diff mbox series

[06/17] nvme: introduce NVME_INLINE_MD_SG_CNT

Message ID 20200327171545.98970-8-maxg@mellanox.com (mailing list archive)
State Not Applicable
Headers show
Series nvme-rdma/nvmet-rdma: Add metadata/T10-PI support | expand

Commit Message

Max Gurtovoy March 27, 2020, 5:15 p.m. UTC 
From: Israel Rukshin <israelr@mellanox.com>

SGL size of metadata is usually small. Thus, 1 inline sg should cover
most cases. The macro will be used for pre-allocate a single SGL entry
for metadata. The preallocation of small inline SGLs depends on SG_CHAIN
capability so if the ARCH doesn't support SG_CHAIN, use the runtime
allocation for the SGL. This patch is a preparation for adding metadata
(T10-PI) over fabric support.

Signed-off-by: Israel Rukshin <israelr@mellanox.com>
Signed-off-by: Max Gurtovoy <maxg@mellanox.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
---
 drivers/nvme/host/nvme.h | 2 ++
 1 file changed, 2 insertions(+)

Comments

Christoph Hellwig April 21, 2020, 12:12 p.m. UTC | #1 
On Fri, Mar 27, 2020 at 08:15:34PM +0300, Max Gurtovoy wrote:
> From: Israel Rukshin <israelr@mellanox.com>
> 
> SGL size of metadata is usually small. Thus, 1 inline sg should cover
> most cases. The macro will be used for pre-allocate a single SGL entry
> for metadata. The preallocation of small inline SGLs depends on SG_CHAIN
> capability so if the ARCH doesn't support SG_CHAIN, use the runtime
> allocation for the SGL. This patch is a preparation for adding metadata
> (T10-PI) over fabric support.

Looks good:

Reviewed-by: Christoph Hellwig <hch@lst.de>
diff mbox series

Patch

diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
index d132af9..08f470d 100644
--- a/drivers/nvme/host/nvme.h
+++ b/drivers/nvme/host/nvme.h
@@ -30,8 +30,10 @@ 
 
 #ifdef CONFIG_ARCH_NO_SG_CHAIN
 #define  NVME_INLINE_SG_CNT  0
+#define  NVME_INLINE_MD_SG_CNT  0
 #else
 #define  NVME_INLINE_SG_CNT  2
+#define  NVME_INLINE_MD_SG_CNT  1
 #endif
 
 extern struct workqueue_struct *nvme_wq;