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[MIPS] Oprofile: Fix computation of number of counters.

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VSMP kernels will split the available performance counters between the two
processors / cores.  But don't do this when we're not on a VSMP system ...

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This commit is contained in:
Ralf Baechle 2007-12-06 09:12:28 +00:00
parent 0e8120e094
commit 5e2862eb5a
1 changed files with 38 additions and 6 deletions
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44
arch/mips/oprofile/op_model_mipsxx.c
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@ -6,6 +6,7 @@
* Copyright (C) 2004, 05, 06 by Ralf Baechle
* Copyright (C) 2005 by MIPS Technologies, Inc.
*/
#include <linux/cpumask.h>
#include <linux/oprofile.h>
#include <linux/interrupt.h>
#include <linux/smp.h>
@ -33,11 +34,45 @@
#ifdef CONFIG_MIPS_MT_SMP
#define WHAT (M_TC_EN_VPE | M_PERFCTL_VPEID(smp_processor_id()))
#define vpe_id() smp_processor_id()
/*
* The number of bits to shift to convert between counters per core and
* counters per VPE. There is no reasonable interface atm to obtain the
* number of VPEs used by Linux and in the 34K this number is fixed to two
* anyways so we hardcore a few things here for the moment. The way it's
* done here will ensure that oprofile VSMP kernel will run right on a lesser
* core like a 24K also or with maxcpus=1.
*/
static inline unsigned int vpe_shift(void)
{
if (num_possible_cpus() > 1)
return 1;
return 0;
}
#else
#define WHAT 0
#define vpe_id() 0
static inline unsigned int vpe_shift(void)
{
return 0;
}
#endif
static inline unsigned int counters_total_to_per_cpu(unsigned int counters)
{
return counters >> vpe_shift();
}
static inline unsigned int counters_per_cpu_to_total(unsigned int counters)
{
return counters << vpe_shift();
}
#define __define_perf_accessors(r, n, np) \
\
static inline unsigned int r_c0_ ## r ## n(void) \
@ -269,9 +304,7 @@ static int __init mipsxx_init(void)
reset_counters(counters);
#ifdef CONFIG_MIPS_MT_SMP
counters >>= 1;
#endif
counters = counters_total_to_per_cpu(counters);
op_model_mipsxx_ops.num_counters = counters;
switch (current_cpu_type()) {
@ -330,9 +363,8 @@ static int __init mipsxx_init(void)
static void mipsxx_exit(void)
{
int counters = op_model_mipsxx_ops.num_counters;
#ifdef CONFIG_MIPS_MT_SMP
counters <<= 1;
#endif
counters = counters_per_cpu_to_total(counters);
reset_counters(counters);
perf_irq = null_perf_irq;