From 1a960b402a51d80abf54e3f8e4972374ffe5f22d Mon Sep 17 00:00:00 2001 From: Jason Yeh Date: Wed, 23 Jul 2008 23:05:53 +0200 Subject: Oprofile Multiplexing Patch This patch introduces multiplexing support for the Oprofile kernel module. It basically adds a new function pointer in oprofile_operator allowing each architecture to supply its callback to switch between different sets of event when the timer expires. Userspace tools can modify the time slice through /dev/oprofile/time_slice. It also modifies the number of counters exposed to the userspace through /dev/oprofile. For example, the number of counters for AMD CPUs are changed to 32 and multiplexed in the sets of 4. Signed-off-by: Jason Yeh Signed-off-by: Robert Richter Cc: oprofile-list Signed-off-by: Ingo Molnar --- arch/x86/oprofile/op_model_amd.c | 76 ++++++++++++++++++++++++---------------- 1 file changed, 46 insertions(+), 30 deletions(-) (limited to 'arch/x86/oprofile/op_model_amd.c') diff --git a/arch/x86/oprofile/op_model_amd.c b/arch/x86/oprofile/op_model_amd.c index d9faf607b3a..bbf2b68bcc5 100644 --- a/arch/x86/oprofile/op_model_amd.c +++ b/arch/x86/oprofile/op_model_amd.c @@ -15,6 +15,7 @@ #include #include #include +#include #include #include @@ -23,8 +24,10 @@ #include "op_x86_model.h" #include "op_counter.h" -#define NUM_COUNTERS 4 -#define NUM_CONTROLS 4 +#define NUM_COUNTERS 32 +#define NUM_HARDWARE_COUNTERS 4 +#define NUM_CONTROLS 32 +#define NUM_HARDWARE_CONTROLS 4 #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) @@ -48,6 +51,7 @@ #define CTRL_SET_GUEST_ONLY(val, h) (val |= ((h & 1) << 8)) static unsigned long reset_value[NUM_COUNTERS]; +DECLARE_PER_CPU(int, switch_index); #ifdef CONFIG_OPROFILE_IBS @@ -130,15 +134,17 @@ static void op_amd_fill_in_addresses(struct op_msrs * const msrs) int i; for (i = 0; i < NUM_COUNTERS; i++) { - if (reserve_perfctr_nmi(MSR_K7_PERFCTR0 + i)) - msrs->counters[i].addr = MSR_K7_PERFCTR0 + i; + int hw_counter = i % NUM_HARDWARE_COUNTERS; + if (reserve_perfctr_nmi(MSR_K7_PERFCTR0 + hw_counter)) + msrs->counters[i].addr = MSR_K7_PERFCTR0 + hw_counter; else msrs->counters[i].addr = 0; } for (i = 0; i < NUM_CONTROLS; i++) { - if (reserve_evntsel_nmi(MSR_K7_EVNTSEL0 + i)) - msrs->controls[i].addr = MSR_K7_EVNTSEL0 + i; + int hw_control = i % NUM_HARDWARE_CONTROLS; + if (reserve_evntsel_nmi(MSR_K7_EVNTSEL0 + hw_control)) + msrs->controls[i].addr = MSR_K7_EVNTSEL0 + hw_control; else msrs->controls[i].addr = 0; } @@ -150,8 +156,16 @@ static void op_amd_setup_ctrs(struct op_msrs const * const msrs) unsigned int low, high; int i; + for (i = 0; i < NUM_HARDWARE_CONTROLS; ++i) { + int offset = i + __get_cpu_var(switch_index); + if (counter_config[offset].enabled) + reset_value[offset] = counter_config[offset].count; + else + reset_value[offset] = 0; + } + /* clear all counters */ - for (i = 0 ; i < NUM_CONTROLS; ++i) { + for (i = 0 ; i < NUM_HARDWARE_CONTROLS; ++i) { if (unlikely(!CTRL_IS_RESERVED(msrs, i))) continue; CTRL_READ(low, high, msrs, i); @@ -161,34 +175,31 @@ static void op_amd_setup_ctrs(struct op_msrs const * const msrs) } /* avoid a false detection of ctr overflows in NMI handler */ - for (i = 0; i < NUM_COUNTERS; ++i) { + for (i = 0; i < NUM_HARDWARE_COUNTERS; ++i) { if (unlikely(!CTR_IS_RESERVED(msrs, i))) continue; CTR_WRITE(1, msrs, i); } /* enable