Stefano Garzarella
2019-May-10 12:58 UTC
[PATCH v2 0/8] vsock/virtio: optimizations to increase the throughput
While I was testing this new series (v2) I discovered an huge use of memory and a memory leak in the virtio-vsock driver in the guest when I sent 1-byte packets to the guest. These issues are present since the introduction of the virtio-vsock driver. I added the patches 1 and 2 to fix them in this series in order to better track the performance trends. v1: https://patchwork.kernel.org/cover/10885431/ v2: - Add patch 1 to limit the memory usage - Add patch 2 to avoid memory leak during the socket release - Add patch 3 to fix locking of fwd_cnt and buf_alloc - Patch 4: fix 'free_space' type (u32 instead of s64) [Stefan] - Patch 5: Avoid integer underflow of iov_len [Stefan] - Patch 5: Fix packet capture in order to see the exact packets that are delivered. [Stefan] - Add patch 8 to make the RX buffer size tunable [Stefan] Below are the benchmarks step by step. I used iperf3 [1] modified with VSOCK support. As Micheal suggested in the v1, I booted host and guest with 'nosmap', and I added a column with virtio-net+vhost-net performance. A brief description of patches: - Patches 1+2: limit the memory usage with an extra copy and avoid memory leak - Patches 3+4: fix locking and reduce the number of credit update messages sent to the transmitter - Patches 5+6: allow the host to split packets on multiple buffers and use VIRTIO_VSOCK_MAX_PKT_BUF_SIZE as the max packet size allowed - Patches 7+8: increase RX buffer size to 64 KiB host -> guest [Gbps] pkt_size before opt p 1+2 p 3+4 p 5+6 p 7+8 virtio-net + vhost TCP_NODELAY 64 0.068 0.063 0.130 0.131 0.128 0.188 0.187 256 0.274 0.236 0.392 0.338 0.282 0.749 0.654 512 0.531 0.457 0.862 0.725 0.602 1.419 1.414 1K 0.954 0.827 1.591 1.598 1.548 2.599 2.640 2K 1.783 1.543 3.731 3.637 3.469 4.530 4.754 4K 3.332 3.436 7.164 7.124 6.494 7.738 7.696 8K 5.792 5.530 11.653 11.787 11.444 12.307 11.850 16K 8.405 8.462 16.372 16.855 17.562 16.936 16.954 32K 14.208 13.669 18.945 20.009 23.128 21.980 23.015 64K 21.082 18.893 20.266 20.903 30.622 27.290 27.383 128K 20.696 20.148 20.112 21.746 32.152 30.446 30.990 256K 20.801 20.589 20.725 22.685 34.721 33.151 32.745 512K 21.220 20.465 20.432 22.106 34.496 36.847 31.096 guest -> host [Gbps] pkt_size before opt p 1+2 p 3+4 p 5+6 p 7+8 virtio-net + vhost TCP_NODELAY 64 0.089 0.091 0.120 0.115 0.117 0.274 0.272 256 0.352 0.354 0.452 0.445 0.451 1.085 1.136 512 0.705 0.704 0.893 0.858 0.898 2.131 1.882 1K 1.394 1.433 1.721 1.669 1.691 3.984 3.576 2K 2.818 2.874 3.316 3.249 3.303 6.719 6.359 4K 5.293 5.397 6.129 5.933 6.082 10.105 9.860 8K 8.890 9.151 10.990 10.545 10.519 15.239 14.868 16K 11.444 11.018 12.074 15.255 15.577 20.551 20.848 32K 11.229 10.875 10.857 24.401 25.227 26.294 26.380 64K 10.832 10.545 10.816 39.487 39.616 34.996 32.041 128K 10.435 10.241 10.500 39.813 40.012 38.379 35.055 256K 10.263 9.866 9.845 34.971 35.143 36.559 37.232 512K 10.224 10.060 10.092 35.469 34.627 34.963 33.401 As Stefan suggested in the v1, this time I measured also the efficiency in this way: efficiency = Mbps / (%CPU_Host + %CPU_Guest) The '%CPU_Guest' is taken inside the VM. I know that it is not the best way, but it's provided for free from iperf3 and could be an indication. host -> guest efficiency [Mbps / (%CPU_Host + %CPU_Guest)] pkt_size before opt p 1+2 p 3+4 p 5+6 p 7+8 virtio-net + vhost TCP_NODELAY 64 0.94 0.59 3.96 4.06 4.09 2.82 2.11 256 2.62 2.50 6.45 6.09 5.81 9.64 8.73 512 5.16 4.87 13.16 12.39 11.67 17.83 17.76 1K 9.16 8.85 24.98 24.97 25.01 32.57 32.04 2K 17.41 17.03 49.09 48.59 49.22 55.31 57.14 4K 32.99 33.62 90.80 90.98 91.72 91.79 91.40 8K 58.51 59.98 153.53 170.83 167.31 137.51 132.85 16K 89.32 95.29 216.98 264.18 260.95 176.05 176.05 32K 152.94 167.10 285.75 387.02 360.81 215.49 226.30 64K 250.38 307.20 317.65 489.53 472.70 238.97 244.27 128K 327.99 335.24 335.76 523.71 486.41 253.29 260.86 256K 327.06 334.24 338.64 533.76 509.85 267.78 266.22 512K 337.36 330.61 334.95 512.90 496.35 280.42 241.43 guest -> host efficiency [Mbps / (%CPU_Host + %CPU_Guest)] pkt_size before opt p 1+2 p 3+4 p 5+6 p 7+8 virtio-net + vhost TCP_NODELAY 64 0.90 0.91 1.37 1.32 1.35 2.15 2.13 256 3.59 3.55 5.23 5.19 5.29 8.50 8.89 512 7.19 7.08 10.21 9.95 10.38 16.74 14.71 1K 14.15 14.34 19.85 19.06 19.33 31.44 28.11 2K 28.44 29.09 37.78 37.18 37.49 53.07 50.63 4K 55.37 57.60 71.02 69.27 70.97 81.56 79.32 8K 105.58 100.45 111.95 124.68 123.61 120.85 118.66 16K 141.63 138.24 137.67 187.41 190.20 160.43 163.00 32K 147.56 143.09 138.48 296.41 301.04 214.64 223.94 64K 144.81 143.27 138.49 433.98 462.26 298.86 269.71 128K 150.14 147.99 146.85 511.36 514.29 350.17 298.09 256K 156.69 152.25 148.69 542.19 549.97 326.42 333.32 512K 157.29 153.35 152.22 546.52 533.24 315.55 302.27 [1] https://github.com/stefano-garzarella/iperf/ Stefano Garzarella (8): vsock/virtio: limit the memory used per-socket vsock/virtio: free packets during the socket release vsock/virtio: fix locking for fwd_cnt and buf_alloc vsock/virtio: reduce credit update messages vhost/vsock: split packets to send using multiple buffers vsock/virtio: change the maximum packet size allowed vsock/virtio: increase RX buffer size to 64 KiB vsock/virtio: make the RX buffer size tunable drivers/vhost/vsock.c | 53 +++++++-- include/linux/virtio_vsock.h | 14 ++- net/vmw_vsock/virtio_transport.c | 28 ++++- net/vmw_vsock/virtio_transport_common.c | 144 ++++++++++++++++++------ 4 files changed, 190 insertions(+), 49 deletions(-) -- 2.20.1
Stefano Garzarella
2019-May-10 12:58 UTC
[PATCH v2 1/8] vsock/virtio: limit the memory used per-socket
Since virtio-vsock was introduced, the buffers filled by the host and pushed to the guest using the vring, are directly queued in a per-socket list avoiding to copy it. These buffers are preallocated by the guest with a fixed size (4 KB). The maximum amount of memory used by each socket should be controlled by the credit mechanism. The default credit available per-socket is 256 KB, but if we use only 1 byte per packet, the guest can queue up to 262144 of 4 KB buffers, using up to 1 GB of memory per-socket. In addition, the guest will continue to fill the vring with new 4 KB free buffers to avoid starvation of other sockets. This patch solves this issue copying the payload in a new buffer. Then it is queued in the per-socket list, and the 4KB buffer used by the host is freed. In this way, the memory used by each socket respects the credit available, and we still avoid starvation, paying the cost of an extra memory copy. When the buffer is completely full we do a "zero-copy", moving the buffer directly in the per-socket list. Signed-off-by: Stefano Garzarella <sgarzare at redhat.com> --- drivers/vhost/vsock.c | 2 + include/linux/virtio_vsock.h | 8 +++ net/vmw_vsock/virtio_transport.c | 1 + net/vmw_vsock/virtio_transport_common.c | 95 ++++++++++++++++++------- 4 files changed, 81 insertions(+), 25 deletions(-) diff --git a/drivers/vhost/vsock.c b/drivers/vhost/vsock.c index bb5fc0e9fbc2..7964e2daee09 100644 --- a/drivers/vhost/vsock.c +++ b/drivers/vhost/vsock.c @@ -320,6 +320,8 @@ vhost_vsock_alloc_pkt(struct vhost_virtqueue *vq, return NULL; } + pkt->buf_len = pkt->len; + nbytes = copy_from_iter(pkt->buf, pkt->len, &iov_iter); if (nbytes != pkt->len) { vq_err(vq, "Expected %u byte payload, got %zu bytes\n", diff --git a/include/linux/virtio_vsock.h b/include/linux/virtio_vsock.h index e223e2632edd..345f04ee9193 100644 --- a/include/linux/virtio_vsock.h +++ b/include/linux/virtio_vsock.h @@ -54,9 +54,17 @@ struct virtio_vsock_pkt { void *buf; u32 len; u32 off; + u32 buf_len; bool reply; }; +struct virtio_vsock_buf { + struct list_head list; + void *addr; + u32 len; + u32 off; +}; + struct virtio_vsock_pkt_info { u32 remote_cid, remote_port; struct vsock_sock *vsk; diff --git a/net/vmw_vsock/virtio_transport.c b/net/vmw_vsock/virtio_transport.c index 15eb5d3d4750..af1d2ce12f54 100644 --- a/net/vmw_vsock/virtio_transport.c +++ b/net/vmw_vsock/virtio_transport.c @@ -280,6 +280,7 @@ static void virtio_vsock_rx_fill(struct virtio_vsock *vsock) break; } + pkt->buf_len = buf_len; pkt->len = buf_len; sg_init_one(&hdr, &pkt->hdr, sizeof(pkt->hdr)); diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c index 602715fc9a75..0248d6808755 100644 --- a/net/vmw_vsock/virtio_transport_common.c +++ b/net/vmw_vsock/virtio_transport_common.c @@ -65,6 +65,9 @@ virtio_transport_alloc_pkt(struct virtio_vsock_pkt_info *info, pkt->buf = kmalloc(len, GFP_KERNEL); if (!pkt->buf) goto out_pkt; + + pkt->buf_len = len; + err = memcpy_from_msg(pkt->buf, info->msg, len); if (err) goto out; @@ -86,6 +89,46 @@ virtio_transport_alloc_pkt(struct virtio_vsock_pkt_info *info, return NULL; } +static struct virtio_vsock_buf * +virtio_transport_alloc_buf(struct virtio_vsock_pkt *pkt, bool zero_copy) +{ + struct virtio_vsock_buf *buf; + + if (pkt->len == 0) + return NULL; + + buf = kzalloc(sizeof(*buf), GFP_KERNEL); + if (!buf) + return