[PATCH] ibmvscsis: increase INITIAL_SRP_LIMIT to 1024

[PATCH] ibmvscsis: increase INITIAL_SRP_LIMIT to 1024

[Tyrel Datwyler]

The adapter request_limit is hardcoded to be INITIAL_SRP_LIMIT which is
currently an arbitrary value of 800. Increase this value to 1024 which
better matches the characteristics of the typical IBMi Initiator that
supports 32 LUNs and a queue depth of 32.

This change also has the secondary benefit of being a power of two as
required by the kfifo API. Since, Commit ab9bb6318b09 ("Partially revert
"kfifo: fix kfifo_alloc() and kfifo_init()"") the size of IU pool for
each target has been rounded down to 512 when attempting to kfifo_init()
those pools with the current request_limit size of 800.

Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>
---
 drivers/scsi/ibmvscsi_tgt/ibmvscsi_tgt.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/scsi/ibmvscsi_tgt/ibmvscsi_tgt.c b/drivers/scsi/ibmvscsi_tgt/ibmvscsi_tgt.c
index 61f06f6885a5..89b9fbce7488 100644
--- a/drivers/scsi/ibmvscsi_tgt/ibmvscsi_tgt.c
+++ b/drivers/scsi/ibmvscsi_tgt/ibmvscsi_tgt.c
@@ -36,7 +36,7 @@
 
 #define IBMVSCSIS_VERSION	"v0.2"
 
-#define	INITIAL_SRP_LIMIT	800
+#define	INITIAL_SRP_LIMIT	1024
 #define	DEFAULT_MAX_SECTORS	256
 #define MAX_TXU			1024 * 1024
 
-- 
2.35.1

Re: [PATCH] ibmvscsis: increase INITIAL_SRP_LIMIT to 1024

[Martin K. Petersen]

Tyrel,

> The adapter request_limit is hardcoded to be INITIAL_SRP_LIMIT which
> is currently an arbitrary value of 800. Increase this value to 1024
> which better matches the characteristics of the typical IBMi Initiator
> that supports 32 LUNs and a queue depth of 32.

Applied to 5.18/scsi-staging, thanks!

-- 
Martin K. Petersen	Oracle Linux Engineering

Re: [PATCH] ibmvscsis: increase INITIAL_SRP_LIMIT to 1024

[Martin K. Petersen]

On Tue, 22 Mar 2022 12:44:43 -0700, Tyrel Datwyler wrote:

> The adapter request_limit is hardcoded to be INITIAL_SRP_LIMIT which is
> currently an arbitrary value of 800. Increase this value to 1024 which
> better matches the characteristics of the typical IBMi Initiator that
> supports 32 LUNs and a queue depth of 32.
> 
> This change also has the secondary benefit of being a power of two as
> required by the kfifo API. Since, Commit ab9bb6318b09 ("Partially revert
> "kfifo: fix kfifo_alloc() and kfifo_init()"") the size of IU pool for
> each target has been rounded down to 512 when attempting to kfifo_init()
> those pools with the current request_limit size of 800.
> 
> [...]

Applied to 5.18/scsi-fixes, thanks!

[1/1] ibmvscsis: increase INITIAL_SRP_LIMIT to 1024
      https://git.kernel.org/mkp/scsi/c/0bade8e53279

-- 
Martin K. Petersen	Oracle Linux Engineering