From: Maxime Coquelin <maxime.coquelin@redhat.com>
To: "Wang, Zhihong" <zhihong.wang@intel.com>, "dev@dpdk.org" <dev@dpdk.org>
Cc: "yuanhan.liu@linux.intel.com" <yuanhan.liu@linux.intel.com>,
"thomas.monjalon@6wind.com" <thomas.monjalon@6wind.com>
Subject: Re: [dpdk-dev] [PATCH v5 5/6] vhost: batch update used ring
Date: Thu, 15 Sep 2016 18:38:06 +0200 [thread overview]
Message-ID: <52dba6dc-ca0d-1aeb-cf18-89470450a183@redhat.com> (raw)
In-Reply-To: <8F6C2BD409508844A0EFC19955BE09414E70FB6A@SHSMSX103.ccr.corp.intel.com>
On 09/14/2016 10:43 AM, Wang, Zhihong wrote:
>
>
>> -----Original Message-----
>> From: Maxime Coquelin [mailto:maxime.coquelin@redhat.com]
>> Sent: Monday, September 12, 2016 11:46 PM
>> To: Wang, Zhihong <zhihong.wang@intel.com>; dev@dpdk.org
>> Cc: yuanhan.liu@linux.intel.com; thomas.monjalon@6wind.com
>> Subject: Re: [PATCH v5 5/6] vhost: batch update used ring
>>
>>
>>
>> On 09/09/2016 05:39 AM, Zhihong Wang wrote:
>>> This patch enables batch update of the used ring for better efficiency.
>>>
>>> Signed-off-by: Zhihong Wang <zhihong.wang@intel.com>
>>> ---
>>> Changes in v4:
>>>
>>> 1. Free shadow used ring in the right place.
>>>
>>> 2. Add failure check for shadow used ring malloc.
>>>
>>> lib/librte_vhost/vhost.c | 20 ++++++++++++--
>>> lib/librte_vhost/vhost.h | 4 +++
>>> lib/librte_vhost/vhost_user.c | 31 +++++++++++++++++----
>>> lib/librte_vhost/virtio_net.c | 64
>> +++++++++++++++++++++++++++++++++++--------
>>> 4 files changed, 101 insertions(+), 18 deletions(-)
>>>
>>> diff --git a/lib/librte_vhost/vhost.c b/lib/librte_vhost/vhost.c
>>> index 46095c3..cb31cdd 100644
>>> --- a/lib/librte_vhost/vhost.c
>>> +++ b/lib/librte_vhost/vhost.c
>>> @@ -119,10 +119,26 @@ cleanup_device(struct virtio_net *dev, int
>> destroy)
>>> static void
>>> free_device(struct virtio_net *dev)
>>> {
>>> + struct vhost_virtqueue *vq_0;
>>> + struct vhost_virtqueue *vq_1;
>>> uint32_t i;
>>>
>>> - for (i = 0; i < dev->virt_qp_nb; i++)
>>> - rte_free(dev->virtqueue[i * VIRTIO_QNUM]);
>>> + for (i = 0; i < dev->virt_qp_nb; i++) {
>>> + vq_0 = dev->virtqueue[i * VIRTIO_QNUM];
>>> + if (vq_0->shadow_used_ring) {
>>> + rte_free(vq_0->shadow_used_ring);
>>> + vq_0->shadow_used_ring = NULL;
>>> + }
>>> +
>>> + vq_1 = dev->virtqueue[i * VIRTIO_QNUM + 1];
>>> + if (vq_1->shadow_used_ring) {
>>> + rte_free(vq_1->shadow_used_ring);
>>> + vq_1->shadow_used_ring = NULL;
>>> + }