NULL; + + /* If the buffer in the virtio_vsock_pkt is full, we can move it to + * the new virtio_vsock_buf avoiding the copy, because we are sure that + * we are not use more memory than that counted by the credit mechanism. + */ + if (zero_copy && pkt->len == pkt->buf_len) { + buf->addr = pkt->buf; + pkt->buf = NULL; + } else { + buf->addr = kmalloc(pkt->len, GFP_KERNEL); + if (!buf->addr) { + kfree(buf); + return NULL; + } + + memcpy(buf->addr, pkt->buf, pkt->len); + } + + buf->len = pkt->len; + + return buf; +} + +static void virtio_transport_free_buf(struct virtio_vsock_buf *buf) +{ + kfree(buf->addr); + kfree(buf); +} + /* Packet capture */ static struct sk_buff *virtio_transport_build_skb(void *opaque) { @@ -190,17 +233,15 @@ static int virtio_transport_send_pkt_info(struct vsock_sock *vsk, return virtio_transport_get_ops()->send_pkt(pkt); } -static void virtio_transport_inc_rx_pkt(struct virtio_vsock_sock *vvs, - struct virtio_vsock_pkt *pkt) +static void virtio_transport_inc_rx_pkt(struct virtio_vsock_sock *vvs, u32 len) { - vvs->rx_bytes += pkt->len; + vvs->rx_bytes += len; } -static void virtio_transport_dec_rx_pkt(struct virtio_vsock_sock *vvs, - struct virtio_vsock_pkt *pkt) +static void virtio_transport_dec_rx_pkt(struct virtio_vsock_sock *vvs, u32 len) { - vvs->rx_bytes -= pkt->len; - vvs->fwd_cnt += pkt->len; + vvs->rx_bytes -= len; + vvs->fwd_cnt += len; } void virtio_transport_inc_tx_pkt(struct virtio_vsock_sock *vvs, struct virtio_vsock_pkt *pkt) @@ -254,36 +295,36 @@ virtio_transport_stream_do_dequeue(struct vsock_sock *vsk, size_t len) { struct virtio_vsock_sock *vvs = vsk->trans; - struct virtio_vsock_pkt *pkt; + struct virtio_vsock_buf *buf; size_t bytes, total = 0; int err = -EFAULT; spin_lock_bh(&vvs->rx_lock); while (total < len && !list_empty(&vvs->rx_queue)) { - pkt = list_first_entry(&vvs->rx_queue, - struct virtio_vsock_pkt, list); + buf = list_first_entry(&vvs->rx_queue, + struct virtio_vsock_buf, list); bytes = len - total; - if (bytes > pkt->len - pkt->off) - bytes = pkt->len - pkt->off; + if (bytes > buf->len - buf->off) + bytes = buf->len - buf->off; /* sk_lock is held by caller so no one else can dequeue. * Unlock rx_lock since memcpy_to_msg() may sleep. */ spin_unlock_bh(&vvs->rx_lock); - err = memcpy_to_msg(msg, pkt->buf + pkt->off, bytes); + err = memcpy_to_msg(msg, buf->addr + buf->off, bytes); if (err) goto out; spin_lock_bh(&vvs->rx_lock); total += bytes; - pkt->off += bytes; - if (pkt->off == pkt->len) { - virtio_transport_dec_rx_pkt(vvs, pkt); - list_del(&pkt->list); - virtio_transport_free_pkt(pkt); + buf->off += bytes; + if (buf->off == buf->len) { + virtio_transport_dec_rx_pkt(vvs, buf->len); + list_del(&buf->list); + virtio_transport_free_buf(buf); } } spin_unlock_bh(&vvs->rx_lock); @@ -841,20 +882,24 @@ virtio_transport_recv_connected(struct sock *sk, { struct vsock_sock *vsk = vsock_sk(sk); struct virtio_vsock_sock *vvs = vsk->trans; + struct virtio_vsock_buf *buf; int err = 0; switch (le16_to_cpu(pkt->hdr.op)) { case VIRTIO_VSOCK_OP_RW: pkt->len = le32_to_cpu(pkt->hdr.len); - pkt->off = 0; + buf = virtio_transport_alloc_buf(pkt, true); - spin_lock_bh(&vvs->rx_lock); - virtio_transport_inc_rx_pkt(vvs, pkt); - list_add_tail(&pkt->list, &vvs->rx_queue); - spin_unlock_bh(&vvs->rx_lock); + if (buf) { + spin_lock_bh(&vvs->rx_lock); + virtio_transport_inc_rx_pkt(vvs, pkt->len); + list_add_tail(&buf->list, &vvs->rx_queue); + spin_unlock_bh(&vvs->rx_lock); - sk->sk_data_ready(sk); - return err; + sk->sk_data_ready(sk); + } + + break; case VIRTIO_VSOCK_OP_CREDIT_UPDATE: sk->sk_write_space(sk); break; -- 2.20.1
Stefano Garzarella
2019-May-10 12:58 UTC
[PATCH v2 2/8] vsock/virtio: free packets during the socket release
When the socket is released, we should free all packets queued in the per-socket list in order to avoid a memory leak. Signed-off-by: Stefano Garzarella <sgarzare at redhat.com> --- net/vmw_vsock/virtio_transport_common.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c index 0248d6808755..65c8b4a23f2b 100644 --- a/net/vmw_vsock/virtio_transport_common.c +++ b/net/vmw_vsock/virtio_transport_common.c @@ -827,12 +827,20 @@ static bool virtio_transport_close(struct vsock_sock *vsk) void virtio_transport_release(struct vsock_sock *vsk) { + struct virtio_vsock_sock *vvs = vsk->trans; + struct virtio_vsock_buf *buf; struct sock *sk = &vsk->sk; bool remove_sock = true; lock_sock(sk); if (sk->sk_type == SOCK_STREAM) remove_sock = virtio_transport_close(vsk); + while (!list_empty(&vvs->rx_queue)) { + buf = list_first_entry(&vvs->rx_queue, + struct virtio_vsock_buf, list); + list_del(&buf->list); + virtio_transport_free_buf(buf); + } release_sock(sk); if (remove_sock) -- 2.20.1
Stefano Garzarella
2019-May-10 12:58 UTC
[PATCH v2 3/8] vsock/virtio: fix locking for fwd_cnt and buf_alloc
fwd_cnt is written with rx_lock, so we should read it using the same spinlock also if we are in the TX path. Move also buf_alloc under rx_lock and add a missing locking when we modify it. Signed-off-by: Stefano Garzarella <sgarzare at redhat.com> --- include/linux/virtio_vsock.h | 2 +- net/vmw_vsock/virtio_transport_common.c | 6 ++++-- 2 files changed, 5 insertions(+), 3 deletions(-) diff --git a/include/linux/virtio_vsock.h b/include/linux/virtio_vsock.h index 345f04ee9193..fb5954fc85c8 100644 --- a/include/linux/virtio_vsock.h +++ b/include/linux/virtio_vsock.h @@ -35,11 +35,11 @@ struct virtio_vsock_sock { /* Protected by tx_lock */ u32 tx_cnt; - u32 buf_alloc; u32 peer_fwd_cnt; u32 peer_buf_alloc; /* Protected by rx_lock */ + u32 buf_alloc; u32 fwd_cnt; u32 rx_bytes; struct list_head rx_queue; diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c index 65c8b4a23f2b..f2e4e128bc86 100644 --- a/net/vmw_vsock/virtio_transport_common.c +++ b/net/vmw_vsock/virtio_transport_common.c @@ -246,10 +246,10 @@ static void virtio_transport_dec_rx_pkt(struct virtio_vsock_sock *vvs, u32 len) void virtio_transport_inc_tx_pkt(struct virtio_vsock_sock *vvs, struct virtio_vsock_pkt *pkt) { - spin_lock_bh(&vvs->tx_lock); + spin_lock_bh(&vvs->rx_lock); pkt->hdr.fwd_cnt = cpu_to_le32(vvs->fwd_cnt); pkt->hdr.buf_alloc = cpu_to_le32(vvs->buf_alloc); - spin_unlock_bh(&vvs->tx_lock); + spin_unlock_bh(&vvs->rx_lock); } EXPORT_SYMBOL_GPL(virtio_transport_inc_tx_pkt); @@ -469,7 +469,9 @@ void virtio_transport_set_buffer_size(struct vsock_sock *vsk, u64 val) if (val > vvs->buf_size_max) vvs->buf_size_max = val; vvs->buf_size = val; + spin_lock_bh(&vvs->rx_lock); vvs->buf_alloc = val; + spin_unlock_bh(&vvs->rx_lock); } EXPORT_SYMBOL_GPL(virtio_transport_set_buffer_size); -- 2.20.1
Stefano Garzarella
2019-May-10 12:58 UTC
[PATCH v2 4/8] vsock/virtio: reduce credit update messages
In order to reduce the number of credit update messages, we send them only when the space available seen by the transmitter is less than VIRTIO_VSOCK_MAX_PKT_BUF_SIZE. Signed-off-by: Stefano Garzarella <sgarzare at redhat.com> --- include/linux/virtio_vsock.h | 1 + net/vmw_vsock/virtio_transport_common.c | 16 +++++++++++++--- 2 files changed, 14 insertions(+), 3 deletions(-) diff --git a/include/linux/virtio_vsock.h b/include/linux/virtio_vsock.h index fb5954fc85c8..84b72026d327 100644 --- a/include/linux/virtio_vsock.h +++ b/include/linux/virtio_vsock.h @@ -41,6 +41,7 @@ struct virtio_vsock_sock { /* Protected by rx_lock */ u32 buf_alloc; u32 fwd_cnt; + u32 last_fwd_cnt; u32 rx_bytes; struct list_head rx_queue; }; diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c index f2e4e128bc86..b61fd5e29a1f 100644 --- a/net/vmw_vsock/virtio_transport_common.c +++ b/net/vmw_vsock/virtio_transport_common.c @@ -247,6 +247,7 @@ static void virtio_transport_dec_rx_pkt(struct virtio_vsock_sock *vvs, u32 len) void virtio_transport_inc_tx_pkt(struct virtio_vsock_sock *vvs, struct virtio_vsock_pkt *pkt) { spin_lock_bh(&vvs->rx_lock); + vvs->last_fwd_cnt = vvs->fwd_cnt; pkt->hdr.fwd_cnt = cpu_to_le32(vvs->fwd_cnt); pkt->hdr.buf_alloc = cpu_to_le32(vvs->buf_alloc); spin_unlock_bh(&vvs->rx_lock); @@ -297,6 +298,7 @@ virtio_transport_stream_do_dequeue(struct vsock_sock *vsk, struct virtio_vsock_sock *vvs = vsk->trans; struct virtio_vsock_buf *buf; size_t bytes, total = 0; + u32 free_space; int err = -EFAULT; spin_lock_bh(&vvs->rx_lock); @@ -327,11 +329,19 @@ virtio_transport_stream_do_dequeue(struct vsock_sock *vsk, virtio_transport_free_buf(buf); } } + + free_space = vvs->buf_alloc - (vvs->fwd_cnt - vvs->last_fwd_cnt); + spin_unlock_bh(&vvs->rx_lock); - /* Send a credit pkt to peer */ - virtio_transport_send_credit_update(vsk, VIRTIO_VSOCK_TYPE_STREAM, - NULL); + /* We send a credit update only when the space available seen + * by the transmitter is less than VIRTIO_VSOCK_MAX_PKT_BUF_SIZE + */ + if (free_space < VIRTIO_VSOCK_MAX_PKT_BUF_SIZE) { + virtio_transport_send_credit_update(vsk, + VIRTIO_VSOCK_TYPE_STREAM, + NULL); + } return total; -- 2.20.1
Stefano Garzarella
2019-May-10 12:58 UTC
[PATCH v2 5/8] vhost/vsock: split packets to send using multiple buffers
