diff options
Diffstat (limited to 'drivers/oprofile')
| -rw-r--r-- | drivers/oprofile/buffer_sync.c | 229 | ||||
| -rw-r--r-- | drivers/oprofile/cpu_buffer.c | 393 | ||||
| -rw-r--r-- | drivers/oprofile/cpu_buffer.h | 72 | ||||
| -rw-r--r-- | drivers/oprofile/event_buffer.c | 4 | ||||
| -rw-r--r-- | drivers/oprofile/oprof.c | 4 | ||||
| -rw-r--r-- | drivers/oprofile/oprof.h | 8 | ||||
| -rw-r--r-- | drivers/oprofile/oprofile_files.c | 24 |
7 files changed, 408 insertions, 326 deletions
diff --git a/drivers/oprofile/buffer_sync.c b/drivers/oprofile/buffer_sync.c index b55cd23ffde..ac014cb2791 100644 --- a/drivers/oprofile/buffer_sync.c +++ b/drivers/oprofile/buffer_sync.c @@ -1,11 +1,12 @@ /** * @file buffer_sync.c * - * @remark Copyright 2002 OProfile authors + * @remark Copyright 2002-2009 OProfile authors * @remark Read the file COPYING * * @author John Levon <levon@movementarian.org> * @author Barry Kasindorf + * @author Robert Richter <robert.richter@amd.com> * * This is the core of the buffer management. Each * CPU buffer is processed and entered into the @@ -268,18 +269,6 @@ lookup_dcookie(struct mm_struct *mm, unsigned long addr, off_t *offset) return cookie; } -static void increment_tail(struct oprofile_cpu_buffer *b) -{ - unsigned long new_tail = b->tail_pos + 1; - - rmb(); /* be sure fifo pointers are synchromized */ - - if (new_tail < b->buffer_size) - b->tail_pos = new_tail; - else - b->tail_pos = 0; -} - static unsigned long last_cookie = INVALID_COOKIE; static void add_cpu_switch(int i) @@ -327,84 +316,73 @@ static void add_trace_begin(void) add_event_entry(TRACE_BEGIN_CODE); } -#ifdef CONFIG_OPROFILE_IBS - -#define IBS_FETCH_CODE_SIZE 2 -#define IBS_OP_CODE_SIZE 5 -#define IBS_EIP(offset) \ - (((struct op_sample *)&cpu_buf->buffer[(offset)])->eip) -#define IBS_EVENT(offset) \ - (((struct op_sample *)&cpu_buf->buffer[(offset)])->event) - -/* - * Add IBS fetch and op entries to event buffer - */ -static void add_ibs_begin(struct oprofile_cpu_buffer *cpu_buf, int code, - struct mm_struct *mm) +static void add_data(struct op_entry *entry, struct mm_struct *mm) { - unsigned long rip; - int i, count; - unsigned long ibs_cookie = 0; + unsigned long code, pc, val; + unsigned long cookie; off_t offset; - increment_tail(cpu_buf); /* move to RIP entry */ - - rip = IBS_EIP(cpu_buf->tail_pos); - -#ifdef __LP64__ - rip += IBS_EVENT(cpu_buf->tail_pos) << 32; -#endif + if (!op_cpu_buffer_get_data(entry, &code)) + return; + if (!op_cpu_buffer_get_data(entry, &pc)) + return; + if (!op_cpu_buffer_get_size(entry)) + return; if (mm) { - ibs_cookie = lookup_dcookie(mm, rip, &offset); + cookie = lookup_dcookie(mm, pc, &offset); - if (ibs_cookie == NO_COOKIE) - offset = rip; - if (ibs_cookie == INVALID_COOKIE) { + if (cookie == NO_COOKIE) + offset = pc; + if (cookie == INVALID_COOKIE) { atomic_inc(&oprofile_stats.sample_lost_no_mapping); - offset = rip; + offset = pc; } - if (ibs_cookie != last_cookie) { - add_cookie_switch(ibs_cookie); - last_cookie = ibs_cookie; + if (cookie != last_cookie) { + add_cookie_switch(cookie); + last_cookie = cookie; } } else - offset = rip; + offset = pc; add_event_entry(ESCAPE_CODE); add_event_entry(code); add_event_entry(offset); /* Offset from