From 1a960b402a51d80abf54e3f8e4972374ffe5f22d Mon Sep 17 00:00:00 2001 From: Jason Yeh Date: Wed, 23 Jul 2008 23:05:53 +0200 Subject: [PATCH] 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/nmi_int.c | 100 +++++++++++++++++++++++++++++++++++--- arch/x86/oprofile/op_counter.h | 3 +- arch/x86/oprofile/op_model_amd.c | 76 +++++++++++++++++------------ arch/x86/oprofile/op_model_p4.c | 4 ++ arch/x86/oprofile/op_model_ppro.c | 2 + arch/x86/oprofile/op_x86_model.h | 3 ++ drivers/oprofile/oprof.c | 58 ++++++++++++++++++++-- drivers/oprofile/oprof.h | 4 +- drivers/oprofile/oprofile_files.c | 39 ++++++++++++++- include/linux/oprofile.h | 3 ++ 10 files changed, 247 insertions(+), 45 deletions(-) diff --git a/arch/x86/oprofile/nmi_int.c b/arch/x86/oprofile/nmi_int.c index 287513a..2a65fe7 100644 --- a/arch/x86/oprofile/nmi_int.c +++ b/arch/x86/oprofile/nmi_int.c @@ -23,12 +23,18 @@ #include "op_counter.h" #include "op_x86_model.h" +DEFINE_PER_CPU(int, switch_index); + static struct op_x86_model_spec const *model; static DEFINE_PER_CPU(struct op_msrs, cpu_msrs); static DEFINE_PER_CPU(unsigned long, saved_lvtpc); static int nmi_start(void); static void nmi_stop(void); +static void nmi_cpu_save_mpx_registers(struct op_msrs *msrs); +static void nmi_cpu_restore_mpx_registers(struct op_msrs *msrs); +static void nmi_cpu_stop(void *dummy); +static void nmi_cpu_start(void *dummy); /* 0 == registered but off, 1 == registered and on */ static int nmi_enabled = 0; @@ -81,6 +87,47 @@ static void exit_sysfs(void) #define exit_sysfs() do { } while (0) #endif /* CONFIG_PM */ +static void nmi_cpu_switch(void *dummy) +{ + int cpu = smp_processor_id(); + int si = per_cpu(switch_index, cpu); + struct op_msrs *msrs = &per_cpu(cpu_msrs, cpu); + + nmi_cpu_stop(NULL); + nmi_cpu_save_mpx_registers(msrs); + + /* move to next set */ + si += model->num_hardware_counters; + if ((si > model->num_counters) || (counter_config[si].count == 0)) + per_cpu(switch_index, smp_processor_id()) = 0; + else + per_cpu(switch_index, smp_processor_id()) = si; + + nmi_cpu_restore_mpx_registers(msrs); + model->setup_ctrs(msrs); + nmi_cpu_start(NULL); +} + +/* + * Quick check to see if multiplexing is necessary. + * The check should be sufficient since counters are used + * in ordre. + */ +static int nmi_multiplex_on(void) +{ + return counter_config[model->num_hardware_counters].count ? 0 : -EINVAL; +} + +static int nmi_switch_event(void) +{ + if (nmi_multiplex_on() < 0) + return -EINVAL; + + on_each_cpu(nmi_cpu_switch, NULL, 0, 1); + + return 0; +} + static int profile_exceptions_notify(struct notifier_block *self, unsigned long val, void *data) { @@ -144,11 +191,10 @@ static void free_msrs(void) static int allocate_msrs(void) { - int success = 1; + int i, success = 1; size_t controls_size = sizeof(struct op_msr) * model->num_controls; size_t counters_size = sizeof(struct op_msr) * model->num_counters; - int i; for_each_possible_cpu(i) { per_cpu(cpu_msrs, i).counters = kmalloc(counters_size, GFP_KERNEL); @@ -156,8 +202,8 @@ static int allocate_msrs(void) success = 0; break; } - per_cpu(cpu_msrs, i).controls = kmalloc(controls_size, - GFP_KERNEL); + per_cpu(cpu_msrs, i).controls = + kmalloc(controls_size, GFP_KERNEL); if (!per_cpu(cpu_msrs, i).controls) { success = 0; break; @@ -201,7 +247,8 @@ static int nmi_setup(void) return err; } - /* We need to serialize save and setup for HT because the subset + /* + * We need to serialize save and setup for HT because the subset * of msrs are distinct for save and setup operations */ @@ -217,7 +264,6 @@ static int nmi_setup(void) per_cpu(cpu_msrs, 0).controls, sizeof(struct