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dm zoned: per-device reclaim
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Instead of having one reclaim workqueue for the entire set we should
be allocating a reclaim workqueue per device; doing so will reduce
contention and should boost performance for a multi-device setup.

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>
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Hannes Reinecke authored and Mike Snitzer committed Jun 5, 2020
1 parent 1897981 commit f97809a
Showing 3 changed files with 88 additions and 57 deletions.
66 changes: 42 additions & 24 deletions drivers/md/dm-zoned-reclaim.c
Original file line number Diff line number Diff line change
@@ -21,6 +21,8 @@ struct dmz_reclaim {
struct dm_kcopyd_throttle kc_throttle;
int kc_err;

int dev_idx;

unsigned long flags;

/* Last target access time */
@@ -198,8 +200,8 @@ static int dmz_reclaim_buf(struct dmz_reclaim *zrc, struct dm_zone *dzone)
struct dmz_metadata *zmd = zrc->metadata;
int ret;

DMDEBUG("(%s): Chunk %u, move buf zone %u (weight %u) to data zone %u (weight %u)",
dmz_metadata_label(zmd),
DMDEBUG("(%s/%u): Chunk %u, move buf zone %u (weight %u) to data zone %u (weight %u)",
dmz_metadata_label(zmd), zrc->dev_idx,
dzone->chunk, bzone->id, dmz_weight(bzone),
dzone->id, dmz_weight(dzone));

@@ -237,8 +239,8 @@ static int dmz_reclaim_seq_data(struct dmz_reclaim *zrc, struct dm_zone *dzone)
struct dmz_metadata *zmd = zrc->metadata;
int ret = 0;

DMDEBUG("(%s): Chunk %u, move data zone %u (weight %u) to buf zone %u (weight %u)",
dmz_metadata_label(zmd),
DMDEBUG("(%s/%u): Chunk %u, move data zone %u (weight %u) to buf zone %u (weight %u)",
dmz_metadata_label(zmd), zrc->dev_idx,
chunk, dzone->id, dmz_weight(dzone),
bzone->id, dmz_weight(bzone));

@@ -295,8 +297,8 @@ static int dmz_reclaim_rnd_data(struct dmz_reclaim *zrc, struct dm_zone *dzone)
if (!szone)
return -ENOSPC;

DMDEBUG("(%s): Chunk %u, move %s zone %u (weight %u) to %s zone %u",
dmz_metadata_label(zmd), chunk,
DMDEBUG("(%s/%u): Chunk %u, move %s zone %u (weight %u) to %s zone %u",
dmz_metadata_label(zmd), zrc->dev_idx, chunk,
dmz_is_cache(dzone) ? "cache" : "rnd",
dzone->id, dmz_weight(dzone),
dmz_is_rnd(szone) ? "rnd" : "seq", szone->id);
@@ -369,8 +371,8 @@ static int dmz_do_reclaim(struct dmz_reclaim *zrc)
/* Get a data zone */
dzone = dmz_get_zone_for_reclaim(zmd, dmz_target_idle(zrc));
if (!dzone) {
DMDEBUG("(%s): No zone found to reclaim",
dmz_metadata_label(zmd));
DMDEBUG("(%s/%u): No zone found to reclaim",
dmz_metadata_label(zmd), zrc->dev_idx);
return -EBUSY;
}

@@ -417,24 +419,26 @@ static int dmz_do_reclaim(struct dmz_reclaim *zrc)
out:
if (ret) {
if (ret == -EINTR)
DMDEBUG("(%s): reclaim zone %u interrupted",
dmz_metadata_label(zmd), rzone->id);
DMDEBUG("(%s/%u): reclaim zone %u interrupted",
dmz_metadata_label(zmd), zrc->dev_idx,
rzone->id);
else
DMDEBUG("(%s): Failed to reclaim zone %u, err %d",
dmz_metadata_label(zmd), rzone->id, ret);
DMDEBUG("(%s/%u): Failed to reclaim zone %u, err %d",
dmz_metadata_label(zmd), zrc->dev_idx,
rzone->id, ret);
dmz_unlock_zone_reclaim(dzone);
return ret;
}

ret = dmz_flush_metadata(zrc->metadata);
if (ret) {
DMDEBUG("(%s): Metadata flush for zone %u failed, err %d",
dmz_metadata_label(zmd), rzone->id, ret);
DMDEBUG("(%s/%u): Metadata flush for zone %u failed, err %d",
dmz_metadata_label(zmd), zrc->dev_idx, rzone->id, ret);
return ret;
}

