On 2021-03-02 21:25, Avri Altman wrote:
In order not to hang on to “cold” regions, we shall inactivate a
region that has no READ access for a predefined amount of time -
READ_TO_MS. For that purpose we shall monitor the active regions list,
polling it on every POLLING_INTERVAL_MS. On timeout expiry we shall add
the region to the "to-be-inactivated" list, unless it is clean and did
not exhaust its READ_TO_EXPIRIES - another parameter.
All this does not apply to pinned regions.
Signed-off-by: Avri Altman <avri.altman@xxxxxxx>
---
drivers/scsi/ufs/ufshpb.c | 65 +++++++++++++++++++++++++++++++++++++++
drivers/scsi/ufs/ufshpb.h | 6 ++++
2 files changed, 71 insertions(+)
diff --git a/drivers/scsi/ufs/ufshpb.c b/drivers/scsi/ufs/ufshpb.c
index 0034fa03fdc6..89a930e72cff 100644
--- a/drivers/scsi/ufs/ufshpb.c
+++ b/drivers/scsi/ufs/ufshpb.c
@@ -18,6 +18,9 @@
#define ACTIVATION_THRESHOLD 4 /* 4 IOs */
#define EVICTION_THRESHOLD (ACTIVATION_THRESHOLD << 6) /* 256 IOs */
+#define READ_TO_MS 1000
+#define READ_TO_EXPIRIES 100
+#define POLLING_INTERVAL_MS 200
/* memory management */
static struct kmem_cache *ufshpb_mctx_cache;
@@ -1024,12 +1027,61 @@ static int
ufshpb_check_srgns_issue_state(struct ufshpb_lu *hpb,
return 0;
}
+static void ufshpb_read_to_handler(struct work_struct *work)
+{
+ struct delayed_work *dwork = to_delayed_work(work);
+ struct ufshpb_lu *hpb;
+ struct victim_select_info *lru_info;
+ struct ufshpb_region *rgn;
+ unsigned long flags;
+ LIST_HEAD(expired_list);
+
+ hpb = container_of(dwork, struct ufshpb_lu, ufshpb_read_to_work);
+
+ spin_lock_irqsave(&hpb->rgn_state_lock, flags);
+
+ lru_info = &hpb->lru_info;
+
+ list_for_each_entry(rgn, &lru_info->lh_lru_rgn, list_lru_rgn) {
+ bool timedout = ktime_after(ktime_get(), rgn->read_timeout);
+
+ if (timedout) {
+ rgn->read_timeout_expiries--;
+ if (is_rgn_dirty(rgn) ||
+ rgn->read_timeout_expiries == 0)
+ list_add(&rgn->list_expired_rgn, &expired_list);
+ else
+ rgn->read_timeout = ktime_add_ms(ktime_get(),
+ READ_TO_MS);
+ }
+ }
+
+ spin_unlock_irqrestore(&hpb->rgn_state_lock, flags);
+
+ list_for_each_entry(rgn, &expired_list, list_expired_rgn) {
Here can be problematic - since you don't have the native expired_list
initialized
before use, if above loop did not insert anything to expired_list, it
shall become
a dead loop here.
And, which lock is protecting rgn->list_expired_rgn? If two
read_to_handler works
are running in parallel, one can be inserting it to its expired_list
while another
can be deleting it.
Can Guo.
