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authorMichael Cree <mcree@orcon.net.nz>2010-08-10 02:20:05 +0200
committerLinus Torvalds <torvalds@linux-foundation.org>2010-08-10 05:45:03 +0200
commit65d920646a1c720c5ba95b7643ab1b46167d9e6a (patch)
tree262f77223f5368bdfdb461e658d8ddd6750f651f /arch/alpha/kernel
parentmm: avoid resetting wb_start after each writeback round (diff)
downloadlinux-65d920646a1c720c5ba95b7643ab1b46167d9e6a.tar.xz
linux-65d920646a1c720c5ba95b7643ab1b46167d9e6a.zip
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>
Diffstat (limited to 'arch/alpha/kernel')
-rw-r--r--arch/alpha/kernel/irq.c7
1 files changed, 5 insertions, 2 deletions
diff --git a/arch/alpha/kernel/irq.c b/arch/alpha/kernel/irq.c
index 7f912ba3d9ad..fe912984d9b1 100644
--- a/arch/alpha/kernel/irq.c
+++ b/arch/alpha/kernel/irq.c
@@ -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;