X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;ds=sidebyside;f=drivers%2Foprofile%2Fcpu_buffer.c;h=0865e48954a22fb697a25262e269d83a8efdbb8a;hb=6a77f38946aaee1cd85eeec6cf4229b204c15071;hp=420dc8e830a5391d300b3287dd3a9908366c985a;hpb=87fc8d1bb10cd459024a742c6a10961fefcef18f;p=linux-2.6.git diff --git a/drivers/oprofile/cpu_buffer.c b/drivers/oprofile/cpu_buffer.c index 420dc8e83..0865e4895 100644 --- a/drivers/oprofile/cpu_buffer.c +++ b/drivers/oprofile/cpu_buffer.c @@ -18,9 +18,11 @@ */ #include +#include #include #include +#include "event_buffer.h" #include "cpu_buffer.h" #include "buffer_sync.h" #include "oprof.h" @@ -32,13 +34,12 @@ static void wq_sync_buffer(void *); #define DEFAULT_TIMER_EXPIRE (HZ / 10) int work_enabled; -static void __free_cpu_buffers(int num) +void free_cpu_buffers(void) { int i; for_each_online_cpu(i) { - if (cpu_buffer[i].buffer) - vfree(cpu_buffer[i].buffer); + vfree(cpu_buffer[i].buffer); } } @@ -58,6 +59,7 @@ int alloc_cpu_buffers(void) 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; @@ -69,17 +71,11 @@ int alloc_cpu_buffers(void) return 0; fail: - __free_cpu_buffers(i); + free_cpu_buffers(); return -ENOMEM; } -void free_cpu_buffers(void) -{ - __free_cpu_buffers(NR_CPUS); -} - - void start_cpu_work(void) { int i; @@ -114,6 +110,18 @@ void end_cpu_work(void) } +/* Resets the cpu buffer to a sane state. */ +void cpu_buffer_reset(struct oprofile_cpu_buffer * cpu_buf) +{ + /* 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; +} + + /* compute number of available slots in cpu_buffer queue */ static unsigned long nr_available_slots(struct oprofile_cpu_buffer const * b) { @@ -135,74 +143,148 @@ static void increment_head(struct oprofile_cpu_buffer * b) * increment is visible */ wmb(); - if (new_head < (b->buffer_size)) + if (new_head < b->buffer_size) b->head_pos = new_head; else b->head_pos = 0; } + + +inline static 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); +} + + +inline static void +add_code(struct oprofile_cpu_buffer * buffer, unsigned long value) +{ + add_sample(buffer, ESCAPE_CODE, value); +} + + /* 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. * * is_kernel is needed because on some architectures you cannot * tell if you are in kernel or user space simply by looking at - * eip. We tag this in the buffer by generating kernel enter/exit + * pc. We tag this in the buffer by generating kernel enter/exit * events whenever is_kernel changes */ -void oprofile_add_sample(unsigned long eip, unsigned int is_kernel, - unsigned long event, int cpu) +static int log_sample(struct oprofile_cpu_buffer * cpu_buf, unsigned long pc, + int is_kernel, unsigned long event) { - struct oprofile_cpu_buffer * cpu_buf = &cpu_buffer[cpu]; struct task_struct * task; - is_kernel = !!is_kernel; - cpu_buf->sample_received++; - if (nr_available_slots(cpu_buf) < 3) { cpu_buf->sample_lost_overflow++; - return; + return 0; } + is_kernel = !!is_kernel; + task = current; /* notice a switch from user->kernel or vice versa */ if (cpu_buf->last_is_kernel != is_kernel) { cpu_buf->last_is_kernel = is_kernel; - cpu_buf->buffer[cpu_buf->head_pos].eip = ~0UL; - cpu_buf->buffer[cpu_buf->head_pos].event = is_kernel; - increment_head(cpu_buf); + add_code(cpu_buf, is_kernel); } /* notice a task switch */ if (cpu_buf->last_task != task) { cpu_buf->last_task = task; - cpu_buf->buffer[cpu_buf->head_pos].eip = ~0UL; - cpu_buf->buffer[cpu_buf->head_pos].event = (unsigned long)task; - increment_head(cpu_buf); + add_code(cpu_buf, (unsigned long)task); } - cpu_buf->buffer[cpu_buf->head_pos].eip = eip; - cpu_buf->buffer[cpu_buf->head_pos].event = event; - increment_head(cpu_buf); + add_sample(cpu_buf, pc, event); + return 1; } +static int oprofile_begin_trace(struct oprofile_cpu_buffer * cpu_buf) +{ + if (nr_available_slots(cpu_buf) < 4) { + cpu_buf->sample_lost_overflow++; + return 0; + } -/* Resets the cpu buffer to a sane state. */ -void cpu_buffer_reset(struct oprofile_cpu_buffer * cpu_buf) + add_code(cpu_buf, CPU_TRACE_BEGIN); + cpu_buf->tracing = 1; + return 1; +} + + +static void oprofile_end_trace(struct oprofile_cpu_buffer * cpu_buf) { - /* 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; + cpu_buf->tracing = 0; +} + + +void oprofile_add_sample(struct pt_regs * const regs, unsigned long event) +{ + struct oprofile_cpu_buffer * cpu_buf = &cpu_buffer[smp_processor_id()]; + unsigned long pc = profile_pc(regs); + int is_kernel = !user_mode(regs); + + if (!backtrace_depth) { + log_sample(cpu_buf, pc, is_kernel, event); + return; + } + + if (!oprofile_begin_trace(cpu_buf)) + 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_end_trace(cpu_buf); } +void oprofile_add_pc(unsigned long pc, int is_kernel, unsigned long event) +{ + struct oprofile_cpu_buffer * cpu_buf = &cpu_buffer[smp_processor_id()]; + log_sample(cpu_buf, pc, is_kernel, event); +} + + +void oprofile_add_trace(unsigned long pc) +{ + struct oprofile_cpu_buffer * cpu_buf = &cpu_buffer[smp_processor_id()]; + + 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) { + cpu_buf->tracing = 0; + cpu_buf->backtrace_aborted++; + return; + } + + add_sample(cpu_buf, pc, 0); +} + + + /* * This serves to avoid cpu buffer overflow, and makes sure * the task mortuary progresses @@ -212,7 +294,7 @@ void cpu_buffer_reset(struct oprofile_cpu_buffer * cpu_buf) */ static void wq_sync_buffer(void * data) { - struct oprofile_cpu_buffer * b = (struct oprofile_cpu_buffer *)data; + struct oprofile_cpu_buffer * b = data; if (b->cpu != smp_processor_id()) { printk("WQ on CPU%d, prefer CPU%d\n", smp_processor_id(), b->cpu);