>>> +
>>> + /* malloc together, free together */
>>> + rte_free(vq_0);
>>> + }
>>>
>>> rte_free(dev);
>>> }
>>> diff --git a/lib/librte_vhost/vhost.h b/lib/librte_vhost/vhost.h
>>> index 9707dfc..381dc27 100644
>>> --- a/lib/librte_vhost/vhost.h
>>> +++ b/lib/librte_vhost/vhost.h
>>> @@ -85,6 +85,10 @@ struct vhost_virtqueue {
>>>
>>> /* Physical address of used ring, for logging */
>>> uint64_t log_guest_addr;
>>> +
>>> + /* Shadow used ring for performance */
>>> + struct vring_used_elem *shadow_used_ring;
>>> + uint32_t shadow_used_idx;
>>> } __rte_cache_aligned;
>>>
>>> /* Old kernels have no such macro defined */
>>> diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c
>>> index eee99e9..d7cf1ed 100644
>>> --- a/lib/librte_vhost/vhost_user.c
>>> +++ b/lib/librte_vhost/vhost_user.c
>>> @@ -193,7 +193,21 @@ static int
>>> vhost_user_set_vring_num(struct virtio_net *dev,
>>> struct vhost_vring_state *state)
>>> {
>>> - dev->virtqueue[state->index]->size = state->num;
>>> + struct vhost_virtqueue *vq;
>>> +
>>> + vq = dev->virtqueue[state->index];
>>> + vq->size = state->num;
>>> + if (!vq->shadow_used_ring) {
>>> + vq->shadow_used_ring = rte_malloc(NULL,
>>> + vq->size * sizeof(struct vring_used_elem),
>>> + RTE_CACHE_LINE_SIZE);
>>> + if (!vq->shadow_used_ring) {
>>> + RTE_LOG(ERR, VHOST_CONFIG,
>>> + "Failed to allocate memory"
>>> + " for shadow used ring.\n");
>>> + return -1;
>>> + }
>>> + }
>>>
>>> return 0;
>>> }
>>> @@ -611,14 +625,21 @@ static int
>>> vhost_user_get_vring_base(struct virtio_net *dev,
>>> struct vhost_vring_state *state)
>>> {
>>> + struct vhost_virtqueue *vq;
>>> +
>>> /* We have to stop the queue (virtio) if it is running. */
>>> if (dev->flags & VIRTIO_DEV_RUNNING) {
>>> dev->flags &= ~VIRTIO_DEV_RUNNING;
>>> notify_ops->destroy_device(dev->vid);
>>> }
>>>
>>> + vq = dev->virtqueue[state->index];
>>> /* Here we are safe to get the last used index */
>>> - state->num = dev->virtqueue[state->index]->last_used_idx;
>>> + state->num = vq->last_used_idx;
>>> + if (vq->shadow_used_ring) {
>>> + rte_free(vq->shadow_used_ring);
>>> + vq->shadow_used_ring = NULL;
>>> + }
>>>
>>> RTE_LOG(INFO, VHOST_CONFIG,
>>> "vring base idx:%d file:%d\n", state->index, state->num);
>>> @@ -627,10 +648,10 @@ vhost_user_get_vring_base(struct virtio_net
>> *dev,
>>> * sent and only sent in vhost_vring_stop.
>>> * TODO: cleanup the vring, it isn't usable since here.
