diff options
Diffstat (limited to 'drivers/oprofile')
| -rw-r--r-- | drivers/oprofile/cpu_buffer.c | 75 | ||||
| -rw-r--r-- | drivers/oprofile/oprof.c | 12 | ||||
| -rw-r--r-- | drivers/oprofile/oprof.h | 3 | ||||
| -rw-r--r-- | drivers/oprofile/timer_int.c | 78 |
4 files changed, 102 insertions, 66 deletions
diff --git a/drivers/oprofile/cpu_buffer.c b/drivers/oprofile/cpu_buffer.c index 166b67e..219f79e 100644 --- a/drivers/oprofile/cpu_buffer.c +++ b/drivers/oprofile/cpu_buffer.c @@ -30,23 +30,7 @@ #define OP_BUFFER_FLAGS 0 -/* - * Read and write access is using spin locking. Thus, writing to the - * buffer by NMI handler (x86) could occur also during critical - * sections when reading the buffer. To avoid this, there are 2 - * buffers for independent read and write access. Read access is in - * process context only, write access only in the NMI handler. If the - * read buffer runs empty, both buffers are swapped atomically. There - * is potentially a small window during swapping where the buffers are - * disabled and samples could be lost. - * - * Using 2 buffers is a little bit overhead, but the solution is clear - * and does not require changes in the ring buffer implementation. It - * can be changed to a single buffer solution when the ring buffer - * access is implemented as non-locking atomic code. - */ -static struct ring_buffer *op_ring_buffer_read; -static struct ring_buffer *op_ring_buffer_write; +static struct ring_buffer *op_ring_buffer; DEFINE_PER_CPU(struct oprofile_cpu_buffer, op_cpu_buffer); static void wq_sync_buffer(struct work_struct *work); @@ -68,12 +52,9 @@ void oprofile_cpu_buffer_inc_smpl_lost(void) void free_cpu_buffers(void) { - if (op_ring_buffer_read) - ring_buffer_free(op_ring_buffer_read); - op_ring_buffer_read = NULL; - if (op_ring_buffer_write) - ring_buffer_free(op_ring_buffer_write); - op_ring_buffer_write = NULL; + if (op_ring_buffer) + ring_buffer_free(op_ring_buffer); + op_ring_buffer = NULL; } #define RB_EVENT_HDR_SIZE 4 @@ -86,11 +67,8 @@ int alloc_cpu_buffers(void) unsigned long byte_size = buffer_size * (sizeof(struct op_sample) + RB_EVENT_HDR_SIZE); - op_ring_buffer_read = ring_buffer_alloc(byte_size, OP_BUFFER_FLAGS); - if (!op_ring_buffer_read) - goto fail; - op_ring_buffer_write = ring_buffer_alloc(byte_size, OP_BUFFER_FLAGS); - if (!op_ring_buffer_write) + op_ring_buffer = ring_buffer_alloc(byte_size, OP_BUFFER_FLAGS); + if (!op_ring_buffer) goto fail; for_each_possible_cpu(i) { @@ -162,16 +140,11 @@ struct op_sample *op_cpu_buffer_write_reserve(struct op_entry *entry, unsigned long size) { entry->event = ring_buffer_lock_reserve - (op_ring_buffer_write, sizeof(struct op_sample) + + (op_ring_buffer, sizeof(struct op_sample) + size * sizeof(entry->sample->data[0])); - if (entry->event) - entry->sample = ring_buffer_event_data(entry->event); - else - entry->sample = NULL; - - if (!entry->sample) + if (!entry->event) return NULL; - + entry->sample = ring_buffer_event_data(entry->event); entry->size = size; entry->data = entry->sample->data; @@ -180,25 +153,16 @@ struct op_sample int op_cpu_buffer_write_commit(struct op_entry *entry) { - return ring_buffer_unlock_commit(op_ring_buffer_write, entry->event); + return ring_buffer_unlock_commit(op_ring_buffer, entry->event); } struct op_sample *op_cpu_buffer_read_entry(struct op_entry *entry, int cpu) { struct ring_buffer_event *e; - e = ring_buffer_consume(op_ring_buffer_read, cpu, NULL); - if (e) - goto event; - if (ring_buffer_swap_cpu(op_ring_buffer_read, - op_ring_buffer_write, - cpu)) + e = ring_buffer_consume(op_ring_buffer, cpu, NULL, NULL); + if (!e) return NULL; - e = ring_buffer_consume(op_ring_buffer_read, cpu, NULL); - if (e) - goto event; - return NULL; -event: entry->event = e; entry->sample = ring_buffer_event_data(e); entry->size = (ring_buffer_event_length(e) - sizeof(struct op_sample)) @@ -209,8 +173,7 @@ event: unsigned long op_cpu_buffer_entries(int cpu) { - return ring_buffer_entries_cpu(op_ring_buffer_read, cpu) - + ring_buffer_entries_cpu(op_ring_buffer_write, cpu); + return ring_buffer_entries_cpu(op_ring_buffer, cpu); } static int @@ -356,8 +319,16 @@ void oprofile_add_ext_sample(unsigned long pc, struct pt_regs * const regs, void oprofile_add_sample(struct pt_regs * const regs, unsigned