disk: gather statistics since boot on FreeBSD

disk_octets and disk_ops are derives, so we don't want rates
but absolute values.

I tested this with fio with a constant IO rate and confirmed
that the values are correct for disk_octets and disk_ops.

disk_time is a different matter and I need some help with that.
devstat_compute_statistics returns a long double and it didn't
seem to increase much on my system, but that might be because I
tested this with a fast SSD.

diff --git a/src/disk.c b/src/disk.c
index f319c9c..bdd3b96 100644 (file)
--- a/src/disk.c
+++ b/src/disk.c
@@ -112,8 +112,6 @@ typedef struct diskstats
 static diskstats_t *disklist;
 /* #endif KERNEL_LINUX */
 #elif KERNEL_FREEBSD
-static void *snap_previous;
-static struct timespec tsnap_previous;
 static struct gmesh geom_tree;
 /* #endif KERNEL_FREEBSD */
 
@@ -244,12 +242,6 @@ static int disk_init (void)
                ERROR ("geom_stats_open() failed, returned %d", rv);
                return (-1);
        }
-       snap_previous = geom_stats_snapshot_get();
-       if (snap_previous == NULL) {
-               ERROR ("geom_stats_snapshot_get() failed");
-               return (-1);
-       }
-       geom_stats_snapshot_timestamp(snap_previous, &tsnap_previous);
 /* #endif KERNEL_FREEBSD */
 
 #elif HAVE_LIBKSTAT
@@ -539,17 +531,14 @@ static int disk_read (void)
        int retry, dirty;
 
        void *snap_present = NULL;
-       struct devstat *snap_present_iter, *snap_previous_iter;
-       struct timespec tsnap_present;
+       struct devstat *snap_present_iter;
 
        struct gident *geom_id;
-       double timedelta;
-       long double ld[11];
 
        const char *disk_name;
-       derive_t read_bytes, write_bytes;
-       derive_t read_ops, write_ops;
-       derive_t read_time, write_time;
+       uint64_t read_bytes, write_bytes;
+       uint64_t read_ops, write_ops;
+       long double read_time, write_time;
 
        for (retry = 0, dirty = 1; retry < 5 && dirty == 1; retry++) {
                if (snap_present != NULL)
@@ -604,22 +593,11 @@ static int disk_read (void)
                }
        }
 
-       /*
-        * Now we have a snapshot that is either clean, or still dirty after 5
-        * reads.
-        */
-       geom_stats_snapshot_timestamp(snap_present, &tsnap_present);
-       timedelta = tsnap_present.tv_sec - tsnap_previous.tv_sec;
-       timedelta += (tsnap_present.tv_nsec - tsnap_previous.tv_nsec) * 1e-9;
-       tsnap_previous = tsnap_present;
-
        /* Reset iterators for both snapshots */
        geom_stats_snapshot_reset(snap_present);
-       geom_stats_snapshot_reset(snap_previous);
        for (;;) {
                snap_present_iter = geom_stats_snapshot_next(snap_present);
-               snap_previous_iter = geom_stats_snapshot_next(snap_previous);
-               if (snap_present_iter == NULL || snap_previous_iter == NULL)
+               if (snap_present_iter == NULL)
                        break;
 
                if (snap_present_iter->id == NULL)
@@ -635,48 +613,31 @@ static int disk_read (void)
                if (dirty && (snap_present_iter->sequence0 != snap_present_iter->sequence1))
                        continue;
 
-               devstat_compute_statistics(snap_present_iter, snap_previous_iter, timedelta,
-                   DSM_TRANSFERS_PER_SECOND, &ld[0],
-
-                   DSM_TRANSFERS_PER_SECOND_READ, &ld[1],
-                   DSM_MB_PER_SECOND_READ, &ld[2],
-                   DSM_MS_PER_TRANSACTION_READ, &ld[3],
-
-                   DSM_TRANSFERS_PER_SECOND_WRITE, &ld[4],
-                   DSM_MB_PER_SECOND_WRITE, &ld[5],
-                   DSM_MS_PER_TRANSACTION_WRITE, &ld[6],
+               devstat_compute_statistics(snap_present_iter, NULL, 10.0,
+                   DSM_TOTAL_TRANSFERS_READ, &read_ops,
+                   DSM_TOTAL_BYTES_READ, &read_bytes,
+                   DSM_TOTAL_DURATION_READ, &read_time,
 
-                   DSM_BUSY_PCT, &ld[7],
+                   DSM_TOTAL_TRANSFERS_WRITE, &write_ops,
+                   DSM_TOTAL_BYTES_WRITE, &write_bytes,
+                   DSM_TOTAL_DURATION_WRITE, &write_time,
 
-                   DSM_TRANSFERS_PER_SECOND_FREE, &ld[8],
-                   DSM_MB_PER_SECOND_FREE, &ld[9],
-                   DSM_MS_PER_TRANSACTION_FREE, &ld[10],
                    DSM_NONE);
-               *snap_previous_iter = *snap_present_iter;
-
-               /* Derive data to be submitted */
-               read_ops = (derive_t)ld[1];
-               write_ops = (derive_t)ld[4];
-               read_bytes = (derive_t)(ld[2] * 1048576LL);
-               write_bytes = (derive_t)(ld[5] * 1048576LL);
-               read_time = (derive_t)ld[3];
-               write_time = (derive_t)ld[6];
 
                disk_name = ((struct gprovider *)geom_id->lg_ptr)->lg_name;
 
                if ((read_bytes != 0) || (write_bytes != 0))
                        disk_submit(disk_name, "disk_octets",
-                                       read_bytes, write_bytes);
+                                       (derive_t)read_bytes, (derive_t)write_bytes);
 
                if ((read_ops != 0) || (write_ops != 0))
                        disk_submit(disk_name, "disk_ops",
-                                       read_ops, write_ops);
+                                       (derive_t)read_ops, (derive_t)write_ops);
 
-               if ((read_time != 0) || (write_time != 0))
+               if ((read_time != 0) || (write_time != 0)) {
                        disk_submit (disk_name, "disk_time",
-                                       read_time, write_time);
-
-               /* TODO: TRIM statistics collected but not reported. */
+                                       (derive_t)(read_time*1000), (derive_t)(write_time*1000));
+               }
        }
        geom_stats_snapshot_free(snap_present);