Gui Jianfeng wrote:
IKEDA, Munehiro wrote:
Hi Gui,
Gui Jianfeng wrote:
Hi Vivek,
This patch enables per-cgroup per-device weight and ioprio_class
handling.
A new cgroup interface "policy" is introduced. You can make use of
this file to configure weight and ioprio_class for each device in a
given cgroup.
The original "weight" and "ioprio_class" files are still available. If
you
don't do special configuration for a particular device, "weight" and
"ioprio_class" are used as default values in this device.
You can use the following format to play with the new interface.
#echo DEV:weight:ioprio_class > /patch/to/cgroup/policy
weight=0 means removing the policy for DEV.
Examples:
Configure weight=300 ioprio_class=2 on /dev/hdb in this cgroup
# echo /dev/hdb:300:2 > io.policy
# cat io.policy
dev weight class
/dev/hdb 300 2
Users can specify a device file of a partition for io.policy.
In this case, io_policy_node::dev_name is set as a name of the
partition device like /dev/sda2.
ex)
# cd /mnt/cgroup
# cat /dev/sda2:500:2 > io.policy
# echo io.policy
dev weight class
/dev/sda2 500 2
I believe io_policy_node::dev_name should be set a generic
device name like /dev/sda.
What do you think about it?
Hi Ikeda-san,
Sorry for the late reply. Thanks for pointing this out.
yes, it does the right thing but shows a wrong name.
IMHO, Inputing a sigle partition should not be allowed since the
policy is disk basis. So how about the following patch?
Signed-off-by: Gui Jianfeng <guijianfeng@xxxxxxxxxxxxxx>
---
diff --git a/block/elevator-fq.c b/block/elevator-fq.c
index 1a0ca07..b620768 100644
--- a/block/elevator-fq.c
+++ b/block/elevator-fq.c
@@ -1650,6 +1650,9 @@ static int devname_to_devnum(const char *buf, dev_t *dev)
return -ENODEV;
disk = get_gendisk(bdev->bd_dev, &part);
+ if (part)
+ return -EINVAL;
+
*dev = MKDEV(disk->major, disk->first_minor);
bdput(bdev);
It looks nicer and reasonable for me.
Thanks!
--
IKEDA, Munehiro
NEC Corporation of America
m-ikeda@xxxxxxxxxxxxx
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