[dm-devel] [PATCH 05/24] dm cache policy mq: implement writeback_work() and mq_{set, clear}_dirty()

[Alasdair G Kergon]

On Thu, Oct 24, 2013 at 02:30:18PM -0400, Mike Snitzer wrote:
> From: Joe Thornber <ejt at redhat.com>
 
> --- a/drivers/md/dm-cache-policy-mq.c

> -	 * We maintain two queues of entries.  The cache proper contains

> +	 * We maintain three queues of entries.  The cache proper,

Does the Documentation file need updating too?

: The multiqueue policy has two sets of 16 queues: one set for entries
: waiting for the cache and another one for those in the cache.

> @@ -580,7 +585,16 @@ static void check_generation(struct mq_policy *mq)

Is the comment about this function no longer accurate?

: * At the moment the threshold is taken by averaging the hit counts of some
: * of the entries in the cache (the first 20 entries of the first level).

- It looks at clean before dirty?
- It looks at more than just the first level if it needs to?

> +// FIXME: can __mq_set_clear_dirty block?

Still to check this before inclusion upstream?

Alasdair