Avoid two 64-bit divisions per scanned block

Change math to make it like the ARC, using multiplications instead. Reviewed-by: Brian Behlendorf <[email protected]> Signed-off-by: Alexander Motin <[email protected]> Sponsored-By: iXsystems, Inc. Closes openzfs#13591
andrewc12 · Sep 23, 2022 · b37cc8b · b37cc8b
1 parent 979f6e7
commit b37cc8b
Showing 1 changed file with 6 additions and 4 deletions.
diff --git a/module/zfs/dsl_scan.c b/module/zfs/dsl_scan.c
@@ -1342,12 +1342,13 @@ dsl_scan_check_suspend(dsl_scan_t *scn, const zbookmark_phys_t *zb)
 	uint64_t scan_time_ns = curr_time_ns - scn->scn_sync_start_time;
 	uint64_t sync_time_ns = curr_time_ns -
 	    scn->scn_dp->dp_spa->spa_sync_starttime;
-	int dirty_pct = scn->scn_dp->dp_dirty_total * 100 / zfs_dirty_data_max;
+	uint64_t dirty_min_bytes = zfs_dirty_data_max *
+	    zfs_vdev_async_write_active_min_dirty_percent / 100;
 	int mintime = (scn->scn_phys.scn_func == POOL_SCAN_RESILVER) ?
 	    zfs_resilver_min_time_ms : zfs_scrub_min_time_ms;
 
 	if ((NSEC2MSEC(scan_time_ns) > mintime &&
-	    (dirty_pct >= zfs_vdev_async_write_active_min_dirty_percent ||
+	    (scn->scn_dp->dp_dirty_total >= dirty_min_bytes ||
 	    txg_sync_waiting(scn->scn_dp) ||
 	    NSEC2SEC(sync_time_ns) >= zfs_txg_timeout)) ||
 	    spa_shutting_down(scn->scn_dp->dp_spa) ||
@@ -2833,12 +2834,13 @@ scan_io_queue_check_suspend(dsl_scan_t *scn)
 	uint64_t scan_time_ns = curr_time_ns - scn->scn_sync_start_time;
 	uint64_t sync_time_ns = curr_time_ns -
 	    scn->scn_dp->dp_spa->spa_sync_starttime;
-	int dirty_pct = scn->scn_dp->dp_dirty_total * 100 / zfs_dirty_data_max;
+	uint64_t dirty_min_bytes = zfs_dirty_data_max *
+	    zfs_vdev_async_write_active_min_dirty_percent / 100;
 	int mintime = (scn->scn_phys.scn_func == POOL_SCAN_RESILVER) ?
 	    zfs_resilver_min_time_ms : zfs_scrub_min_time_ms;
 
 	return ((NSEC2MSEC(scan_time_ns) > mintime &&
-	    (dirty_pct >= zfs_vdev_async_write_active_min_dirty_percent ||
+	    (scn->scn_dp->dp_dirty_total >= dirty_min_bytes ||
 	    txg_sync_waiting(scn->scn_dp) ||
 	    NSEC2SEC(sync_time_ns) >= zfs_txg_timeout)) ||
 	    spa_shutting_down(scn->scn_dp->dp_spa));