diff options
Diffstat (limited to 'drivers/oprofile/cpu_buffer.c')
-rw-r--r-- | drivers/oprofile/cpu_buffer.c | 465 |
1 files changed, 0 insertions, 465 deletions
diff --git a/drivers/oprofile/cpu_buffer.c b/drivers/oprofile/cpu_buffer.c deleted file mode 100644 index 9210a95cb4e6..000000000000 --- a/drivers/oprofile/cpu_buffer.c +++ /dev/null @@ -1,465 +0,0 @@ -/** - * @file cpu_buffer.c - * - * @remark Copyright 2002-2009 OProfile authors - * @remark Read the file COPYING - * - * @author John Levon <levon@movementarian.org> - * @author Barry Kasindorf <barry.kasindorf@amd.com> - * @author Robert Richter <robert.richter@amd.com> - * - * Each CPU has a local buffer that stores PC value/event - * pairs. We also log context switches when we notice them. - * Eventually each CPU's buffer is processed into the global - * event buffer by sync_buffer(). - * - * We use a local buffer for two reasons: an NMI or similar - * interrupt cannot synchronise, and high sampling rates - * would lead to catastrophic global synchronisation if - * a global buffer was used. - */ - -#include <linux/sched.h> -#include <linux/oprofile.h> -#include <linux/errno.h> - -#include <asm/ptrace.h> - -#include "event_buffer.h" -#include "cpu_buffer.h" -#include "buffer_sync.h" -#include "oprof.h" - -#define OP_BUFFER_FLAGS 0 - -static struct trace_buffer *op_ring_buffer; -DEFINE_PER_CPU(struct oprofile_cpu_buffer, op_cpu_buffer); - -static void wq_sync_buffer(struct work_struct *work); - -#define DEFAULT_TIMER_EXPIRE (HZ / 10) -static int work_enabled; - -unsigned long oprofile_get_cpu_buffer_size(void) -{ - return oprofile_cpu_buffer_size; -} - -void oprofile_cpu_buffer_inc_smpl_lost(void) -{ - struct oprofile_cpu_buffer *cpu_buf = this_cpu_ptr(&op_cpu_buffer); - - cpu_buf->sample_lost_overflow++; -} - -void free_cpu_buffers(void) -{ - if (op_ring_buffer) - ring_buffer_free(op_ring_buffer); - op_ring_buffer = NULL; -} - -#define RB_EVENT_HDR_SIZE 4 - -int alloc_cpu_buffers(void) -{ - int i; - - unsigned long buffer_size = oprofile_cpu_buffer_size; - unsigned long byte_size = buffer_size * (sizeof(struct op_sample) + - RB_EVENT_HDR_SIZE); - - op_ring_buffer = ring_buffer_alloc(byte_size, OP_BUFFER_FLAGS); - if (!op_ring_buffer) - goto fail; - - for_each_possible_cpu(i) { - struct oprofile_cpu_buffer *b = &per_cpu(op_cpu_buffer, i); - - b->last_task = NULL; - b->last_is_kernel = -1; - b->tracing = 0; - b->buffer_size = buffer_size; - b->sample_received = 0; - b->sample_lost_overflow = 0; - b->backtrace_aborted = 0; - b->sample_invalid_eip = 0; - b->cpu = i; - INIT_DELAYED_WORK(&b->work, wq_sync_buffer); - } - return 0; - -fail: - free_cpu_buffers(); - return -ENOMEM; -} - -void start_cpu_work(void) -{ - int i; - - work_enabled = 1; - - for_each_online_cpu(i) { - struct oprofile_cpu_buffer *b = &per_cpu(op_cpu_buffer, i); - - /* - * Spread the work by 1 jiffy per cpu so they dont all - * fire at once. - */ - schedule_delayed_work_on(i, &b->work, DEFAULT_TIMER_EXPIRE + i); - } -} - -void end_cpu_work(void) -{ - work_enabled = 0; -} - -void flush_cpu_work(void) -{ - int i; - - for_each_online_cpu(i) { - struct oprofile_cpu_buffer *b = &per_cpu(op_cpu_buffer, i); - - /* these works are per-cpu, no need for flush_sync */ - flush_delayed_work(&b->work); - } -} - -/* - * This function prepares the cpu buffer to write a sample. - * - * Struct op_entry is used during operations on the ring buffer while - * struct op_sample contains the data that is stored in the ring - * buffer. Struct entry can be uninitialized. The function reserves a - * data array that is specified by size. Use - * op_cpu_buffer_write_commit() after preparing the sample. In case of - * errors a null pointer is