active counters */ - for (i = 0; i < NUM_COUNTERS; ++i) { - if ((counter_config[i].enabled) && (CTR_IS_RESERVED(msrs, i))) { - reset_value[i] = counter_config[i].count; - - CTR_WRITE(counter_config[i].count, msrs, i); + for (i = 0; i < NUM_HARDWARE_COUNTERS; ++i) { + int offset = i + __get_cpu_var(switch_index); + if ((counter_config[offset].enabled) && (CTR_IS_RESERVED(msrs, i))) { + CTR_WRITE(counter_config[offset].count, msrs, i); CTRL_READ(low, high, msrs, i); CTRL_CLEAR_LO(low); CTRL_CLEAR_HI(high); CTRL_SET_ENABLE(low); - CTRL_SET_USR(low, counter_config[i].user); - CTRL_SET_KERN(low, counter_config[i].kernel); - CTRL_SET_UM(low, counter_config[i].unit_mask); - CTRL_SET_EVENT_LOW(low, counter_config[i].event); - CTRL_SET_EVENT_HIGH(high, counter_config[i].event); + CTRL_SET_USR(low, counter_config[offset].user); + CTRL_SET_KERN(low, counter_config[offset].kernel); + CTRL_SET_UM(low, counter_config[offset].unit_mask); + CTRL_SET_EVENT_LOW(low, counter_config[offset].event); + CTRL_SET_EVENT_HIGH(high, counter_config[offset].event); CTRL_SET_HOST_ONLY(high, 0); CTRL_SET_GUEST_ONLY(high, 0); CTRL_WRITE(low, high, msrs, i); - } else { - reset_value[i] = 0; } } } @@ -276,13 +287,14 @@ static int op_amd_check_ctrs(struct pt_regs * const regs, unsigned int low, high; int i; - for (i = 0 ; i < NUM_COUNTERS; ++i) { - if (!reset_value[i]) + for (i = 0 ; i < NUM_HARDWARE_COUNTERS ; ++i) { + int offset = i + __get_cpu_var(switch_index); + if (!reset_value[offset]) continue; CTR_READ(low, high, msrs, i); if (CTR_OVERFLOWED(low)) { - oprofile_add_sample(regs, i); - CTR_WRITE(reset_value[i], msrs, i); + oprofile_add_sample(regs, offset); + CTR_WRITE(reset_value[offset], msrs, i); } } @@ -298,8 +310,10 @@ static void op_amd_start(struct op_msrs const * const msrs) { unsigned int low, high; int i; - for (i = 0 ; i < NUM_COUNTERS ; ++i) { - if (reset_value[i]) { + + for (i = 0 ; i < NUM_HARDWARE_COUNTERS ; ++i) { + int offset = i + __get_cpu_var(switch_index); + if (reset_value[offset]) { CTRL_READ(low, high, msrs, i); CTRL_SET_ACTIVE(low); CTRL_WRITE(low, high, msrs, i); @@ -329,8 +343,8 @@ static void op_amd_stop(struct op_msrs const * const msrs) /* Subtle: stop on all counters to avoid race with * setting our pm callback */ - for (i = 0 ; i < NUM_COUNTERS ; ++i) { - if (!reset_value[i]) + for (i = 0 ; i < NUM_HARDWARE_COUNTERS ; ++i) { + if (!reset_value[i + per_cpu(switch_index, smp_processor_id())]) continue; CTRL_READ(low, high, msrs, i); CTRL_SET_INACTIVE(low); @@ -356,11 +370,11 @@ static void op_amd_shutdown(struct op_msrs const * const msrs) { int i; - for (i = 0 ; i < NUM_COUNTERS ; ++i) { + for (i = 0 ; i < NUM_HARDWARE_COUNTERS ; ++i) { if (CTR_IS_RESERVED(msrs, i)) release_perfctr_nmi(MSR_K7_PERFCTR0 + i); } - for (i = 0 ; i < NUM_CONTROLS ; ++i) { + for (i = 0 ; i < NUM_HARDWARE_COUNTERS ; ++i) { if (CTRL_IS_RESERVED(msrs, i)) release_evntsel_nmi(MSR_K7_EVNTSEL0 + i); } @@ -534,6 +548,8 @@ struct op_x86_model_spec const op_amd_spec = { .exit = op_amd_exit, .num_counters = NUM_COUNTERS, .num_controls = NUM_CONTROLS, + .num_hardware_counters = NUM_HARDWARE_COUNTERS, + .num_hardware_controls = NUM_HARDWARE_CONTROLS, .fill_in_addresses = &op_amd_fill_in_addresses, .setup_ctrs = &op_amd_setup_ctrs, .check_ctrs = &op_amd_check_ctrs, -- cgit v1.2.3