[PATCH 03/10] softirq: Turn default irq_cpustat_t to standard per-cpu

From: Frederic Weisbecker
Date: Wed Mar 28 2018 - 22:28:58 EST


In order to optimize and consolidate softirq mask accesses, let's
convert the default irq_cpustat_t implementation to per-CPU standard API.

Signed-off-by: Frederic Weisbecker <frederic@xxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
Cc: David S. Miller <davem@xxxxxxxxxxxxx>
Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Cc: James E.J. Bottomley <jejb@xxxxxxxxxxxxxxxx>
Cc: Helge Deller <deller@xxxxxx>
Cc: Tony Luck <tony.luck@xxxxxxxxx>
Cc: Fenghua Yu <fenghua.yu@xxxxxxxxx>
---
include/linux/irq_cpustat.h | 4 ++--
kernel/softirq.c | 4 ++--
2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/include/linux/irq_cpustat.h b/include/linux/irq_cpustat.h
index 4954948..ddea03c 100644
--- a/include/linux/irq_cpustat.h
+++ b/include/linux/irq_cpustat.h
@@ -18,8 +18,8 @@
*/

#ifndef __ARCH_IRQ_STAT
-extern irq_cpustat_t irq_stat[]; /* defined in asm/hardirq.h */
-#define __IRQ_STAT(cpu, member) (irq_stat[cpu].member)
+DECLARE_PER_CPU_ALIGNED(irq_cpustat_t, irq_stat); /* defined in asm/hardirq.h */
+#define __IRQ_STAT(cpu, member) (per_cpu(irq_stat.member, cpu))
#endif

/* arch independent irq_stat fields */
diff --git a/kernel/softirq.c b/kernel/softirq.c
index 24d243e..fdbb171 100644
--- a/kernel/softirq.c
+++ b/kernel/softirq.c
@@ -49,8 +49,8 @@
*/

#ifndef __ARCH_IRQ_STAT
-irq_cpustat_t irq_stat[NR_CPUS] ____cacheline_aligned;
-EXPORT_SYMBOL(irq_stat);
+DEFINE_PER_CPU_ALIGNED(irq_cpustat_t, irq_stat);
+EXPORT_PER_CPU_SYMBOL(irq_stat);
#endif

static struct softirq_action softirq_vec[NR_SOFTIRQS] __cacheline_aligned_in_smp;
--
2.7.4