If the packets to sent to the guest are bigger than the buffer available, we can split them, using multiple buffers and fixing the length in the packet header. This is safe since virtio-vsock supports only stream sockets. Signed-off-by: Stefano Garzarella <sgarzare at redhat.com> --- drivers/vhost/vsock.c | 51 +++++++++++++++++++------ net/vmw_vsock/virtio_transport_common.c | 15 ++++++-- 2 files changed, 52 insertions(+), 14 deletions(-) diff --git a/drivers/vhost/vsock.c b/drivers/vhost/vsock.c index 7964e2daee09..fb731d09f5f1 100644 --- a/drivers/vhost/vsock.c +++ b/drivers/vhost/vsock.c @@ -94,7 +94,7 @@ vhost_transport_do_send_pkt(struct vhost_vsock *vsock, struct iov_iter iov_iter; unsigned out, in; size_t nbytes; - size_t len; + size_t iov_len, payload_len; int head; spin_lock_bh(&vsock->send_pkt_list_lock); @@ -139,8 +139,24 @@ vhost_transport_do_send_pkt(struct vhost_vsock *vsock, break; } - len = iov_length(&vq->iov[out], in); - iov_iter_init(&iov_iter, READ, &vq->iov[out], in, len); + iov_len = iov_length(&vq->iov[out], in); + if (iov_len < sizeof(pkt->hdr)) { + virtio_transport_free_pkt(pkt); + vq_err(vq, "Buffer len [%zu] too small\n", iov_len); + break; + } + + iov_iter_init(&iov_iter, READ, &vq->iov[out], in, iov_len); + payload_len = pkt->len - pkt->off; + + /* If the packet is greater than the space available in the + * buffer, we split it using multiple buffers. + */ + if (payload_len > iov_len - sizeof(pkt->hdr)) + payload_len = iov_len - sizeof(pkt->hdr); + + /* Set the correct length in the header */ + pkt->hdr.len = cpu_to_le32(payload_len); nbytes = copy_to_iter(&pkt->hdr, sizeof(pkt->hdr), &iov_iter); if (nbytes != sizeof(pkt->hdr)) { @@ -149,16 +165,34 @@ vhost_transport_do_send_pkt(struct vhost_vsock *vsock, break; } - nbytes = copy_to_iter(pkt->buf, pkt->len, &iov_iter); - if (nbytes != pkt->len) { + nbytes = copy_to_iter(pkt->buf + pkt->off, payload_len, + &iov_iter); + if (nbytes != payload_len) { virtio_transport_free_pkt(pkt); vq_err(vq, "Faulted on copying pkt buf\n"); break; } - vhost_add_used(vq, head, sizeof(pkt->hdr) + pkt->len); + vhost_add_used(vq, head, sizeof(pkt->hdr) + payload_len); added = true; + /* Deliver to monitoring devices all correctly transmitted + * packets. + */ + virtio_transport_deliver_tap_pkt(pkt); + + pkt->off += payload_len; + + /* If we didn't send all the payload we can requeue the packet + * to send it with the next available buffer. + */ + if (pkt->off < pkt->len) { + spin_lock_bh(&vsock->send_pkt_list_lock); + list_add(&pkt->list, &vsock->send_pkt_list); + spin_unlock_bh(&vsock->send_pkt_list_lock); + continue; + } + if (pkt->reply) { int val; @@ -169,11 +203,6 @@ vhost_transport_do_send_pkt(struct vhost_vsock *vsock, restart_tx = true; } - /* Deliver to monitoring devices all correctly transmitted - * packets. - */ - virtio_transport_deliver_tap_pkt(pkt); - virtio_transport_free_pkt(pkt); } if (added) diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c index b61fd5e29a1f..3f313bcd6a26 100644 --- a/net/vmw_vsock/virtio_transport_common.c +++ b/net/vmw_vsock/virtio_transport_common.c @@ -135,8 +135,17 @@ static struct sk_buff *virtio_transport_build_skb(void *opaque) struct virtio_vsock_pkt *pkt = opaque; struct af_vsockmon_hdr *hdr; struct sk_buff *skb; + size_t payload_len; + void *payload_buf; - skb = alloc_skb(sizeof(*hdr) + sizeof(pkt->hdr) + pkt->len, + /* A packet could be split to fit the RX buffer, so we can retrieve + * the payload length from the header and the buffer pointer taking + * care of the offset in the original packet. + */ + payload_len = le32_to_cpu(pkt->hdr.len); + payload_buf = pkt->buf + pkt->off; + + skb = alloc_skb(sizeof(*hdr) + sizeof(pkt->hdr) + payload_len, GFP_ATOMIC); if (!skb) return NULL; @@ -176,8 +185,8 @@ static struct sk_buff *virtio_transport_build_skb(void *opaque) skb_put_data(skb, &pkt->hdr, sizeof(pkt->hdr)); - if (pkt->len) { - skb_put_data(skb, pkt->buf, pkt->len); + if (payload_len) { + skb_put_data(skb, payload_buf, payload_len); } return skb; -- 2.20.1
Stefano Garzarella
2019-May-10 12:58 UTC
[PATCH v2 6/8] vsock/virtio: change the maximum packet size allowed
Since now we are able to split packets, we can avoid limiting their sizes to VIRTIO_VSOCK_DEFAULT_RX_BUF_SIZE. Instead, we can use VIRTIO_VSOCK_MAX_PKT_BUF_SIZE as the max packet size. Signed-off-by: Stefano Garzarella <sgarzare at redhat.com> --- net/vmw_vsock/virtio_transport_common.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c index 3f313bcd6a26..63606525755d 100644 --- a/net/vmw_vsock/virtio_transport_common.c +++ b/net/vmw_vsock/virtio_transport_common.c @@ -219,8 +219,8 @@ static int virtio_transport_send_pkt_info(struct vsock_sock *vsk, vvs = vsk->trans; /* we can send less than pkt_len bytes */ - if (pkt_len > VIRTIO_VSOCK_DEFAULT_RX_BUF_SIZE) - pkt_len = VIRTIO_VSOCK_DEFAULT_RX_BUF_SIZE; + if (pkt_len > VIRTIO_VSOCK_MAX_PKT_BUF_SIZE) + pkt_len = VIRTIO_VSOCK_MAX_PKT_BUF_SIZE; /* virtio_transport_get_credit might return less than pkt_len credit */ pkt_len = virtio_transport_get_credit(vvs, pkt_len); -- 2.20.1
Stefano Garzarella
2019-May-10 12:58 UTC
[PATCH v2 7/8] vsock/virtio: increase RX buffer size to 64 KiB
In order to increase host -> guest throughput with large packets, we can use 64 KiB RX buffers. Signed-off-by: Stefano Garzarella <sgarzare at redhat.com> --- include/linux/virtio_vsock.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/include/linux/virtio_vsock.h b/include/linux/virtio_vsock.h index 84b72026d327..5a9d25be72df 100644 --- a/include/linux/virtio_vsock.h +++ b/include/linux/virtio_vsock.h @@ -10,7 +10,7 @@ #define VIRTIO_VSOCK_DEFAULT_MIN_BUF_SIZE 128 #define VIRTIO_VSOCK_DEFAULT_BUF_SIZE (1024 * 256) #define VIRTIO_VSOCK_DEFAULT_MAX_BUF_SIZE (1024 * 256) -#define VIRTIO_VSOCK_DEFAULT_RX_BUF_SIZE (1024 * 4) +#define VIRTIO_VSOCK_DEFAULT_RX_BUF_SIZE (1024 * 64) #define VIRTIO_VSOCK_MAX_BUF_SIZE 0xFFFFFFFFUL #define VIRTIO_VSOCK_MAX_PKT_BUF_SIZE (1024 * 64) -- 2.20.1
Stefano Garzarella
2019-May-10 12:58 UTC
[PATCH v2 8/8] vsock/virtio: make the RX buffer size tunable
The RX buffer size determines the memory consumption of the vsock/virtio guest driver, so we make it tunable through a module parameter. The size allowed are between 4 KB and 64 KB in order to be compatible with old host drivers. Suggested-by: Stefan Hajnoczi <stefanha at redhat.com> Signed-off-by: Stefano Garzarella <sgarzare at redhat.com> --- include/linux/virtio_vsock.h | 1 + net/vmw_vsock/virtio_transport.c | 27 ++++++++++++++++++++++++++- 2 files changed, 27 insertions(+), 1 deletion(-) diff --git a/include/linux/virtio_vsock.h b/include/linux/virtio_vsock.h index 5a9d25be72df..b9f8c3d91f80 100644 --- a/include/linux/virtio_vsock.h +++ b/include/linux/virtio_vsock.h @@ -13,6 +13,7 @@ #define VIRTIO_VSOCK_DEFAULT_RX_BUF_SIZE (1024 * 64) #define VIRTIO_VSOCK_MAX_BUF_SIZE 0xFFFFFFFFUL #define VIRTIO_VSOCK_MAX_PKT_BUF_SIZE (1024 * 64) +#define VIRTIO_VSOCK_MIN_PKT_BUF_SIZE (1024 * 4) enum { VSOCK_VQ_RX = 0, /* for host to guest data */ diff --git a/net/vmw_vsock/virtio_transport.c b/net/vmw_vsock/virtio_transport.c index af1d2ce12f54..732398b4e28f 100644 --- a/net/vmw_vsock/virtio_transport.c +++ b/net/vmw_vsock/virtio_transport.c @@ -66,6 +66,31 @@ struct virtio_vsock { u32 guest_cid; }; +static unsigned int rx_buf_size = VIRTIO_VSOCK_DEFAULT_RX_BUF_SIZE; + +static int param_set_rx_buf_size(const char *val, const struct kernel_param *kp) +{ + unsigned int size; + int ret; + + ret = kstrtouint(val, 0, &size); + if (ret) + return ret; + + if (size < VIRTIO_VSOCK_MIN_PKT_BUF_SIZE || + size > VIRTIO_VSOCK_MAX_PKT_BUF_SIZE) + return -EINVAL; + + return param_set_uint(val, kp); +}; + +static const struct kernel_param_ops param_ops_rx_buf_size = { + .set = param_set_rx_buf_size, + .get = param_get_uint, +}; + +module_param_cb(rx_buf_size, ¶m_ops_rx_buf_size, &rx_buf_size, 0644); + static struct virtio_vsock *virtio_vsock_get(void) { return the_virtio_vsock; @@ -261,7 +286,7 @@ virtio_transport_cancel_pkt(struct vsock_sock *vsk) static void virtio_vsock_rx_fill(struct virtio_vsock *vsock) { - int buf_len = VIRTIO_VSOCK_DEFAULT_RX_BUF_SIZE; + int buf_len = rx_buf_size; struct virtio_vsock_pkt *pkt; struct scatterlist hdr, buf, *sgs[2]; struct virtqueue *vq; -- 2.20.1
David Miller
2019-May-10 22:20 UTC
[PATCH v2 2/8] vsock/virtio: free packets during the socket release
From: Stefano Garzarella <sgarzare at redhat.com> Date: Fri, 10 May 2019 14:58:37 +0200> @@ -827,12 +827,20 @@ static bool virtio_transport_close(struct vsock_sock *vsk) > > void virtio_transport_release(struct vsock_sock *vsk) > { > + struct virtio_vsock_sock *vvs = vsk->trans; > + struct virtio_vsock_buf *buf; > struct sock *sk = &vsk->sk; > bool remove_sock = true; > > lock_sock(sk); > if (sk->sk_type == SOCK_STREAM) > remove_sock = virtio_transport_close(vsk); > + while (!list_empty(&vvs->rx_queue)) { > + buf = list_first_entry(&vvs->rx_queue, > + struct virtio_vsock_buf, list);Please use list_for_each_entry_safe().
