cedd4e8d6450659015212 /include/linux/irqdesc.h | |
| parent | 558bbb2fc75fd9676e07e347c021865e326c56db (diff) | |
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/irqdesc.h')
| -rw-r--r-- | include/linux/irqdesc.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/include/linux/irqdesc.h b/include/linux/irqdesc.h index 979c68cc745..6a64c6fa81a 100644 --- a/include/linux/irqdesc.h +++ b/include/linux/irqdesc.h @@ -57,7 +57,7 @@ struct irq_desc { #endif struct timer_rand_state *timer_rand_state; - unsigned int *kstat_irqs; + unsigned int __percpu *kstat_irqs; irq_flow_handler_t handle_irq; struct irqaction *action; /* IRQ action list */ unsigned int status; /* IRQ status */ |