Adaptive io latency distrobution "histogram"
Log ranges all the way down to microseconds, and display the most
appropriate values for those ranges.
This makes the latency usable for sub-milisecond devices as well.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/io_u.c b/io_u.c
index 9aab97f..e0614bd 100644
--- a/io_u.c
+++ b/io_u.c
@@ -387,38 +387,98 @@
td->ts.total_io_u[io_u->ddir]++;
}
-static void io_u_mark_latency(struct thread_data *td, unsigned long msec)
+static void io_u_mark_lat_usec(struct thread_data *td, unsigned long usec)
+{
+ int index = 0;
+
+ assert(usec < 1000);
+
+ switch (usec) {
+ case 750 ... 999:
+ index = 9;
+ break;
+ case 500 ... 749:
+ index = 8;
+ break;
+ case 250 ... 499:
+ index = 7;
+ break;
+ case 100 ... 249:
+ index = 6;
+ break;
+ case 50 ... 99:
+ index = 5;
+ break;
+ case 20 ... 49:
+ index = 4;
+ break;
+ case 10 ... 19:
+ index = 3;
+ break;
+ case 4 ... 9:
+ index = 2;
+ break;
+ case 2 ... 3:
+ index = 1;
+ case 0 ... 1:
+ break;
+ }
+
+ assert(index < FIO_IO_U_LAT_U_NR);
+ td->ts.io_u_lat_u[index]++;
+}
+
+static void io_u_mark_lat_msec(struct thread_data *td, unsigned long msec)
{
int index = 0;
switch (msec) {
default:
- index++;
+ index = 11;
+ break;
case 1000 ... 1999:
- index++;
+ index = 10;
+ break;
case 750 ... 999:
- index++;
+ index = 9;
+ break;
case 500 ... 749:
- index++;
+ index = 8;
+ break;
case 250 ... 499:
- index++;
+ index = 7;
+ break;
case 100 ... 249:
- index++;
+ index = 6;
+ break;
case 50 ... 99:
- index++;
+ index = 5;
+ break;
case 20 ... 49:
- index++;
+ index = 4;
+ break;
case 10 ... 19:
- index++;
+ index = 3;
+ break;
case 4 ... 9:
- index++;
+ index = 2;
+ break;
case 2 ... 3:
- index++;
+ index = 1;
case 0 ... 1:
break;
}
- td->ts.io_u_lat[index]++;
+ assert(index < FIO_IO_U_LAT_M_NR);
+ td->ts.io_u_lat_m[index]++;
+}
+
+static void io_u_mark_latency(struct thread_data *td, unsigned long usec)
+{
+ if (usec < 1000)
+ io_u_mark_lat_usec(td, usec);
+ else
+ io_u_mark_lat_msec(td, usec / 1000);
}
/*
@@ -682,7 +742,7 @@
add_clat_sample(td, idx, usec);
add_bw_sample(td, idx, &icd->time);
- io_u_mark_latency(td, usec / 1000);
+ io_u_mark_latency(td, usec);
if (td_write(td) && idx == DDIR_WRITE &&
td->o.verify != VERIFY_NONE)