DMDEBUG("(%s): Reclaimed zone %u in %u ms",
dmz_metadata_label(zmd),
DMDEBUG("(%s/%u): Reclaimed zone %u in %u ms",
dmz_metadata_label(zmd), zrc->dev_idx,
rzone->id, jiffies_to_msecs(jiffies - start));
return 0;
}
@@ -461,10 +465,20 @@ 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);
unsigned int nr_reclaim;

nr_reclaim = dmz_nr_rnd_zones(zrc->metadata);

if (dmz_nr_cache_zones(zrc->metadata))
if (dmz_nr_cache_zones(zrc->metadata)) {
/*
* The first device in a multi-device
* setup only contains cache zones, so
* never start reclaim there.
*/
if (zrc->dev_idx == 0)
return false;
nr_reclaim += dmz_nr_cache_zones(zrc->metadata);
}

/* Reclaim when idle */
if (dmz_target_idle(zrc) && nr_reclaim)
@@ -488,7 +502,7 @@ static void dmz_reclaim_work(struct work_struct *work)
{
struct dmz_reclaim *zrc = container_of(work, struct dmz_reclaim, work.work);
struct dmz_metadata *zmd = zrc->metadata;
unsigned int p_unmap;
unsigned int p_unmap, nr_unmap_rnd = 0, nr_rnd = 0;
int ret;

if (dmz_dev_is_dying(zmd))
@@ -514,8 +528,11 @@ static void dmz_reclaim_work(struct work_struct *work)
zrc->kc_throttle.throttle = min(75U, 100U - p_unmap / 2);
}

DMDEBUG("(%s): Reclaim (%u): %s, %u%% free zones (%u/%u cache %u/%u random)",
dmz_metadata_label(zmd),
nr_unmap_rnd = dmz_nr_unmap_rnd_zones(zmd);
nr_rnd = dmz_nr_rnd_zones(zmd);

DMDEBUG("(%s/%u): Reclaim (%u): %s, %u%% free zones (%u/%u cache %u/%u random)",
dmz_metadata_label(zmd), zrc->dev_idx,
zrc->kc_throttle.throttle,
(dmz_target_idle(zrc) ? "Idle" : "Busy"),
p_unmap, dmz_nr_unmap_cache_zones(zmd),
@@ -536,7 +553,7 @@ static void dmz_reclaim_work(struct work_struct *work)
* Initialize reclaim.
*/
int dmz_ctr_reclaim(struct dmz_metadata *zmd,
struct dmz_reclaim **reclaim)
struct dmz_reclaim **reclaim, int idx)
{
struct dmz_reclaim *zrc;
int ret;
@@ -547,6 +564,7 @@ int dmz_ctr_reclaim(struct dmz_metadata *zmd,

zrc->metadata = zmd;
zrc->atime = jiffies;
zrc->dev_idx = idx;

/* Reclaim kcopyd client */
zrc->kc = dm_kcopyd_client_create(&zrc->kc_throttle);
@@ -558,8 +576,8 @@ int dmz_ctr_reclaim(struct dmz_metadata *zmd,

/* Reclaim work */
INIT_DELAYED_WORK(&zrc->work, dmz_reclaim_work);
zrc->wq = alloc_ordered_workqueue("dmz_rwq_%s", WQ_MEM_RECLAIM,
dmz_metadata_label(zmd));
zrc->wq = alloc_ordered_workqueue("dmz_rwq_%s_%d", WQ_MEM_RECLAIM,
dmz_metadata_label(zmd), idx);
if (!zrc->wq) {
ret = -ENOMEM;
goto err;
41 changes: 26 additions & 15 deletions drivers/md/dm-zoned-target.c
Original file line number Diff line number Diff line change
@@ -41,6 +41,7 @@ struct dm_chunk_work {
*/
struct dmz_target {
struct dm_dev *ddev[DMZ_MAX_DEVS];
unsigned int nr_ddevs;

unsigned long flags;