>>> */
>>> - if (dev->virtqueue[state->index]->kickfd >= 0)
>>> - close(dev->virtqueue[state->index]->kickfd);
>>> + if (vq->kickfd >= 0)
>>> + close(vq->kickfd);
>>>
>>> - dev->virtqueue[state->index]->kickfd =
>> VIRTIO_UNINITIALIZED_EVENTFD;
>>> + vq->kickfd = VIRTIO_UNINITIALIZED_EVENTFD;
>>>
>>> return 0;
>>> }
>>> diff --git a/lib/librte_vhost/virtio_net.c b/lib/librte_vhost/virtio_net.c
>>> index b38f18f..e9f6353 100644
>>> --- a/lib/librte_vhost/virtio_net.c
>>> +++ b/lib/librte_vhost/virtio_net.c
>>> @@ -134,17 +134,52 @@ virtio_enqueue_offload(struct rte_mbuf
>> *m_buf, struct virtio_net_hdr *net_hdr)
>>> }
>>>
>>> static inline void __attribute__((always_inline))
>>> -update_used_ring(struct virtio_net *dev, struct vhost_virtqueue *vq,
>>> - uint32_t desc_chain_head, uint32_t desc_chain_len)
>>> +update_used_ring(struct vhost_virtqueue *vq, uint32_t
>> desc_chain_head,
>>> + uint32_t desc_chain_len)
>>> {
>>> - uint32_t used_idx = vq->last_used_idx & (vq->size - 1);
>>> -
>>> - vq->used->ring[used_idx].id = desc_chain_head;
>>> - vq->used->ring[used_idx].len = desc_chain_len;
>>> + vq->shadow_used_ring[vq->shadow_used_idx].id =
>> desc_chain_head;
>>> + vq->shadow_used_ring[vq->shadow_used_idx].len =
>> desc_chain_len;
>>> + vq->shadow_used_idx++;
>>> vq->last_used_idx++;
>>> - vhost_log_used_vring(dev, vq, offsetof(struct vring_used,
>>> - ring[used_idx]),
>>> - sizeof(vq->used->ring[used_idx]));
>>> +}
>>> +
>>> +static inline void __attribute__((always_inline))
>>> +flush_used_ring(struct virtio_net *dev, struct vhost_virtqueue *vq,
>>> + uint32_t used_idx_start)
>>> +{
>>> + if (used_idx_start + vq->shadow_used_idx < vq->size) {
>>> + rte_memcpy(&vq->used->ring[used_idx_start],
>>> + &vq->shadow_used_ring[0],
>>> + vq->shadow_used_idx *
>>> + sizeof(struct vring_used_elem));
>>> + vhost_log_used_vring(dev, vq,
>>> + offsetof(struct vring_used,
>>> + ring[used_idx_start]),
>>> + vq->shadow_used_idx *
>>> + sizeof(struct vring_used_elem));
>>> + } else {
>>> + uint32_t part_1 = vq->size - used_idx_start;
>>> + uint32_t part_2 = vq->shadow_used_idx - part_1;
>>> +
>>> + rte_memcpy(&vq->used->ring[used_idx_start],
>>> + &vq->shadow_used_ring[0],
>>> + part_1 *
>>> + sizeof(struct vring_used_elem));
>>> + vhost_log_used_vring(dev, vq,
>>> + offsetof(struct vring_used,
>>> + ring[used_idx_start]),
>>> + part_1 *
>>> + sizeof(struct vring_used_elem));
>>> + rte_memcpy(&vq->used->ring[0],
>>> + &vq->shadow_used_ring[part_1],
>>> + part_2 *
>>> + sizeof(struct vring_used_elem));
>>> + vhost_log_used_vring(dev, vq,
>>> + offsetof(struct vring_used,
>>> + ring[0]),
>>> + part_2 *
>>> + sizeof(struct vring_used_elem));
>>> + }
>>> }
>> Is expanding the code done for performance purpose?
>
> Hi Maxime,
>
> Yes theoretically this has the least branch number.
> And I think the logic is simpler this way.
Ok, in that case, maybe you could create a function to
do the rte_memcpy and the vhost_log_used on a given range.
I don't have a strong opinion on this, if Yuanhan is fine
with current code, that's ok for me.
Thanks,
Maxime
>
> Thanks
> Zhihong
>
>> Or maybe we could have a loop to do that?
