On Tue, Mar 19, 2019 at 02:43:06PM +0800, Tiwei Bie wrote:
Cache the AVAIL, USED and WRITE bits to avoid calculating
them as much as possible. Note that, the WRITE bit isn't
cached for control queue.
Signed-off-by: Tiwei Bie <tiwei....@intel.com>
---
drivers/net/virtio/virtio_ethdev.c | 35 ++++++++++++++----------------
drivers/net/virtio/virtio_rxtx.c | 31 ++++++++++----------------
drivers/net/virtio/virtqueue.h | 8 +++----
3 files changed, 32 insertions(+), 42 deletions(-)
diff --git a/drivers/net/virtio/virtio_ethdev.c
b/drivers/net/virtio/virtio_ethdev.c
index ff16fb63e..9060b6b33 100644
--- a/drivers/net/virtio/virtio_ethdev.c
+++ b/drivers/net/virtio/virtio_ethdev.c
@@ -149,7 +149,7 @@ virtio_send_command_packed(struct virtnet_ctl *cvq,
int head;
struct vring_packed_desc *desc = vq->ring_packed.desc_packed;
struct virtio_pmd_ctrl *result;
- bool avail_wrap_counter;
+ uint16_t flags;
int sum = 0;
int nb_descs = 0;
int k;
@@ -161,14 +161,15 @@ virtio_send_command_packed(struct virtnet_ctl *cvq,
* One RX packet for ACK.
*/
head = vq->vq_avail_idx;
- avail_wrap_counter = vq->avail_wrap_counter;
+ flags = vq->cached_flags;
desc[head].addr = cvq->virtio_net_hdr_mem;
desc[head].len = sizeof(struct virtio_net_ctrl_hdr);
vq->vq_free_cnt--;
nb_descs++;
if (++vq->vq_avail_idx >= vq->vq_nentries) {
vq->vq_avail_idx -= vq->vq_nentries;
- vq->avail_wrap_counter ^= 1;
+ vq->cached_flags ^=
+ VRING_DESC_F_AVAIL(1) | VRING_DESC_F_USED(1);
Maybe name it avail_used_flags instead of cached flags. Also we could
use a constant value.
}
for (k = 0; k < pkt_num; k++) {
@@ -177,34 +178,31 @@ virtio_send_command_packed(struct virtnet_ctl *cvq,
+ sizeof(ctrl->status) + sizeof(uint8_t) * sum;
desc[vq->vq_avail_idx].len = dlen[k];
desc[vq->vq_avail_idx].flags = VRING_DESC_F_NEXT |
- VRING_DESC_F_AVAIL(vq->avail_wrap_counter) |
- VRING_DESC_F_USED(!vq->avail_wrap_counter);
+ vq->cached_flags;
sum += dlen[k];
vq->vq_free_cnt--;
nb_descs++;
if (++vq->vq_avail_idx >= vq->vq_nentries) {
vq->vq_avail_idx -= vq->vq_nentries;
- vq->avail_wrap_counter ^= 1;
+ vq->cached_flags ^=
+ VRING_DESC_F_AVAIL(1) | VRING_DESC_F_USED(1);
}
}
desc[vq->vq_avail_idx].addr = cvq->virtio_net_hdr_mem
+ sizeof(struct virtio_net_ctrl_hdr);
desc[vq->vq_avail_idx].len = sizeof(ctrl->status);
- desc[vq->vq_avail_idx].flags = VRING_DESC_F_WRITE |
- VRING_DESC_F_AVAIL(vq->avail_wrap_counter) |
- VRING_DESC_F_USED(!vq->avail_wrap_counter);
+ desc[vq->vq_avail_idx].flags = VRING_DESC_F_WRITE | vq->cached_flags;
vq->vq_free_cnt--;
nb_descs++;
if (++vq->vq_avail_idx >= vq->vq_nentries) {
vq->vq_avail_idx -= vq->vq_nentries;
- vq->avail_wrap_counter ^= 1;
+ vq->cached_flags ^=
+ VRING_DESC_F_AVAIL(1) | VRING_DESC_F_USED(1);
}
virtio_wmb(vq->hw->weak_barriers);
- desc[head].flags = VRING_DESC_F_NEXT |
- VRING_DESC_F_AVAIL(avail_wrap_counter) |
- VRING_DESC_F_USED(!avail_wrap_counter);
+ desc[head].flags = VRING_DESC_F_NEXT | flags;
virtio_wmb(vq->hw->weak_barriers);
virtqueue_notify(vq);
@@ -226,12 +224,12 @@ virtio_send_command_packed(struct virtnet_ctl *cvq,
PMD_INIT_LOG(DEBUG, "vq->vq_free_cnt=%d\n"
"vq->vq_avail_idx=%d\n"
"vq->vq_used_cons_idx=%d\n"
- "vq->avail_wrap_counter=%d\n"
+ "vq->cached_flags=0x%x\n"
"vq->used_wrap_counter=%d\n",
vq->vq_free_cnt,
vq->vq_avail_idx,
vq->vq_used_cons_idx,
- vq->avail_wrap_counter,
+ vq->cached_flags,
vq->used_wrap_counter);
result = cvq->virtio_net_hdr_mz->addr;
@@ -491,11 +489,10 @@ virtio_init_queue(struct rte_eth_dev *dev, uint16_t
vtpci_queue_idx)
vq->vq_nentries = vq_size;
vq->event_flags_shadow = 0;
if (vtpci_packed_queue(hw)) {
- vq->avail_wrap_counter = 1;
vq->used_wrap_counter = 1;
- vq->avail_used_flags =
- VRING_DESC_F_AVAIL(vq->avail_wrap_counter) |
- VRING_DESC_F_USED(!vq->avail_wrap_counter);
+ vq->cached_flags = VRING_DESC_F_AVAIL(1);
+ if (queue_type == VTNET_RQ)
+ vq->cached_flags |= VRING_DESC_F_WRITE;
}
/*
diff --git a/drivers/net/virtio/virtio_rxtx.c b/drivers/net/virtio/virtio_rxtx.c
index 771d3c3f6..3c354baef 100644
--- a/drivers/net/virtio/virtio_rxtx.c
+++ b/drivers/net/virtio/virtio_rxtx.c
@@ -431,7 +431,7 @@ virtqueue_enqueue_recv_refill_packed(struct virtqueue *vq,
struct rte_mbuf **cookie, uint16_t num)
{
struct vring_packed_desc *start_dp = vq->ring_packed.desc_packed;
- uint16_t flags = VRING_DESC_F_WRITE | vq->avail_used_flags;
+ uint16_t flags = vq->cached_flags;
struct virtio_hw *hw = vq->hw;
struct vq_desc_extra *dxp;
uint16_t idx;
@@ -460,11 +460,9 @@ virtqueue_enqueue_recv_refill_packed(struct virtqueue *vq,
start_dp[idx].flags = flags;
if (++vq->vq_avail_idx >= vq->vq_nentries) {
vq->vq_avail_idx -= vq->vq_nentries;
- vq->avail_wrap_counter ^= 1;
- vq->avail_used_flags =
- VRING_DESC_F_AVAIL(vq->avail_wrap_counter) |
- VRING_DESC_F_USED(!vq->avail_wrap_counter);
- flags = VRING_DESC_F_WRITE | vq->avail_used_flags;
+ vq->cached_flags ^=
+ VRING_DESC_F_AVAIL(1) | VRING_DESC_F_USED(1);
+ flags = vq->cached_flags;
same here. it's not really cached, it's pre-calculated. And here we
could also use a pre-calculated constand/define.
Otherwise looks good! Did you see any performance improvements?
regards,
Jens
