[PATCH] PER_CPU [2/4] - PER_CPU-irq_stat

[Shai Fultheim]

Andrew,

Please find below one out of collection of patched that move NR_CPU array variables to the per-cpu area.  Please consider applying,
any comment will highly appreciated.

1/4. PER_CPU-cpu_tlbstate
2/4. PER_CPU-irq_stat
3/4. PER_CPU-init_tss
4/4. PER_CPU-cpu_gdt_table

PER_CPU-irq_stat:
 arch/i386/kernel/apic.c     |    2 +-
 arch/i386/kernel/io_apic.c  |    2 +-
 arch/i386/kernel/irq.c      |    3 ++-
 arch/i386/kernel/nmi.c      |    4 ++--
 arch/i386/kernel/process.c  |    2 +-
 include/linux/irq_cpustat.h |    4 ++--
 kernel/softirq.c            |    4 ++--
 7 files changed, 11 insertions(+), 10 deletions(-)

Signed-off-by: Martin Hicks <mort@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Shai Fultheim <shai@xxxxxxxxxxxx>

=================================================================================
diff -Nru a/arch/i386/kernel/apic.c b/arch/i386/kernel/apic.c
--- a/arch/i386/kernel/apic.c	2004-07-08 14:43:13 -07:00
+++ b/arch/i386/kernel/apic.c	2004-07-08 14:43:13 -07:00
@@ -1083,7 +1083,7 @@
 	/*
 	 * the NMI deadlock-detector uses this.
 	 */
-	irq_stat[cpu].apic_timer_irqs++;
+	per_cpu(irq_stat, cpu).apic_timer_irqs++;
 
 	/*
 	 * NOTE! We'd better ACK the irq immediately,
diff -Nru a/arch/i386/kernel/io_apic.c b/arch/i386/kernel/io_apic.c
--- a/arch/i386/kernel/io_apic.c	2004-07-08 14:43:13 -07:00
+++ b/arch/i386/kernel/io_apic.c	2004-07-08 14:43:13 -07:00
@@ -313,7 +313,7 @@
 #define IRQ_DELTA(cpu,irq) 	(irq_cpu_data[cpu].irq_delta[irq])
 
 #define IDLE_ENOUGH(cpu,now) \
-		(idle_cpu(cpu) && ((now) - irq_stat[(cpu)].idle_timestamp > 1))
+		(idle_cpu(cpu) && ((now) - per_cpu(irq_stat, (cpu)).idle_timestamp > 1))
 
 #define IRQ_ALLOWED(cpu, allowed_mask)	cpu_isset(cpu, allowed_mask)
 
diff -Nru a/arch/i386/kernel/irq.c b/arch/i386/kernel/irq.c
--- a/arch/i386/kernel/irq.c	2004-07-08 14:43:13 -07:00
+++ b/arch/i386/kernel/irq.c	2004-07-08 14:43:13 -07:00
@@ -188,7 +188,8 @@
 		seq_printf(p, "LOC: ");
 		for (j = 0; j < NR_CPUS; j++)
 			if (cpu_online(j))
-				seq_printf(p, "%10u ", irq_stat[j].apic_timer_irqs);
+				seq_printf(p, "%10u ",
+					   per_cpu(irq_stat, j).apic_timer_irqs);
 		seq_putc(p, '\n');
 #endif
 		seq_printf(p, "ERR: %10u\n", atomic_read(&irq_err_count));
diff -Nru a/arch/i386/kernel/nmi.c b/arch/i386/kernel/nmi.c
--- a/arch/i386/kernel/nmi.c	2004-07-08 14:43:13 -07:00
+++ b/arch/i386/kernel/nmi.c	2004-07-08 14:43:13 -07:00
@@ -106,7 +106,7 @@
 	printk(KERN_INFO "testing NMI watchdog ... ");
 
 	for (cpu = 0; cpu < NR_CPUS; cpu++)
-		prev_nmi_count[cpu] = irq_stat[cpu].__nmi_count;
+		prev_nmi_count[cpu] = per_cpu(irq_stat, cpu).__nmi_count;
 	local_irq_enable();
 	mdelay((10*1000)/nmi_hz); // wait 10 ticks
 
@@ -469,7 +469,7 @@
 	 */
 	int sum, cpu = smp_processor_id();
 
-	sum = irq_stat[cpu].apic_timer_irqs;
+	sum = per_cpu(irq_stat, cpu).apic_timer_irqs;
 
 	if (last_irq_sums[cpu] == sum) {
 		/*
diff -Nru a/arch/i386/kernel/process.c b/arch/i386/kernel/process.c
--- a/arch/i386/kernel/process.c	2004-07-08 14:43:13 -07:00
+++ b/arch/i386/kernel/process.c	2004-07-08 14:43:13 -07:00
@@ -147,7 +147,7 @@
 			if (!idle)
 				idle = default_idle;
 
-			irq_stat[smp_processor_id()].idle_timestamp = jiffies;
+			__get_cpu_var(irq_stat).idle_timestamp = jiffies;
 			idle();
 		}
 		schedule();
diff -Nru a/include/linux/irq_cpustat.h b/include/linux/irq_cpustat.h
--- a/include/linux/irq_cpustat.h	2004-07-08 14:43:13 -07:00
+++ b/include/linux/irq_cpustat.h	2004-07-08 14:43:13 -07:00
@@ -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(irq_cpustat_t, irq_stat);	/* defined in kernel/softirq.h */
+#define __IRQ_STAT(cpu, member)	(per_cpu(irq_stat, cpu).member)
 #endif
 
   /* arch independent irq_stat fields */
diff -Nru a/kernel/softirq.c b/kernel/softirq.c
--- a/kernel/softirq.c	2004-07-08 14:43:13 -07:00
+++ b/kernel/softirq.c	2004-07-08 14:43:13 -07:00
@@ -36,8 +36,8 @@
  */
 
 #ifndef __ARCH_IRQ_STAT
-irq_cpustat_t irq_stat[NR_CPUS] ____cacheline_aligned;
-EXPORT_SYMBOL(irq_stat);
+DEFINE_PER_CPU(irq_cpustat_t, irq_stat ____cacheline_maxaligned_in_smp);
+EXPORT_PER_CPU_SYMBOL(irq_stat);
 #endif
 
 static struct softirq_action softirq_vec[32] __cacheline_aligned_in_smp;
=================================================================================

 
-----------------
Shai Fultheim
Scalex86.org



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