Commit d6c4f8cf authored by Tomasz Zawadzki's avatar Tomasz Zawadzki
Browse files

lib/event: refactor _spdk_scheduler_set() 



By default g_scheduler is now NULL. It can be set
either by event framework or RPC.
To keep RPC consistent, the 'static' scheduler was kept.

All access to the g_scheduler is done via _spdk_scheduler_get().
Access to its members is done to balance, get name for RPC and
through _spdk_scheduler_set(). All of them happen on scheduling
reactor and don't pose race condition when changing scheduler.
There is no need to delay init/deinit of scheduler via g_new_scheduler.
This variable was removed and all that happens in _spdk_scheduler_set().

To unset and deinitialize current scheduler,
_spdk_scheduler_set(NULL) has to be called.
This results in moving scheduler deinitalization to that
call too.

Every spdk_scheduler callback is now mandatory.

Signed-off-by: default avatarTomasz Zawadzki <tomasz.zawadzki@intel.com>
Change-Id: I1fed766989de9bcaeb7e82b490c1275f3572d77d
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/8811


Tested-by: default avatarSPDK CI Jenkins <sys_sgci@intel.com>
Community-CI: Mellanox Build Bot
Community-CI: Broadcom CI <spdk-ci.pdl@broadcom.com>
Reviewed-by: default avatarBen Walker <benjamin.walker@intel.com>
Reviewed-by: default avatarKonrad Sztyber <konrad.sztyber@gmail.com>
Reviewed-by: default avatarJim Harris <james.r.harris@intel.com>
parent 2e394521

include/spdk_internal/event.h

+4 −1
Original line number Diff line number Diff line
@@ -291,7 +291,10 @@ struct spdk_scheduler { 
void _spdk_scheduler_list_add(struct spdk_scheduler *scheduler);



/**

 * Change current scheduler.

 * Change current scheduler. If another scheduler was used prior,

 * it will be deinitalized. No scheduler will be set if name parameter

 * is NULL.

 * This function should be invoked from scheduling reactor.

 *

 * \param name Name of the scheduler to be used.

 *

lib/event/reactor.c

+28 −34
Original line number Diff line number Diff line
@@ -66,8 +66,7 @@ static struct spdk_mempool *g_spdk_event_mempool = NULL; 
TAILQ_HEAD(, spdk_scheduler) g_scheduler_list

	= TAILQ_HEAD_INITIALIZER(g_scheduler_list);



static struct spdk_scheduler *g_scheduler;

static struct spdk_scheduler *g_new_scheduler;

static struct spdk_scheduler *g_scheduler = NULL;

static struct spdk_reactor *g_scheduling_reactor;

bool g_scheduling_in_progress = false;

static uint64_t g_scheduler_period;
@@ -100,32 +99,36 @@ int 
_spdk_scheduler_set(char *name)

{

	struct spdk_scheduler *scheduler;

	int rc = 0;



	/* NULL scheduler was specifically requested */

	if (name == NULL) {

		if (g_scheduler) {

			g_scheduler->deinit();

		}

		g_scheduler = NULL;

		return 0;

	}



	scheduler = _scheduler_find(name);

	if (scheduler == NULL) {

		SPDK_ERRLOG("Requested scheduler is missing\n");

		return -ENOENT;

		return -EINVAL;

	}



	if (g_scheduling_in_progress) {

		if (g_scheduler != g_new_scheduler) {

			/* Scheduler already changed, cannot defer multiple deinits */

			return -EBUSY;

	if (g_scheduler == scheduler) {

		return 0;

	}

	} else {

		if (g_scheduler != NULL && g_scheduler->deinit != NULL) {



	rc = scheduler->init();

	if (rc == 0) {

		if (g_scheduler) {

			g_scheduler->deinit();

		}

		g_scheduler = scheduler;

	}



	g_new_scheduler = scheduler;



	if (scheduler->init != NULL) {

		scheduler->init();

	}



	return 0;

	return rc;

}



struct spdk_scheduler *
@@ -299,9 +302,7 @@ spdk_reactors_fini(void) 
		return;

	}



	if (g_scheduler->deinit != NULL) {

		g_scheduler->deinit();

	}

	_spdk_scheduler_set(NULL);



	spdk_thread_lib_fini();
@@ -750,8 +751,10 @@ _reactors_scheduler_update_core_mode(void *ctx) 
static void

_reactors_scheduler_balance(void *arg1, void *arg2)

{

	if (g_reactor_state == SPDK_REACTOR_STATE_RUNNING) {

		g_scheduler->balance(g_core_infos, g_reactor_count);

	struct spdk_scheduler *scheduler = _spdk_scheduler_get();



	if (g_reactor_state == SPDK_REACTOR_STATE_RUNNING && scheduler != NULL) {

		scheduler->balance(g_core_infos, g_reactor_count);



		g_scheduler_core_number = spdk_env_get_first_core();

		_reactors_scheduler_update_core_mode(NULL);
@@ -956,19 +959,10 @@ reactor_run(void *arg) 
				  (reactor->tsc_last - last_sched) > g_scheduler_period &&

				  reactor == g_scheduling_reactor &&

				  !g_scheduling_in_progress)) {

			if (spdk_unlikely(g_scheduler != g_new_scheduler)) {

				if (g_scheduler->deinit != NULL) {

					g_scheduler->deinit();

				}

				g_scheduler = g_new_scheduler;

			}



			if (spdk_unlikely(g_scheduler->balance != NULL)) {

			last_sched = reactor->tsc_last;

			g_scheduling_in_progress = true;

			_reactors_scheduler_gather_metrics(NULL, NULL);

		}

		}



		if (g_reactor_state != SPDK_REACTOR_STATE_RUNNING) {

			break;

lib/event/scheduler_static.c

+19 −3
Original line number Diff line number Diff line
@@ -39,10 +39,26 @@ 


#include "spdk_internal/event.h"



static int

init_static(void)

{

	return 0;

}



static void

deinit_static(void)

{

}



static void

balance_static(struct spdk_scheduler_core_info *cores, int core_count)

{

}



static struct spdk_scheduler scheduler = {

	.name = "static",

	.init = NULL,

	.deinit = NULL,

	.balance = NULL,

	.init = init_static,

	.deinit = deinit_static,

	.balance = balance_static,

};

SPDK_SCHEDULER_REGISTER(scheduler);