+ list_del_init(&rgn->list_expired_rgn);
+ spin_lock_irqsave(&hpb->rsp_list_lock, flags);
+ ufshpb_update_inactive_info(hpb, rgn->rgn_idx);
+ hpb->stats.rb_inactive_cnt++;
+ spin_unlock_irqrestore(&hpb->rsp_list_lock, flags);
+ }
+
+ ufshpb_kick_map_work(hpb);
+
+ schedule_delayed_work(&hpb->ufshpb_read_to_work,
+ msecs_to_jiffies(POLLING_INTERVAL_MS));
+}
+
static void ufshpb_add_lru_info(struct victim_select_info *lru_info,
struct ufshpb_region *rgn)
{
rgn->rgn_state = HPB_RGN_ACTIVE;
list_add_tail(&rgn->list_lru_rgn, &lru_info->lh_lru_rgn);
atomic_inc(&lru_info->active_cnt);
+ if (rgn->hpb->is_hcm) {
+ rgn->read_timeout = ktime_add_ms(ktime_get(), READ_TO_MS);
+ rgn->read_timeout_expiries = READ_TO_EXPIRIES;
+ }
}
static void ufshpb_hit_lru_info(struct victim_select_info *lru_info,
@@ -1813,6 +1865,7 @@ static int ufshpb_alloc_region_tbl(struct
ufs_hba *hba, struct ufshpb_lu *hpb)
INIT_LIST_HEAD(&rgn->list_inact_rgn);
INIT_LIST_HEAD(&rgn->list_lru_rgn);
+ INIT_LIST_HEAD(&rgn->list_expired_rgn);
if (rgn_idx == hpb->rgns_per_lu - 1) {
srgn_cnt = ((hpb->srgns_per_lu - 1) %
@@ -1834,6 +1887,7 @@ static int ufshpb_alloc_region_tbl(struct
ufs_hba *hba, struct ufshpb_lu *hpb)
}
rgn->rgn_flags = 0;
+ rgn->hpb = hpb;
}
return 0;
@@ -2053,6 +2107,8 @@ static int ufshpb_lu_hpb_init(struct ufs_hba
*hba, struct ufshpb_lu *hpb)
ufshpb_normalization_work_handler);
INIT_WORK(&hpb->ufshpb_lun_reset_work,
ufshpb_reset_work_handler);
+ INIT_DELAYED_WORK(&hpb->ufshpb_read_to_work,
+ ufshpb_read_to_handler);
}
hpb->map_req_cache = kmem_cache_create("ufshpb_req_cache",
@@ -2087,6 +2143,10 @@ static int ufshpb_lu_hpb_init(struct ufs_hba
*hba, struct ufshpb_lu *hpb)
ufshpb_stat_init(hpb);
ufshpb_param_init(hpb);
+ if (hpb->is_hcm)
+ schedule_delayed_work(&hpb->ufshpb_read_to_work,
+ msecs_to_jiffies(POLLING_INTERVAL_MS));
+
return 0;
release_pre_req_mempool:
@@ -2154,6 +2214,7 @@ static void ufshpb_discard_rsp_lists(struct
ufshpb_lu *hpb)
static void ufshpb_cancel_jobs(struct ufshpb_lu *hpb)
{
if (hpb->is_hcm) {
+ cancel_delayed_work_sync(&hpb->ufshpb_read_to_work);
cancel_work_sync(&hpb->ufshpb_lun_reset_work);
cancel_work_sync(&hpb->ufshpb_normalization_work);
}
@@ -2264,6 +2325,10 @@ void ufshpb_resume(struct ufs_hba *hba)
continue;
ufshpb_set_state(hpb, HPB_PRESENT);
ufshpb_kick_map_work(hpb);
+ if (hpb->is_hcm)
+ schedule_delayed_work(&hpb->ufshpb_read_to_work,
+ msecs_to_jiffies(POLLING_INTERVAL_MS));
+
}
}
diff --git a/drivers/scsi/ufs/ufshpb.h b/drivers/scsi/ufs/ufshpb.h
index 37c1b0ea0c0a..b49e9a34267f 100644
--- a/drivers/scsi/ufs/ufshpb.h
+++ b/drivers/scsi/ufs/ufshpb.h
@@ -109,6 +109,7 @@ struct ufshpb_subregion {
};
struct ufshpb_region {
+ struct ufshpb_lu *hpb;
struct ufshpb_subregion *srgn_tbl;
enum HPB_RGN_STATE rgn_state;
int rgn_idx;
@@ -126,6 +127,10 @@ struct ufshpb_region {
/* region reads - for host mode */
spinlock_t rgn_lock;
unsigned int reads;
+ /* region "cold" timer - for host mode */
+ ktime_t read_timeout;
+ unsigned int read_timeout_expiries;
+ struct list_head list_expired_rgn;
};
#define for_each_sub_region(rgn, i, srgn) \
@@ -219,6 +224,7 @@ struct ufshpb_lu {
struct victim_select_info lru_info;
struct work_struct ufshpb_normalization_work;
struct work_struct ufshpb_lun_reset_work;
+ struct delayed_work ufshpb_read_to_work;
/* pinned region information */
u32 lu_pinned_start;
