From: "Manoj N. Kumar" <ma...@linux.vnet.ibm.com>
With the current value of cmd_per_lun at 16, the throughput
over a single adapter is limited to around 150kIOPS.
Increase the value of cmd_per_lun to 256 to improve
throughput. With this change a single adapter is able to
attain close to the maximum throughput (380kIOPS).
Also change the number of RRQ entries that can be queued.
Signed-off-by: Manoj N. Kumar <ma...@linux.vnet.ibm.com>
---
drivers/scsi/cxlflash/common.h | 8 +++++---
drivers/scsi/cxlflash/main.c | 2 +-
2 files changed, 6 insertions(+), 4 deletions(-)
diff --git a/drivers/scsi/cxlflash/common.h b/drivers/scsi/cxlflash/common.h
index 5ada926..a8ac4c0 100644
--- a/drivers/scsi/cxlflash/common.h
+++ b/drivers/scsi/cxlflash/common.h
@@ -34,7 +34,6 @@ extern const struct file_operations cxlflash_cxl_fops;
sectors
*/
-#define NUM_RRQ_ENTRY 16 /* for master issued cmds */
#define MAX_RHT_PER_CONTEXT (PAGE_SIZE / sizeof(struct sisl_rht_entry))
/* AFU command retry limit */
@@ -48,9 +47,12 @@ extern const struct file_operations cxlflash_cxl_fops;
index derivation
*/
-#define CXLFLASH_MAX_CMDS 16
+#define CXLFLASH_MAX_CMDS 256
#define CXLFLASH_MAX_CMDS_PER_LUN CXLFLASH_MAX_CMDS
+/* RRQ for master issued cmds */
+#define NUM_RRQ_ENTRY CXLFLASH_MAX_CMDS
+
static inline void check_sizes(void)
{
@@ -149,7 +151,7 @@ struct afu_cmd {
struct afu {
/* Stuff requiring alignment go first. */
- u64 rrq_entry[NUM_RRQ_ENTRY]; /* 128B RRQ */
+ u64 rrq_entry[NUM_RRQ_ENTRY]; /* 2K RRQ */
/*
* Command & data for AFU commands.
*/
diff --git a/drivers/scsi/cxlflash/main.c b/drivers/scsi/cxlflash/main.c
index 0f062a4..3879b46 100644
--- a/drivers/scsi/cxlflash/main.c
+++ b/drivers/scsi/cxlflash/main.c
@@ -2253,7 +2253,7 @@ static struct scsi_host_template driver_template = {
.eh_device_reset_handler = cxlflash_eh_device_reset_handler,
.eh_host_reset_handler = cxlflash_eh_host_reset_handler,
.change_queue_depth = cxlflash_change_queue_depth,
- .cmd_per_lun = 16,
+ .cmd_per_lun = CXLFLASH_MAX_CMDS_PER_LUN,
.can_queue = CXLFLASH_MAX_CMDS,
.this_id = -1,
.sg_tablesize = SG_NONE, /* No scatter gather support */
--
2.1.0
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