dm zoned: reclaim random zones when idle

When the system is idle we should be starting reclaiming
random zones, too.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

diff --git a/drivers/md/dm-zoned-metadata.c b/drivers/md/dm-zoned-metadata.c
index 6c009a8b36a49036cfd2f384904cd8bff2a626b6..b5fd67eff04623730414532fca75f813a28e2de6 100644 (file)
--- a/drivers/md/dm-zoned-metadata.c
+++ b/drivers/md/dm-zoned-metadata.c
@@ -1859,15 +1859,20 @@ static void dmz_wait_for_reclaim(struct dmz_metadata *zmd, struct dm_zone *zone)
 /*
  * Select a cache or random write zone for reclaim.
  */
-static struct dm_zone *dmz_get_rnd_zone_for_reclaim(struct dmz_metadata *zmd)
+static struct dm_zone *dmz_get_rnd_zone_for_reclaim(struct dmz_metadata *zmd,
+                                                   bool idle)
 {
        struct dm_zone *dzone = NULL;
        struct dm_zone *zone;
        struct list_head *zone_list = &zmd->map_rnd_list;
 
        /* If we have cache zones select from the cache zone list */
-       if (zmd->nr_cache)
+       if (zmd->nr_cache) {
                zone_list = &zmd->map_cache_list;
+               /* Try to relaim random zones, too, when idle */
+               if (idle && list_empty(zone_list))
+                       zone_list = &zmd->map_rnd_list;
+       }
 
        list_for_each_entry(zone, zone_list, link) {
                if (dmz_is_buf(zone))
@@ -1901,7 +1906,7 @@ static struct dm_zone *dmz_get_seq_zone_for_reclaim(struct dmz_metadata *zmd)
 /*
  * Select a zone for reclaim.
  */
-struct dm_zone *dmz_get_zone_for_reclaim(struct dmz_metadata *zmd)
+struct dm_zone *dmz_get_zone_for_reclaim(struct dmz_metadata *zmd, bool idle)
 {
        struct dm_zone *zone;
 
@@ -1917,7 +1922,7 @@ struct dm_zone *dmz_get_zone_for_reclaim(struct dmz_metadata *zmd)
        if (list_empty(&zmd->reserved_seq_zones_list))
                zone = dmz_get_seq_zone_for_reclaim(zmd);
        else
-               zone = dmz_get_rnd_zone_for_reclaim(zmd);
+               zone = dmz_get_rnd_zone_for_reclaim(zmd, idle);
        dmz_unlock_map(zmd);
 
        return zone;

diff --git a/drivers/md/dm-zoned-reclaim.c b/drivers/md/dm-zoned-reclaim.c
index d566dedcd8b88c6326fdda10b3e9973f41e8a372..bd62245d4556af1f261b95b92222de46d212f2ff 100644 (file)
--- a/drivers/md/dm-zoned-reclaim.c
+++ b/drivers/md/dm-zoned-reclaim.c
@@ -284,7 +284,10 @@ static int dmz_reclaim_rnd_data(struct dmz_reclaim *zrc, struct dm_zone *dzone)
        int alloc_flags = dmz_nr_cache_zones(zmd) ?
                DMZ_ALLOC_RND : DMZ_ALLOC_SEQ;
 
-       /* Get a free sequential zone */
+       /* Always use sequential zones to reclaim random zones */
+       if (dmz_is_rnd(dzone))
+               alloc_flags = DMZ_ALLOC_SEQ;
+       /* Get a free random or sequential zone */
        dmz_lock_map(zmd);
        szone = dmz_alloc_zone(zmd, alloc_flags | DMZ_ALLOC_RECLAIM);
        dmz_unlock_map(zmd);
@@ -343,6 +346,14 @@ static void dmz_reclaim_empty(struct dmz_reclaim *zrc, struct dm_zone *dzone)
        dmz_unlock_flush(zmd);
 }
 
+/*
+ * Test if the target device is idle.
+ */
+static inline int dmz_target_idle(struct dmz_reclaim *zrc)
+{
+       return time_is_before_jiffies(zrc->atime + DMZ_IDLE_PERIOD);
+}
+
 /*
  * Find a candidate zone for reclaim and process it.
  */
@@ -355,7 +366,7 @@ static int dmz_do_reclaim(struct dmz_reclaim *zrc)
        int ret;
 
        /* Get a data zone */
-       dzone = dmz_get_zone_for_reclaim(zmd);
+       dzone = dmz_get_zone_for_reclaim(zmd, dmz_target_idle(zrc));
        if (!dzone)
                return -EBUSY;
 
@@ -418,14 +429,6 @@ out:
        return 0;
 }
 
-/*
- * Test if the target device is idle.
- */
-static inline int dmz_target_idle(struct dmz_reclaim *zrc)
-{
-       return time_is_before_jiffies(zrc->atime + DMZ_IDLE_PERIOD);
-}
-
 static unsigned int dmz_reclaim_percentage(struct dmz_reclaim *zrc)
 {
        struct dmz_metadata *zmd = zrc->metadata;
@@ -448,8 +451,13 @@ static unsigned int dmz_reclaim_percentage(struct dmz_reclaim *zrc)
  */
 static bool dmz_should_reclaim(struct dmz_reclaim *zrc, unsigned int p_unmap)
 {
+       unsigned int nr_reclaim = dmz_nr_rnd_zones(zrc->metadata);
+
+       if (dmz_nr_cache_zones(zrc->metadata))
+               nr_reclaim += dmz_nr_cache_zones(zrc->metadata);
+
        /* Reclaim when idle */
-       if (dmz_target_idle(zrc) && p_unmap < 100)
+       if (dmz_target_idle(zrc) && nr_reclaim)
                return true;
 
        /* If there are still plenty of cache zones, do not reclaim */

diff --git a/drivers/md/dm-zoned.h b/drivers/md/dm-zoned.h
index 29e01a853f8470fa62e1c2aab96467257a2ebee4..288054dd7cf421804b7ceaf3d5d1813a52efffca 100644 (file)
--- a/drivers/md/dm-zoned.h
+++ b/drivers/md/dm-zoned.h
@@ -240,7 +240,7 @@ static inline bool dmz_is_active(struct dm_zone *zone)
 
 int dmz_lock_zone_reclaim(struct dm_zone *zone);
 void dmz_unlock_zone_reclaim(struct dm_zone *zone);
-struct dm_zone *dmz_get_zone_for_reclaim(struct dmz_metadata *zmd);
+struct dm_zone *dmz_get_zone_for_reclaim(struct dmz_metadata *zmd, bool idle);
 
 struct dm_zone *dmz_get_chunk_mapping(struct dmz_metadata *zmd,
                                      unsigned int chunk, int op);