Commit e64b0c80 authored by Christophe JAILLET's avatar Christophe JAILLET Committed by Keith Busch
Browse files

nvmet: reorder fields in 'struct nvmf_ctrl_options' 



Group some variables based on their sizes to reduce holes.
On x86_64, this shrinks the size of 'struct nvmf_ctrl_options' from 136 to
128 bytes.

When such a structure is allocated in nvmf_create_ctrl(), because of the
way memory allocation works, when 136 bytes were requested, 192 bytes were
allocated.

So this saves 64 bytes per allocation, 1 cache line to hold the whole
structure and a few cycles when zeroing the memory in nvmf_create_ctrl().

Signed-off-by: default avatarChristophe JAILLET <christophe.jaillet@wanadoo.fr>
Reviewed-by: default avatarSagi Grimberg <sagi@grimberg.me>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarKeith Busch <kbusch@kernel.org>
parent 9d217fb0

drivers/nvme/host/fabrics.h

+4 −4
Original line number Diff line number Diff line
@@ -77,6 +77,9 @@ enum { 
 *			      with the parsing opts enum.

 * @mask:	Used by the fabrics library to parse through sysfs options

 *		on adding a NVMe controller.

 * @max_reconnects: maximum number of allowed reconnect attempts before removing

 *		the controller, (-1) means reconnect forever, zero means remove

 *		immediately;

 * @transport:	Holds the fabric transport "technology name" (for a lack of

 *		better description) that will be used by an NVMe controller

 *		being added.
@@ -96,9 +99,6 @@ enum { 
 * @discovery_nqn: indicates if the subsysnqn is the well-known discovery NQN.

 * @kato:	Keep-alive timeout.

 * @host:	Virtual NVMe host, contains the NQN and Host ID.

 * @max_reconnects: maximum number of allowed reconnect attempts before removing

 *              the controller, (-1) means reconnect forever, zero means remove

 *              immediately;

 * @dhchap_secret: DH-HMAC-CHAP secret

 * @dhchap_ctrl_secret: DH-HMAC-CHAP controller secret for bi-directional

 *              authentication
@@ -112,6 +112,7 @@ enum { 
 */

struct nvmf_ctrl_options {

	unsigned		mask;

	int			max_reconnects;

	char			*transport;

	char			*subsysnqn;

	char			*traddr;
@@ -125,7 +126,6 @@ struct nvmf_ctrl_options { 
	bool			duplicate_connect;

	unsigned int		kato;

	struct nvmf_host	*host;

	int			max_reconnects;

	char			*dhchap_secret;

	char			*dhchap_ctrl_secret;

	bool			disable_sqflow;