>> Something like this (not compiled, not tested):
>>
>> static inline void __attribute__((always_inline))
>> flush_used_ring(struct virtio_net *dev, struct vhost_virtqueue *vq,
>> {
>> uint32_t to = used_idx_start;
>> uint32_t from = 0;
>> uint32_t count;
>>
>> if (used_idx_start + vq->shadow_used_idx < vq->size)
>> count = vq->shadow_used_idx;
>> else
>> count = vq->size - used_idx_start;
>>
>> do {
>> rte_memcpy(&vq->used->ring[to],
>> &vq->shadow_used_ring[from],
>> count * sizeof(struct vring_used_elem));
>> vhost_log_used_vring(dev, vq,
>> offsetof(struct vring_used, ring[to]),
>> count * sizeof(struct vring_used_elem));
>>
>> to = (to + count) & (vq->size - 1);
>> from += count;
>> count = vq->shadow_used_idx - count;
>> } while (count);
>> }
>>
>> Regards,
>> Maxime
next prev parent reply other threads:[~2016-09-15 16:38 UTC|newest]
Thread overview: 140+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-08-16 3:50 [dpdk-dev] [PATCH] optimize vhost enqueue Zhihong Wang
2016-08-16 13:59 ` Maxime Coquelin
2016-08-17 1:45 ` Wang, Zhihong
2016-08-17 2:38 ` Yuanhan Liu
2016-08-17 6:41 ` Wang, Zhihong
2016-08-17 9:17 ` Maxime Coquelin
2016-08-17 9:51 ` Yuanhan Liu
2016-08-18 13:44 ` Wang, Zhihong
2016-08-17 10:07 ` Wang, Zhihong
2016-08-18 6:33 ` [dpdk-dev] [PATCH v2 0/6] vhost: optimize enqueue Zhihong Wang
2016-08-18 6:33 ` [dpdk-dev] [PATCH v2 1/6] vhost: rewrite enqueue Zhihong Wang
2016-08-19 2:39 ` Yuanhan Liu
2016-08-19 7:07 ` Wang, Zhihong
2016-08-18 6:33 ` [dpdk-dev] [PATCH v2 2/6] vhost: remove obsolete Zhihong Wang
2016-08-19 2:32 ` Yuanhan Liu
2016-08-19 7:08 ` Wang, Zhihong
2016-08-18 6:33 ` [dpdk-dev] [PATCH v2 3/6] vhost: remove useless volatile Zhihong Wang
2016-08-18 6:33 ` [dpdk-dev] [PATCH v2 4/6] vhost: add desc prefetch Zhihong Wang
2016-08-18 6:33 ` [dpdk-dev] [PATCH v2 5/6] vhost: batch update used ring Zhihong Wang
2016-08-18 6:33 ` [dpdk-dev] [PATCH v2 6/6] vhost: optimize cache access Zhihong Wang
2016-08-19 5:43 ` [dpdk-dev] [PATCH v3 0/5] vhost: optimize enqueue Zhihong Wang
2016-08-19 5:43 ` [dpdk-dev] [PATCH v3 1/5] vhost: rewrite enqueue Zhihong Wang
2016-08-22 9:35 ` Maxime Coquelin
2016-08-23 2:27 ` Wang, Zhihong
2016-08-25 4:00 ` Yuanhan Liu
2016-08-19 5:43 ` [dpdk-dev] [PATCH v3 2/5] vhost: remove useless volatile Zhihong Wang
2016-08-19 5:43 ` [dpdk-dev] [PATCH v3 3/5] vhost: add desc prefetch Zhihong Wang
2016-08-19 5:43 ` [dpdk-dev] [PATCH v3 4/5] vhost: batch update used ring Zhihong Wang
2016-08-25 3:48 ` Yuanhan Liu
2016-08-25 5:19 ` Wang, Zhihong
2016-08-19 5:43 ` [dpdk-dev] [PATCH v3 5/5] vhost: optimize cache access Zhihong Wang