Dcookie */ - /* we send the Dcookie offset, but send the raw Linear Add also*/ - add_event_entry(IBS_EIP(cpu_buf->tail_pos)); - add_event_entry(IBS_EVENT(cpu_buf->tail_pos)); - - if (code == IBS_FETCH_CODE) - count = IBS_FETCH_CODE_SIZE; /*IBS FETCH is 2 int64s*/ - else - count = IBS_OP_CODE_SIZE; /*IBS OP is 5 int64s*/ - - for (i = 0; i < count; i++) { - increment_tail(cpu_buf); - add_event_entry(IBS_EIP(cpu_buf->tail_pos)); - add_event_entry(IBS_EVENT(cpu_buf->tail_pos)); - } + while (op_cpu_buffer_get_data(entry, &val)) + add_event_entry(val); } -#endif - -static void add_sample_entry(unsigned long offset, unsigned long event) +static inline void add_sample_entry(unsigned long offset, unsigned long event) { add_event_entry(offset); add_event_entry(event); } -static int add_us_sample(struct mm_struct *mm, struct op_sample *s) +/* + * Add a sample to the global event buffer. If possible the + * sample is converted into a persistent dentry/offset pair + * for later lookup from userspace. Return 0 on failure. + */ +static int +add_sample(struct mm_struct *mm, struct op_sample *s, int in_kernel) { unsigned long cookie; off_t offset; + if (in_kernel) { + add_sample_entry(s->eip, s->event); + return 1; + } + + /* add userspace sample */ + + if (!mm) { + atomic_inc(&oprofile_stats.sample_lost_no_mm); + return 0; + } + cookie = lookup_dcookie(mm, s->eip, &offset); if (cookie == INVALID_COOKIE) { @@ -423,25 +401,6 @@ static int add_us_sample(struct mm_struct *mm, struct op_sample *s) } -/* Add a sample to the global event buffer. If possible the - * sample is converted into a persistent dentry/offset pair - * for later lookup from userspace. - */ -static int -add_sample(struct mm_struct *mm, struct op_sample *s, int in_kernel) -{ - if (in_kernel) { - add_sample_entry(s->eip, s->event); - return 1; - } else if (mm) { - return add_us_sample(mm, s); - } else { - atomic_inc(&oprofile_stats.sample_lost_no_mm); - } - return 0; -} - - static void release_mm(struct mm_struct *mm) { if (!mm) @@ -466,33 +425,6 @@ static inline int is_code(unsigned long val) } -/* "acquire" as many cpu buffer slots as we can */ -static unsigned long get_slots(struct oprofile_cpu_buffer *b) -{ - unsigned long head = b->head_pos; - unsigned long tail = b->tail_pos; - - /* - * Subtle. This resets the persistent last_task - * and in_kernel values used for switching notes. - * BUT, there is a small window between reading - * head_pos, and this call, that means samples - * can appear at the new head position, but not - * be prefixed with the notes for switching - * kernel mode or a task switch. This small hole - * can lead to mis-attribution or samples where - * we don't know if it's in the kernel or not, - * at the start of an event buffer. - */ - cpu_buffer_reset(b); - - if (head >= tail) - return head - tail; - - return head + (b->buffer_size - tail); -} - - /* Move tasks along towards death. Any tasks on dead_tasks * will definitely have no remaining references in any * CPU buffers at this point, because we use two lists, @@ -559,71 +491,72 @@ typedef enum { */ void sync_buffer(int cpu) { - struct oprofile_cpu_buffer *cpu_buf = &per_cpu(cpu_buffer, cpu); struct mm_struct *mm = NULL; + struct mm_struct *oldmm; + unsigned long val; struct task_struct *new; unsigned long cookie = 0; int in_kernel = 1; sync_buffer_state state = sb_buffer_start; -#ifndef CONFIG_OPROFILE_IBS unsigned int i; unsigned long available; -#endif + unsigned long flags; + struct op_entry entry; + struct op_sample *sample; mutex_lock(&buffer_mutex); add_cpu_switch(cpu); - /* Remember, only we can modify tail_pos */ - -#ifndef CONFIG_OPROFILE_IBS - available = get_slots(cpu_buf); + op_cpu_buffer_reset(cpu); + available = op_cpu_buffer_entries(cpu); for (i = 0; i < available; ++i) { -#else - while (get_slots(cpu_buf)) { -#endif - struct op_sample *s = &cpu_buf->buffer[cpu_buf->tail_pos]; + sample = op_cpu_buffer_read_entry(&entry, cpu); + if (!sample) + break; - if (is_code(s->eip)) { - if (s->event <= CPU_IS_KERNEL) { + if (is_code(sample->eip)) { + flags = sample->event; + if (flags & TRACE_BEGIN) { + state = sb_bt_start; + add_trace_begin(); + } + if (flags & KERNEL_CTX_SWITCH) { /* kernel/userspace switch */ - in_kernel = s->event; + in_kernel = flags & IS_KERNEL; if (state == sb_buffer_start) state = sb_sample_start; - add_kernel_ctx_switch(s->event); - } else if (s->event == CPU_TRACE_BEGIN) { - state = sb_bt_start; - add_trace_begin(); -#ifdef CONFIG_OPROFILE_IBS - } else if (s->event == IBS_FETCH_BEGIN) { - state = sb_bt_start; - add_ibs_begin(cpu_buf, IBS_FETCH_CODE, mm); - } else if (s->event == IBS_OP_BEGIN) { - state = sb_bt_start; - add_ibs_begin(cpu_buf, IBS_OP_CODE, mm); -#endif - } else { - struct mm_struct *oldmm = mm; - + add_kernel_ctx_switch(flags & IS_KERNEL); + } + if (flags & USER_CTX_SWITCH + && op_cpu_buffer_get_data(&entry, &val)) { /* userspace context switch */ - new = (struct task_struct *)s->event; - + new = (struct task_struct *)val; + oldmm = mm; release_mm(oldmm); mm = take_tasks_mm(new); if (mm != oldmm) cookie = get_exec_dcookie(mm); add_user_ctx_switch(new, cookie); } - } else if (state >= sb_bt_start && - !add_sample(mm, s, in_kernel)) { - if (state == sb_bt_start) { - state = sb_bt_ignore; - atomic_inc(&oprofile_stats.bt_lost_no_mapping); - } + if (op_cpu_buffer_get_size(&entry)) + add_data(&entry, mm); + continue; } - increment_tail(cpu_buf); + if (state < sb_bt_start) + /* ignore sample */ + continue; + + if (add_sample(mm, sample, in_kernel)) + continue; + + /* ignore backtraces if failed to add a sample */ + if (state == sb_bt_start) { + state = sb_bt_ignore; + atomic_inc(&oprofile_stats.bt_lost_no_mapping); + } } release_mm(mm); diff --git a/drivers/oprofile/cpu_buffer.c b/drivers/oprofile/cpu_buffer.c index 01d38e78cde..2e03b6d796d 100644 --- a/drivers/oprofile/cpu_buffer.c +++ b/drivers/oprofile/cpu_buffer.c @@ -1,11 +1,12 @@ /** * @file cpu_buffer.c * - * @remark Copyright 2002 OProfile authors + * @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. @@ -28,6 +29,25 @@ #include "buffer_sync.h" #include "oprof.h" +#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; DEFINE_PER_CPU(struct oprofile_cpu_buffer, cpu_buffer); static void wq_sync_buffer(struct work_struct *work); @@ -35,19 +55,9 @@ static void wq_sync_buffer(struct work_struct *work); #define DEFAULT_TIMER_EXPIRE (HZ / 10) static int work_enabled; -void free_cpu_buffers(void) -{ - int