scsi: ufs: ufshpb: Make eviction depend on region's reads

In host mode, eviction is considered an extreme measure. Verify that the
entering region has enough reads, and the exiting region has fewer reads.

Link: https://lore.kernel.org/r/20210712095039.8093-6-avri.altman@wdc.com
Reviewed-by: Daejun Park <daejun7.park@samsung.com>
Signed-off-by: Avri Altman <avri.altman@wdc.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
This commit is contained in:
Avri Altman 2021-07-12 12:50:32 +03:00 committed by Martin K. Petersen
parent c76a188856
commit 6c59cb501b
1 changed files with 17 additions and 1 deletions

View File

@ -17,6 +17,7 @@
#include "../sd.h"
#define ACTIVATION_THRESHOLD 8 /* 8 IOs */
#define EVICTION_THRESHOLD (ACTIVATION_THRESHOLD << 5) /* 256 IOs */
/* memory management */
static struct kmem_cache *ufshpb_mctx_cache;
@ -1056,6 +1057,13 @@ static struct ufshpb_region *ufshpb_victim_lru_info(struct ufshpb_lu *hpb)
if (ufshpb_check_srgns_issue_state(hpb, rgn))
continue;
/*
* in host control mode, verify that the exiting region
* has fewer reads
*/
if (hpb->is_hcm && rgn->reads > (EVICTION_THRESHOLD >> 1))
continue;
victim_rgn = rgn;
break;
}
@ -1223,7 +1231,7 @@ unlock_out:
static int ufshpb_add_region(struct ufshpb_lu *hpb, struct ufshpb_region *rgn)
{
struct ufshpb_region *victim_rgn;
struct ufshpb_region *victim_rgn = NULL;
struct victim_select_info *lru_info = &hpb->lru_info;
unsigned long flags;
int ret = 0;
@ -1250,7 +1258,15 @@ static int ufshpb_add_region(struct ufshpb_lu *hpb, struct ufshpb_region *rgn)
* It is okay to evict the least recently used region,
* because the device could detect this region
* by not issuing HPB_READ
*
* in host control mode, verify that the entering
* region has enough reads
*/
if (hpb->is_hcm && rgn->reads < EVICTION_THRESHOLD) {
ret = -EACCES;
goto out;
}
victim_rgn = ufshpb_victim_lru_info(hpb);
if (!victim_rgn) {
dev_warn(&hpb->sdev_ufs_lu->sdev_dev,