2016-08-22 8:11 ` [dpdk-dev] [PATCH v3 0/5] vhost: optimize enqueue Maxime Coquelin
2016-08-22 10:01 ` Maxime Coquelin
2016-08-22 10:35 ` Thomas Monjalon
2016-08-24 3:37 ` Wang, Zhihong
2016-08-23 2:31 ` Wang, Zhihong
2016-08-23 10:43 ` Wang, Zhihong
2016-08-23 12:16 ` Maxime Coquelin
2016-08-23 12:22 ` Yuanhan Liu
2016-08-23 2:15 ` Wang, Zhihong
2016-09-21 8:50 ` Jianbo Liu
2016-09-21 9:27 ` Wang, Zhihong
2016-09-21 12:54 ` Jianbo Liu
2016-09-22 2:11 ` Wang, Zhihong
2016-09-22 2:29 ` Yuanhan Liu
2016-09-22 5:47 ` Jianbo Liu
2016-09-22 6:58 ` Wang, Zhihong
2016-09-22 9:01 ` Jianbo Liu
2016-09-22 10:04 ` Wang, Zhihong
2016-09-22 14:41 ` Jianbo Liu
2016-09-23 2:56 ` Wang, Zhihong
2016-09-23 10:41 ` Jianbo Liu
2016-09-23 13:41 ` Thomas Monjalon
2016-09-25 5:41 ` Wang, Zhihong
2016-09-26 5:12 ` Jianbo Liu
2016-09-26 5:25 ` Wang, Zhihong
2016-09-26 5:38 ` Jianbo Liu
2016-09-26 6:00 ` Wang, Zhihong
2016-09-26 4:24 ` Jianbo Liu
2016-09-26 5:37 ` Luke Gorrie
2016-09-26 5:40 ` Jianbo Liu
2016-09-27 10:21 ` Yuanhan Liu
2016-09-27 16:45 ` Wang, Zhihong
2016-10-09 12:09 ` Wang, Zhihong
2016-10-10 2:44 ` Yuanhan Liu
2016-10-10 5:31 ` Jianbo Liu
2016-10-10 6:22 ` Wang, Zhihong
2016-10-10 6:57 ` Jianbo Liu
2016-10-10 7:25 ` Wang, Zhihong
2016-10-12 2:53 ` Yuanhan Liu
2016-10-12 12:22 ` Wang, Zhihong
2016-10-12 15:31 ` Thomas Monjalon
2016-10-13 1:21 ` Wang, Zhihong
2016-10-13 3:51 ` Jianbo Liu
2016-10-13 5:33 ` Yuanhan Liu
2016-10-13 5:35 ` Yuanhan Liu
2016-10-13 6:02 ` Wang, Zhihong
2016-10-13 7:54 ` Maxime Coquelin
2016-10-13 9:23 ` Maxime Coquelin
2016-10-14 10:11 ` Yuanhan Liu
2016-08-30 3:35 ` [dpdk-dev] [PATCH v4 0/6] " Zhihong Wang
2016-08-30 3:35 ` [dpdk-dev] [PATCH v4 1/6] vhost: fix windows vm hang Zhihong Wang
2016-09-05 5:24 ` [dpdk-dev] [dpdk-stable] " Yuanhan Liu
2016-09-05 5:25 ` Wang, Zhihong
2016-09-05 5:40 ` Yuanhan Liu
2016-08-30 3:36 ` [dpdk-dev] [PATCH v4 2/6] vhost: rewrite enqueue Zhihong Wang
2016-09-05 6:39 ` Yuanhan Liu
2016-09-07 5:33 ` Yuanhan Liu
2016-09-07 5:39 ` Wang, Zhihong
2016-08-30 3:36 ` [dpdk-dev] [PATCH v4 3/6] vhost: remove useless volatile Zhihong Wang
2016-08-30 3:36 ` [dpdk-dev] [PATCH v4 4/6] vhost: add desc prefetch Zhihong Wang
2016-08-30 3:36 ` [dpdk-dev] [PATCH v4 5/6] vhost: batch update used ring Zhihong Wang
2016-08-30 3:36 ` [dpdk-dev] [PATCH v4 6/6] vhost: optimize cache access Zhihong Wang
2016-09-09 3:39 ` [dpdk-dev] [PATCH v5 0/6] vhost: optimize enqueue Zhihong Wang
2016-09-09 3:39 ` [dpdk-dev] [PATCH v5 1/6] vhost: fix windows vm hang Zhihong Wang
2016-09-09 3:39 ` [dpdk-dev] [PATCH v5 2/6] vhost: rewrite enqueue Zhihong Wang
2016-09-12 15:42 ` Maxime Coquelin
2016-09-14 8:20 ` Wang, Zhihong
