scsi: ufs: ufshpb: Limit the number of in-flight map requests

In host control mode the host is the originator of map requests. To not
flood the device with map requests, use a simple throttling mechanism that
limits the number of in-flight map requests.

Link: https://lore.kernel.org/r/20210712095039.8093-10-avri.altman@wdc.com
Reviewed-by: Daejun Park <daejun7.park@samsung.com>
Signed-off-by: Avri Altman <avri.altman@wdc.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
This commit is contained in:
Avri Altman 2021-07-12 12:50:36 +03:00 committed by Martin K. Petersen
parent 13c044e916
commit 33845a2d84
2 changed files with 12 additions and 0 deletions

View file

@ -21,6 +21,7 @@
#define READ_TO_MS 1000
#define READ_TO_EXPIRIES 100
#define POLLING_INTERVAL_MS 200
#define THROTTLE_MAP_REQ_DEFAULT 1
/* memory management */
static struct kmem_cache *ufshpb_mctx_cache;
@ -742,6 +743,14 @@ static struct ufshpb_req *ufshpb_get_map_req(struct ufshpb_lu *hpb,
struct ufshpb_req *map_req;
struct bio *bio;
if (hpb->is_hcm &&
hpb->num_inflight_map_req >= THROTTLE_MAP_REQ_DEFAULT) {
dev_info(&hpb->sdev_ufs_lu->sdev_dev,
"map_req throttle. inflight %d throttle %d",
hpb->num_inflight_map_req, THROTTLE_MAP_REQ_DEFAULT);
return NULL;
}
map_req = ufshpb_get_req(hpb, srgn->rgn_idx, REQ_OP_DRV_IN, false);
if (!map_req)
return NULL;
@ -756,6 +765,7 @@ static struct ufshpb_req *ufshpb_get_map_req(struct ufshpb_lu *hpb,
map_req->rb.srgn_idx = srgn->srgn_idx;
map_req->rb.mctx = srgn->mctx;
hpb->num_inflight_map_req++;
return map_req;
}
@ -765,6 +775,7 @@ static void ufshpb_put_map_req(struct ufshpb_lu *hpb,
{
bio_put(map_req->bio);
ufshpb_put_req(hpb, map_req);
hpb->num_inflight_map_req--;
}
static int ufshpb_clear_dirty_bitmap(struct ufshpb_lu *hpb,

View file

@ -217,6 +217,7 @@ struct ufshpb_lu {
struct ufshpb_req *pre_req;
int num_inflight_pre_req;
int throttle_pre_req;
int num_inflight_map_req;
struct list_head lh_pre_req_free;
int cur_read_id;
int pre_req_min_tr_len;