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authorJoe Thornber <ejt@redhat.com>2017-05-11 09:07:16 -0400
committerMike Snitzer <snitzer@redhat.com>2017-05-14 21:54:33 -0400
commit49b7f768900f4084a65c3689d955b2fceac39e53 (patch)
treecfd9685c74734879c00ab2861498e64de35bcd5e /drivers/md
parent701e03e4e180f0cd97d4139a32e2b2d879d12da2 (diff)
downloadlinux-49b7f768900f4084a65c3689d955b2fceac39e53.tar.bz2
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.c9
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)