i; - - for_each_possible_cpu(i) { - vfree(per_cpu(cpu_buffer, i).buffer); - per_cpu(cpu_buffer, i).buffer = NULL; - } -} - unsigned long oprofile_get_cpu_buffer_size(void) { - return fs_cpu_buffer_size; + return oprofile_cpu_buffer_size; } void oprofile_cpu_buffer_inc_smpl_lost(void) @@ -58,26 +68,36 @@ void oprofile_cpu_buffer_inc_smpl_lost(void) cpu_buf->sample_lost_overflow++; } +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; +} + int alloc_cpu_buffers(void) { int i; - unsigned long buffer_size = fs_cpu_buffer_size; + unsigned long buffer_size = oprofile_cpu_buffer_size; + + op_ring_buffer_read = ring_buffer_alloc(buffer_size, OP_BUFFER_FLAGS); + if (!op_ring_buffer_read) + goto fail; + op_ring_buffer_write = ring_buffer_alloc(buffer_size, OP_BUFFER_FLAGS); + if (!op_ring_buffer_write) + goto fail; for_each_possible_cpu(i) { struct oprofile_cpu_buffer *b = &per_cpu(cpu_buffer, i); - b->buffer = vmalloc_node(sizeof(struct op_sample) * buffer_size, - cpu_to_node(i)); - if (!b->buffer) - goto fail; - b->last_task = NULL; b->last_is_kernel = -1; b->tracing = 0; b->buffer_size = buffer_size; - b->tail_pos = 0; - b->head_pos = 0; b->sample_received = 0; b->sample_lost_overflow = 0; b->backtrace_aborted = 0; @@ -124,73 +144,156 @@ void end_cpu_work(void) flush_scheduled_work(); } -/* Resets the cpu buffer to a sane state. */ -void cpu_buffer_reset(struct oprofile_cpu_buffer *cpu_buf) +/* + * 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) { - /* reset these to invalid values; the next sample - * collected will populate the buffer with proper - * values to initialize the buffer - */ - cpu_buf->last_is_kernel = -1; - cpu_buf->last_task = NULL; + entry->event = ring_buffer_lock_reserve + (op_ring_buffer_write, sizeof(struct op_sample) + + size * sizeof(entry->sample->data[0]), &entry->irq_flags); + if (entry->event) + entry->sample = ring_buffer_event_data(entry->event); + else + entry->sample = NULL; + + if (!entry->sample) + return NULL; + + entry->size = size; + entry->data = entry->sample->data; + + return entry->sample; } -/* compute number of available slots in cpu_buffer queue */ -static unsigned long nr_available_slots(struct oprofile_cpu_buffer const *b) +int op_cpu_buffer_write_commit(struct op_entry *entry) { - unsigned long head = b->head_pos; - unsigned long tail = b->tail_pos; + return ring_buffer_unlock_commit(op_ring_buffer_write, entry->event, + entry->irq_flags); +} - if (tail > head) - return (tail - head) - 1; +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)) + 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)) + / sizeof(entry->sample->data[0]); + entry->data = entry->sample->data; + return entry->sample; +} - return tail + (b->buffer_size - head) - 1; +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); } -static void increment_head(struct oprofile_cpu_buffer *b) +static int +op_add_code(struct oprofile_cpu_buffer *cpu_buf, unsigned long backtrace, + int is_kernel, struct task_struct *task) { - unsigned long new_head = b->head_pos + 1; + struct op_entry entry; + struct op_sample *sample; + unsigned long flags; + int size; + + flags = 0; - /* Ensure anything written to the slot before we - * increment is visible */ - wmb(); + 