Michael S. Tsirkin
2019-May-12 16:57 UTC
[PATCH v2 1/8] vsock/virtio: limit the memory used per-socket
On Fri, May 10, 2019 at 02:58:36PM +0200, Stefano Garzarella wrote:> Since virtio-vsock was introduced, the buffers filled by the host > and pushed to the guest using the vring, are directly queued in > a per-socket list avoiding to copy it. > These buffers are preallocated by the guest with a fixed > size (4 KB). > > The maximum amount of memory used by each socket should be > controlled by the credit mechanism. > The default credit available per-socket is 256 KB, but if we use > only 1 byte per packet, the guest can queue up to 262144 of 4 KB > buffers, using up to 1 GB of memory per-socket. In addition, the > guest will continue to fill the vring with new 4 KB free buffers > to avoid starvation of other sockets. > > This patch solves this issue copying the payload in a new buffer. > Then it is queued in the per-socket list, and the 4KB buffer used > by the host is freed. > > In this way, the memory used by each socket respects the credit > available, and we still avoid starvation, paying the cost of an > extra memory copy. When the buffer is completely full we do a > "zero-copy", moving the buffer directly in the per-socket list. > > Signed-off-by: Stefano Garzarella <sgarzare at redhat.com> > --- > drivers/vhost/vsock.c | 2 + > include/linux/virtio_vsock.h | 8 +++ > net/vmw_vsock/virtio_transport.c | 1 + > net/vmw_vsock/virtio_transport_common.c | 95 ++++++++++++++++++------- > 4 files changed, 81 insertions(+), 25 deletions(-) > > diff --git a/drivers/vhost/vsock.c b/drivers/vhost/vsock.c > index bb5fc0e9fbc2..7964e2daee09 100644 > --- a/drivers/vhost/vsock.c > +++ b/drivers/vhost/vsock.c > @@ -320,6 +320,8 @@ vhost_vsock_alloc_pkt(struct vhost_virtqueue *vq, > return NULL; > } > > + pkt->buf_len = pkt->len; > + > nbytes = copy_from_iter(pkt->buf, pkt->len, &iov_iter); > if (nbytes != pkt->len) { > vq_err(vq, "Expected %u byte payload, got %zu bytes\n", > diff --git a/include/linux/virtio_vsock.h b/include/linux/virtio_vsock.h > index e223e2632edd..345f04ee9193 100644 > --- a/include/linux/virtio_vsock.h > +++ b/include/linux/virtio_vsock.h > @@ -54,9 +54,17 @@ struct virtio_vsock_pkt { > void *buf; > u32 len; > u32 off; > + u32 buf_len; > bool reply; > }; > > +struct virtio_vsock_buf { > + struct list_head list; > + void *addr; > + u32 len; > + u32 off; > +}; > + > struct virtio_vsock_pkt_info { > u32 remote_cid, remote_port; > struct vsock_sock *vsk; > diff --git a/net/vmw_vsock/virtio_transport.c b/net/vmw_vsock/virtio_transport.c > index 15eb5d3d4750..af1d2ce12f54 100644 > --- a/net/vmw_vsock/virtio_transport.c > +++ b/net/vmw_vsock/virtio_transport.c > @@ -280,6 +280,7 @@ static void virtio_vsock_rx_fill(struct virtio_vsock *vsock) > break; > } > > + pkt->buf_len = buf_len; > pkt->len = buf_len; > > sg_init_one(&hdr, &pkt->hdr, sizeof(pkt->hdr)); > diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c > index 602715fc9a75..0248d6808755 100644 > --- a/net/vmw_vsock/virtio_transport_common.c > +++ b/net/vmw_vsock/virtio_transport_common.c > @@ -65,6 +65,9 @@ virtio_transport_alloc_pkt(struct virtio_vsock_pkt_info *info, > pkt->buf = kmalloc(len, GFP_KERNEL); > if (!pkt->buf) > goto out_pkt; > + > + pkt->buf_len = len; > + > err = memcpy_from_msg(pkt->buf, info->msg, len); > if (err) > goto out; > @@ -86,6 +89,46 @@ virtio_transport_alloc_pkt(struct virtio_vsock_pkt_info *info, > return NULL; > } > > +static struct virtio_vsock_buf * > +virtio_transport_alloc_buf(struct virtio_vsock_pkt *pkt, bool zero_copy) > +{ > + struct virtio_vsock_buf *buf; > + > + if (pkt->len == 0) > + return NULL; > + > + buf = kzalloc(sizeof(*buf), GFP_KERNEL); > + if (!buf) > + return NULL; > + > + /* If the buffer in the virtio_vsock_pkt is full, we can move it to > + * the new virtio_vsock_buf avoiding the copy, because we are sure that > + * we are not usewe do not use> more memory than that counted by the credit mechanism. > + */ > + if (zero_copy && pkt->len == pkt->buf_len) { > + buf->addr = pkt->buf; > + pkt->buf = NULL; > + } else { > + buf->addr = kmalloc(pkt->len, GFP_KERNEL); > + if (!buf->addr) { > + kfree(buf); > + return NULL; > + } > + > + memcpy(buf->addr, pkt->buf, pkt->len); > + } > + > + buf->len = pkt->len; > + > + return buf; > +} > + > +static void virtio_transport_free_buf(struct virtio_vsock_buf *buf) > +{ > + kfree(buf->addr); > + kfree(buf); > +} > + > /* Packet capture */ > static struct sk_buff *virtio_transport_build_skb(void *opaque) > { > @@ -190,17 +233,15 @@ static int virtio_transport_send_pkt_info(struct vsock_sock *vsk, > return virtio_transport_get_ops()->send_pkt(pkt); > } > > -static void virtio_transport_inc_rx_pkt(struct virtio_vsock_sock *vvs, > - struct virtio_vsock_pkt *pkt) > +static void virtio_transport_inc_rx_pkt(struct virtio_vsock_sock *vvs, u32 len) > { > - vvs->rx_bytes += pkt->len; > + vvs->rx_bytes += len; > } > > -static void virtio_transport_dec_rx_pkt(struct virtio_vsock_sock *vvs, > - struct virtio_vsock_pkt *pkt) > +static void virtio_transport_dec_rx_pkt(struct virtio_vsock_sock *vvs, u32 len) > { > - vvs->rx_bytes -= pkt->len; > - vvs->fwd_cnt += pkt->len; > + vvs->rx_bytes -= len; > + vvs->fwd_cnt += len; > } > > void virtio_transport_inc_tx_pkt(struct virtio_vsock_sock *vvs, struct virtio_vsock_pkt *pkt) > @@ -254,36 +295,36 @@ virtio_transport_stream_do_dequeue(struct vsock_sock *vsk, > size_t len) > { > struct virtio_vsock_sock *vvs = vsk->trans; > - struct virtio_vsock_pkt *pkt; > + struct virtio_vsock_buf *buf; > size_t bytes, total = 0; > int err = -EFAULT; > > spin_lock_bh(&vvs->rx_lock); > while (total < len && !list_empty(&vvs->rx_queue)) { > - pkt = list_first_entry(&vvs->rx_queue, > - struct virtio_vsock_pkt, list); > + buf = list_first_entry(&vvs->rx_queue, > + struct virtio_vsock_buf, list); > > bytes = len - total; > - if (bytes > pkt->len - pkt->off) > - bytes = pkt->len - pkt->off; > + if (bytes > buf->len - buf->off) > + bytes = buf->len - buf->off; > > /* sk_lock is held by caller so no one else can dequeue. > * Unlock rx_lock since memcpy_to_msg() may sleep. > */ > spin_unlock_bh(&vvs->rx_lock); > > - err = memcpy_to_msg(msg, pkt->buf + pkt->off, bytes); > + err = memcpy_to_msg(msg, buf->addr + buf->off, bytes); > if (err) > goto out; > > spin_lock_bh(&vvs->rx_lock); > > total += bytes; > - pkt->off += bytes; > - if (pkt->off == pkt->len) { > - virtio_transport_dec_rx_pkt(vvs, pkt); > - list_del(&pkt->list); > - virtio_transport_free_pkt(pkt); > + buf->off += bytes; > + if (buf->off == buf->len) { > + virtio_transport_dec_rx_pkt(vvs, buf->len); > + list_del(&buf->list); > + virtio_transport_free_buf(buf); > } > } > spin_unlock_bh(&vvs->rx_lock); > @@ -841,20 +882,24 @@ virtio_transport_recv_connected(struct sock *sk, > { > struct vsock_sock *vsk = vsock_sk(sk); > struct virtio_vsock_sock *vvs = vsk->trans; > + struct virtio_vsock_buf *buf; > int err = 0; > > switch (le16_to_cpu(pkt->hdr.op)) { > case VIRTIO_VSOCK_OP_RW: > pkt->len = le32_to_cpu(pkt->hdr.len); > - pkt->off = 0; > + buf = virtio_transport_alloc_buf(pkt, true);This seems to be the only callers and second parameter is always true. So why is it needed?> > - spin_lock_bh(&vvs->rx_lock); > - virtio_transport_inc_rx_pkt(vvs, pkt); > - list_add_tail(&pkt->list, &vvs->rx_queue); > - spin_unlock_bh(&vvs->rx_lock); > + if (buf) { > + spin_lock_bh(&vvs->rx_lock); > + virtio_transport_inc_rx_pkt(vvs, pkt->len); > + list_add_tail(&buf->list, &vvs->rx_queue); > + spin_unlock_bh(&vvs->rx_lock); > > - sk->sk_data_ready(sk); > - return err; > + sk->sk_data_ready(sk); > + } > + > + break; > case VIRTIO_VSOCK_OP_CREDIT_UPDATE: > sk->sk_write_space(sk); > break; > -- > 2.20.1
Jason Wang
2019-May-13 09:33 UTC
[PATCH v2 0/8] vsock/virtio: optimizations to increase the throughput
