Commit 76b72102 authored by Maciej Szwed's avatar Maciej Szwed Committed by Jim Harris
Browse files

scheduler_dynamic: refactor out searching for target core 



Refactors logic for finding the optimal core for a thread
to single function.

Signed-off-by: default avatarMaciej Szwed <maciej.szwed@intel.com>
Signed-off-by: default avatarTomasz Zawadzki <tomasz.zawadzki@intel.com>
Change-Id: Ifc2b09acb6f698640ce9602fec4f567eb32b79fa
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/6732


Tested-by: default avatarSPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: default avatarShuhei Matsumoto <shuhei.matsumoto.xt@hitachi.com>
Reviewed-by: default avatarPaul Luse <paul.e.luse@intel.com>
Reviewed-by: default avatarJim Harris <james.r.harris@intel.com>
parent 537b01bf

lib/event/scheduler_dynamic.c

+36 −31
Original line number Diff line number Diff line
@@ -110,6 +110,36 @@ _move_thread(struct spdk_lw_thread *lw_thread, uint32_t dst_core) 
	lw_thread->lcore = dst_core;

}



static uint32_t

_find_optimal_core(struct spdk_lw_thread *lw_thread)

{

	uint32_t i;

	uint32_t target_lcore;

	struct spdk_thread *thread = spdk_thread_get_from_ctx(lw_thread);

	struct spdk_cpuset *cpumask = spdk_thread_get_cpumask(thread);

	uint64_t thread_busy = lw_thread->current_stats.busy_tsc;



	/* Find a core that can fit the thread. */

	for (i = 0; i < spdk_env_get_core_count(); i++) {

		target_lcore = _get_next_target_core();



		/* Ignore cores outside cpumask. */

		if (!spdk_cpuset_get_cpu(cpumask, target_lcore)) {

			continue;

		}



		/* Do not use main core if it is too busy for new thread. */

		if (target_lcore == g_main_lcore && thread_busy > g_cores[g_main_lcore].idle) {

			continue;

		}



		return target_lcore;

	}



	/* If no better core is found, remain on the same one. */

	return lw_thread->lcore;

}



static int

init(struct spdk_governor *governor)

{
@@ -168,9 +198,8 @@ balance(struct spdk_scheduler_core_info *cores_info, int cores_count, 
	struct spdk_scheduler_core_info *core;

	struct spdk_cpuset *cpumask;

	struct core_stats *main_core;

	uint64_t thread_busy;

	uint32_t target_lcore;

	uint32_t i, j, k;

	uint32_t i, j;

	int rc;

	uint8_t load;

	bool busy_threads_present = false;
@@ -190,43 +219,19 @@ balance(struct spdk_scheduler_core_info *cores_info, int cores_count, 
			lw_thread = core->threads[j];

			thread = spdk_thread_get_from_ctx(lw_thread);

			cpumask = spdk_thread_get_cpumask(thread);



			thread_busy = lw_thread->current_stats.busy_tsc;



			load = _get_thread_load(lw_thread);



			if (i == g_main_lcore && load >= SCHEDULER_LOAD_LIMIT) {

				/* This thread is active and on the main core, we need to pick a core to move it to */

				for (k = 0; k < spdk_env_get_core_count(); k++) {

					target_lcore = _get_next_target_core();



					/* Do not use main core if it is too busy for new thread */

					if (target_lcore == g_main_lcore && thread_busy > main_core->idle) {

						continue;

					}



					if (spdk_cpuset_get_cpu(cpumask, target_lcore)) {

				target_lcore = _find_optimal_core(lw_thread);

				_move_thread(lw_thread, target_lcore);

						break;

					}

				}

			} else if (i != g_main_lcore && load < SCHEDULER_LOAD_LIMIT) {

				/* This thread is idle but not on the main core, so we need to move it to the main core */

				_move_thread(lw_thread, g_main_lcore);

			} else {

			} else if (i != g_main_lcore && !spdk_cpuset_get_cpu(cpumask, i)) {

				/* Move busy thread only if cpumask does not match current core (except main core) */

				if (i != g_main_lcore) {

					if (!spdk_cpuset_get_cpu(cpumask, i)) {

						for (k = 0; k < spdk_env_get_core_count(); k++) {

							target_lcore = _get_next_target_core();



							if (spdk_cpuset_get_cpu(cpumask, target_lcore)) {

				target_lcore = _find_optimal_core(lw_thread);

				_move_thread(lw_thread, target_lcore);

								break;

							}

						}

					}

				}

			}

		}

	}