dm cache: tune migration throttling

Tune the dm cache migration throttling.

i) Issue a tick every second, just in case there's no i/o going through.

ii) Drop the migration threshold right down to something suitable for
background work.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
This commit is contained in:
Joe Thornber 2013-05-10 14:37:16 +01:00 committed by Alasdair G Kergon
parent 042bcef889
commit f8350daf7a

View File

@ -1445,6 +1445,7 @@ static void do_worker(struct work_struct *ws)
static void do_waker(struct work_struct *ws)
{
struct cache *cache = container_of(to_delayed_work(ws), struct cache, waker);
policy_tick(cache->policy);
wake_worker(cache);
queue_delayed_work(cache->wq, &cache->waker, COMMIT_PERIOD);
}
@ -1886,7 +1887,7 @@ static sector_t calculate_discard_block_size(sector_t cache_block_size,
return discard_block_size;
}
#define DEFAULT_MIGRATION_THRESHOLD (2048 * 100)
#define DEFAULT_MIGRATION_THRESHOLD 2048
static int cache_create(struct cache_args *ca, struct cache **result)
{