Commit 0241b85b authored by Shuhei Matsumoto's avatar Shuhei Matsumoto Committed by Jim Harris
Browse files

iscsi: Remove DPDK dependency and simplify load balancing 



Load balancing for idle iSCSI connections uses the RTE EAL Launch
state and uses DPDK RTE EAL API.

But all SPDK reactors will exit simultaneously because each SPDK
reactor checks if the global state is RUNNING to exit.

Hence calling rte_eal_get_lcore_state() is not necessary.

When the reactor hot-plug function is supported, this implementation
will be reconsidered together.

Change-Id: I34eaf3e42b5b7deae6473d2bfaf0910aaa9da6de
Signed-off-by: default avatarShuhei Matsumoto <shuhei.matsumoto.xt@hitachi.com>
Reviewed-on: https://review.gerrithub.io/391339


Tested-by: default avatarSPDK Automated Test System <sys_sgsw@intel.com>
Reviewed-by: default avatarBen Walker <benjamin.walker@intel.com>
Reviewed-by: default avatarJim Harris <james.r.harris@intel.com>
parent 855d8e03

lib/iscsi/conn.c

+15 −41
Original line number Diff line number Diff line
@@ -35,7 +35,6 @@ 
#include "spdk/stdinc.h"



#include <rte_config.h>

#include <rte_mempool.h>



#if defined(__FreeBSD__)

#include <sys/event.h>
@@ -1591,46 +1590,23 @@ static uint32_t 
spdk_iscsi_conn_allocate_reactor(uint64_t cpumask)

{

	uint32_t i, selected_core;

	enum rte_lcore_state_t state;

	uint32_t first_core = spdk_env_get_first_core();

	int32_t num_pollers, min_pollers;



	cpumask &= spdk_app_get_core_mask();

	if (cpumask == 0) {

		return first_core;

	}



	min_pollers = INT_MAX;

	selected_core = 0;

	selected_core = spdk_env_get_first_core();



	/* we use u64 as CPU core mask */

	for (i = 0; i < RTE_MAX_LCORE && i < 64; i++) {

	SPDK_ENV_FOREACH_CORE(i) {

		if (!((1ULL << i) & cpumask)) {

			continue;

		}



		/*

		 * DPDK returns WAIT for the master core instead of RUNNING.

		 * So we always treat the reactor on master core as RUNNING.

		 */

		if (i == first_core) {

			state = RUNNING;

		} else {

			state = rte_eal_get_lcore_state(i);

		}



		switch (state) {

		case WAIT:

		case FINISHED:

			/* reactor does not run on the lcore */

			break;

		case RUNNING:

			/* This lcore is running. Check how many pollers it already has. */

		/* This core is running. Check how many pollers it already has. */

		num_pollers = g_num_connections[i];



		if ((num_pollers > 0) && (num_pollers < g_connections_per_lcore)) {

				/* Fewer than the maximum connections per lcore,

				 * but at least 1. Use this lcore.

			/* Fewer than the maximum connections per core,

			 * but at least 1. Use this core.

			 */

			return i;

		} else if (num_pollers < min_pollers) {
@@ -1640,8 +1616,6 @@ spdk_iscsi_conn_allocate_reactor(uint64_t cpumask) 
			selected_core = i;

			min_pollers = num_pollers;

		}

			break;

		}

	}



	return selected_core;