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 (new_head < b->buffer_size) - b->head_pos = new_head; + if (flags & USER_CTX_SWITCH) + size = 1; else - b->head_pos = 0; -} + size = 0; -static inline void -add_sample(struct oprofile_cpu_buffer *cpu_buf, - unsigned long pc, unsigned long event) -{ - struct op_sample *entry = &cpu_buf->buffer[cpu_buf->head_pos]; - entry->eip = pc; - entry->event = event; - increment_head(cpu_buf); + 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 void -add_code(struct oprofile_cpu_buffer *buffer, unsigned long value) +static inline int +op_add_sample(struct oprofile_cpu_buffer *cpu_buf, + unsigned long pc, unsigned long event) { - add_sample(buffer, ESCAPE_CODE, value); + 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. It's safe writing here - * because of the head/tail separation of the writer and reader - * of the CPU buffer. +/* + * 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, - int is_kernel, unsigned long event) +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; - cpu_buf->sample_received++; if (pc == ESCAPE_CODE) { @@ -198,131 +301,115 @@ static int log_sample(struct oprofile_cpu_buffer *cpu_buf, unsigned long pc, return 0; } - if (nr_available_slots(cpu_buf) < 3) { - cpu_buf->sample_lost_overflow++; - return 0; - } - - is_kernel = !!is_kernel; + if (op_add_code(cpu_buf, backtrace, is_kernel, current)) + goto fail; - task = current; + if (op_add_sample(cpu_buf, pc, event)) + goto fail; - /* notice a switch from user->kernel or vice versa */ - if (cpu_buf->last_is_kernel != is_kernel) { - cpu_buf->last_is_kernel = is_kernel; - add_code(cpu_buf, is_kernel); - } - - /* notice a task switch */ - if (cpu_buf->last_task != task) { - cpu_buf->last_task = task; - add_code(cpu_buf, (unsigned long)task); - } - - add_sample(cpu_buf, pc, event); return 1; + +fail: + cpu_buf->sample_lost_overflow++; + return 0; } -static int oprofile_begin_trace(struct oprofile_cpu_buffer *cpu_buf) +static inline void oprofile_begin_trace(struct oprofile_cpu_buffer *cpu_buf) { - if (nr_available_slots(cpu_buf) < 4) { - cpu_buf->sample_lost_overflow++; - return 0; - } - - add_code(cpu_buf, CPU_TRACE_BEGIN); cpu_buf->tracing = 1; - return 1; } -static void oprofile_end_trace(struct oprofile_cpu_buffer *cpu_buf) +static inline void oprofile_end_trace(struct oprofile_cpu_buffer *cpu_buf) { cpu_buf->tracing = 0; } -void oprofile_add_ext_sample(unsigned long pc, struct pt_regs * const regs, - unsigned long event, int is_kernel) +static inline void +__oprofile_add_ext_sample(unsigned long pc, struct pt_regs * const regs, + unsigned long event, int is_kernel) { struct oprofile_cpu_buffer *cpu_buf = &__get_cpu_var(cpu_buffer); + unsigned long backtrace = oprofile_backtrace_depth; - if (!backtrace_depth) { - log_sample(cpu_buf, pc, is_kernel, event); + /* + * 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)) + /* failed */ return; - } - if (!oprofile_begin_trace(cpu_buf)) + if (!backtrace) return; - /* if log_sample() fail we can't backtrace since we lost the source - * of this event */ - if (log_sample(cpu_buf, pc, is_kernel, event)) - oprofile_ops.backtrace(regs, backtrace_depth); + oprofile_begin_trace(cpu_buf); + oprofile_ops.backtrace(regs, backtrace); oprofile_end_trace(cpu_buf); } +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); +} + void