blk-cgroup: Initialize ioc->cgroup_changed at ioc creation time

If we don't explicitly initialize it to zero, CFQ might think that cgroup of ioc has changed and it generates lots of unnecessary calls to call_for_each_cic(changed_cgroup). Fix it. cfq_get_io_context() cfq_ioc_set_cgroup() call_for_each_cic(ioc, changed_cgroup) Signed-off-by: Vivek Goyal <[email protected]> Signed-off-by: Jens Axboe <[email protected]>
marineam · May 23, 2011 · 4cbadbd · 4cbadbd
1 parent 7e69723
commit 4cbadbd
Showing 1 changed file with 3 additions and 0 deletions.
diff --git a/block/blk-ioc.c b/block/blk-ioc.c
@@ -96,6 +96,9 @@ struct io_context *alloc_io_context(gfp_t gfp_flags, int node)
 		INIT_RADIX_TREE(&ret->radix_root, GFP_ATOMIC | __GFP_HIGH);
 		INIT_HLIST_HEAD(&ret->cic_list);
 		ret->ioc_data = NULL;
+#if defined(CONFIG_BLK_CGROUP) || defined(CONFIG_BLK_CGROUP_MODULE)
+		ret->cgroup_changed = 0;
+#endif
 	}
 
 	return ret;