returned, otherwise the pointer to the - * sample. - * - */ -struct op_sample -*op_cpu_buffer_write_reserve(struct op_entry *entry, unsigned long size) -{ - entry->event = ring_buffer_lock_reserve - (op_ring_buffer, sizeof(struct op_sample) + - size * sizeof(entry->sample->data[0])); - if (!entry->event) - return NULL; - entry->sample = ring_buffer_event_data(entry->event); - entry->size = size; - entry->data = entry->sample->data; - - return entry->sample; -} - -int op_cpu_buffer_write_commit(struct op_entry *entry) -{ - 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, cpu, NULL, NULL); - if (!e) - return NULL; - - entry->event = e; - entry->sample = ring_buffer_event_data(e); - entry->size = (ring_buffer_event_length(e) - sizeof(struct op_sample)) - / sizeof(entry->sample->data[0]); - entry->data = entry->sample->data; - return entry->sample; -} - -unsigned long op_cpu_buffer_entries(int cpu) -{ - return ring_buffer_entries_cpu(op_ring_buffer, cpu); -} - -static int -op_add_code(struct oprofile_cpu_buffer *cpu_buf, unsigned long backtrace, - int is_kernel, struct task_struct *task) -{ - struct op_entry entry; - struct op_sample *sample; - unsigned long flags; - int size; - - flags = 0; - - if (backtrace) - flags |= TRACE_BEGIN; - - /* notice a switch from user->kernel or vice versa */ - is_kernel = !!is_kernel; - if (cpu_buf->last_is_kernel != is_kernel) { - cpu_buf->last_is_kernel = is_kernel; - flags |= KERNEL_CTX_SWITCH; - if (is_kernel) - flags |= IS_KERNEL; - } - - /* notice a task switch */ - if (cpu_buf->last_task != task) { - cpu_buf->last_task = task; - flags |= USER_CTX_SWITCH; - } - - if (!flags) - /* nothing to do */ - return 0; - - if (flags & USER_CTX_SWITCH) - size = 1; - else - size = 0; - - sample = op_cpu_buffer_write_reserve(&entry, size); - if (!sample) - return -ENOMEM; - - sample->eip = ESCAPE_CODE; - sample->event = flags; - - if (size) - op_cpu_buffer_add_data(&entry, (unsigned long)task); - - op_cpu_buffer_write_commit(&entry); - - return 0; -} - -static inline int -op_add_sample(struct oprofile_cpu_buffer *cpu_buf, - unsigned long pc, unsigned long event) -{ - struct op_entry entry; - struct op_sample *sample; - - sample = op_cpu_buffer_write_reserve(&entry, 0); - if (!sample) - return -ENOMEM; - - sample->eip = pc; - sample->event = event; - - return op_cpu_buffer_write_commit(&entry); -} - -/* - * This must be safe from any context. - * - * is_kernel is needed because on some architectures you cannot - * tell if you are in kernel or user space simply by looking at - * pc. We tag this in the buffer by generating kernel enter/exit - * events whenever is_kernel changes - */ -static int -log_sample(struct oprofile_cpu_buffer *cpu_buf, unsigned long pc, - unsigned long backtrace, int is_kernel, unsigned long event, - struct task_struct *task) -{ - struct task_struct *tsk = task ? task : current; - cpu_buf->sample_received++; - - if (pc == ESCAPE_CODE) { - cpu_buf->sample_invalid_eip++; - return 0; - } - - if (op_add_code(cpu_buf, backtrace, is_kernel, tsk)) - goto fail; - - if (op_add_sample(cpu_buf, pc, event)) - goto fail; - - return 1; - -fail: - cpu_buf->sample_lost_overflow++; - return 0; -} - -static inline void oprofile_begin_trace(struct oprofile_cpu_buffer *cpu_buf) -{ - cpu_buf->tracing = 1; -} - -static inline void oprofile_end_trace(struct oprofile_cpu_buffer *cpu_buf) -{ - cpu_buf->tracing = 0; -} - -static inline void -__oprofile_add_ext_sample(unsigned long pc, struct pt_regs * const regs, - unsigned long event, int is_kernel, - struct task_struct *task) -{ - struct oprofile_cpu_buffer *cpu_buf = this_cpu_ptr(&op_cpu_buffer); - unsigned long backtrace = oprofile_backtrace_depth; - - /* - * if log_sample() fail