@@ -50,9 +51,6 @@ struct dmz_target {
/* For metadata handling */
struct dmz_metadata *metadata;

/* For reclaim */
struct dmz_reclaim *reclaim;

/* For chunk work */
struct radix_tree_root chunk_rxtree;
struct workqueue_struct *chunk_wq;
@@ -404,14 +402,15 @@ static void dmz_handle_bio(struct dmz_target *dmz, struct dm_chunk_work *cw,
dm_per_bio_data(bio, sizeof(struct dmz_bioctx));
struct dmz_metadata *zmd = dmz->metadata;
struct dm_zone *zone;
int ret;
int i, ret;

/*
* Write may trigger a zone allocation. So make sure the
* allocation can succeed.
*/
if (bio_op(bio) == REQ_OP_WRITE)
dmz_schedule_reclaim(dmz->reclaim);
for (i = 0; i < dmz->nr_ddevs; i++)
dmz_schedule_reclaim(dmz->dev[i].reclaim);

dmz_lock_metadata(zmd);

@@ -431,6 +430,7 @@ static void dmz_handle_bio(struct dmz_target *dmz, struct dm_chunk_work *cw,
if (zone) {
dmz_activate_zone(zone);
bioctx->zone = zone;
dmz_reclaim_bio_acc(zone->dev->reclaim);
}

switch (bio_op(bio)) {
@@ -577,7 +577,6 @@ static int dmz_queue_chunk_work(struct dmz_target *dmz, struct bio *bio)

bio_list_add(&cw->bio_list, bio);

dmz_reclaim_bio_acc(dmz->reclaim);
if (queue_work(dmz->chunk_wq, &cw->work))
dmz_get_chunk_work(cw);
out:
@@ -822,7 +821,7 @@ static int dmz_fixup_devices(struct dm_target *ti)
static int dmz_ctr(struct dm_target *ti, unsigned int argc, char **argv)
{
struct dmz_target *dmz;
int ret;
int ret, i;

/* Check arguments */
if (argc < 1 || argc > 2) {
@@ -842,6 +841,7 @@ static int dmz_ctr(struct dm_target *ti, unsigned int argc, char **argv)
kfree(dmz);
return -ENOMEM;
}
dmz->nr_ddevs = argc;
ti->private = dmz;

/* Get the target zoned block device */
@@ -916,10 +916,12 @@ static int dmz_ctr(struct dm_target *ti, unsigned int argc, char **argv)
mod_delayed_work(dmz->flush_wq, &dmz->flush_work, DMZ_FLUSH_PERIOD);

/* Initialize reclaim */
ret = dmz_ctr_reclaim(dmz->metadata, &dmz->reclaim);
if (ret) {
ti->error = "Zone reclaim initialization failed";
goto err_fwq;
for (i = 0; i < dmz->nr_ddevs; i++) {
ret = dmz_ctr_reclaim(dmz->metadata, &dmz->dev[i].reclaim, i);
if (ret) {
ti->error = "Zone reclaim initialization failed";
goto err_fwq;
}
}

DMINFO("(%s): Target device: %llu 512-byte logical sectors (%llu blocks)",
@@ -952,11 +954,13 @@ static int dmz_ctr(struct dm_target *ti, unsigned int argc, char **argv)
static void dmz_dtr(struct dm_target *ti)
{
struct dmz_target *dmz = ti->private;
int i;

flush_workqueue(dmz->chunk_wq);
destroy_workqueue(dmz->chunk_wq);

dmz_dtr_reclaim(dmz->reclaim);
for (i = 0; i < dmz->nr_ddevs; i++)
dmz_dtr_reclaim(dmz->dev[i].reclaim);

cancel_delayed_work_sync(&dmz->flush_work);
destroy_workqueue(dmz->flush_wq);
@@ -1025,9 +1029,11 @@ static int dmz_prepare_ioctl(struct dm_target *ti, struct block_device **bdev)
static void dmz_suspend(struct dm_target *ti)
{
struct dmz_target *dmz = ti->private;
int i;

flush_workqueue(dmz->chunk_wq);
dmz_suspend_reclaim(dmz->reclaim);
for (i = 0; i < dmz->nr_ddevs; i++)
dmz_suspend_reclaim(dmz->dev[i].reclaim);
cancel_delayed_work_sync(&dmz->flush_work);
}

