* [PATCH 5/4] Make Generic irq_stat Structure Use per-cpu
@ 2003-07-03 8:47 Rusty Russell
0 siblings, 0 replies; only message in thread
From: Rusty Russell @ 2003-07-03 8:47 UTC (permalink / raw)
To: torvalds; +Cc: linux-kernel
[ Sorry about the counting thing, decided to split this patch after I'd
sent the first two. ]
Changes the generic irq_stat structure to use DECLARE_PER_CPU.
This saves a little space, and is more efficient on some archs.
Only i386 is fixed here.
Some archs refer to this in assembler: this is easy on UP (append
__per_cpu to the symbol name), but more complex on SMP (you need to
add __per_cpu_offset[smp_processor_id()]). If that's too hard then
you can just stop using the generic structure. Please remember to
drop the ____cacheline_aligned from the typedef of irq_cpustat_t!
Name: Make Generic irq_stat Structure Use per-cpu
Author: Rusty Russell
Status: Tested on 2.5.74
Depends: Percpu/local_softirq_pending.patch.gz
D: Changes the generic irq_stat structure to use DECLARE_PER_CPU.
D: This saves a little space, and is more efficient on some archs.
D:
D: Only i386 is fixed here.
D:
D: Some archs refer to this in assembler: this is easy on UP (append
D: __per_cpu to the symbol name), but more complex on SMP (you need
D: to add __per_cpu_offset[smp_processor_id()]). If that's too hard
D: then you can just stop using the generic structure.
D: Please remember to drop the ____cacheline_aligned from the typedef
D: of irq_cpustat_t!
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .15631-linux-2.5.74/arch/i386/kernel/apic.c .15631-linux-2.5.74.updated/arch/i386/kernel/apic.c
--- .15631-linux-2.5.74/arch/i386/kernel/apic.c 2003-07-03 09:43:41.000000000 +1000
+++ .15631-linux-2.5.74.updated/arch/i386/kernel/apic.c 2003-07-03 16:24:21.000000000 +1000
@@ -1039,12 +1039,10 @@ inline void smp_local_timer_interrupt(st
void smp_apic_timer_interrupt(struct pt_regs regs)
{
- int cpu = smp_processor_id();
-
/*
* the NMI deadlock-detector uses this.
*/
- irq_stat[cpu].apic_timer_irqs++;
+ __get_cpu_var(irq_stat).apic_timer_irqs++;
/*
* NOTE! We'd better ACK the irq immediately,
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .15631-linux-2.5.74/arch/i386/kernel/io_apic.c .15631-linux-2.5.74.updated/arch/i386/kernel/io_apic.c
--- .15631-linux-2.5.74/arch/i386/kernel/io_apic.c 2003-07-03 09:43:41.000000000 +1000
+++ .15631-linux-2.5.74.updated/arch/i386/kernel/io_apic.c 2003-07-03 16:24:21.000000000 +1000
@@ -304,7 +304,7 @@ struct irq_cpu_info {
#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) \
((1 << cpu) & (allowed_mask))
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .15631-linux-2.5.74/arch/i386/kernel/irq.c .15631-linux-2.5.74.updated/arch/i386/kernel/irq.c
--- .15631-linux-2.5.74/arch/i386/kernel/irq.c 2003-06-15 11:29:47.000000000 +1000
+++ .15631-linux-2.5.74.updated/arch/i386/kernel/irq.c 2003-07-03 16:24:21.000000000 +1000
@@ -181,7 +181,8 @@ skip:
