diff options
| author |   Joe Thornber <ejt@redhat.com> | 2017-05-11 09:07:16 -0400 |
|---|---|---|
| committer |   Mike Snitzer <snitzer@redhat.com> | 2017-05-14 21:54:33 -0400 |
| commit | 49b7f768900f4084a65c3689d955b2fceac39e53 (patch) | |
| tree | cfd9685c74734879c00ab2861498e64de35bcd5e /drivers/md | |
| parent | dm cache: track all IO to the cache rather than just the origin device's IO (diff) | |
| download | linux-dev-49b7f768900f4084a65c3689d955b2fceac39e53.tar.xz linux-dev-49b7f768900f4084a65c3689d955b2fceac39e53.zip | |
dm cache: simplify the IDLE vs BUSY state calculation
Drop the MODERATE state since it wasn't buying us much.
Also, in check_migrations(), prepare for the next commit ("dm cache
policy smq: don't do any writebacks unless IDLE") by deferring to the
policy to make the final decision on whether writebacks can be
serviced.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Diffstat (limited to 'drivers/md')
| -rw-r--r-- | drivers/md/dm-cache-target.c | 9 |
1 files changed, 3 insertions, 6 deletions
diff --git a/drivers/md/dm-cache-target.c b/drivers/md/dm-cache-target.c index 232078e48167..d682a0511381 100644 --- a/drivers/md/dm-cache-target.c +++ b/drivers/md/dm-cache-target.c @@ -1718,7 +1718,6 @@ static int invalidate_start(struct cache *cache, dm_cblock_t cblock, enum busy { IDLE, - MODERATE, BUSY }; @@ -1728,10 +1727,10 @@ static enum busy spare_migration_bandwidth(struct cache *cache) sector_t current_volume = (atomic_read(&cache->nr_io_migrations) + 1) * cache->sectors_per_block; - if (current_volume <= cache->migration_threshold) - return idle ? IDLE : MODERATE; + if (idle && current_volume <= cache->migration_threshold) + return IDLE; else - return idle ? MODERATE : BUSY; + return BUSY; } static void inc_hit_counter(struct cache *cache, struct bio *bio) @@ -2047,8 +2046,6 @@ static void check_migrations(struct work_struct *ws) for (;;) { b = spare_migration_bandwidth(cache); - if (b == BUSY) - break; r = policy_get_background_work(cache->policy, b == IDLE, &op); if (r == -ENODATA) |