Commit fb8acd90 authored by Jim Harris's avatar Jim Harris
Browse files

util: make spdk_io_channel_get_ctx() inline 



This requires exposing struct spdk_io_channel in the
public header - mark it as internal with Doxygen
comments to make it extra clear that applications
should not use the data structure directly.

This is a very hot function in the main I/O path,
so making this function inline has a significant
performance benefit.  A bdevperf microbenchmark
using null bdevs shows a 11% improvement.

Signed-off-by: default avatarJim Harris <james.r.harris@intel.com>
Change-Id: I70e30e184000705704bb004e8da1c7476a6aceeb

Reviewed-on: https://review.gerrithub.io/393824


Reviewed-by: default avatarBen Walker <benjamin.walker@intel.com>
Tested-by: default avatarSPDK Automated Test System <sys_sgsw@intel.com>
Reviewed-by: default avatarChangpeng Liu <changpeng.liu@intel.com>
parent 5b9b47fa

include/spdk/io_channel.h

+29 −2
Original line number Diff line number Diff line
@@ -47,7 +47,6 @@ extern "C" { 
#endif



struct spdk_thread;

struct spdk_io_channel;

struct spdk_io_channel_iter;

struct spdk_poller;
@@ -70,6 +69,30 @@ typedef void (*spdk_io_device_unregister_cb)(void *io_device); 
typedef void (*spdk_channel_msg)(struct spdk_io_channel_iter *i);

typedef void (*spdk_channel_for_each_cpl)(struct spdk_io_channel_iter *i, int status);



/**

 * \brief Represents a per-thread channel for accessing an I/O device.

 *

 * An I/O device may be a physical entity (i.e. NVMe controller) or a software

 *  entity (i.e. a blobstore).

 *

 * This structure is not part of the API - all accesses should be done through

 *  spdk_io_channel function calls.

 */

struct spdk_io_channel {

	struct spdk_thread		*thread;

	struct io_device		*dev;

	uint32_t			ref;

	TAILQ_ENTRY(spdk_io_channel)	tailq;

	spdk_io_channel_destroy_cb	destroy_cb;



	/*

	 * Modules will allocate extra memory off the end of this structure

	 *  to store references to hardware-specific references (i.e. NVMe queue

	 *  pairs, or references to child device spdk_io_channels (i.e.

	 *  virtual bdevs).

	 */

};



/**

 * \brief Initializes the calling thread for I/O channel allocation.

 *
@@ -198,7 +221,11 @@ void spdk_put_io_channel(struct spdk_io_channel *ch); 
/**

 * \brief Returns the context buffer associated with an I/O channel.

 */

void *spdk_io_channel_get_ctx(struct spdk_io_channel *ch);

static inline void *

spdk_io_channel_get_ctx(struct spdk_io_channel *ch)

{

	return (uint8_t *)ch + sizeof(*ch);

}



/**

 *  \brief Returns an I/O channel from a context buffer. This is

lib/util/io_channel.c

+0 −21
Original line number Diff line number Diff line
@@ -60,21 +60,6 @@ struct io_device { 


static TAILQ_HEAD(, io_device) g_io_devices = TAILQ_HEAD_INITIALIZER(g_io_devices);



struct spdk_io_channel {

	struct spdk_thread		*thread;

	struct io_device		*dev;

	uint32_t			ref;

	TAILQ_ENTRY(spdk_io_channel)	tailq;

	spdk_io_channel_destroy_cb	destroy_cb;



	/*

	 * Modules will allocate extra memory off the end of this structure

	 *  to store references to hardware-specific references (i.e. NVMe queue

	 *  pairs, or references to child device spdk_io_channels (i.e.

	 *  virtual bdevs).

	 */

};



struct spdk_thread {

	pthread_t thread_id;

	spdk_thread_pass_msg msg_fn;
@@ -496,12 +481,6 @@ spdk_put_io_channel(struct spdk_io_channel *ch) 
	spdk_thread_send_msg(ch->thread, _spdk_put_io_channel, ch);

}



void *

spdk_io_channel_get_ctx(struct spdk_io_channel *ch)

{

	return (uint8_t *)ch + sizeof(*ch);

}



struct spdk_io_channel *

spdk_io_channel_from_ctx(void *ctx)

{

test/unit/lib/blob/bs_dev_common.c

+1 −3
Original line number Diff line number Diff line
@@ -37,9 +37,7 @@ 
uint8_t *g_dev_buffer;



/* Define here for UT only. */

struct spdk_io_channel {

	struct spdk_thread		*thread;

} g_io_channel;

struct spdk_io_channel g_io_channel;



static struct spdk_io_channel *

dev_create_channel(struct spdk_bs_dev *dev)

test/unit/lib/vhost/test_vhost.c

+0 −8
Original line number Diff line number Diff line
@@ -45,14 +45,6 @@ struct spdk_conf_section { 
	struct spdk_conf_item *item;

};



struct spdk_io_channel {

	struct spdk_thread		*thread;

	struct io_device		*dev;

	uint32_t			ref;

	TAILQ_ENTRY(spdk_io_channel)	tailq;

	spdk_io_channel_destroy_cb	destroy_cb;

};



DEFINE_STUB(spdk_ring_enqueue, size_t, (struct spdk_ring *ring, void **objs, size_t count), 0);

DEFINE_STUB(spdk_ring_dequeue, size_t, (struct spdk_ring *ring, void **objs, size_t count), 0);

DEFINE_STUB(spdk_vhost_vq_get_desc, int, (struct spdk_vhost_dev *vdev,