On 2019/5/10 ??8:58, Stefano Garzarella wrote:> While I was testing this new series (v2) I discovered an huge use of memory > and a memory leak in the virtio-vsock driver in the guest when I sent > 1-byte packets to the guest. > > These issues are present since the introduction of the virtio-vsock > driver. I added the patches 1 and 2 to fix them in this series in order > to better track the performance trends. > > v1: https://patchwork.kernel.org/cover/10885431/ > > v2: > - Add patch 1 to limit the memory usage > - Add patch 2 to avoid memory leak during the socket release > - Add patch 3 to fix locking of fwd_cnt and buf_alloc > - Patch 4: fix 'free_space' type (u32 instead of s64) [Stefan] > - Patch 5: Avoid integer underflow of iov_len [Stefan] > - Patch 5: Fix packet capture in order to see the exact packets that are > delivered. [Stefan] > - Add patch 8 to make the RX buffer size tunable [Stefan] > > Below are the benchmarks step by step. I used iperf3 [1] modified with VSOCK > support. > As Micheal suggested in the v1, I booted host and guest with 'nosmap', and I > added a column with virtio-net+vhost-net performance. > > A brief description of patches: > - Patches 1+2: limit the memory usage with an extra copy and avoid memory leak > - Patches 3+4: fix locking and reduce the number of credit update messages sent > to the transmitter > - Patches 5+6: allow the host to split packets on multiple buffers and use > VIRTIO_VSOCK_MAX_PKT_BUF_SIZE as the max packet size allowed > - Patches 7+8: increase RX buffer size to 64 KiB > > host -> guest [Gbps] > pkt_size before opt p 1+2 p 3+4 p 5+6 p 7+8 virtio-net + vhost > TCP_NODELAY > 64 0.068 0.063 0.130 0.131 0.128 0.188 0.187 > 256 0.274 0.236 0.392 0.338 0.282 0.749 0.654 > 512 0.531 0.457 0.862 0.725 0.602 1.419 1.414 > 1K 0.954 0.827 1.591 1.598 1.548 2.599 2.640 > 2K 1.783 1.543 3.731 3.637 3.469 4.530 4.754 > 4K 3.332 3.436 7.164 7.124 6.494 7.738 7.696 > 8K 5.792 5.530 11.653 11.787 11.444 12.307 11.850 > 16K 8.405 8.462 16.372 16.855 17.562 16.936 16.954 > 32K 14.208 13.669 18.945 20.009 23.128 21.980 23.015 > 64K 21.082 18.893 20.266 20.903 30.622 27.290 27.383 > 128K 20.696 20.148 20.112 21.746 32.152 30.446 30.990 > 256K 20.801 20.589 20.725 22.685 34.721 33.151 32.745 > 512K 21.220 20.465 20.432 22.106 34.496 36.847 31.096 > > guest -> host [Gbps] > pkt_size before opt p 1+2 p 3+4 p 5+6 p 7+8 virtio-net + vhost > TCP_NODELAY > 64 0.089 0.091 0.120 0.115 0.117 0.274 0.272 > 256 0.352 0.354 0.452 0.445 0.451 1.085 1.136 > 512 0.705 0.704 0.893 0.858 0.898 2.131 1.882 > 1K 1.394 1.433 1.721 1.669 1.691 3.984 3.576 > 2K 2.818 2.874 3.316 3.249 3.303 6.719 6.359 > 4K 5.293 5.397 6.129 5.933 6.082 10.105 9.860 > 8K 8.890 9.151 10.990 10.545 10.519 15.239 14.868 > 16K 11.444 11.018 12.074 15.255 15.577 20.551 20.848 > 32K 11.229 10.875 10.857 24.401 25.227 26.294 26.380 > 64K 10.832 10.545 10.816 39.487 39.616 34.996 32.041 > 128K 10.435 10.241 10.500 39.813 40.012 38.379 35.055 > 256K 10.263 9.866 9.845 34.971 35.143 36.559 37.232 > 512K 10.224 10.060 10.092 35.469 34.627 34.963 33.401 > > As Stefan suggested in the v1, this time I measured also the efficiency in this > way: > efficiency = Mbps / (%CPU_Host + %CPU_Guest) > > The '%CPU_Guest' is taken inside the VM. I know that it is not the best way, > but it's provided for free from iperf3 and could be an indication. > > host -> guest efficiency [Mbps / (%CPU_Host + %CPU_Guest)] > pkt_size before opt p 1+2 p 3+4 p 5+6 p 7+8 virtio-net + vhost > TCP_NODELAY > 64 0.94 0.59 3.96 4.06 4.09 2.82 2.11 > 256 2.62 2.50 6.45 6.09 5.81 9.64 8.73 > 512 5.16 4.87 13.16 12.39 11.67 17.83 17.76 > 1K 9.16 8.85 24.98 24.97 25.01 32.57 32.04 > 2K 17.41 17.03 49.09 48.59 49.22 55.31 57.14 > 4K 32.99 33.62 90.80 90.98 91.72 91.79 91.40 > 8K 58.51 59.98 153.53 170.83 167.31 137.51 132.85 > 16K 89.32 95.29 216.98 264.18 260.95 176.05 176.05 > 32K 152.94 167.10 285.75 387.02 360.81 215.49 226.30 > 64K 250.38 307.20 317.65 489.53 472.70 238.97 244.27 > 128K 327.99 335.24 335.76 523.71 486.41 253.29 260.86 > 256K 327.06 334.24 338.64 533.76 509.85 267.78 266.22 > 512K 337.36 330.61 334.95 512.90 496.35 280.42 241.43 > > guest -> host efficiency [Mbps / (%CPU_Host + %CPU_Guest)] > pkt_size before opt p 1+2 p 3+4 p 5+6 p 7+8 virtio-net + vhost > TCP_NODELAY > 64 0.90 0.91 1.37 1.32 1.35 2.15 2.13 > 256 3.59 3.55 5.23 5.19 5.29 8.50 8.89 > 512 7.19 7.08 10.21 9.95 10.38 16.74 14.71 > 1K 14.15 14.34 19.85 19.06 19.33 31.44 28.11 > 2K 28.44 29.09 37.78 37.18 37.49 53.07 50.63 > 4K 55.37 57.60 71.02 69.27 70.97 81.56 79.32 > 8K 105.58 100.45 111.95 124.68 123.61 120.85 118.66 > 16K 141.63 138.24 137.67 187.41 190.20 160.43 163.00 > 32K 147.56 143.09 138.48 296.41 301.04 214.64 223.94 > 64K 144.81 143.27 138.49 433.98 462.26 298.86 269.71 > 128K 150.14 147.99 146.85 511.36 514.29 350.17 298.09 > 256K 156.69 152.25 148.69 542.19 549.97 326.42 333.32 > 512K 157.29 153.35 152.22 546.52 533.24 315.55 302.27 > > [1] https://github.com/stefano-garzarella/iperf/Hi: Do you have any explanation that vsock is better here? Is this because of the mergeable buffer? If you, we need test with mrg_rxbuf=off. Thanks> > Stefano Garzarella (8): > vsock/virtio: limit the memory used per-socket > vsock/virtio: free packets during the socket release > vsock/virtio: fix locking for fwd_cnt and buf_alloc > vsock/virtio: reduce credit update messages > vhost/vsock: split packets to send using multiple buffers > vsock/virtio: change the maximum packet size allowed > vsock/virtio: increase RX buffer size to 64 KiB > vsock/virtio: make the RX buffer size tunable > > drivers/vhost/vsock.c | 53 +++++++-- > include/linux/virtio_vsock.h | 14 ++- > net/vmw_vsock/virtio_transport.c | 28 ++++- > net/vmw_vsock/virtio_transport_common.c | 144 ++++++++++++++++++------ > 4 files changed, 190 insertions(+), 49 deletions(-) >
Jason Wang
2019-May-13 09:58 UTC
[PATCH v2 1/8] vsock/virtio: limit the memory used per-socket
On 2019/5/10 ??8:58, Stefano Garzarella wrote:> Since virtio-vsock was introduced, the buffers filled by the host > and pushed to the guest using the vring, are directly queued in > a per-socket list avoiding to copy it. > These buffers are preallocated by the guest with a fixed > size (4 KB). > > The maximum amount of memory used by each socket should be > controlled by the credit mechanism. > The default credit available per-socket is 256 KB, but if we use > only 1 byte per packet, the guest can queue up to 262144 of 4 KB > buffers, using up to 1 GB of memory per-socket. In addition, the > guest will continue to fill the vring with new 4 KB free buffers > to avoid starvation of other sockets. > > This patch solves this issue copying the payload in a new buffer. > Then it is queued in the per-socket list, and the 4KB buffer used > by the host is freed. > > In this way, the memory used by each socket respects the credit > available, and we still avoid starvation, paying the cost of an > extra memory copy. When the buffer is completely full we do a > "zero-copy", moving the buffer directly in the per-socket list.I wonder in the long run we should use generic socket accouting mechanism provided by kernel (e.g socket, skb, sndbuf, recvbug, truesize) instead of vsock specific thing to avoid duplicating efforts.