On Tue, Feb 02, 2021 at 10:30:01AM +0200, 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@xxxxxxx> > --- > drivers/scsi/ufs/ufshpb.c | 109 ++++++++++++++++++++++++++++++++------ > drivers/scsi/ufs/ufshpb.h | 6 +++ > 2 files changed, 100 insertions(+), 15 deletions(-) > > diff --git a/drivers/scsi/ufs/ufshpb.c b/drivers/scsi/ufs/ufshpb.c > index 61de80a778a7..de4866d42df0 100644 > --- a/drivers/scsi/ufs/ufshpb.c > +++ b/drivers/scsi/ufs/ufshpb.c > @@ -16,6 +16,9 @@ > #include "ufshpb.h" > #include "../sd.h" > > +#define WORK_PENDING 0 This should be next to the variable you define that uses this, right? Otherwise we would think this is a valid value, when in reality it is the bit number, correct? > +#define ACTIVATION_THRSHLD 4 /* 4 IOs */ You can spell things out "ACTIVATION_THRESHOLD" :) thanks, greg k-h
