sf_buffer
struct sf_buffer sfb; /* Sampling buffer */
struct sf_buffer *sfb;
static void free_sampling_buffer(struct sf_buffer *sfb)
static int realloc_sampling_buffer(struct sf_buffer *sfb,
static int alloc_sampling_buffer(struct sf_buffer *sfb, unsigned long num_sdb)
static unsigned long sfb_pending_allocs(struct sf_buffer *sfb,
static void extend_sampling_buffer(struct sf_buffer *sfb,
struct sf_buffer sfb;