2016-09-15 16:35 ` Maxime Coquelin
2016-09-12 16:26 ` Maxime Coquelin
2016-09-14 8:22 ` Wang, Zhihong
2016-09-18 14:19 ` Yuanhan Liu
2016-09-19 3:29 ` Wang, Zhihong
2016-09-09 3:39 ` [dpdk-dev] [PATCH v5 3/6] vhost: remove useless volatile Zhihong Wang
2016-09-09 3:39 ` [dpdk-dev] [PATCH v5 4/6] vhost: add desc prefetch Zhihong Wang
2016-09-09 3:39 ` [dpdk-dev] [PATCH v5 5/6] vhost: batch update used ring Zhihong Wang
2016-09-12 15:45 ` Maxime Coquelin
2016-09-14 8:43 ` Wang, Zhihong
2016-09-15 16:38 ` Maxime Coquelin [this message]
2016-09-18 2:55 ` Yuanhan Liu
2016-09-18 2:57 ` Wang, Zhihong
2016-09-09 3:39 ` [dpdk-dev] [PATCH v5 6/6] vhost: optimize cache access Zhihong Wang
2016-09-12 13:52 ` [dpdk-dev] [PATCH v5 0/6] vhost: optimize enqueue Maxime Coquelin
2016-09-12 13:56 ` Maxime Coquelin
2016-09-12 14:01 ` Yuanhan Liu
2016-09-20 2:00 ` [dpdk-dev] [PATCH v6 " Zhihong Wang
2016-09-20 2:00 ` [dpdk-dev] [PATCH v6 1/6] vhost: fix windows vm hang Zhihong Wang
2016-10-13 6:18 ` [dpdk-dev] [dpdk-stable] " Yuanhan Liu
2016-09-20 2:00 ` [dpdk-dev] [PATCH v6 2/6] vhost: rewrite enqueue Zhihong Wang
2016-09-22 9:58 ` Jianbo Liu
2016-09-22 10:13 ` Wang, Zhihong
2016-09-20 2:00 ` [dpdk-dev] [PATCH v6 3/6] vhost: remove useless volatile Zhihong Wang
2016-09-20 2:00 ` [dpdk-dev] [PATCH v6 4/6] vhost: add desc prefetch Zhihong Wang
2016-09-20 2:00 ` [dpdk-dev] [PATCH v6 5/6] vhost: batch update used ring Zhihong Wang
2016-09-20 2:00 ` [dpdk-dev] [PATCH v6 6/6] vhost: optimize cache access Zhihong Wang
2016-09-21 2:26 ` [dpdk-dev] [PATCH v6 0/6] vhost: optimize enqueue Yuanhan Liu
2016-09-21 4:39 ` Maxime Coquelin
2016-10-14 9:34 ` [dpdk-dev] [PATCH v7 0/7] vhost: optimize mergeable Rx path Yuanhan Liu
2016-10-14 9:34 ` [dpdk-dev] [PATCH v7 1/7] vhost: remove useless volatile Yuanhan Liu
2016-10-14 9:34 ` [dpdk-dev] [PATCH v7 2/7] vhost: optimize cache access Yuanhan Liu
2016-10-14 9:34 ` [dpdk-dev] [PATCH v7 3/7] vhost: simplify mergeable Rx vring reservation Yuanhan Liu
2016-10-25 22:08 ` Thomas Monjalon
2016-10-26 2:56 ` Yuanhan Liu
2016-10-14 9:34 ` [dpdk-dev] [PATCH v7 4/7] vhost: use last avail idx for avail ring reservation Yuanhan Liu
2016-10-14 9:34 ` [dpdk-dev] [PATCH v7 5/7] vhost: shadow used ring update Yuanhan Liu
2016-10-14 9:34 ` [dpdk-dev] [PATCH v7 6/7] vhost: prefetch avail ring Yuanhan Liu
2016-10-14 9:34 ` [dpdk-dev] [PATCH v7 7/7] vhost: retrieve avail head once Yuanhan Liu
2016-10-18 2:25 ` [dpdk-dev] [PATCH v7 0/7] vhost: optimize mergeable Rx path Jianbo Liu
2016-10-18 14:53 ` Maxime Coquelin
2016-10-21 7:51 ` Yuanhan Liu
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