oprofile_add_sample(struct pt_regs * const regs, unsigned long event) { int is_kernel = !user_mode(regs); unsigned long pc = profile_pc(regs); - oprofile_add_ext_sample(pc, regs, event, is_kernel); + __oprofile_add_ext_sample(pc, regs, event, is_kernel); } -#ifdef CONFIG_OPROFILE_IBS - -#define MAX_IBS_SAMPLE_SIZE 14 - -void oprofile_add_ibs_sample(struct pt_regs *const regs, - unsigned int *const ibs_sample, int ibs_code) +/* + * 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 = &__get_cpu_var(cpu_buffer); - struct task_struct *task; cpu_buf->sample_received++; - if (nr_available_slots(cpu_buf) < MAX_IBS_SAMPLE_SIZE) { - /* we can't backtrace since we lost the source of this event */ - cpu_buf->sample_lost_overflow++; - return; - } + /* no backtraces for samples with data */ + if (op_add_code(cpu_buf, 0, is_kernel, current)) + goto fail; - /* notice a switch from user->kernel or vice versa */ - if (cpu_buf->last_is_kernel != is_kernel) { - cpu_buf->last_is_kernel = is_kernel; - add_code(cpu_buf, is_kernel); - } + sample = op_cpu_buffer_write_reserve(entry, size + 2); + if (!sample) + goto fail; + sample->eip = ESCAPE_CODE; + sample->event = 0; /* no flags */ - /* notice a task switch */ - if (!is_kernel) { - task = current; - if (cpu_buf->last_task != task) { - cpu_buf->last_task = task; - add_code(cpu_buf, (unsigned long)task); - } - } + op_cpu_buffer_add_data(entry, code); + op_cpu_buffer_add_data(entry, pc); - add_code(cpu_buf, ibs_code); - add_sample(cpu_buf, ibs_sample[0], ibs_sample[1]); - add_sample(cpu_buf, ibs_sample[2], ibs_sample[3]); - add_sample(cpu_buf, ibs_sample[4], ibs_sample[5]); + return; - if (ibs_code == IBS_OP_BEGIN) { - add_sample(cpu_buf, ibs_sample[6], ibs_sample[7]); - add_sample(cpu_buf, ibs_sample[8], ibs_sample[9]); - add_sample(cpu_buf, ibs_sample[10], ibs_sample[11]); - } +fail: + cpu_buf->sample_lost_overflow++; +} - if (backtrace_depth) - oprofile_ops.backtrace(regs, backtrace_depth); +int oprofile_add_data(struct op_entry *entry, unsigned long val) +{ + return op_cpu_buffer_add_data(entry, val); } -#endif +int oprofile_write_commit(struct op_entry *entry) +{ + 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 = &__get_cpu_var(cpu_buffer); - log_sample(cpu_buf, pc, is_kernel, event); + log_sample(cpu_buf, pc, 0, is_kernel, event); } void oprofile_add_trace(unsigned long pc) @@ -332,21 +419,21 @@ void oprofile_add_trace(unsigned long pc) if (!cpu_buf->tracing) return; - if (nr_available_slots(cpu_buf) < 1) { - cpu_buf->tracing = 0; - cpu_buf->sample_lost_overflow++; - 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; - /* 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) { - cpu_buf->tracing = 0; - cpu_buf->backtrace_aborted++; - return; - } + if (op_add_sample(cpu_buf, pc, 0)) + goto fail; - add_sample(cpu_buf, pc, 0); + return; +fail: + cpu_buf->tracing = 0; + cpu_buf->backtrace_aborted++; + return; } /* diff --git a/drivers/oprofile/cpu_buffer.h b/drivers/oprofile/cpu_buffer.h index d3cc26264db..63f81c44846 100644 --- a/drivers/oprofile/cpu_buffer.h +++ b/drivers/oprofile/cpu_buffer.h @@ -1,10 +1,11 @@ /** * @file