Re: [PATCH] bdi_congestion_funp (was: Re: [PATCH] per process request limits (was Re: IO scheduler, queue depth, nr_requests))

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Fri, Feb 20, 2004 at 03:40:42PM +0100, Miquel van Smoorenburg wrote:
> --- linux-2.6.3/drivers/md/dm-table.c.ORIG	2004-02-04 04:44:59.000000000 +0100
> +++ linux-2.6.3/drivers/md/dm-table.c	2004-02-20 15:14:35.000000000 +0100

<snip>

> +	if ((t = dm_get_table(md)) == NULL)
> +		return 0;

struct mapped_device has no business in this file.  You should move
this function to dm.c, and provide accessor fns in dm-table.c.

> +	devices = dm_table_get_devices(t);
> +	for (d = devices->next; d != devices; d = d->next) {
> +		struct dm_dev *dd = list_entry(d, struct dm_dev, list);
> +		request_queue_t *q = bdev_get_queue(dd->bdev);
> +		r |= test_bit(bdi_state, &(q->backing_dev_info.state));

Shouldn't this be calling your bdi_*_congested function rather than
assuming it is a real device under dm ? (often not true).

I'm also very slightly worried that or'ing together the congestion
results for all the seperate devices isn't always the right thing.
These devices include anything that the targets are using, exception
stores for snapshots, logs for mirror, all paths for multipath (or'ing
is most likely to be wrong for multipath).

- Joe

_______________________________________________
linux-lvm mailing list
linux-lvm@redhat.com
https://www.redhat.com/mailman/listinfo/linux-lvm
read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/

[Index of Archives]     [Gluster Users]     [Kernel Development]     [Linux Clusters]     [Device Mapper]     [Security]     [Bugtraq]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]

  Powered by Linux