Commit 4cbadbd1 authored May 23, 2011 by Vivek Goyal Committed by Jens Axboe May 23, 2011

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 <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

parent 7e69723f

block/blk-ioc.c

+3 −0

Original line number	Diff line number	Diff line
		@@ -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;