cpu_buffer.h * - * @remark Copyright 2002 OProfile authors + * @remark Copyright 2002-2009 OProfile authors * @remark Read the file COPYING * * @author John Levon <levon@movementarian.org> + * @author Robert Richter <robert.richter@amd.com> */ #ifndef OPROFILE_CPU_BUFFER_H @@ -15,6 +16,7 @@ #include <linux/workqueue.h> #include <linux/cache.h> #include <linux/sched.h> +#include <linux/ring_buffer.h> struct task_struct; @@ -30,16 +32,16 @@ void end_cpu_work(void); struct op_sample { unsigned long eip; unsigned long event; + unsigned long data[0]; }; +struct op_entry; + struct oprofile_cpu_buffer { - volatile unsigned long head_pos; - volatile unsigned long tail_pos; unsigned long buffer_size; struct task_struct *last_task; int last_is_kernel; int tracing; - struct op_sample *buffer; unsigned long sample_received; unsigned long sample_lost_overflow; unsigned long backtrace_aborted; @@ -50,12 +52,62 @@ struct oprofile_cpu_buffer { DECLARE_PER_CPU(struct oprofile_cpu_buffer, cpu_buffer); -void cpu_buffer_reset(struct oprofile_cpu_buffer *cpu_buf); +/* + * Resets the cpu buffer to a sane state. + * + * reset these to invalid values; the next sample collected will + * populate the buffer with proper values to initialize the buffer + */ +static inline void op_cpu_buffer_reset(int cpu) +{ + struct oprofile_cpu_buffer *cpu_buf = &per_cpu(cpu_buffer, cpu); + + cpu_buf->last_is_kernel = -1; + cpu_buf->last_task = NULL; +} + +struct op_sample +*op_cpu_buffer_write_reserve(struct op_entry *entry, unsigned long size); +int op_cpu_buffer_write_commit(struct op_entry *entry); +struct op_sample *op_cpu_buffer_read_entry(struct op_entry *entry, int cpu); +unsigned long op_cpu_buffer_entries(int cpu); + +/* returns the remaining free size of data in the entry */ +static inline +int op_cpu_buffer_add_data(struct op_entry *entry, unsigned long val) +{ + if (!entry->size) + return 0; + *entry->data = val; + entry->size--; + entry->data++; + return entry->size; +} + +/* returns the size of data in the entry */ +static inline +int op_cpu_buffer_get_size(struct op_entry *entry) +{ + return entry->size; +} + +/* returns 0 if empty or the size of data including the current value */ +static inline +int op_cpu_buffer_get_data(struct op_entry *entry, unsigned long *val) +{ + int size = entry->size; + if (!size) + return 0; + *val = *entry->data; + entry->size--; + entry->data++; + return size; +} -/* transient events for the CPU buffer -> event buffer */ -#define CPU_IS_KERNEL 1 -#define CPU_TRACE_BEGIN 2 -#define IBS_FETCH_BEGIN 3 -#define IBS_OP_BEGIN 4 +/* extra data flags */ +#define KERNEL_CTX_SWITCH (1UL << 0) +#define IS_KERNEL (1UL << 1) +#define TRACE_BEGIN (1UL << 2) +#define USER_CTX_SWITCH (1UL << 3) #endif /* OPROFILE_CPU_BUFFER_H */ diff --git a/drivers/oprofile/event_buffer.c b/drivers/oprofile/event_buffer.c index 191a3202cec..2b7ae366ceb 100644 --- a/drivers/oprofile/event_buffer.c +++ b/drivers/oprofile/event_buffer.c @@ -73,8 +73,8 @@ int alloc_event_buffer(void) unsigned long flags; spin_lock_irqsave(&oprofilefs_lock, flags); - buffer_size = fs_buffer_size; - buffer_watershed = fs_buffer_watershed; + buffer_size = oprofile_buffer_size; + buffer_watershed = oprofile_buffer_watershed; spin_unlock_irqrestore(&oprofilefs_lock, flags); if (buffer_watershed >= buffer_size) diff --git a/drivers/oprofile/oprof.c b/drivers/oprofile/oprof.c index cd375907f26..3cffce90f82 100644 --- a/drivers/oprofile/oprof.c +++ b/drivers/oprofile/oprof.c @@ -23,7 +23,7 @@ struct oprofile_operations oprofile_ops; unsigned long oprofile_started; -unsigned long backtrace_depth; +unsigned long oprofile_backtrace_depth; static unsigned long is_setup; static DEFINE_MUTEX(start_mutex); @@ -172,7 +172,7 @@ int oprofile_set_backtrace(unsigned long val) goto out; } - backtrace_depth = val; + oprofile_backtrace_depth = val; out: mutex_unlock(&start_mutex); diff --git a/drivers/oprofile/oprof.h b/drivers/oprofile/oprof.h index 5df0c21a608..c288d3c24b5 100644 --- a/drivers/oprofile/oprof.h +++ b/drivers/oprofile/oprof.h @@ -21,12 +21,12 @@ void oprofile_stop(void); struct oprofile_operations; -extern unsigned long fs_buffer_size; -extern unsigned long fs_cpu_buffer_size; -extern unsigned long fs_buffer_watershed; +extern unsigned long oprofile_buffer_size; +extern unsigned long oprofile_cpu_buffer_size; +extern unsigned long oprofile_buffer_watershed; extern struct oprofile_operations oprofile_ops; extern unsigned long oprofile_started; -extern unsigned long backtrace_depth; +extern unsigned long oprofile_backtrace_depth; struct super_block; struct dentry; diff --git a/drivers/oprofile/oprofile_files.c b/drivers/oprofile/oprofile_files.c index cc106d503ac..5d36ffc30dd 100644 --- a/drivers/oprofile/oprofile_files.c +++ b/drivers/oprofile/oprofile_files.c @@ -14,13 +14,18 @@ #include "oprofile_stats.h" #include "oprof.h" -unsigned long fs_buffer_size = 131072; -unsigned long fs_cpu_buffer_size = 8192; -unsigned long fs_buffer_watershed = 32768; /* FIXME: tune */ +#define BUFFER_SIZE_DEFAULT 131072 +#define CPU_BUFFER_SIZE_DEFAULT 8192 +#define BUFFER_WATERSHED_DEFAULT 32768 /* FIXME: tune */ + +unsigned long oprofile_buffer_size; +unsigned long oprofile_cpu_buffer_size; +unsigned long oprofile_buffer_watershed; 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); + return oprofilefs_ulong_to_user(oprofile_backtrace_depth, buf, count, + offset); } @@ -120,12 +125,17 @@ static const struct file_operations dump_fops = { void oprofile_create_files(struct super_block *sb, struct dentry *root) { + /* reinitialize default values */ + oprofile_buffer_size = BUFFER_SIZE_DEFAULT; + oprofile_cpu_buffer_size = CPU_BUFFER_SIZE_DEFAULT; + oprofile_buffer_watershed = BUFFER_WATERSHED_DEFAULT; + oprofilefs_create_file(sb, root, "enable", &enable_fops); oprofilefs_create_file_perm(sb, root, "dump", &dump_fops, 0666); oprofilefs_create_file(sb, root, "buffer", &event_buffer_fops); - oprofilefs_create_ulong(sb, root, "buffer_size", &fs_buffer_size); - oprofilefs_create_ulong(sb, root, "buffer_watershed", &fs_buffer_watershed); - oprofilefs_create_ulong(sb, root, "cpu_buffer_size", &fs_cpu_buffer_size); + oprofilefs_create_ulong(sb, root, "buffer_size", &oprofile_buffer_size); + oprofilefs_create_ulong(sb, root, "buffer_watershed", &oprofile_buffer_watershed); + oprofilefs_create_ulong(sb, root, "cpu_buffer_size", &oprofile_cpu_buffer_size); 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); |