Commit c5ff3d7d authored by Dariusz Stojaczyk's avatar Dariusz Stojaczyk Committed by Jim Harris
Browse files

bdev: make module init asynchronous again 



bdev_virtio requires us to do SCSI inquiry for
each device and wait for a response. It currently
polls inline for this response, taking up entire
reactor exclusively. Making it async would allow
other pollers to run while bdev_virtio still has
to wait.

Change-Id: Iefc88e0a2efb5b791ffe23b2e623b7c50d759084
Signed-off-by: default avatarDariusz Stojaczyk <dariuszx.stojaczyk@intel.com>
Reviewed-on: https://review.gerrithub.io/375573


Tested-by: default avatarSPDK Automated Test System <sys_sgsw@intel.com>
Reviewed-by: default avatarJim Harris <james.r.harris@intel.com>
Reviewed-by: default avatarDaniel Verkamp <daniel.verkamp@intel.com>
parent 55578433

include/spdk_internal/bdev.h

+16 −6
Original line number Diff line number Diff line
@@ -115,10 +115,10 @@ struct spdk_bdev_module_if { 
	void (*examine)(struct spdk_bdev *bdev);



	/**

	 * Count of bdev examinations in progress.  Used by generic bdev layer and must

	 * not be modified by bdev modules.

	 * Count of bdev inits/examinations in progress. Used by generic bdev

	 * layer and must not be modified by bdev modules.

	 */

	uint32_t examine_in_progress;

	uint32_t action_in_progress;



	TAILQ_ENTRY(spdk_bdev_module_if) tailq;

};
@@ -384,7 +384,7 @@ void spdk_vbdev_register(struct spdk_bdev *vbdev, struct spdk_bdev **base_bdevs, 
void spdk_vbdev_unregister(struct spdk_bdev *vbdev);



void spdk_bdev_module_examine_done(struct spdk_bdev_module_if *module);



void spdk_bdev_module_init_done(struct spdk_bdev_module_if *module);

int spdk_bdev_module_claim_bdev(struct spdk_bdev *bdev, struct spdk_bdev_desc *desc,

				struct spdk_bdev_module_if *module);

void spdk_bdev_module_release_bdev(struct spdk_bdev *bdev);
@@ -451,7 +451,17 @@ spdk_bdev_io_from_ctx(void *ctx) 
	    spdk_bdev_module_list_add(&_name ## _if);                  				\

	}



#define SPDK_GET_BDEV_MODULE(name) &name ## _if

#define SPDK_GET_BDEV_MODULE(name) (&name ## _if)



/*

 * Set module initialization to be asynchronous. After using this macro, the module

 * initialization has to be explicitly finished by calling spdk_bdev_module_init_done().

 */

#define SPDK_BDEV_MODULE_ASYNC_INIT(name)							\

	__attribute__((constructor)) static void name ## _async_init(void)			\

	{											\

		SPDK_GET_BDEV_MODULE(name)->action_in_progress = 1;				\

	}



/*

 * Modules are not required to use this macro.  It allows modules to reference the module with

lib/bdev/bdev.c

+33 −22
Original line number Diff line number Diff line
@@ -366,24 +366,53 @@ spdk_bdev_module_action_complete(void) 
	struct spdk_bdev_module_if *m;



	/*

	 * Check all bdev modules for an examinations in progress.  If any

	 * Don't finish bdev subsystem initialization if

	 * module pre-initialization is still in progress, or

	 * the subsystem been already initialized.

	 */

	if (!g_bdev_mgr.module_init_complete || g_bdev_mgr.init_complete) {

		return;

	}



	/*

	 * Check all bdev modules for inits/examinations in progress. If any

	 * exist, return immediately since we cannot finish bdev subsystem

	 * initialization until all are completed.

	 */

	TAILQ_FOREACH(m, &g_bdev_mgr.bdev_modules, tailq) {

		if (m->examine_in_progress > 0) {

		if (m->action_in_progress > 0) {

			return;

		}

	}



	/*

	 * Modules already finished initialization - now that all

	 * the bdev moduless have finished their asynchronous I/O

	 * the bdev modules have finished their asynchronous I/O

	 * processing, the entire bdev layer can be marked as complete.

	 */

	spdk_bdev_init_complete(0);

}



static void

spdk_bdev_module_action_done(struct spdk_bdev_module_if *module)

{

	assert(module->action_in_progress > 0);

	module->action_in_progress--;

	spdk_bdev_module_action_complete();

}



void

spdk_bdev_module_init_done(struct spdk_bdev_module_if *module)

{

	spdk_bdev_module_action_done(module);

}



void

spdk_bdev_module_examine_done(struct spdk_bdev_module_if *module)

{

	spdk_bdev_module_action_done(module);

}



static int

spdk_bdev_modules_init(void)

{
@@ -1433,7 +1462,7 @@ _spdk_bdev_register(struct spdk_bdev *bdev) 


	TAILQ_FOREACH(module, &g_bdev_mgr.bdev_modules, tailq) {

		if (module->examine) {

			module->examine_in_progress++;

			module->action_in_progress++;

			module->examine(bdev);

		}

	}
@@ -1510,24 +1539,6 @@ spdk_vbdev_unregister(struct spdk_bdev *vbdev) 
	spdk_bdev_unregister(vbdev);

}



void

spdk_bdev_module_examine_done(struct spdk_bdev_module_if *module)

{

	assert(module->examine_in_progress > 0);

	module->examine_in_progress--;



	if (!g_bdev_mgr.module_init_complete || g_bdev_mgr.init_complete) {

		/*

		 * Don't finish bdev subsystem initialization if

		 * module initialization is still in progress, or

		 * the subsystem been already initialized.

		 */

		return;

	}



	spdk_bdev_module_action_complete();

}



int

spdk_bdev_open(struct spdk_bdev *bdev, bool write, spdk_bdev_remove_cb_t remove_cb,

	       void *remove_ctx, struct spdk_bdev_desc **_desc)