block: expose the statistics in blkio.time and blkio.sectors for the …

…root cgroup Currently, the io statistics for the root cgroup are maintained, but they are not shown because the device information is not available at the point that the root blkio cgroup is created. This patch updates the device information when the statistics are updated so that the statistics become visible. Signed-off-by: Ricky Benitez <[email protected]> Acked-by: Vivek Goyal <[email protected]> Signed-off-by: Jens Axboe <[email protected]>
cbmeeks · Apr 5, 2010 · a74b2ad · a74b2ad
1 parent 1442145
commit a74b2ad
Showing 1 changed file with 5 additions and 0 deletions.
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
@@ -948,6 +948,11 @@ cfq_find_alloc_cfqg(struct cfq_data *cfqd, struct cgroup *cgroup, int create)
 	unsigned int major, minor;
 
 	cfqg = cfqg_of_blkg(blkiocg_lookup_group(blkcg, key));
+	if (cfqg && !cfqg->blkg.dev && bdi->dev && dev_name(bdi->dev)) {
+		sscanf(dev_name(bdi->dev), "%u:%u", &major, &minor);
+		cfqg->blkg.dev = MKDEV(major, minor);
+		goto done;
+	}
 	if (cfqg || !create)
 		goto done;