op_msr) * model->num_controls); } - } on_each_cpu(nmi_save_registers, NULL, 1); on_each_cpu(nmi_cpu_setup, NULL, 1); @@ -225,7 +271,41 @@ static int nmi_setup(void) return 0; } -static void nmi_restore_registers(struct op_msrs *msrs) +static void nmi_cpu_save_mpx_registers(struct op_msrs *msrs) +{ + unsigned int si = __get_cpu_var(switch_index); + unsigned int const nr_ctrs = model->num_hardware_counters; + struct op_msr *counters = &msrs->counters[si]; + unsigned int i; + + for (i = 0; i < nr_ctrs; ++i) { + int offset = i + si; + if (counters[offset].addr) { + rdmsr(counters[offset].addr, + counters[offset].multiplex.low, + counters[offset].multiplex.high); + } + } +} + +static void nmi_cpu_restore_mpx_registers(struct op_msrs *msrs) +{ + unsigned int si = __get_cpu_var(switch_index); + unsigned int const nr_ctrs = model->num_hardware_counters; + struct op_msr *counters = &msrs->counters[si]; + unsigned int i; + + for (i = 0; i < nr_ctrs; ++i) { + int offset = i + si; + if (counters[offset].addr) { + wrmsr(counters[offset].addr, + counters[offset].multiplex.low, + counters[offset].multiplex.high); + } + } +} + +static void nmi_cpu_restore_registers(struct op_msrs *msrs) { unsigned int const nr_ctrs = model->num_counters; unsigned int const nr_ctrls = model->num_controls; @@ -265,7 +345,8 @@ static void nmi_cpu_shutdown(void *dummy) apic_write(APIC_LVTERR, v | APIC_LVT_MASKED); apic_write(APIC_LVTPC, per_cpu(saved_lvtpc, cpu)); apic_write(APIC_LVTERR, v); - nmi_restore_registers(msrs); + nmi_cpu_restore_registers(msrs); + __get_cpu_var(switch_index) = 0; } static void nmi_shutdown(void) @@ -328,6 +409,7 @@ static int nmi_create_files(struct super_block *sb, struct dentry *root) oprofilefs_create_ulong(sb, dir, "unit_mask", &counter_config[i].unit_mask); oprofilefs_create_ulong(sb, dir, "kernel", &counter_config[i].kernel); oprofilefs_create_ulong(sb, dir, "user", &counter_config[i].user); + counter_config[i].save_count_low = 0; } return 0; @@ -469,12 +551,14 @@ int __init op_nmi_init(struct oprofile_operations *ops) } /* default values, can be overwritten by model */ + __get_cpu_var(switch_index) = 0; ops->create_files = nmi_create_files; ops->setup = nmi_setup; ops->shutdown = nmi_shutdown; ops->start = nmi_start; ops->stop = nmi_stop; ops->cpu_type = cpu_type; + ops->switch_events = nmi_switch_event; if (model->init) ret = model->init(ops); diff --git a/arch/x86/oprofile/op_counter.h b/arch/x86/oprofile/op_counter.h index 2880b15..786d6e0 100644 --- a/arch/x86/oprofile/op_counter.h +++ b/arch/x86/oprofile/op_counter.h @@ -10,13 +10,14 @@ #ifndef OP_COUNTER_H #define OP_COUNTER_H -#define OP_MAX_COUNTER 8 +#define OP_MAX_COUNTER 32 /* Per-perfctr configuration as set via * oprofilefs. */ struct op_counter_config { unsigned long count; + unsigned long save_count_low; unsigned long enabled; unsigned long event; unsigned long kernel; diff --git a/arch/x86/oprofile/op_model_amd.c b/arch/x86/oprofile/op_model_amd.c index d9faf60..bbf2b68 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, diff --git a/arch/x86/oprofile/op_model_p4.c b/arch/x86/oprofile/op_model_p4.c index 56b4757..e641545 100644 --- a/arch/x86/oprofile/op_model_p4.c +++ b/arch/x86/oprofile/op_model_p4.c @@ -701,6 +701,8 @@ static void p4_shutdown(struct op_msrs const * const msrs) struct op_x86_model_spec const op_p4_ht2_spec = { .num_counters = NUM_COUNTERS_HT2, .num_controls = NUM_CONTROLS_HT2, + .num_hardware_counters = NUM_COUNTERS_HT2, + .num_hardware_controls = NUM_CONTROLS_HT2, .fill_in_addresses = &p4_fill_in_addresses, .setup_ctrs = &p4_setup_ctrs, .check_ctrs = &p4_check_ctrs, @@ -713,6 +715,8 @@ struct op_x86_model_spec const op_p4_ht2_spec = { struct