From 5e2862eb5a263a0339a85545d96fb20995d67b1f Mon Sep 17 00:00:00 2001 From: Ralf Baechle Date: Thu, 6 Dec 2007 09:12:28 +0000 Subject: [PATCH] [MIPS] Oprofile: Fix computation of number of counters. 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 --- arch/mips/oprofile/op_model_mipsxx.c | 44 ++++++++++++++++++++++++---- 1 file changed, 38 insertions(+), 6 deletions(-) diff --git a/arch/mips/oprofile/op_model_mipsxx.c b/arch/mips/oprofile/op_model_mipsxx.c index 423bc2c473..bdfa07aecd 100644 --- a/arch/mips/oprofile/op_model_mipsxx.c +++ b/arch/mips/oprofile/op_model_mipsxx.c @@ -6,6 +6,7 @@ * Copyright (C) 2004, 05, 06 by Ralf Baechle * Copyright (C) 2005 by MIPS Technologies, Inc. */ +#include #include #include #include @@ -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; -- 2.39.5