From bf589e32960181fa8cbca7bfdd92265e49dc2dfa Mon Sep 17 00:00:00 2001 From: Robert Richter Date: Thu, 27 Nov 2008 22:33:37 +0100 Subject: [PATCH] oprofile: adding cpu_buffer_entries() This is in preparation for changes in the cpu buffer implementation. Signed-off-by: Robert Richter --- drivers/oprofile/buffer_sync.c | 31 ++----------------------------- drivers/oprofile/cpu_buffer.h | 27 +++++++++++++++++++++++++++ 2 files changed, 29 insertions(+), 29 deletions(-) diff --git a/drivers/oprofile/buffer_sync.c b/drivers/oprofile/buffer_sync.c index 44f676c8a51..aed286c3f16 100644 --- a/drivers/oprofile/buffer_sync.c +++ b/drivers/oprofile/buffer_sync.c @@ -464,33 +464,6 @@ 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, @@ -576,11 +549,11 @@ void sync_buffer(int cpu) /* Remember, only we can modify tail_pos */ #ifndef CONFIG_OPROFILE_IBS - available = get_slots(cpu_buf); + available = cpu_buffer_entries(cpu_buf); for (i = 0; i < available; ++i) { #else - while (get_slots(cpu_buf)) { + while (cpu_buffer_entries(cpu_buf)) { #endif struct op_sample *s = cpu_buffer_read_entry(cpu_buf); diff --git a/drivers/oprofile/cpu_buffer.h b/drivers/oprofile/cpu_buffer.h index e6089768ae6..6055b567839 100644 --- a/drivers/oprofile/cpu_buffer.h +++ b/drivers/oprofile/cpu_buffer.h @@ -81,6 +81,33 @@ struct op_sample *cpu_buffer_read_entry(struct oprofile_cpu_buffer *cpu_buf) return &cpu_buf->buffer[cpu_buf->tail_pos]; } +/* "acquire" as many cpu buffer slots as we can */ +static inline +unsigned long cpu_buffer_entries(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); +} + /* transient events for the CPU buffer -> event buffer */ #define CPU_IS_KERNEL 1 #define CPU_TRACE_BEGIN 2 -- 2.41.1