Commit fe2f8096 authored by Tomasz Zawadzki's avatar Tomasz Zawadzki Committed by Ben Walker
Browse files

scheduler_dynamic: start core selection from first core 



The round-robin logic is no longer necessary to spread
the threads around the cores. Starting from core other
than first is even counter-productive to bunching up
threads.

Signed-off-by: default avatarTomasz Zawadzki <tomasz.zawadzki@intel.com>
Change-Id: I5fcee2bacc2d0b4af26336caf381ed954814d731
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/8085


Tested-by: default avatarSPDK CI Jenkins <sys_sgci@intel.com>
Community-CI: Broadcom CI <spdk-ci.pdl@broadcom.com>
Community-CI: Mellanox Build Bot
Reviewed-by: default avatarPaul Luse <paul.e.luse@intel.com>
Reviewed-by: default avatarShuhei Matsumoto <shuhei.matsumoto.xt@hitachi.com>
Reviewed-by: default avatarBen Walker <benjamin.walker@intel.com>
Reviewed-by: default avatarKonrad Sztyber <konrad.sztyber@intel.com>
Reviewed-by: default avatarJim Harris <james.r.harris@intel.com>
parent a5999f63

lib/event/scheduler_dynamic.c

+8 −27
Original line number Diff line number Diff line
@@ -40,7 +40,6 @@ 
#include "spdk/thread.h"

#include "spdk_internal/event.h"



static uint32_t g_next_lcore = SPDK_ENV_LCORE_ID_ANY;

static uint32_t g_main_lcore;

static bool g_core_mngmnt_available;
@@ -56,21 +55,6 @@ static struct core_stats *g_cores; 
#define SCHEDULER_LOAD_LIMIT 50

#define SCHEDULER_CORE_LIMIT 95



static uint32_t

_get_next_target_core(void)

{

	uint32_t target_lcore;



	if (g_next_lcore == SPDK_ENV_LCORE_ID_ANY) {

		g_next_lcore = spdk_env_get_first_core();

	}



	target_lcore = g_next_lcore;

	g_next_lcore = spdk_env_get_next_core(g_next_lcore);



	return target_lcore;

}



static uint8_t

_get_thread_load(struct spdk_lw_thread *lw_thread)

{
@@ -188,7 +172,6 @@ static uint32_t 
_find_optimal_core(struct spdk_lw_thread *lw_thread)

{

	uint32_t i;

	uint32_t target_lcore;

	uint32_t current_lcore = lw_thread->lcore;

	uint32_t least_busy_lcore = lw_thread->lcore;

	struct spdk_thread *thread = spdk_thread_get_from_ctx(lw_thread);
@@ -196,30 +179,28 @@ _find_optimal_core(struct spdk_lw_thread *lw_thread) 
	bool core_over_limit = _is_core_over_limit(current_lcore);



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

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

		target_lcore = _get_next_target_core();



	SPDK_ENV_FOREACH_CORE(i) {

		/* Ignore cores outside cpumask. */

		if (!spdk_cpuset_get_cpu(cpumask, target_lcore)) {

		if (!spdk_cpuset_get_cpu(cpumask, i)) {

			continue;

		}



		/* Search for least busy core. */

		if (g_cores[target_lcore].busy < g_cores[least_busy_lcore].busy) {

			least_busy_lcore = target_lcore;

		if (g_cores[i].busy < g_cores[least_busy_lcore].busy) {

			least_busy_lcore = i;

		}



		/* Skip cores that cannot fit the thread and current one. */

		if (!_can_core_fit_thread(lw_thread, target_lcore) || target_lcore == current_lcore) {

		if (!_can_core_fit_thread(lw_thread, i) || i == current_lcore) {

			continue;

		}



		if (target_lcore < current_lcore) {

		if (i < current_lcore) {

			/* Lower core id was found, move to consolidate threads on lowest core ids. */

			return target_lcore;

			return i;

		} else if (core_over_limit) {

			/* When core is over the limit, even higher core ids are better than current one. */

			return target_lcore;

			return i;

		}

	}