> > Signed-off-by: Stefano Garzarella <sgarzare at redhat.com> > --- > drivers/vhost/vsock.c | 2 + > include/linux/virtio_vsock.h | 8 +++ > net/vmw_vsock/virtio_transport.c | 1 + > net/vmw_vsock/virtio_transport_common.c | 95 ++++++++++++++++++------- > 4 files changed, 81 insertions(+), 25 deletions(-) > > diff --git a/drivers/vhost/vsock.c b/drivers/vhost/vsock.c > index bb5fc0e9fbc2..7964e2daee09 100644 > --- a/drivers/vhost/vsock.c > +++ b/drivers/vhost/vsock.c > @@ -320,6 +320,8 @@ vhost_vsock_alloc_pkt(struct vhost_virtqueue *vq, > return NULL; > } > > + pkt->buf_len = pkt->len; > + > nbytes = copy_from_iter(pkt->buf, pkt->len, &iov_iter); > if (nbytes != pkt->len) { > vq_err(vq, "Expected %u byte payload, got %zu bytes\n", > diff --git a/include/linux/virtio_vsock.h b/include/linux/virtio_vsock.h > index e223e2632edd..345f04ee9193 100644 > --- a/include/linux/virtio_vsock.h > +++ b/include/linux/virtio_vsock.h > @@ -54,9 +54,17 @@ struct virtio_vsock_pkt { > void *buf; > u32 len; > u32 off; > + u32 buf_len; > bool reply; > }; > > +struct virtio_vsock_buf { > + struct list_head list; > + void *addr; > + u32 len; > + u32 off; > +}; > + > struct virtio_vsock_pkt_info { > u32 remote_cid, remote_port; > struct vsock_sock *vsk; > diff --git a/net/vmw_vsock/virtio_transport.c b/net/vmw_vsock/virtio_transport.c > index 15eb5d3d4750..af1d2ce12f54 100644 > --- a/net/vmw_vsock/virtio_transport.c > +++ b/net/vmw_vsock/virtio_transport.c > @@ -280,6 +280,7 @@ static void virtio_vsock_rx_fill(struct virtio_vsock *vsock) > break; > } > > + pkt->buf_len = buf_len; > pkt->len = buf_len; > > sg_init_one(&hdr, &pkt->hdr, sizeof(pkt->hdr)); > diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c > index 602715fc9a75..0248d6808755 100644 > --- a/net/vmw_vsock/virtio_transport_common.c > +++ b/net/vmw_vsock/virtio_transport_common.c > @@ -65,6 +65,9 @@ virtio_transport_alloc_pkt(struct virtio_vsock_pkt_info *info, > pkt->buf = kmalloc(len, GFP_KERNEL); > if (!pkt->buf) > goto out_pkt; > + > + pkt->buf_len = len; > + > err = memcpy_from_msg(pkt->buf, info->msg, len); > if (err) > goto out; > @@ -86,6 +89,46 @@ virtio_transport_alloc_pkt(struct virtio_vsock_pkt_info *info, > return NULL; > } > > +static struct virtio_vsock_buf * > +virtio_transport_alloc_buf(struct virtio_vsock_pkt *pkt, bool zero_copy) > +{ > + struct virtio_vsock_buf *buf; > + > + if (pkt->len == 0) > + return NULL; > + > + buf = kzalloc(sizeof(*buf), GFP_KERNEL); > + if (!buf) > + return NULL; > + > + /* If the buffer in the virtio_vsock_pkt is full, we can move it to > + * the new virtio_vsock_buf avoiding the copy, because we are sure that > + * we are not use more memory than that counted by the credit mechanism. > + */ > + if (zero_copy && pkt->len == pkt->buf_len) { > + buf->addr = pkt->buf; > + pkt->buf = NULL; > + } else {Is the copy still needed if we're just few bytes less? We meet similar issue for virito-net, and virtio-net solve this by always copy first 128bytes for big packets. See receive_big(). Thanks> + buf->addr = kmalloc(pkt->len, GFP_KERNEL); > + if (!buf->addr) { > + kfree(buf); > + return NULL; > + } > + > + memcpy(buf->addr, pkt->buf, pkt->len); > + } > + > + buf->len = pkt->len; > + > + return buf; > +} > + > +static void virtio_transport_free_buf(struct virtio_vsock_buf *buf) > +{ > + kfree(buf->addr); > + kfree(buf); > +} > + > /* Packet capture */ > static struct sk_buff *virtio_transport_build_skb(void *opaque) > { > @@ -190,17 +233,15 @@ static int virtio_transport_send_pkt_info(struct vsock_sock *vsk, > return virtio_transport_get_ops()->send_pkt(pkt); > } > > -static void virtio_transport_inc_rx_pkt(struct virtio_vsock_sock *vvs, > - struct virtio_vsock_pkt *pkt) > +static void virtio_transport_inc_rx_pkt(struct virtio_vsock_sock *vvs, u32 len) > { > - vvs->rx_bytes += pkt->len; > + vvs->rx_bytes += len; > } > > -static void virtio_transport_dec_rx_pkt(struct virtio_vsock_sock *vvs, > - struct virtio_vsock_pkt *pkt) > +static void virtio_transport_dec_rx_pkt(struct virtio_vsock_sock *vvs, u32 len) > { > - vvs->rx_bytes -= pkt->len; > - vvs->fwd_cnt += pkt->len; > + vvs->rx_bytes -= len; > + vvs->fwd_cnt += len; > } > > void virtio_transport_inc_tx_pkt(struct virtio_vsock_sock *vvs, struct virtio_vsock_pkt *pkt) > @@ -254,36 +295,36 @@ virtio_transport_stream_do_dequeue(struct vsock_sock *vsk, > size_t len) > { > struct virtio_vsock_sock *vvs = vsk->trans; > - struct virtio_vsock_pkt *pkt; > + struct virtio_vsock_buf *buf; > size_t bytes, total = 0; > int err = -EFAULT; > > spin_lock_bh(&vvs->rx_lock); > while (total < len && !list_empty(&vvs->rx_queue)) { > - pkt = list_first_entry(&vvs->rx_queue, > - struct virtio_vsock_pkt, list); > + buf = list_first_entry(&vvs->rx_queue, > + struct virtio_vsock_buf, list); > > bytes = len - total; > - if (bytes > pkt->len - pkt->off) > - bytes = pkt->len - pkt->off; > + if (bytes > buf->len - buf->off) > + bytes = buf->len - buf->off; > > /* sk_lock is held by caller so no one else can dequeue. > * Unlock rx_lock since memcpy_to_msg() may sleep. > */ > spin_unlock_bh(&vvs->rx_lock); > > - err = memcpy_to_msg(msg, pkt->buf + pkt->off, bytes); > + err = memcpy_to_msg(msg, buf->addr + buf->off, bytes); > if (err) > goto out; > > spin_lock_bh(&vvs->rx_lock); > > total += bytes; > - pkt->off += bytes; > - if (pkt->off == pkt->len) { > - virtio_transport_dec_rx_pkt(vvs, pkt); > - list_del(&pkt->list); > - virtio_transport_free_pkt(pkt); > + buf->off += bytes; > + if (buf->off == buf->len) { > + virtio_transport_dec_rx_pkt(vvs, buf->len); > + list_del(&buf->list); > + virtio_transport_free_buf(buf); > } > } > spin_unlock_bh(&vvs->rx_lock); > @@ -841,20 +882,24 @@ virtio_transport_recv_connected(struct sock *sk, > { > struct vsock_sock *vsk = vsock_sk(sk); > struct virtio_vsock_sock *vvs = vsk->trans; > + struct virtio_vsock_buf *buf; > int err = 0; > > switch (le16_to_cpu(pkt->hdr.op)) { > case VIRTIO_VSOCK_OP_RW: > pkt->len = le32_to_cpu(pkt->hdr.len); > - pkt->off = 0; > + buf = virtio_transport_alloc_buf(pkt, true); > > - spin_lock_bh(&vvs->rx_lock); > - virtio_transport_inc_rx_pkt(vvs, pkt); > - list_add_tail(&pkt->list, &vvs->rx_queue); > - spin_unlock_bh(&vvs->rx_lock); > + if (buf) { > + spin_lock_bh(&vvs->rx_lock); > + virtio_transport_inc_rx_pkt(vvs, pkt->len); > + list_add_tail(&buf->list, &vvs->rx_queue); > + spin_unlock_bh(&vvs->rx_lock); > > - sk->sk_data_ready(sk); > - return err; > + sk->sk_data_ready(sk); > + } > + > + break; > case VIRTIO_VSOCK_OP_CREDIT_UPDATE: > sk->sk_write_space(sk); > break;
Jason Wang
2019-May-13 10:01 UTC
[PATCH v2 7/8] vsock/virtio: increase RX buffer size to 64 KiB
On 2019/5/10 ??8:58, Stefano Garzarella wrote:> In order to increase host -> guest throughput with large packets, > we can use 64 KiB RX buffers. > > Signed-off-by: Stefano Garzarella <sgarzare at redhat.com> > --- > include/linux/virtio_vsock.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/include/linux/virtio_vsock.h b/include/linux/virtio_vsock.h > index 84b72026d327..5a9d25be72df 100644 > --- a/include/linux/virtio_vsock.h > +++ b/include/linux/virtio_vsock.h > @@ -10,7 +10,7 @@ > #define VIRTIO_VSOCK_DEFAULT_MIN_BUF_SIZE 128 > #define VIRTIO_VSOCK_DEFAULT_BUF_SIZE (1024 * 256) > #define VIRTIO_VSOCK_DEFAULT_MAX_BUF_SIZE (1024 * 256) > -#define VIRTIO_VSOCK_DEFAULT_RX_BUF_SIZE (1024 * 4) > +#define VIRTIO_VSOCK_DEFAULT_RX_BUF_SIZE (1024 * 64) > #define VIRTIO_VSOCK_MAX_BUF_SIZE 0xFFFFFFFFUL > #define VIRTIO_VSOCK_MAX_PKT_BUF_SIZE (1024 * 64) >We probably don't want such high order allocation. It's better to switch to use order 0 pages in this case. See add_recvbuf_big() for virtio-net. If we get datapath unified, we will get more stuffs set. Thanks
Jason Wang
2019-May-13 10:05 UTC
[PATCH v2 8/8] vsock/virtio: make the RX buffer size tunable
On 2019/5/10 ??8:58, Stefano Garzarella wrote:> The RX buffer size determines the memory consumption of the > vsock/virtio guest driver, so we make it tunable through > a module parameter. > > The size allowed are between 4 KB and 64 KB in order to be > compatible with old host drivers. > > Suggested-by: Stefan Hajnoczi <stefanha at redhat.com> > Signed-off-by: Stefano Garzarella <sgarzare at redhat.com>I don't see much value of doing this through kernel command line. We should deal with them automatically like what virtio-net did. Or even a module parameter is better. Thanks> --- > include/linux/virtio_vsock.h | 1 + > net/vmw_vsock/virtio_transport.c | 27 ++++++++++++++++++++++++++- > 2 files changed, 27 insertions(+), 1 deletion(-) > > diff --git a/include/linux/virtio_vsock.h b/include/linux/virtio_vsock.h > index 5a9d25be72df..b9f8c3d91f80 100644 > --- a/include/linux/virtio_vsock.h > +++ b/include/linux/virtio_vsock.h > @@ -13,6 +13,7 @@ > #define VIRTIO_VSOCK_DEFAULT_RX_BUF_SIZE (1024 * 64) > #define VIRTIO_VSOCK_MAX_BUF_SIZE 0xFFFFFFFFUL > #define VIRTIO_VSOCK_MAX_PKT_BUF_SIZE (1024 * 64) > +#define VIRTIO_VSOCK_MIN_PKT_BUF_SIZE (1024 * 4) > > enum { > VSOCK_VQ_RX = 0, /* for host to guest data */ > diff --git a/net/vmw_vsock/virtio_transport.c b/net/vmw_vsock/virtio_transport.c > index af1d2ce12f54..732398b4e28f 100644 > --- a/net/vmw_vsock/virtio_transport.c > +++ b/net/vmw_vsock/virtio_transport.c > @@ -66,6 +66,31 @@ struct virtio_vsock { > u32 guest_cid; > }; > > +static unsigned int rx_buf_size = VIRTIO_VSOCK_DEFAULT_RX_BUF_SIZE; > + > +static int param_set_rx_buf_size(const char *val, const struct kernel_param *kp) > +{ > + unsigned int size; > + int ret; > + > + ret = kstrtouint(val, 0, &size); > + if (ret) > + return ret; > + > + if (size < VIRTIO_VSOCK_MIN_PKT_BUF_SIZE || > + size > VIRTIO_VSOCK_MAX_PKT_BUF_SIZE) > + return -EINVAL; > + > + return param_set_uint(val, kp); > +}; > + > +static const struct kernel_param_ops param_ops_rx_buf_size = { > + .set = param_set_rx_buf_size, > + .get = param_get_uint, > +}; > + > +module_param_cb(rx_buf_size, ¶m_ops_rx_buf_size, &rx_buf_size, 0644); > + > static struct virtio_vsock *virtio_vsock_get(void) > { > return the_virtio_vsock; > @@ -261,7 +286,7 @@ virtio_transport_cancel_pkt(struct vsock_sock *vsk) > > static void virtio_vsock_rx_fill(struct virtio_vsock *vsock) > { > - int buf_len = VIRTIO_VSOCK_DEFAULT_RX_BUF_SIZE; > + int buf_len = rx_buf_size; > struct virtio_vsock_pkt *pkt; > struct scatterlist hdr, buf, *sgs[2]; > struct virtqueue *vq;
