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/os/os-linux.h b/os/os-linux.h
index 4e837da..acc5a20 100644
--- a/os/os-linux.h
+++ b/os/os-linux.h
@@ -35,6 +35,7 @@
#define FIO_HAVE_TRIM
#define FIO_HAVE_BINJECT
#define FIO_HAVE_GETTID
+#define FIO_HAVE_SCHED_IDLE
#define FIO_USE_GENERIC_INIT_RANDOM_STATE
#ifdef MAP_HUGETLB
@@ -246,4 +247,10 @@
return errno;
}
+static inline int fio_set_sched_idle(void)
+{
+ struct sched_param p = { .sched_priority = 0, };
+ return sched_setscheduler(gettid(), SCHED_IDLE, &p);
+}
+
#endif
diff --git a/os/os-windows.h b/os/os-windows.h
index ef71dd7..2d57891 100644
--- a/os/os-windows.h
+++ b/os/os-windows.h
@@ -21,6 +21,7 @@
#define FIO_HAVE_CPU_AFFINITY
#define FIO_HAVE_CHARDEV_SIZE
#define FIO_HAVE_GETTID
+#define FIO_HAVE_SCHED_IDLE
#define FIO_USE_GENERIC_RAND
#define FIO_PREFERRED_ENGINE "windowsaio"
@@ -247,4 +248,11 @@
}
+static inline int fio_set_sched_idle(void)
+{
+ /* SetThreadPriority returns nonzero for success */
+ return (SetThreadPriority(GetCurrentThread(), THREAD_PRIORITY_IDLE))? 0 : -1;
+}
+
+
#endif /* FIO_OS_WINDOWS_H */