Messages in this thread | | | Date | Thu, 11 Mar 2021 15:52:46 +0800 | From | Can Guo <> | Subject | Re: [PATCH v5 03/10] scsi: ufshpb: Add region's reads counter |
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Hi Avri,
On 2021-03-02 21:24, Avri Altman wrote: > In host control mode, reads are the major source of activation trials. > Keep track of those reads counters, for both active as well inactive > regions. > > We reset the read counter upon write - we are only interested in > "clean" > reads. less intuitive however, is that we also reset it upon region's > deactivation. Region deactivation is often due to the fact that > eviction took place: a region become active on the expense of another. > This is happening when the max-active-regions limit has crossed. If we > don’t reset the counter, we will trigger a lot of trashing of the HPB > database, since few reads (or even one) to the region that was > deactivated, will trigger a re-activation trial. > > Keep those counters normalized, as we are using those reads as a > comparative score, to make various decisions. > If during consecutive normalizations an active region has exhaust its > reads - inactivate it. > > Signed-off-by: Avri Altman <avri.altman@wdc.com> > --- > drivers/scsi/ufs/ufshpb.c | 102 ++++++++++++++++++++++++++++++++------ > drivers/scsi/ufs/ufshpb.h | 5 ++ > 2 files changed, 92 insertions(+), 15 deletions(-) > > diff --git a/drivers/scsi/ufs/ufshpb.c b/drivers/scsi/ufs/ufshpb.c > index 044fec9854a0..a8f8d13af21a 100644 > --- a/drivers/scsi/ufs/ufshpb.c > +++ b/drivers/scsi/ufs/ufshpb.c > @@ -16,6 +16,8 @@ > #include "ufshpb.h" > #include "../sd.h" > > +#define ACTIVATION_THRESHOLD 4 /* 4 IOs */
Can this param be added as a sysfs entry?
Thanks, Can Guo
> + > /* memory management */ > static struct kmem_cache *ufshpb_mctx_cache; > static mempool_t *ufshpb_mctx_pool; > @@ -554,6 +556,21 @@ static int ufshpb_issue_pre_req(struct ufshpb_lu > *hpb, struct scsi_cmnd *cmd, > return ret; > } > > +static void ufshpb_update_active_info(struct ufshpb_lu *hpb, int > rgn_idx, > + int srgn_idx) > +{ > + struct ufshpb_region *rgn; > + struct ufshpb_subregion *srgn; > + > + rgn = hpb->rgn_tbl + rgn_idx; > + srgn = rgn->srgn_tbl + srgn_idx; > + > + list_del_init(&rgn->list_inact_rgn); > + > + if (list_empty(&srgn->list_act_srgn)) > + list_add_tail(&srgn->list_act_srgn, &hpb->lh_act_srgn); > +} > + > /* > * This function will set up HPB read command using host-side L2P map > data. > */ > @@ -600,12 +617,44 @@ int ufshpb_prep(struct ufs_hba *hba, struct > ufshcd_lrb *lrbp) > ufshpb_set_ppn_dirty(hpb, rgn_idx, srgn_idx, srgn_offset, > transfer_len); > spin_unlock_irqrestore(&hpb->rgn_state_lock, flags); > + > + if (hpb->is_hcm) { > + spin_lock_irqsave(&rgn->rgn_lock, flags); > + rgn->reads = 0; > + spin_unlock_irqrestore(&rgn->rgn_lock, flags); > + } > + > return 0; > } > > if (!ufshpb_is_support_chunk(hpb, transfer_len)) > return 0; > > + if (hpb->is_hcm) { > + bool activate = false; > + /* > + * in host control mode, reads are the main source for > + * activation trials. > + */ > + spin_lock_irqsave(&rgn->rgn_lock, flags); > + rgn->reads++; > + if (rgn->reads == ACTIVATION_THRESHOLD) > + activate = true; > + spin_unlock_irqrestore(&rgn->rgn_lock, flags); > + if (activate) { > + spin_lock_irqsave(&hpb->rsp_list_lock, flags); > + ufshpb_update_active_info(hpb, rgn_idx, srgn_idx); > + hpb->stats.rb_active_cnt++; > + spin_unlock_irqrestore(&hpb->rsp_list_lock, flags); > + dev_dbg(&hpb->sdev_ufs_lu->sdev_dev, > + "activate region %d-%d\n", rgn_idx, srgn_idx); > + } > + > + /* keep those counters normalized */ > + if (rgn->reads > hpb->entries_per_srgn) > + schedule_work(&hpb->ufshpb_normalization_work); > + } > + > spin_lock_irqsave(&hpb->rgn_state_lock, flags); > if (ufshpb_test_ppn_dirty(hpb, rgn_idx, srgn_idx, srgn_offset, > transfer_len)) { > @@ -745,21 +794,6 @@ static int ufshpb_clear_dirty_bitmap(struct > ufshpb_lu *hpb, > return 0; > } > > -static void ufshpb_update_active_info(struct ufshpb_lu *hpb, int > rgn_idx, > - int srgn_idx) > -{ > - struct ufshpb_region *rgn; > - struct ufshpb_subregion *srgn; > - > - rgn = hpb->rgn_tbl + rgn_idx; > - srgn = rgn->srgn_tbl + srgn_idx; > - > - list_del_init(&rgn->list_inact_rgn); > - > - if (list_empty(&srgn->list_act_srgn)) > - list_add_tail(&srgn->list_act_srgn, &hpb->lh_act_srgn); > -} > - > static void ufshpb_update_inactive_info(struct ufshpb_lu *hpb, int > rgn_idx) > { > struct ufshpb_region *rgn; > @@ -1079,6 +1113,14 @@ static void __ufshpb_evict_region(struct > ufshpb_lu *hpb, > > ufshpb_cleanup_lru_info(lru_info, rgn); > > + if (hpb->is_hcm) { > + unsigned long flags; > + > + spin_lock_irqsave(&rgn->rgn_lock, flags); > + rgn->reads = 0; > + spin_unlock_irqrestore(&rgn->rgn_lock, flags); > + } > + > for_each_sub_region(rgn, srgn_idx, srgn) > ufshpb_purge_active_subregion(hpb, srgn); > } > @@ -1523,6 +1565,31 @@ static void > ufshpb_run_inactive_region_list(struct ufshpb_lu *hpb) > spin_unlock_irqrestore(&hpb->rsp_list_lock, flags); > } > > +static void ufshpb_normalization_work_handler(struct work_struct > *work) > +{ > + struct ufshpb_lu *hpb; > + int rgn_idx; > + unsigned long flags; > + > + hpb = container_of(work, struct ufshpb_lu, > ufshpb_normalization_work); > + > + for (rgn_idx = 0; rgn_idx < hpb->rgns_per_lu; rgn_idx++) { > + struct ufshpb_region *rgn = hpb->rgn_tbl + rgn_idx; > + > + spin_lock_irqsave(&rgn->rgn_lock, flags); > + rgn->reads = (rgn->reads >> 1); > + spin_unlock_irqrestore(&rgn->rgn_lock, flags); > + > + if (rgn->rgn_state != HPB_RGN_ACTIVE || rgn->reads) > + continue; > + > + /* if region is active but has no reads - inactivate it */ > + spin_lock(&hpb->rsp_list_lock); > + ufshpb_update_inactive_info(hpb, rgn->rgn_idx); > + spin_unlock(&hpb->rsp_list_lock); > + } > +} > + > static void ufshpb_map_work_handler(struct work_struct *work) > { > struct ufshpb_lu *hpb = container_of(work, struct ufshpb_lu, > map_work); > @@ -1913,6 +1980,9 @@ static int ufshpb_lu_hpb_init(struct ufs_hba > *hba, struct ufshpb_lu *hpb) > INIT_LIST_HEAD(&hpb->list_hpb_lu); > > INIT_WORK(&hpb->map_work, ufshpb_map_work_handler); > + if (hpb->is_hcm) > + INIT_WORK(&hpb->ufshpb_normalization_work, > + ufshpb_normalization_work_handler); > > hpb->map_req_cache = kmem_cache_create("ufshpb_req_cache", > sizeof(struct ufshpb_req), 0, 0, NULL); > @@ -2012,6 +2082,8 @@ static void ufshpb_discard_rsp_lists(struct > ufshpb_lu *hpb) > > static void ufshpb_cancel_jobs(struct ufshpb_lu *hpb) > { > + if (hpb->is_hcm) > + cancel_work_sync(&hpb->ufshpb_normalization_work); > cancel_work_sync(&hpb->map_work); > } > > diff --git a/drivers/scsi/ufs/ufshpb.h b/drivers/scsi/ufs/ufshpb.h > index 8119b1a3d1e5..bd4308010466 100644 > --- a/drivers/scsi/ufs/ufshpb.h > +++ b/drivers/scsi/ufs/ufshpb.h > @@ -121,6 +121,10 @@ struct ufshpb_region { > struct list_head list_lru_rgn; > unsigned long rgn_flags; > #define RGN_FLAG_DIRTY 0 > + > + /* region reads - for host mode */ > + spinlock_t rgn_lock; > + unsigned int reads; > }; > > #define for_each_sub_region(rgn, i, srgn) \ > @@ -211,6 +215,7 @@ struct ufshpb_lu { > > /* for selecting victim */ > struct victim_select_info lru_info; > + struct work_struct ufshpb_normalization_work; > > /* pinned region information */ > u32 lu_pinned_start;
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