Stefano Garzarella
2019-May-13 16:49 UTC
[PATCH v2 0/8] vsock/virtio: optimizations to increase the throughput
On Mon, May 13, 2019 at 05:33:40PM +0800, Jason Wang wrote:> > On 2019/5/10 ??8:58, Stefano Garzarella wrote: > > While I was testing this new series (v2) I discovered an huge use of memory > > and a memory leak in the virtio-vsock driver in the guest when I sent > > 1-byte packets to the guest. > > > > These issues are present since the introduction of the virtio-vsock > > driver. I added the patches 1 and 2 to fix them in this series in order > > to better track the performance trends. > > > > v1: https://patchwork.kernel.org/cover/10885431/ > > > > v2: > > - Add patch 1 to limit the memory usage > > - Add patch 2 to avoid memory leak during the socket release > > - Add patch 3 to fix locking of fwd_cnt and buf_alloc > > - Patch 4: fix 'free_space' type (u32 instead of s64) [Stefan] > > - Patch 5: Avoid integer underflow of iov_len [Stefan] > > - Patch 5: Fix packet capture in order to see the exact packets that are > > delivered. [Stefan] > > - Add patch 8 to make the RX buffer size tunable [Stefan] > > > > Below are the benchmarks step by step. I used iperf3 [1] modified with VSOCK > > support. > > As Micheal suggested in the v1, I booted host and guest with 'nosmap', and I > > added a column with virtio-net+vhost-net performance. > > > > A brief description of patches: > > - Patches 1+2: limit the memory usage with an extra copy and avoid memory leak > > - Patches 3+4: fix locking and reduce the number of credit update messages sent > > to the transmitter > > - Patches 5+6: allow the host to split packets on multiple buffers and use > > VIRTIO_VSOCK_MAX_PKT_BUF_SIZE as the max packet size allowed > > - Patches 7+8: increase RX buffer size to 64 KiB > > > > host -> guest [Gbps] > > pkt_size before opt p 1+2 p 3+4 p 5+6 p 7+8 virtio-net + vhost > > TCP_NODELAY > > 64 0.068 0.063 0.130 0.131 0.128 0.188 0.187 > > 256 0.274 0.236 0.392 0.338 0.282 0.749 0.654 > > 512 0.531 0.457 0.862 0.725 0.602 1.419 1.414 > > 1K 0.954 0.827 1.591 1.598 1.548 2.599 2.640 > > 2K 1.783 1.543 3.731 3.637 3.469 4.530 4.754 > > 4K 3.332 3.436 7.164 7.124 6.494 7.738 7.696 > > 8K 5.792 5.530 11.653 11.787 11.444 12.307 11.850 > > 16K 8.405 8.462 16.372 16.855 17.562 16.936 16.954 > > 32K 14.208 13.669 18.945 20.009 23.128 21.980 23.015 > > 64K 21.082 18.893 20.266 20.903 30.622 27.290 27.383 > > 128K 20.696 20.148 20.112 21.746 32.152 30.446 30.990 > > 256K 20.801 20.589 20.725 22.685 34.721 33.151 32.745 > > 512K 21.220 20.465 20.432 22.106 34.496 36.847 31.096 > > > > guest -> host [Gbps] > > pkt_size before opt p 1+2 p 3+4 p 5+6 p 7+8 virtio-net + vhost > > TCP_NODELAY > > 64 0.089 0.091 0.120 0.115 0.117 0.274 0.272 > > 256 0.352 0.354 0.452 0.445 0.451 1.085 1.136 > > 512 0.705 0.704 0.893 0.858 0.898 2.131 1.882 > > 1K 1.394 1.433 1.721 1.669 1.691 3.984 3.576 > > 2K 2.818 2.874 3.316 3.249 3.303 6.719 6.359 > > 4K 5.293 5.397 6.129 5.933 6.082 10.105 9.860 > > 8K 8.890 9.151 10.990 10.545 10.519 15.239 14.868 > > 16K 11.444 11.018 12.074 15.255 15.577 20.551 20.848 > > 32K 11.229 10.875 10.857 24.401 25.227 26.294 26.380 > > 64K 10.832 10.545 10.816 39.487 39.616 34.996 32.041 > > 128K 10.435 10.241 10.500 39.813 40.012 38.379 35.055 > > 256K 10.263 9.866 9.845 34.971 35.143 36.559 37.232 > > 512K 10.224 10.060 10.092 35.469 34.627 34.963 33.401 > > > > As Stefan suggested in the v1, this time I measured also the efficiency in this > > way: > > efficiency = Mbps / (%CPU_Host + %CPU_Guest) > > > > The '%CPU_Guest' is taken inside the VM. I know that it is not the best way, > > but it's provided for free from iperf3 and could be an indication. > > > > host -> guest efficiency [Mbps / (%CPU_Host + %CPU_Guest)] > > pkt_size before opt p 1+2 p 3+4 p 5+6 p 7+8 virtio-net + vhost > > TCP_NODELAY > > 64 0.94 0.59 3.96 4.06 4.09 2.82 2.11 > > 256 2.62 2.50 6.45 6.09 5.81 9.64 8.73 > > 512 5.16 4.87 13.16 12.39 11.67 17.83 17.76 > > 1K 9.16 8.85 24.98 24.97 25.01 32.57 32.04 > > 2K 17.41 17.03 49.09 48.59 49.22 55.31 57.14 > > 4K 32.99 33.62 90.80 90.98 91.72 91.79 91.40 > > 8K 58.51 59.98 153.53 170.83 167.31 137.51 132.85 > > 16K 89.32 95.29 216.98 264.18 260.95 176.05 176.05 > > 32K 152.94 167.10 285.75 387.02 360.81 215.49 226.30 > > 64K 250.38 307.20 317.65 489.53 472.70 238.97 244.27 > > 128K 327.99 335.24 335.76 523.71 486.41 253.29 260.86 > > 256K 327.06 334.24 338.64 533.76 509.85 267.78 266.22 > > 512K 337.36 330.61 334.95 512.90 496.35 280.42 241.43 > > > > guest -> host efficiency [Mbps / (%CPU_Host + %CPU_Guest)] > > pkt_size before opt p 1+2 p 3+4 p 5+6 p 7+8 virtio-net + vhost > > TCP_NODELAY > > 64 0.90 0.91 1.37 1.32 1.35 2.15 2.13 > > 256 3.59 3.55 5.23 5.19 5.29 8.50 8.89 > > 512 7.19 7.08 10.21 9.95 10.38 16.74 14.71 > > 1K 14.15 14.34 19.85 19.06 19.33 31.44 28.11 > > 2K 28.44 29.09 37.78 37.18 37.49 53.07 50.63 > > 4K 55.37 57.60 71.02 69.27 70.97 81.56 79.32 > > 8K 105.58 100.45 111.95 124.68 123.61 120.85 118.66 > > 16K 141.63 138.24 137.67 187.41 190.20 160.43 163.00 > > 32K 147.56 143.09 138.48 296.41 301.04 214.64 223.94 > > 64K 144.81 143.27 138.49 433.98 462.26 298.86 269.71 > > 128K 150.14 147.99 146.85 511.36 514.29 350.17 298.09 > > 256K 156.69 152.25 148.69 542.19 549.97 326.42 333.32 > > 512K 157.29 153.35 152.22 546.52 533.24 315.55 302.27 > > > > [1] https://github.com/stefano-garzarella/iperf/ > > > Hi: > > Do you have any explanation that vsock is better here? Is this because of > the mergeable buffer? If you, we need test with mrg_rxbuf=off.Hi Jason, virtio-net stays faster for packets with size up tp 16K/32K, maybe, as you suggested, could be releated to mergeable buffer. I'll try to disable it and re-run the tests. Thanks, Stefano
Stefan Hajnoczi
2019-May-16 15:25 UTC
[PATCH v2 1/8] vsock/virtio: limit the memory used per-socket
