RE: [PATCH 3/8] scsi: ufshpb: Add region's reads counter

Avri Altman
2021-02-01T07:14:29Z

> > +#define WORK_PENDING 0
> > +#define ACTIVATION_THRSHLD 4 /* 4 IOs */
> Rather than fixing it with macro, how about using sysfs and make it
> configurable?
Yes.
I will add a patch making all the logic configurable.
As all those are hpb-related parameters, I think module parameters are more adequate.

>
> > @@ -306,12 +325,39 @@ void 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 (ufshpb_mode == HPB_HOST_CONTROL)
> > + atomic64_set(&rgn->reads, 0);
> > +
> > return;
> > }
> >
> > + if (ufshpb_mode == HPB_HOST_CONTROL)
> > + reads = atomic64_inc_return(&rgn->reads);
> > +
> > if (!ufshpb_is_support_chunk(transfer_len))
> > return; <- *this*
> >
> > + if (ufshpb_mode == HPB_HOST_CONTROL) {
> > + /*
> > + * in host control mode, reads are the main source for
> > + * activation trials.
> > + */
> > + if (reads == ACTIVATION_THRSHLD) {
> If the chunk size is not supported, we can not active this region
> permanently. It may be returned before get this statement.
Yes.
I already noticed that replying to Greg.
Fixed that when I dropped the use of atomic variables.

>
> > diff --git a/drivers/scsi/ufs/ufshpb.h b/drivers/scsi/ufs/ufshpb.h
> > index 8a34b0f42754..b0e78728af38 100644
> > --- a/drivers/scsi/ufs/ufshpb.h
> > +++ b/drivers/scsi/ufs/ufshpb.h
> > @@ -115,6 +115,9 @@ struct ufshpb_region {
> > /* below information is used by lru */
> > struct list_head list_lru_rgn;
> > unsigned long rgn_flags;
> > +
> > + /* region reads - for host mode */
> > + atomic64_t reads;
> I think 32 bits are suitable, because it is normalized by worker on every
> specific time.
Done.