From: Vivek Goyal <vgoyal@redhat.com>
To: Jens Axboe <jaxboe@fusionio.com>,
linux kernel mailing list <linux-kernel@vger.kernel.org>
Cc: Paul Bolle <pebolle@tiscali.nl>
Subject: [PATCH] blk-cgroup: Initialize ioc->cgroup_changed at ioc creation time
Date: Mon, 23 May 2011 10:55:39 -0400 [thread overview]
Message-ID: <20110523145539.GA4019@redhat.com> (raw)
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>
---
block/blk-ioc.c | 3 +++
1 file changed, 3 insertions(+)
Index: linux-2.6-block/block/blk-ioc.c
===================================================================
--- linux-2.6-block.orig/block/blk-ioc.c 2011-03-08 09:40:58.057296008 -0500
+++ linux-2.6-block/block/blk-ioc.c 2011-05-23 10:33:51.875994035 -0400
@@ -96,6 +96,9 @@ struct io_context *alloc_io_context(gfp_
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;
next reply other threads:[~2011-05-23 14:55 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-05-23 14:55 Vivek Goyal [this message]
2011-05-23 17:35 ` [PATCH] blk-cgroup: Initialize ioc->cgroup_changed at ioc creation time Jens Axboe
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