On Fri, May 10, 2019 at 02:58:36PM +0200, Stefano Garzarella wrote:> +struct virtio_vsock_buf {Please add a comment describing the purpose of this struct and to differentiate its use from struct virtio_vsock_pkt.> +static struct virtio_vsock_buf * > +virtio_transport_alloc_buf(struct virtio_vsock_pkt *pkt, bool zero_copy) > +{ > + struct virtio_vsock_buf *buf; > + > + if (pkt->len == 0) > + return NULL; > + > + buf = kzalloc(sizeof(*buf), GFP_KERNEL); > + if (!buf) > + return NULL; > + > + /* If the buffer in the virtio_vsock_pkt is full, we can move it to > + * the new virtio_vsock_buf avoiding the copy, because we are sure that > + * we are not use more memory than that counted by the credit mechanism. > + */ > + if (zero_copy && pkt->len == pkt->buf_len) { > + buf->addr = pkt->buf; > + pkt->buf = NULL; > + } else { > + buf->addr = kmalloc(pkt->len, GFP_KERNEL);buf and buf->addr could be allocated in a single call, though I'm not sure how big an optimization this is.> @@ -841,20 +882,24 @@ virtio_transport_recv_connected(struct sock *sk, > { > struct vsock_sock *vsk = vsock_sk(sk); > struct virtio_vsock_sock *vvs = vsk->trans; > + struct virtio_vsock_buf *buf; > int err = 0; > > switch (le16_to_cpu(pkt->hdr.op)) { > case VIRTIO_VSOCK_OP_RW: > pkt->len = le32_to_cpu(pkt->hdr.len); > - pkt->off = 0; > + buf = virtio_transport_alloc_buf(pkt, true); > > - spin_lock_bh(&vvs->rx_lock); > - virtio_transport_inc_rx_pkt(vvs, pkt); > - list_add_tail(&pkt->list, &vvs->rx_queue); > - spin_unlock_bh(&vvs->rx_lock); > + if (buf) { > + spin_lock_bh(&vvs->rx_lock); > + virtio_transport_inc_rx_pkt(vvs, pkt->len); > + list_add_tail(&buf->list, &vvs->rx_queue); > + spin_unlock_bh(&vvs->rx_lock); > > - sk->sk_data_ready(sk); > - return err; > + sk->sk_data_ready(sk); > + }The return value of this function isn't used but the code still makes an effort to return errors. Please return -ENOMEM when buf == NULL. If you'd like to remove the return value that's fine too, but please do it for the whole function to be consistent. -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 488 bytes Desc: not available URL: <http://lists.linuxfoundation.org/pipermail/virtualization/attachments/20190516/1570bbca/attachment-0001.sig>
Stefan Hajnoczi
2019-May-16 15:32 UTC
[PATCH v2 2/8] vsock/virtio: free packets during the socket release
On Fri, May 10, 2019 at 02:58:37PM +0200, Stefano Garzarella wrote:> When the socket is released, we should free all packets > queued in the per-socket list in order to avoid a memory > leak. > > Signed-off-by: Stefano Garzarella <sgarzare at redhat.com> > --- > net/vmw_vsock/virtio_transport_common.c | 8 ++++++++ > 1 file changed, 8 insertions(+)Ouch, this would be nice as a separate patch that can be merged right away (with s/virtio_vsock_buf/virtio_vsock_pkt/). -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 488 bytes Desc: not available URL: <http://lists.linuxfoundation.org/pipermail/virtualization/attachments/20190516/70384c84/attachment.sig>
Stefano Garzarella
2019-May-20 14:09 UTC
[PATCH v2 0/8] vsock/virtio: optimizations to increase the throughput
On Mon, May 13, 2019 at 05:33:40PM +0800, Jason Wang wrote:> > On 2019/5/10 ??8:58, Stefano Garzarella wrote: > > While I was testing this new series (v2) I discovered an huge use of memory > > and a memory leak in the virtio-vsock driver in the guest when I sent > > 1-byte packets to the guest. > > > > These issues are present since the introduction of the virtio-vsock > > driver. I added the patches 1 and 2 to fix them in this series in order > > to better track the performance trends. > > > > v1: https://patchwork.kernel.org/cover/10885431/ > > > > v2: > > - Add patch 1 to limit the memory usage > > - Add patch 2 to avoid memory leak during the socket release > > - Add patch 3 to fix locking of fwd_cnt and buf_alloc > > - Patch 4: fix 'free_space' type (u32 instead of s64) [Stefan] > > - Patch 5: Avoid integer underflow of iov_len [Stefan] > > - Patch 5: Fix packet capture in order to see the exact packets that are > > delivered. [Stefan] > > - Add patch 8 to make the RX buffer size tunable [Stefan] > > > > Below are the benchmarks step by step. I used iperf3 [1] modified with VSOCK > > support. > > As Micheal suggested in the v1, I booted host and guest with 'nosmap', and I > > added a column with virtio-net+vhost-net performance. > > > > A brief description of patches: > > - Patches 1+2: limit the memory usage with an extra copy and avoid memory leak > > - Patches 3+4: fix locking and reduce the number of credit update messages sent > > to the transmitter > > - Patches 5+6: allow the host to split packets on multiple buffers and use > > VIRTIO_VSOCK_MAX_PKT_BUF_SIZE as the max packet size allowed > > - Patches 7+8: increase RX buffer size to 64 KiB > > > > host -> guest [Gbps] > > pkt_size before opt p 1+2 p 3+4 p 5+6 p 7+8 virtio-net + vhost > > TCP_NODELAY > > 64 0.068 0.063 0.130 0.131 0.128 0.188 0.187 > > 256 0.274 0.236 0.392 0.338 0.282 0.749 0.654 > > 512 0.531 0.457 0.862 0.725 0.602 1.419 1.414 > > 1K 0.954 0.827 1.591 1.598 1.548 2.599 2.640 > > 2K 1.783 1.543 3.731 3.637 3.469 4.530 4.754 > > 4K 3.332 3.436 7.164 7.124 6.494 7.738 7.696 > > 8K 5.792 5.530 11.653 11.787 11.444 12.307 11.850 > > 16K 8.405 8.462 16.372 16.855 17.562 16.936 16.954 > > 32K 14.208 13.669 18.945 20.009 23.128 21.980 23.015 > > 64K 21.082 18.893 20.266 20.903 30.622 27.290 27.383 > > 128K 20.696 20.148 20.112 21.746 32.152 30.446 30.990 > > 256K 20.801 20.589 20.725 22.685 34.721 33.151 32.745 > > 512K 21.220 20.465 20.432 22.106 34.496 36.847 31.096 > > > > guest -> host [Gbps] > > pkt_size before opt p 1+2 p 3+4 p 5+6 p 7+8 virtio-net + vhost > > TCP_NODELAY > > 64 0.089 0.091 0.120 0.115 0.117 0.274 0.272 > > 256 0.352 0.354 0.452 0.445 0.451 1.085 1.136 > > 512 0.705 0.704 0.893 0.858 0.898 2.131 1.882 > > 1K 1.394 1.433 1.721 1.669 1.691 3.984 3.576 > > 2K 2.818 2.874 3.316 3.249 3.303 6.719 6.359 > > 4K 5.293 5.397 6.129 5.933 6.082 10.105 9.860 > > 8K 8.890 9.151 10.990 10.545 10.519 15.239 14.868 > > 16K 11.444 11.018 12.074 15.255 15.577 20.551 20.848 > > 32K 11.229 10.875 10.857 24.401 25.227 26.294 26.380 > > 64K 10.832 10.545 10.816 39.487 39.616 34.996 32.041 > > 128K 10.435 10.241 10.500 39.813 40.012 38.379 35.055 > > 256K 10.263 9.866 9.845 34.971 35.143 36.559 37.232 > > 512K 10.224 10.060 10.092 35.469 34.627 34.963 33.401 > > > > As Stefan suggested in the v1, this time I measured also the efficiency in this > > way: > > efficiency = Mbps / (%CPU_Host + %CPU_Guest) > > > > The '%CPU_Guest' is taken inside the VM. I know that it is not the best way, > > but it's provided for free from iperf3 and could be an indication. > > > > host -> guest efficiency [Mbps / (%CPU_Host + %CPU_Guest)] > > pkt_size before opt p 1+2 p 3+4 p 5+6 p 7+8 virtio-net + vhost > > TCP_NODELAY > > 64 0.94 0.59 3.96 4.06 4.09 2.82 2.11 > > 256 2.62 2.50 6.45 6.09 5.81 9.64 8.73 > > 512 5.16 4.87 13.16 12.39 11.67 17.83 17.76 > > 1K 9.16 8.85 24.98 24.97 25.01 32.57 32.04 > > 2K 17.41 17.03 49.09 48.59 49.22 55.31 57.14 > > 4K 32.99 33.62 90.80 90.98 91.72 91.79 91.40 > > 8K 58.51 59.98 153.53 170.83 167.31 137.51 132.85 > > 16K 89.32 95.29 216.98 264.18 260.95 176.05 176.05 > > 32K 152.94 167.10 285.75 387.02 360.81 215.49 226.30 > > 64K 250.38 307.20 317.65 489.53 472.70 238.97 244.27 > > 128K 327.99 335.24 335.76 523.71 486.41 253.29 260.86 > > 256K 327.06 334.24 338.64 533.76 509.85 267.78 266.22 > > 512K 337.36 330.61 334.95 512.90 496.35 280.42 241.43 > > > > guest -> host efficiency [Mbps / (%CPU_Host + %CPU_Guest)] > > pkt_size before opt p 1+2 p 3+4 p 5+6 p 7+8 virtio-net + vhost > > TCP_NODELAY > > 64 0.90 0.91 1.37 1.32 1.35 2.15 2.13 > > 256 3.59 3.55 5.23 5.19 5.29 8.50 8.89 > > 512 7.19 7.08 10.21 9.95 10.38 16.74 14.71 > > 1K 14.15 14.34 19.85 19.06 19.33 31.44 28.11 > > 2K 28.44 29.09 37.78 37.18 37.49 53.07 50.63 > > 4K 55.37 57.60 71.02 69.27 70.97 81.56 79.32 > > 8K 105.58 100.45 111.95 124.68 123.61 120.85 118.66 > > 16K 141.63 138.24 137.67 187.41 190.20 160.43 163.00 > > 32K 147.56 143.09 138.48 296.41 301.04 214.64 223.94 > > 64K 144.81 143.27 138.49 433.98 462.26 298.86 269.71 > > 128K 150.14 147.99 146.85 511.36 514.29 350.17 298.09 > > 256K 156.69 152.25 148.69 542.19 549.97 326.42 333.32 > > 512K 157.29 153.35 152.22 546.52 533.24 315.55 302.27 > > > > [1] https://github.com/stefano-garzarella/iperf/ > > > Hi: > > Do you have any explanation that vsock is better here? Is this because of > the mergeable buffer? If you, we need test with mrg_rxbuf=off. >Hi Jason, I tried to disable the mergeable buffer but I had even worst performance with virtio-net. Do you think the differences could be related to the TCP/IP stack? Thanks, Stefano
Reasonably Related Threads
- [PATCH v2 1/8] vsock/virtio: limit the memory used per-socket
- [PATCH v2 1/8] vsock/virtio: limit the memory used per-socket
- [PATCH v2 1/8] vsock/virtio: limit the memory used per-socket
- [PATCH v2 1/8] vsock/virtio: limit the memory used per-socket
- [PATCH v2 0/8] vsock/virtio: optimizations to increase the throughput