Re: linux-2.6.28-rc2 regression : oprofile doesnt work anymore ?

[Andi Kleen]

Can you please test this patch and see if it solves the problem?

Thanks,
-Andi

---

oprofile: Fix p6 counter overflow check

Fix the counter overflow check for CPUs with counter width > 32

I had a similar change in a different patch that I didn't submit
and I didn't notice the problem earlier because it was always
tested together.

Signed-off-by: Andi Kleen <ak@xxxxxxxxxxxxxxx>

---
 arch/x86/oprofile/op_model_ppro.c |    9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

Index: linux-2.6.28-rc3-test/arch/x86/oprofile/op_model_ppro.c
===================================================================
--- linux-2.6.28-rc3-test.orig/arch/x86/oprofile/op_model_ppro.c	2008-11-07 13:46:23.000000000 +0100
+++ linux-2.6.28-rc3-test/arch/x86/oprofile/op_model_ppro.c	2008-11-07 13:50:57.000000000 +0100
@@ -27,8 +27,7 @@
 static int counter_width = 32;
 
 #define CTR_IS_RESERVED(msrs, c) (msrs->counters[(c)].addr ? 1 : 0)
-#define CTR_READ(l, h, msrs, c) do {rdmsr(msrs->counters[(c)].addr, (l), (h)); } while (0)
-#define CTR_OVERFLOWED(n) (!((n) & (1U<<(counter_width-1))))
+#define CTR_OVERFLOWED(n) (!((n) & (1ULL<<(counter_width-1))))
 
 #define CTRL_IS_RESERVED(msrs, c) (msrs->controls[(c)].addr ? 1 : 0)
 #define CTRL_READ(l, h, msrs, c) do {rdmsr((msrs->controls[(c)].addr), (l), (h)); } while (0)
@@ -124,14 +123,14 @@
 static int ppro_check_ctrs(struct pt_regs * const regs,
 			   struct op_msrs const * const msrs)
 {
-	unsigned int low, high;
+	u64 val;
 	int i;
 
 	for (i = 0 ; i < num_counters; ++i) {
 		if (!reset_value[i])
 			continue;
-		CTR_READ(low, high, msrs, i);
-		if (CTR_OVERFLOWED(low)) {
+		rdmsrl(msrs->counters[i].addr, val);
+		if (CTR_OVERFLOWED(val)) {
 			oprofile_add_sample(regs, i);
 			wrmsrl(msrs->counters[i].addr, -reset_value[i]);
 		}


-- 
ak@xxxxxxxxxxxxxxx
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