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 -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .15631-linux-2.5.74/arch/i386/kernel/nmi.c .15631-linux-2.5.74.updated/arch/i386/kernel/nmi.c
--- .15631-linux-2.5.74/arch/i386/kernel/nmi.c 2003-06-23 10:52:42.000000000 +1000
+++ .15631-linux-2.5.74.updated/arch/i386/kernel/nmi.c 2003-07-03 16:24:21.000000000 +1000
@@ -90,7 +90,7 @@ int __init check_nmi_watchdog (void)
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] = nmi_count(cpu);
local_irq_enable();
mdelay((10*1000)/nmi_hz); // wait 10 ticks
@@ -409,7 +409,7 @@ void nmi_watchdog_tick (struct pt_regs *
*/
int sum, cpu = smp_processor_id();
- sum = irq_stat[cpu].apic_timer_irqs;
+ sum = __get_cpu_var(irq_stat).apic_timer_irqs;
if (last_irq_sums[cpu] == sum) {
/*
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .15631-linux-2.5.74/arch/i386/kernel/process.c .15631-linux-2.5.74.updated/arch/i386/kernel/process.c
--- .15631-linux-2.5.74/arch/i386/kernel/process.c 2003-06-23 10:52:42.000000000 +1000
+++ .15631-linux-2.5.74.updated/arch/i386/kernel/process.c 2003-07-03 16:24:21.000000000 +1000
@@ -141,7 +141,7 @@ void cpu_idle (void)
void (*idle)(void) = pm_idle;
if (!idle)
idle = default_idle;
- irq_stat[smp_processor_id()].idle_timestamp = jiffies;
+ __get_cpu_var(irq_stat).idle_timestamp = jiffies;
while (!need_resched())
idle();
schedule();
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .15631-linux-2.5.74/arch/i386/kernel/traps.c .15631-linux-2.5.74.updated/arch/i386/kernel/traps.c
--- .15631-linux-2.5.74/arch/i386/kernel/traps.c 2003-07-03 09:43:41.000000000 +1000
+++ .15631-linux-2.5.74.updated/arch/i386/kernel/traps.c 2003-07-03 16:24:21.000000000 +1000
@@ -475,7 +475,7 @@ asmlinkage void do_nmi(struct pt_regs *
nmi_enter();
cpu = smp_processor_id();
- ++nmi_count(cpu);
+ ++local_nmi_count();
if (!nmi_callback(regs, cpu))
default_do_nmi(regs);
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .15631-linux-2.5.74/arch/x86_64/kernel/irq.c .15631-linux-2.5.74.updated/arch/x86_64/kernel/irq.c
--- .15631-linux-2.5.74/arch/x86_64/kernel/irq.c 2003-06-15 11:29:50.000000000 +1000
+++ .15631-linux-2.5.74.updated/arch/x86_64/kernel/irq.c 2003-07-03 16:24:22.000000000 +1000
@@ -173,7 +173,7 @@ skip:
seq_printf(p, "NMI: ");
for (j = 0; j < NR_CPUS; j++)
if (cpu_online(j))
- seq_printf(p, "%10u ", cpu_pda[j].__nmi_count);
+ seq_printf(p, "%10u ", nmi_count(j));
seq_putc(p, '\n');
#ifdef CONFIG_X86_LOCAL_APIC
seq_printf(p, "LOC: ");
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .15631-linux-2.5.74/arch/x86_64/kernel/nmi.c .15631-linux-2.5.74.updated/arch/x86_64/kernel/nmi.c
--- .15631-linux-2.5.74/arch/x86_64/kernel/nmi.c 2003-07-03 09:43:46.000000000 +1000
+++ .15631-linux-2.5.74.updated/arch/x86_64/kernel/nmi.c 2003-07-03 16:26:24.000000000 +1000
@@ -86,17 +86,17 @@ int __init check_nmi_watchdog (void)
printk(KERN_INFO "testing NMI watchdog ... ");
for (cpu = 0; cpu < NR_CPUS; cpu++)
- counts[cpu] = cpu_pda[cpu].__nmi_count;
+ counts[cpu] = nmi_count(cpu);
local_irq_enable();
mdelay((10*1000)/nmi_hz); // wait 10 ticks