long event) { - int is_kernel = !user_mode(regs); - unsigned long pc = profile_pc(regs); + int is_kernel; + unsigned long pc; + + if (likely(regs)) { + is_kernel = !user_mode(regs); + pc = profile_pc(regs); + } else { + is_kernel = 0; /* This value will not be used */ + pc = ESCAPE_CODE; /* as this causes an early return. */ + } __oprofile_add_ext_sample(pc, regs, event, is_kernel); } diff --git a/drivers/oprofile/oprof.c b/drivers/oprofile/oprof.c index dc8a042..b336cd9 100644 --- a/drivers/oprofile/oprof.c +++ b/drivers/oprofile/oprof.c @@ -253,22 +253,26 @@ static int __init oprofile_init(void) int err; err = oprofile_arch_init(&oprofile_ops); - if (err < 0 || timer) { printk(KERN_INFO "oprofile: using timer interrupt.\n"); - oprofile_timer_init(&oprofile_ops); + err = oprofile_timer_init(&oprofile_ops); + if (err) + goto out_arch; } - err = oprofilefs_register(); if (err) - oprofile_arch_exit(); + goto out_arch; + return 0; +out_arch: + oprofile_arch_exit(); return err; } static void __exit oprofile_exit(void) { + oprofile_timer_exit(); oprofilefs_unregister(); oprofile_arch_exit(); } diff --git a/drivers/oprofile/oprof.h b/drivers/oprofile/oprof.h index cb92f5c..47e12cb 100644 --- a/drivers/oprofile/oprof.h +++ b/drivers/oprofile/oprof.h @@ -34,7 +34,8 @@ struct super_block; struct dentry; void oprofile_create_files(struct super_block *sb, struct dentry *root); -void oprofile_timer_init(struct oprofile_operations *ops); +int oprofile_timer_init(struct oprofile_operations *ops); +void oprofile_timer_exit(void); int oprofile_set_backtrace(unsigned long depth); int oprofile_set_timeout(unsigned long time); diff --git a/drivers/oprofile/timer_int.c b/drivers/oprofile/timer_int.c index 333f915..dc0ae4d 100644 --- a/drivers/oprofile/timer_int.c +++ b/drivers/oprofile/timer_int.c @@ -13,34 +13,94 @@ #include <linux/oprofile.h> #include <linux/profile.h> #include <linux/init.h> +#include <linux/cpu.h> +#include <linux/hrtimer.h> +#include <asm/irq_regs.h> #include <asm/ptrace.h> #include "oprof.h" -static int timer_notify(struct pt_regs *regs) +static DEFINE_PER_CPU(struct hrtimer, oprofile_hrtimer); + +static enum hrtimer_restart oprofile_hrtimer_notify(struct hrtimer *hrtimer) +{ + oprofile_add_sample(get_irq_regs(), 0); + hrtimer_forward_now(hrtimer, ns_to_ktime(TICK_NSEC)); + return HRTIMER_RESTART; +} + +static void __oprofile_hrtimer_start(void *unused) +{ + struct hrtimer *hrtimer = &__get_cpu_var(oprofile_hrtimer); + + hrtimer_init(hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); + hrtimer->function = oprofile_hrtimer_notify; + + hrtimer_start(hrtimer, ns_to_ktime(TICK_NSEC), + HRTIMER_MODE_REL_PINNED); +} + +static int oprofile_hrtimer_start(void) { - oprofile_add_sample(regs, 0); + on_each_cpu(__oprofile_hrtimer_start, NULL, 1); return 0; } -static int timer_start(void) +static void __oprofile_hrtimer_stop(int cpu) { - return register_timer_hook(timer_notify); + struct hrtimer *hrtimer = &per_cpu(oprofile_hrtimer, cpu); + + hrtimer_cancel(hrtimer); } +static void oprofile_hrtimer_stop(void) +{ + int cpu; + + for_each_online_cpu(cpu) + __oprofile_hrtimer_stop(cpu); +} -static void timer_stop(void) +static int __cpuinit oprofile_cpu_notify(struct notifier_block *self, + unsigned long action, void *hcpu) { - unregister_timer_hook(timer_notify); + long cpu = (long) hcpu; + + switch (action) { + case CPU_ONLINE: + case CPU_ONLINE_FROZEN: + smp_call_function_single(cpu, __oprofile_hrtimer_start, + NULL, 1); + break; + case CPU_DEAD: + case CPU_DEAD_FROZEN: + __oprofile_hrtimer_stop(cpu); + break; + } + return NOTIFY_OK; } +static struct notifier_block __refdata oprofile_cpu_notifier = { + .notifier_call = oprofile_cpu_notify, +}; -void __init oprofile_timer_init(struct oprofile_operations *ops) +int __init oprofile_timer_init(struct oprofile_operations *ops) { + int rc; + + rc = register_hotcpu_notifier(&oprofile_cpu_notifier); + if (rc) + return rc; ops->create_files = NULL; ops->setup = NULL; ops->shutdown = NULL; - ops->start = timer_start; - ops->stop = timer_stop; + ops->start = oprofile_hrtimer_start; + ops->stop = oprofile_hrtimer_stop; ops->cpu_type = "timer"; + return 0; +} + +void __exit oprofile_timer_exit(void) +{ + unregister_hotcpu_notifier(&oprofile_cpu_notifier); } |
