split affinity

split_affinity.c

/**
 * Assign the packet parsing threads to the top half of the CPUs supplied in the
 * config. The bottom half of the CPUs will be used for the channel threads.
 *
 * @param teb		Pointer to our TEB.
 *
 * @retval		BL_OK.
 */
__BL_STATIC int
drone_sysmgr_aff_core_split(bl_teb_t *teb)
{
	if (DRONE_CTX.num_desired_channels > 1)
		DRONE_CTX.num_desired_channels /= 2;

	if (DRONE_CTX.num_desired_irq_cores > 1)
		DRONE_CTX.num_desired_irq_cores /= 2;

	bl_assert(DRONE_CTX.num_desired_channels
	          <= bl_arraysz(DRONE_CTX.aff_packet_cores));
	bl_assert(DRONE_CTX.num_desired_channels
	          <= bl_arraysz(GlobalDroneConfig.channel_affinities));
	bl_assert(DRONE_CTX.num_desired_irq_cores <= bl_arraysz(DRONE_CTX.aff_irq_cores));
	bl_assert(DRONE_CTX.num_desired_irq_cores
	          <= bl_arraysz(GlobalDroneConfig.irq_affinities));

	/* Assign the packet threads to the upper half of the cores.
	 * Offset the CPU index by the number of channels as the lower half will
	 * be used for the XDP program. */
	for (int aff = 0; aff < DRONE_CTX.num_desired_channels; aff++)
	{
		DRONE_CTX.aff_packet_cores[aff] =
		    GlobalDroneConfig
			.channel_affinities[aff + DRONE_CTX.num_desired_channels];

		/*
		Assign lower half of cores to IRQ handling
		ie. do not offset by the number of channels
		*/
		DRONE_CTX.aff_irq_cores[aff] = GlobalDroneConfig.irq_affinities[aff];
	}

	/* Turn on the cores affinity flag for the drone. */
	DRONE_CTX.aff_packet_flags = BL_EX_AFF_CORES;

	return BL_OK;
}