@@ -1037,9 +1043,11 @@ static void dmz_suspend(struct dm_target *ti)
static void dmz_resume(struct dm_target *ti)
{
struct dmz_target *dmz = ti->private;
int i;

queue_delayed_work(dmz->flush_wq, &dmz->flush_work, DMZ_FLUSH_PERIOD);
dmz_resume_reclaim(dmz->reclaim);
for (i = 0; i < dmz->nr_ddevs; i++)
dmz_resume_reclaim(dmz->dev[i].reclaim);
}

static int dmz_iterate_devices(struct dm_target *ti,
@@ -1100,7 +1108,10 @@ static int dmz_message(struct dm_target *ti, unsigned int argc, char **argv,
int r = -EINVAL;

if (!strcasecmp(argv[0], "reclaim")) {
dmz_schedule_reclaim(dmz->reclaim);
int i;

for (i = 0; i < dmz->nr_ddevs; i++)
dmz_schedule_reclaim(dmz->dev[i].reclaim);
r = 0;
} else
DMERR("unrecognized message %s", argv[0]);
38 changes: 20 additions & 18 deletions drivers/md/dm-zoned.h
Original file line number Diff line number Diff line change
@@ -54,6 +54,7 @@ struct dmz_reclaim;
struct dmz_dev {
struct block_device *bdev;
struct dmz_metadata *metadata;
struct dmz_reclaim *reclaim;

char name[BDEVNAME_SIZE];
uuid_t uuid;
@@ -229,23 +230,6 @@ static inline void dmz_activate_zone(struct dm_zone *zone)
atomic_inc(&zone->refcount);
}

/*
* Deactivate a zone. This decrement the zone reference counter
* indicating that all BIOs to the zone have completed when the count is 0.
*/
static inline void dmz_deactivate_zone(struct dm_zone *zone)
{
atomic_dec(&zone->refcount);
}

/*
* Test if a zone is active, that is, has a refcount > 0.
*/
static inline bool dmz_is_active(struct dm_zone *zone)
{
return atomic_read(&zone->refcount);
}

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, bool idle);
@@ -272,7 +256,7 @@ int dmz_merge_valid_blocks(struct dmz_metadata *zmd, struct dm_zone *from_zone,
/*
* Functions defined in dm-zoned-reclaim.c
*/
int dmz_ctr_reclaim(struct dmz_metadata *zmd, struct dmz_reclaim **zrc);
int dmz_ctr_reclaim(struct dmz_metadata *zmd, struct dmz_reclaim **zrc, int idx);
void dmz_dtr_reclaim(struct dmz_reclaim *zrc);
void dmz_suspend_reclaim(struct dmz_reclaim *zrc);
void dmz_resume_reclaim(struct dmz_reclaim *zrc);
@@ -285,4 +269,22 @@ void dmz_schedule_reclaim(struct dmz_reclaim *zrc);
bool dmz_bdev_is_dying(struct dmz_dev *dmz_dev);
bool dmz_check_bdev(struct dmz_dev *dmz_dev);

/*
* Deactivate a zone. This decrement the zone reference counter
* indicating that all BIOs to the zone have completed when the count is 0.
*/
static inline void dmz_deactivate_zone(struct dm_zone *zone)
{
dmz_reclaim_bio_acc(zone->dev->reclaim);
atomic_dec(&zone->refcount);
}

/*
* Test if a zone is active, that is, has a refcount > 0.
*/
static inline bool dmz_is_active(struct dm_zone *zone)
{
return atomic_read(&zone->refcount);
}

#endif /* DM_ZONED_H */

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