| Message ID | 20210302132503.224670-8-avri.altman@wdc.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | Add Host control mode to HPB | expand |
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@wdc.com> > --- > 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 ufshpb_lu *hpb = container_of(work, struct ufshpb_lu, ufshpb_read_to_work.work); usually we use this to get data of a delayed work. > + struct victim_select_info *lru_info; struct victim_select_info *lru_info = &hpb->lru_info; This can save some lines. Thanks, Can Guo. > + struct ufshpb_region *rgn; > + unsigned long flags; > + LIST_HEAD(expired_list); > + > + spin_lock_irqsave(&hpb->rgn_state_lock, flags); > + > + 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) { > + 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;
> > > > +static void ufshpb_read_to_handler(struct work_struct *work) > > +{ > > + struct delayed_work *dwork = to_delayed_work(work); > > + struct ufshpb_lu *hpb; > > struct ufshpb_lu *hpb = container_of(work, struct ufshpb_lu, > ufshpb_read_to_work.work); > > usually we use this to get data of a delayed work. > > > + struct victim_select_info *lru_info; > > struct victim_select_info *lru_info = &hpb->lru_info; > > This can save some lines. Done. Thanks, Avri > Thanks, > Can Guo. > > > + struct ufshpb_region *rgn; > > + unsigned long flags; > > + LIST_HEAD(expired_list);
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@wdc.com> > --- > 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;
> > +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. Not sure what you meant by native initialization. LIST_HEAD is statically initializing an empty list, resulting the same outcome as INIT_LIST_HEAD. > > 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. The timeout handler, being a delayed work, is meant to run every polling period. Originally, I had it protected from 2 handlers running concurrently, But I removed it following Daejun's comment, which I accepted, Since it is always scheduled using the same polling period. Thanks, Avri > > 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;
On 2021-03-16 17:21, Avri Altman wrote: >> > +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. > Not sure what you meant by native initialization. > LIST_HEAD is statically initializing an empty list, resulting the same > outcome as INIT_LIST_HEAD. > Sorry for making you confused, you should use list_for_each_entry_safe() instead of list_for_each_entry() as you are deleting entries within the loop, otherwise, this can become an infinite loop. Again, have you tested this patch before upload? I am sure this is problematic - when it becomes an inifinite loop, below path will hang... ufshcd_suspend()->ufshpb_suspend()->cancel_jobs()->cancel_delayed_work() >> >> 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. > The timeout handler, being a delayed work, is meant to run every > polling period. > Originally, I had it protected from 2 handlers running concurrently, > But I removed it following Daejun's comment, which I accepted, > Since it is always scheduled using the same polling period. But one can set the delay to 0 through sysfs, right? Thanks, Can Guo. > > Thanks, > Avri > >> >> 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;
> On 2021-03-16 17:21, Avri Altman wrote: > >> > +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. > > Not sure what you meant by native initialization. > > LIST_HEAD is statically initializing an empty list, resulting the same > > outcome as INIT_LIST_HEAD. > > > > Sorry for making you confused, you should use list_for_each_entry_safe() > instead of list_for_each_entry() as you are deleting entries within the > loop, > otherwise, this can become an infinite loop. Again, have you tested this > patch > before upload? I am sure this is problematic - when it becomes an > inifinite > loop, below path will hang... > > ufshcd_suspend()->ufshpb_suspend()->cancel_jobs()->cancel_delayed_work() Ahh - yes. You are right. Originally I used list_for_each_entry_safe. Not sure why I changed it here. Will fix it. I openly disclosed that I am testing the code on gs20 and mi10. Those are v4.19 platforms, and I am using a driver adopted from the original public hpb driver Published by Samsung with the gs20 code. I am also concern as those drivers are drifted apart as the review process commences. Will try to bring-up a more advanced platform (gs21) and apply the mainline hpb driver. > > >> > >> 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. > > The timeout handler, being a delayed work, is meant to run every > > polling period. > > Originally, I had it protected from 2 handlers running concurrently, > > But I removed it following Daejun's comment, which I accepted, > > Since it is always scheduled using the same polling period. > > But one can set the delay to 0 through sysfs, right? Will restore the protection. Thanks. Thanks, Avri > > Thanks, > Can Guo. > > > > > Thanks, > > Avri > > > >> > >> 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;
On 3/17/21 12:55 AM, Avri Altman wrote: >> On 2021-03-16 17:21, Avri Altman wrote: [ ... ] >>>> 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. >>> The timeout handler, being a delayed work, is meant to run every >>> polling period. >>> Originally, I had it protected from 2 handlers running concurrently, >>> But I removed it following Daejun's comment, which I accepted, >>> Since it is always scheduled using the same polling period. >> >> But one can set the delay to 0 through sysfs, right? > > Will restore the protection. Thanks. (replying to an email from 2.5 months ago) Hi Can, How can two read_to_handler works run in parallel? How can it make a difference whether or not the delay can be set to zero? Are you aware that since kernel v3.7 (released in 2012) all workqueues are non-reentrant? See also commit dbf2576e37da ("workqueue: make all workqueues non-reentrant"). From the description of that commit: This patch makes all workqueues non-reentrant. If a work item is executing on a different CPU when queueing is requested, it is always queued to that CPU. This guarantees that any given work item can be executing on one CPU at maximum and if a work item is queued and executing, both are on the same CPU. Thanks, Bart.
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) { + 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;
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@wdc.com> --- drivers/scsi/ufs/ufshpb.c | 65 +++++++++++++++++++++++++++++++++++++++ drivers/scsi/ufs/ufshpb.h | 6 ++++ 2 files changed, 71 insertions(+)