op_x86_model_spec const op_p4_spec = { .num_counters = NUM_COUNTERS_NON_HT, .num_controls = NUM_CONTROLS_NON_HT, + .num_hardware_counters = NUM_COUNTERS_NON_HT, + .num_hardware_controls = NUM_CONTROLS_NON_HT, .fill_in_addresses = &p4_fill_in_addresses, .setup_ctrs = &p4_setup_ctrs, .check_ctrs = &p4_check_ctrs, diff --git a/arch/x86/oprofile/op_model_ppro.c b/arch/x86/oprofile/op_model_ppro.c index eff431f..e5811aa 100644 --- a/arch/x86/oprofile/op_model_ppro.c +++ b/arch/x86/oprofile/op_model_ppro.c @@ -183,6 +183,8 @@ static void ppro_shutdown(struct op_msrs const * const msrs) struct op_x86_model_spec const op_ppro_spec = { .num_counters = NUM_COUNTERS, .num_controls = NUM_CONTROLS, + .num_hardware_counters = NUM_COUNTERS, + .num_hardware_controls = NUM_CONTROLS, .fill_in_addresses = &ppro_fill_in_addresses, .setup_ctrs = &ppro_setup_ctrs, .check_ctrs = &ppro_check_ctrs, diff --git a/arch/x86/oprofile/op_x86_model.h b/arch/x86/oprofile/op_x86_model.h index 05a0261..e07ba10 100644 --- a/arch/x86/oprofile/op_x86_model.h +++ b/arch/x86/oprofile/op_x86_model.h @@ -19,6 +19,7 @@ struct op_saved_msr { struct op_msr { unsigned long addr; struct op_saved_msr saved; + struct op_saved_msr multiplex; }; struct op_msrs { @@ -34,6 +35,8 @@ struct pt_regs; struct op_x86_model_spec { int (*init)(struct oprofile_operations *ops); void (*exit)(void); + unsigned int const num_hardware_counters; + unsigned int const num_hardware_controls; unsigned int const num_counters; unsigned int const num_controls; void (*fill_in_addresses)(struct op_msrs * const msrs); diff --git a/drivers/oprofile/oprof.c b/drivers/oprofile/oprof.c index 2c64517..b2fa5df 100644 --- a/drivers/oprofile/oprof.c +++ b/drivers/oprofile/oprof.c @@ -12,6 +12,8 @@ #include #include #include +#include +#include #include #include "oprof.h" @@ -19,13 +21,18 @@ #include "cpu_buffer.h" #include "buffer_sync.h" #include "oprofile_stats.h" + +static unsigned long is_setup; +static void switch_worker(struct work_struct *work); +static DECLARE_DELAYED_WORK(switch_work, switch_worker); +static DEFINE_MUTEX(start_mutex); struct oprofile_operations oprofile_ops; +unsigned long timeout_jiffies; unsigned long oprofile_started; unsigned long backtrace_depth; -static unsigned long is_setup; -static DEFINE_MUTEX(start_mutex); +/* Multiplexing defaults at 1 msec*/ /* timer 0 - use performance monitoring hardware if available @@ -87,6 +94,16 @@ out: return err; } +static void start_switch_worker(void) +{ + schedule_delayed_work(&switch_work, timeout_jiffies); +} + +static void switch_worker(struct work_struct *work) +{ + if (!oprofile_ops.switch_events()) + start_switch_worker(); +} /* Actually start profiling (echo 1>/dev/oprofile/enable) */ int oprofile_start(void) @@ -94,7 +111,6 @@ int oprofile_start(void) int err = -EINVAL; mutex_lock(&start_mutex); - if (!is_setup) goto out; @@ -108,6 +124,9 @@ int oprofile_start(void) if ((err = oprofile_ops.start())) goto out; + if (oprofile_ops.switch_events) + start_switch_worker(); + oprofile_started = 1; out: mutex_unlock(&start_mutex); @@ -123,6 +142,7 @@ void oprofile_stop(void) goto out; oprofile_ops.stop(); oprofile_started = 0; + cancel_delayed_work_sync(&switch_work); /* wake up the daemon to read what remains */ wake_up_buffer_waiter(); out: @@ -155,6 +175,32 @@ post_sync: mutex_unlock(&start_mutex); } +/* User inputs in ms, converts to jiffies */ +int oprofile_set_timeout(unsigned long val_msec) +{ + int err = 0; + + mutex_lock(&start_mutex); + + if (oprofile_started) { + err = -EBUSY; + goto out; + } + + if (!oprofile_ops.switch_events) { + err = -EINVAL; + goto out; + } + + timeout_jiffies = msecs_to_jiffies(val_msec); + if (timeout_jiffies == MAX_JIFFY_OFFSET) + timeout_jiffies = msecs_to_jiffies(1); + +out: + mutex_unlock(&start_mutex); + return err; + +} int oprofile_set_backtrace(unsigned long val) { @@ -179,10 +225,16 @@ out: return err; } +static void __init oprofile_switch_timer_init(void) +{ + timeout_jiffies = msecs_to_jiffies(1); +} + static int __init oprofile_init(void) { int err; + oprofile_switch_timer_init(); err = oprofile_arch_init(&oprofile_ops); if (err < 0 || timer) { diff --git a/drivers/oprofile/oprof.h b/drivers/oprofile/oprof.h index 1832365..c4406a7 100644 --- a/drivers/oprofile/oprof.h +++ b/drivers/oprofile/oprof.h @@ -27,7 +27,8 @@ extern unsigned long fs_buffer_watershed; extern struct oprofile_operations oprofile_ops; extern unsigned long oprofile_started; extern unsigned long backtrace_depth; - +extern unsigned long timeout_jiffies; + struct super_block; struct dentry; @@ -35,5 +36,6 @@ void oprofile_create_files(struct super_block * sb, struct dentry * root); void oprofile_timer_init(struct oprofile_operations * ops); int oprofile_set_backtrace(unsigned long depth); +int oprofile_set_timeout(unsigned long time); #endif /* OPROF_H */ diff --git a/drivers/oprofile/oprofile_files.c b/drivers/oprofile/oprofile_files.c index ef953ba..cc4f5a1 100644 --- a/drivers/oprofile/oprofile_files.c +++ b/drivers/oprofile/oprofile_files.c @@ -9,6 +9,7 @@ #include #include +#include #include "event_buffer.h" #include "oprofile_stats.h" @@ -18,6 +19,40 @@ unsigned long fs_buffer_size = 131072; unsigned long fs_cpu_buffer_size = 8192; unsigned long fs_buffer_watershed = 32768; /* FIXME: tune */ +static ssize_t timeout_read(struct file *file, char __user *buf, + size_t count, loff_t *offset) +{ + return oprofilefs_ulong_to_user(jiffies_to_msecs(timeout_jiffies), + buf, count, offset); +} + + +static ssize_t timeout_write(struct file *file, char const __user *buf, + size_t count, loff_t *offset) +{ + unsigned long val; + int retval; + + if (*offset) + return -EINVAL; + + retval = oprofilefs_ulong_from_user(&val, buf, count); + if (retval) + return retval; + + retval = oprofile_set_timeout(val); + + if (retval) + return retval; + return count; +} + +static const struct file_operations timeout_fops = { + .read = timeout_read, + .write = timeout_write, +}; + + static ssize_t depth_read(struct file * file, char __user * buf, size_t count, loff_t * offset) { return oprofilefs_ulong_to_user(backtrace_depth, buf, count, offset); @@ -85,11 +120,10 @@ static ssize_t enable_write(struct file * file, char const __user * buf, size_t if (*offset) return -EINVAL; - retval = oprofilefs_ulong_from_user(&val, buf, count); if (retval) return retval; - + if (val) retval = oprofile_start(); else @@ -129,6 +163,7 @@ void oprofile_create_files(struct super_block * sb, struct dentry * root) oprofilefs_create_file(sb, root, "cpu_type", &cpu_type_fops); oprofilefs_create_file(sb, root, "backtrace_depth", &depth_fops); oprofilefs_create_file(sb, root, "pointer_size", &pointer_size_fops); + oprofilefs_create_file(sb, root, "timeout_ms", &timeout_fops); oprofile_create_stats_files(sb, root); if (oprofile_ops.create_files) oprofile_ops.create_files(sb, root); diff --git a/include/linux/oprofile.h b/include/linux/oprofile.h index bcb8f72..687f2f4 100644 --- a/include/linux/oprofile.h +++ b/include/linux/oprofile.h @@ -67,6 +67,9 @@ struct oprofile_operations { /* Initiate a stack backtrace. Optional. */ void (*backtrace)(struct pt_regs * const regs, unsigned int depth); + + /* Multiplex between different events. Optional. */ + int (*switch_events)(void); /* CPU identification string. */ char * cpu_type; }; -- 1.8.2.3