we can't backtrace since we lost the - * source of this event - */ - if (!log_sample(cpu_buf, pc, backtrace, is_kernel, event, task)) - /* failed */ - return; - - if (!backtrace) - return; - - oprofile_begin_trace(cpu_buf); - oprofile_ops.backtrace(regs, backtrace); - oprofile_end_trace(cpu_buf); -} - -void oprofile_add_ext_hw_sample(unsigned long pc, struct pt_regs * const regs, - unsigned long event, int is_kernel, - struct task_struct *task) -{ - __oprofile_add_ext_sample(pc, regs, event, is_kernel, task); -} - -void oprofile_add_ext_sample(unsigned long pc, struct pt_regs * const regs, - unsigned long event, int is_kernel) -{ - __oprofile_add_ext_sample(pc, regs, event, is_kernel, NULL); -} - -void oprofile_add_sample(struct pt_regs * const regs, unsigned long event) -{ - 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, NULL); -} - -/* - * Add samples with data to the ring buffer. - * - * Use oprofile_add_data(&entry, val) to add data and - * oprofile_write_commit(&entry) to commit the sample. - */ -void -oprofile_write_reserve(struct op_entry *entry, struct pt_regs * const regs, - unsigned long pc, int code, int size) -{ - struct op_sample *sample; - int is_kernel = !user_mode(regs); - struct oprofile_cpu_buffer *cpu_buf = this_cpu_ptr(&op_cpu_buffer); - - cpu_buf->sample_received++; - - /* no backtraces for samples with data */ - if (op_add_code(cpu_buf, 0, is_kernel, current)) - goto fail; - - sample = op_cpu_buffer_write_reserve(entry, size + 2); - if (!sample) - goto fail; - sample->eip = ESCAPE_CODE; - sample->event = 0; /* no flags */ - - op_cpu_buffer_add_data(entry, code); - op_cpu_buffer_add_data(entry, pc); - - return; - -fail: - entry->event = NULL; - cpu_buf->sample_lost_overflow++; -} - -int oprofile_add_data(struct op_entry *entry, unsigned long val) -{ - if (!entry->event) - return 0; - return op_cpu_buffer_add_data(entry, val); -} - -int oprofile_add_data64(struct op_entry *entry, u64 val) -{ - if (!entry->event) - return 0; - if (op_cpu_buffer_get_size(entry) < 2) - /* - * the function returns 0 to indicate a too small - * buffer, even if there is some space left - */ - return 0; - if (!op_cpu_buffer_add_data(entry, (u32)val)) - return 0; - return op_cpu_buffer_add_data(entry, (u32)(val >> 32)); -} - -int oprofile_write_commit(struct op_entry *entry) -{ - if (!entry->event) - return -EINVAL; - return op_cpu_buffer_write_commit(entry); -} - -void oprofile_add_pc(unsigned long pc, int is_kernel, unsigned long event) -{ - struct oprofile_cpu_buffer *cpu_buf = this_cpu_ptr(&op_cpu_buffer); - log_sample(cpu_buf, pc, 0, is_kernel, event, NULL); -} - -void oprofile_add_trace(unsigned long pc) -{ - struct oprofile_cpu_buffer *cpu_buf = this_cpu_ptr(&op_cpu_buffer); - - if (!cpu_buf->tracing) - return; - - /* - * broken frame can give an eip with the same value as an - * escape code, abort the trace if we get it - */ - if (pc == ESCAPE_CODE) - goto fail; - - if (op_add_sample(cpu_buf, pc, 0)) - goto fail; - - return; -fail: - cpu_buf->tracing = 0; - cpu_buf->backtrace_aborted++; - return; -} - -/* - * This serves to avoid cpu buffer overflow, and makes sure - * the task mortuary progresses - * - * By using schedule_delayed_work_on and then schedule_delayed_work - * we guarantee this will stay on the correct cpu - */ -static void wq_sync_buffer(struct work_struct *work) -{ - struct oprofile_cpu_buffer *b = - container_of(work, struct oprofile_cpu_buffer, work.work); - if (b->cpu != smp_processor_id() && !cpu_online(b->cpu)) { - cancel_delayed_work(&b->work); - return; - } - sync_buffer(b->cpu); - - /* don't re-add the work if we're shutting down */ - if (work_enabled) - schedule_delayed_work(&b->work, DEFAULT_TIMER_EXPIRE); -} |