Add support for idletime profiling
Idletime profiling allows a benchmark to run while filling the
idle cycles on the server, hence giving you some metric of how
much pressure the system is under. This is useful to be able
to profile and compare changes in a setup or driver, for instance.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/idletime.h b/idletime.h
new file mode 100644
index 0000000..acb8407
--- /dev/null
+++ b/idletime.h
@@ -0,0 +1,57 @@
+#ifndef FIO_IDLETIME_H
+#define FIO_IDLETIME_H
+
+#include "fio.h"
+
+#define CALIBRATE_RUNS 10
+#define CALIBRATE_SCALE 1000
+#define MAX_CPU_STR_LEN 32
+
+enum {
+ IDLE_PROF_OPT_NONE,
+ IDLE_PROF_OPT_CALI, /* calibration only */
+ IDLE_PROF_OPT_SYSTEM,
+ IDLE_PROF_OPT_PERCPU
+};
+
+enum {
+ IDLE_PROF_STATUS_OK,
+ IDLE_PROF_STATUS_CALI_STOP,
+ IDLE_PROF_STATUS_PROF_STOP,
+ IDLE_PROF_STATUS_ABORT
+};
+
+struct idle_prof_thread {
+ pthread_t thread;
+ int cpu;
+ int state;
+ struct timeval tps;
+ struct timeval tpe;
+ double cali_time; /* microseconds to finish a unit wrok */
+ double loops;
+ double idleness;
+ unsigned char *data; /* bytes to be touched */
+ pthread_cond_t cond;
+ pthread_mutex_t init_lock;
+ pthread_mutex_t start_lock;
+};
+
+struct idle_prof_common {
+ struct idle_prof_thread *ipts;
+ int nr_cpus;
+ int status;
+ int opt;
+ double cali_mean;
+ double cali_stddev;
+ void *buf; /* single data allocation for all threads */
+};
+
+extern int fio_idle_prof_parse_opt(const char *);
+
+extern void fio_idle_prof_init(void);
+extern void fio_idle_prof_start(void);
+extern void fio_idle_prof_stop(void);
+
+extern void show_idle_prof_stats(int, struct json_object *);
+
+#endif