for (cpu = 0; cpu < NR_CPUS; cpu++) {
if (!cpu_online(cpu))
continue;
- if (cpu_pda[cpu].__nmi_count - counts[cpu] <= 5) {
+ if (nmi_count(cpu) - counts[cpu] <= 5) {
printk("CPU#%d: NMI appears to be stuck (%d)!\n",
cpu,
- cpu_pda[cpu].__nmi_count);
+ nmi_count(cpu));
nmi_active = 0;
return -1;
}
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .15631-linux-2.5.74/include/asm-i386/hardirq.h .15631-linux-2.5.74.updated/include/asm-i386/hardirq.h
--- .15631-linux-2.5.74/include/asm-i386/hardirq.h 2003-07-03 16:24:19.000000000 +1000
+++ .15631-linux-2.5.74.updated/include/asm-i386/hardirq.h 2003-07-03 16:24:22.000000000 +1000
@@ -10,7 +10,7 @@ typedef struct {
unsigned long idle_timestamp;
unsigned int __nmi_count; /* arch dependent */
unsigned int apic_timer_irqs; /* arch dependent */
-} ____cacheline_aligned irq_cpustat_t;
+} irq_cpustat_t;
#include <linux/irq_cpustat.h> /* Standard mappings for irq_cpustat_t above */
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .15631-linux-2.5.74/include/linux/irq_cpustat.h .15631-linux-2.5.74.updated/include/linux/irq_cpustat.h
--- .15631-linux-2.5.74/include/linux/irq_cpustat.h 2003-07-03 16:24:19.000000000 +1000
+++ .15631-linux-2.5.74.updated/include/linux/irq_cpustat.h 2003-07-03 16:24:22.000000000 +1000
@@ -10,6 +10,7 @@
*/
#include <linux/config.h>
+#include <linux/percpu.h>
/*
* Simple wrappers reducing source bloat. Define all irq_stat fields
@@ -18,19 +19,17 @@
*/
#ifndef __ARCH_IRQ_STAT
-extern irq_cpustat_t irq_stat[]; /* defined in asm/hardirq.h */
-#ifdef CONFIG_SMP
-#define __IRQ_STAT(cpu, member) (irq_stat[cpu].member)
-#else
-#define __IRQ_STAT(cpu, member) ((void)(cpu), irq_stat[0].member)
-#endif
+DECLARE_PER_CPU(irq_cpustat_t, irq_stat); /* defined in asm/hardirq.h */
+#define __IRQ_STAT(cpu, member) (per_cpu(irq_stat, (cpu)).member)
+#define __LOCAL_IRQ_STAT(member) (__get_cpu_var(irq_stat).member)
#endif
/* arch independent irq_stat fields */
-#define softirq_pending(cpu) __IRQ_STAT((cpu), __softirq_pending)
-#define local_softirq_pending() softirq_pending(smp_processor_id())
+#define local_softirq_pending() __LOCAL_IRQ_STAT(__softirq_pending)
/* arch dependent irq_stat fields */
-#define nmi_count(cpu) __IRQ_STAT((cpu), __nmi_count) /* i386 */
+/* i386, x86-64 */
+#define nmi_count(cpu) __IRQ_STAT((cpu), __nmi_count)
+#define local_nmi_count() __LOCAL_IRQ_STAT(__nmi_count)
#endif /* __irq_cpustat_h */
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .15631-linux-2.5.74/kernel/softirq.c .15631-linux-2.5.74.updated/kernel/softirq.c
--- .15631-linux-2.5.74/kernel/softirq.c 2003-07-03 16:24:19.000000000 +1000
+++ .15631-linux-2.5.74.updated/kernel/softirq.c 2003-07-03 16:24:22.000000000 +1000
@@ -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);
+EXPORT_PER_CPU_SYMBOL(irq_stat);
#endif
static struct softirq_action softirq_vec[32] __cacheline_aligned_in_smp;
--
Anyone who quotes me in their sig is an idiot. -- Rusty Russell.
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