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alpha: add performance monitor interrupt counter 

The following patches implement hardware performance events for the Alpha
EV67 and later CPUs.  I have had this running on a Compaq XP1000 (EV67,
single CPU) for a few days now.  Pretty cool -- discovered that the glibc
exp2() library routine uses on average 985 cycles to execute 777 CPU
instructions whereas Compaq's CPML library version of exp2() uses on
average 32 cycles to execute 47 CPU instructions to achieve the same
thing!

This patch:

Add performance monitor interrupt counternd and export the count to user
space via /proc/interrupts.

Signed-off-by: Michael Cree <mcree@orcon.net.nz>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Jay Estabrook <jay.estabrook@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Michael Cree 2010-08-09 17:20:05 -07:00 committed by Linus Torvalds
parent 7624ee72aa
commit 65d920646a
2 changed files with 6 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
arch/alpha/include/asm/hw_irq.h
View File

@ -3,6 +3,7 @@
extern volatile unsigned long irq_err_count;
DECLARE_PER_CPU(unsigned long, irq_pmi_count);
#ifdef CONFIG_ALPHA_GENERIC
#define ACTUAL_NR_IRQS alpha_mv.nr_irqs

7
arch/alpha/kernel/irq.c
View File

@ -31,6 +31,7 @@
#include <asm/uaccess.h>
volatile unsigned long irq_err_count;
DEFINE_PER_CPU(unsigned long, irq_pmi_count);
void ack_bad_irq(unsigned int irq)
{
@ -63,9 +64,7 @@ int irq_select_affinity(unsigned int irq)
int
show_interrupts(struct seq_file *p, void *v)
{
#ifdef CONFIG_SMP
int j;
#endif
int irq = *(loff_t *) v;
struct irqaction * action;
unsigned long flags;
@ -112,6 +111,10 @@ unlock:
seq_printf(p, "%10lu ", cpu_data[j].ipi_count);
seq_putc(p, '\n');
#endif
seq_puts(p, "PMI: ");
for_each_online_cpu(j)
seq_printf(p, "%10lu ", per_cpu(irq_pmi_count, j));
seq_puts(p, " Performance Monitoring\n");
seq_printf(p, "ERR: %10lu\n", irq_err_count);
}
return 0;