[dpdk-dev] [PATCH 3/3] common/qat: optimise calculation of cookie index
Adam Dybkowski
adamx.dybkowski at intel.com
Wed Mar 11 13:26:08 CET 2020
From: Fiona Trahe <fiona.trahe at intel.com>
Avoid costly division, use shift instead.
Signed-off-by: Fiona Trahe <fiona.trahe at intel.com>
---
drivers/common/qat/qat_qp.c | 9 ++++++---
drivers/common/qat/qat_qp.h | 1 +
2 files changed, 7 insertions(+), 3 deletions(-)
diff --git a/drivers/common/qat/qat_qp.c b/drivers/common/qat/qat_qp.c
index 9958789f0..b0a206434 100644
--- a/drivers/common/qat/qat_qp.c
+++ b/drivers/common/qat/qat_qp.c
@@ -430,6 +430,9 @@ qat_queue_create(struct qat_pci_device *qat_dev, struct qat_queue *queue,
queue->tail = 0;
queue->msg_size = desc_size;
+ /* For fast calculation of cookie index, relies on msg_size being 2^n */
+ queue->trailz = __builtin_ctz(desc_size);
+
/*
* Write an unused pattern to the queue memory.
*/
@@ -623,7 +626,7 @@ qat_enqueue_op_burst(void *qp, void **ops, uint16_t nb_ops)
while (nb_ops_sent != nb_ops_possible) {
ret = tmp_qp->build_request(*ops, base_addr + tail,
- tmp_qp->op_cookies[tail / queue->msg_size],
+ tmp_qp->op_cookies[tail >> queue->trailz],
tmp_qp->qat_dev_gen);
if (ret != 0) {
tmp_qp->stats.enqueue_err_count++;
@@ -665,12 +668,12 @@ qat_dequeue_op_burst(void *qp, void **ops, uint16_t nb_ops)
qat_sym_process_response(ops, resp_msg);
else if (tmp_qp->service_type == QAT_SERVICE_COMPRESSION)
qat_comp_process_response(ops, resp_msg,
- tmp_qp->op_cookies[head / rx_queue->msg_size],
+ tmp_qp->op_cookies[head >> rx_queue->trailz],
&tmp_qp->stats.dequeue_err_count);
else if (tmp_qp->service_type == QAT_SERVICE_ASYMMETRIC) {
#ifdef BUILD_QAT_ASYM
qat_asym_process_response(ops, resp_msg,
- tmp_qp->op_cookies[head / rx_queue->msg_size]);
+ tmp_qp->op_cookies[head >> rx_queue->trailz]);
#endif
}
diff --git a/drivers/common/qat/qat_qp.h b/drivers/common/qat/qat_qp.h
index 0b95ea3c9..0d6896d7b 100644
--- a/drivers/common/qat/qat_qp.h
+++ b/drivers/common/qat/qat_qp.h
@@ -54,6 +54,7 @@ struct qat_queue {
uint32_t modulo_mask;
uint32_t msg_size;
uint32_t queue_size;
+ uint8_t trailz;
uint8_t hw_bundle_number;
uint8_t hw_queue_number;
/* HW queue aka ring offset on bundle */
--
2.17.1
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