Commit 2cd9f395 authored by Changpeng Liu's avatar Changpeng Liu Committed by Daniel Verkamp
Browse files

vhost/nvme: move completion irq signal into IO poller context 



Previously after IO is finished, we will put completion entry and
irq event notice at the same IO completion callback, for performance
consideration, move the irq event routine into IO poller context, this
can be used to implement interrupt coalescing feature in future.

Change-Id: Ic20b50af47b73ffcb91938802e18b316c07a4d11
Signed-off-by: default avatarChangpeng Liu <changpeng.liu@intel.com>
Reviewed-on: https://review.gerrithub.io/408943


Tested-by: default avatarSPDK Automated Test System <sys_sgsw@intel.com>
Reviewed-by: default avatarDaniel Verkamp <daniel.verkamp@intel.com>
Reviewed-by: default avatarPawel Wodkowski <pawelx.wodkowski@intel.com>
Reviewed-by: default avatarJim Harris <james.r.harris@intel.com>
parent cb094a03

lib/vhost/vhost_nvme.c

+28 −4
Original line number Diff line number Diff line
@@ -72,6 +72,7 @@ struct spdk_vhost_nvme_cq { 
	volatile struct spdk_nvme_cpl *cq_cqe;

	uint16_t cq_head;

	uint16_t guest_signaled_cq_head;

	uint32_t need_signaled_cnt;

	STAILQ_HEAD(, spdk_vhost_nvme_task) cq_full_waited_tasks;

	bool irq_enabled;

	int virq;
@@ -284,6 +285,28 @@ spdk_nvme_map_prps(struct spdk_vhost_nvme_dev *nvme, struct spdk_nvme_cmd *cmd, 
	return 0;

}



static void

spdk_nvme_cq_signal_fd(struct spdk_vhost_nvme_dev *nvme)

{

	struct spdk_vhost_nvme_cq *cq;

	uint32_t qid, cq_head;



	assert(nvme != NULL);



	for (qid = 1; qid <= MAX_IO_QUEUES; qid++) {

		cq = spdk_vhost_nvme_get_cq_from_qid(nvme, qid);

		if (!cq || !cq->valid) {

			continue;

		}



		cq_head = nvme->dbbuf_dbs[cq_offset(qid, 1)];

		if (cq->irq_enabled && cq->need_signaled_cnt && (cq->cq_head != cq_head)) {

			eventfd_write(cq->virq, (eventfd_t)1);

			cq->need_signaled_cnt = 0;

		}

	}

}



static void

blk_request_complete_cb(struct spdk_bdev_io *bdev_io, bool success, void *cb_arg)

{
@@ -338,14 +361,11 @@ blk_request_complete_cb(struct spdk_bdev_io *bdev_io, bool success, void *cb_arg 
	cq->cq_cqe[cq->cq_head].status.p = cq->phase;



	nvme_inc_cq_head(cq);

	cq->need_signaled_cnt++;



	/* MMIO Controll */

	nvme->dbbuf_eis[cq_offset(cqid, 1)] = (uint32_t)(cq->guest_signaled_cq_head - 1);



	if (cq->irq_enabled && (cq->cq_head != cq->guest_signaled_cq_head)) {

		eventfd_write(cq->virq, (eventfd_t)1);

	}



	STAILQ_INSERT_TAIL(&nvme->free_tasks, task, stailq);

}
@@ -570,6 +590,9 @@ nvme_worker(void *arg) 
		}

	}



	/* Completion Queue */

	spdk_nvme_cq_signal_fd(nvme);



	return count;

}
@@ -716,6 +739,7 @@ vhost_nvme_create_io_cq(struct spdk_vhost_nvme_dev *nvme, 
	cq->virq = -1;

	cq->cq_head = 0;

	cq->guest_signaled_cq_head = 0;

	cq->need_signaled_cnt = 0;

	requested_len = sizeof(struct spdk_nvme_cpl) * cq->size;

	cq->cq_cqe = spdk_vhost_gpa_to_vva(&nvme->vdev, dma_addr, requested_len);

	if (!cq->cq_cqe) {