From 7426b1a51803ba2d368177363a134b98b0a8d1c0 Mon Sep 17 00:00:00 2001 From: stephen hemminger Date: Fri, 28 Jul 2017 08:59:45 -0700 Subject: netvsc: optimize receive completions Optimize how receive completion ring are managed. * Allocate only as many slots as needed for all buffers from host * Allocate before setting up sub channel for better error detection * Don't need to keep copy of initial receive section message * Precompute the watermark for when receive flushing is needed * Replace division with conditional test * Replace atomic per-device variable with per-channel check. * Handle corner case where receive completion send fails if ring buffer to host is full. Signed-off-by: Stephen Hemminger Signed-off-by: David S. Miller --- drivers/net/hyperv/netvsc.c | 267 ++++++++++++++++++-------------------------- 1 file changed, 109 insertions(+), 158 deletions(-) (limited to 'drivers/net/hyperv/netvsc.c') diff --git a/drivers/net/hyperv/netvsc.c b/drivers/net/hyperv/netvsc.c index d3c0b19f6d34..4c709b454d34 100644 --- a/drivers/net/hyperv/netvsc.c +++ b/drivers/net/hyperv/netvsc.c @@ -72,9 +72,6 @@ static struct netvsc_device *alloc_net_device(void) if (!net_device) return NULL; - net_device->chan_table[0].mrc.buf - = vzalloc(NETVSC_RECVSLOT_MAX * sizeof(struct recv_comp_data)); - init_waitqueue_head(&net_device->wait_drain); net_device->destroy = false; atomic_set(&net_device->open_cnt, 0); @@ -92,7 +89,7 @@ static void free_netvsc_device(struct rcu_head *head) int i; for (i = 0; i < VRSS_CHANNEL_MAX; i++) - vfree(nvdev->chan_table[i].mrc.buf); + vfree(nvdev->chan_table[i].mrc.slots); kfree(nvdev); } @@ -171,12 +168,6 @@ static void netvsc_destroy_buf(struct hv_device *device) net_device->recv_buf = NULL; } - if (net_device->recv_section) { - net_device->recv_section_cnt = 0; - kfree(net_device->recv_section); - net_device->recv_section = NULL; - } - /* Deal with the send buffer we may have setup. * If we got a send section size, it means we received a * NVSP_MSG1_TYPE_SEND_SEND_BUF_COMPLETE msg (ie sent @@ -239,11 +230,26 @@ static void netvsc_destroy_buf(struct hv_device *device) kfree(net_device->send_section_map); } +int netvsc_alloc_recv_comp_ring(struct netvsc_device *net_device, u32 q_idx) +{ + struct netvsc_channel *nvchan = &net_device->chan_table[q_idx]; + int node = cpu_to_node(nvchan->channel->target_cpu); + size_t size; + + size = net_device->recv_completion_cnt * sizeof(struct recv_comp_data); + nvchan->mrc.slots = vzalloc_node(size, node); + if (!nvchan->mrc.slots) + nvchan->mrc.slots = vzalloc(size); + + return nvchan->mrc.slots ? 0 : -ENOMEM; +} + static int netvsc_init_buf(struct hv_device *device, struct netvsc_device *net_device) { int ret = 0; struct nvsp_message *init_packet; + struct nvsp_1_message_send_receive_buffer_complete *resp; struct net_device *ndev; size_t map_words; int node; @@ -300,43 +306,41 @@ static int netvsc_init_buf(struct hv_device *device, wait_for_completion(&net_device->channel_init_wait); /* Check the response */ - if (init_packet->msg.v1_msg. - send_recv_buf_complete.status != NVSP_STAT_SUCCESS) { - netdev_err(ndev, "Unable to complete receive buffer " - "initialization with NetVsp - status %d\n", - init_packet->msg.v1_msg. - send_recv_buf_complete.status); + resp = &init_packet->msg.v1_msg.send_recv_buf_complete; + if (resp->status != NVSP_STAT_SUCCESS) { + netdev_err(ndev, + "Unable to complete receive buffer initialization with NetVsp - status %d\n", + resp->status); ret = -EINVAL; goto cleanup; } /* Parse the response */ + netdev_dbg(ndev, "Receive sections: %u sub_allocs: size %u count: %u\n", + resp->num_sections, resp->sections[0].sub_alloc_size, + resp->sections[0].num_sub_allocs); - net_device->recv_section_cnt = init_packet->msg. - v1_msg.send_recv_buf_complete.num_sections; - - net_device->recv_section = kmemdup( - init_packet->msg.v1_msg.send_recv_buf_complete.sections, - net_device->recv_section_cnt * - sizeof(struct nvsp_1_receive_buffer_section), - GFP_KERNEL); - if (net_device->recv_section == NULL) { - ret = -EINVAL; - goto cleanup; - } + net_device->recv_section_cnt = resp->num_sections; /* * For 1st release, there should only be 1 section that represents the * entire receive buffer */ if (net_device->recv_section_cnt != 1 || - net_device->recv_section->offset != 0) { + resp->sections[0].offset != 0) { ret = -EINVAL; goto cleanup; } - /* Now setup the send buffer. - */ + /* Setup receive completion ring */ + net_device->recv_completion_cnt + = round_up(resp->sections[0].num_sub_allocs + 1, + PAGE_SIZE / sizeof(u64)); + ret = netvsc_alloc_recv_comp_ring(net_device, 0); + if (ret) + goto cleanup; + + /* Now setup the send buffer. */ net_device->send_buf = vzalloc_node(net_device->send_buf_size, node); if (!net_device->send_buf) net_device->send_buf = vzalloc(net_device->send_buf_size); @@ -951,130 +955,94 @@ send_now: return ret; } -static int netvsc_send_recv_completion(struct vmbus_channel *channel, - u64 transaction_id, u32 status) +/* Send pending recv completions */ +static int send_recv_completions(struct netvsc_channel *nvchan) { - struct nvsp_message recvcompMessage; + struct netvsc_device *nvdev = nvchan->net_device; + struct multi_recv_comp *mrc = &nvchan->mrc; + struct recv_comp_msg { + struct nvsp_message_header hdr; + u32 status; + } __packed; + struct recv_comp_msg msg = { + .hdr.msg_type = NVSP_MSG1_TYPE_SEND_RNDIS_PKT_COMPLETE, + }; int ret; - recvcompMessage.hdr.msg_type = - NVSP_MSG1_TYPE_SEND_RNDIS_PKT_COMPLETE; - - recvcompMessage.msg.v1_msg.send_rndis_pkt_complete.status = status; - - /* Send the completion */ - ret = vmbus_sendpacket(channel, &recvcompMessage, - sizeof(struct nvsp_message_header) + sizeof(u32), - transaction_id, VM_PKT_COMP, 0); + while (mrc->first != mrc->next) { + const struct recv_comp_data *rcd + = mrc->slots + mrc->first; - return ret; -} - -static inline void count_recv_comp_slot(struct netvsc_device *nvdev, u16 q_idx, - u32 *filled, u32 *avail) -{ - struct multi_recv_comp *mrc = &nvdev->chan_table[q_idx].mrc; - u32 first = mrc->first; - u32 next = mrc->next; + msg.status = rcd->status; + ret = vmbus_sendpacket(nvchan->channel, &msg, sizeof(msg), + rcd->tid, VM_PKT_COMP, 0); + if (unlikely(ret)) + return ret; - *filled = (first > next) ? NETVSC_RECVSLOT_MAX - first + next : - next - first; - - *avail = NETVSC_RECVSLOT_MAX - *filled - 1; -} - -/* Read the first filled slot, no change to index */ -static inline struct recv_comp_data *read_recv_comp_slot(struct netvsc_device - *nvdev, u16 q_idx) -{ - struct multi_recv_comp *mrc = &nvdev->chan_table[q_idx].mrc; - u32 filled, avail; - - if (unlikely(!mrc->buf)) - return NULL; + if (++mrc->first == nvdev->recv_completion_cnt) + mrc->first = 0; + } - count_recv_comp_slot(nvdev, q_idx, &filled, &avail); - if (!filled) - return NULL; + /* receive completion ring has been emptied */ + if (unlikely(nvdev->destroy)) + wake_up(&nvdev->wait_drain); - return mrc->buf + mrc->first * sizeof(struct recv_comp_data); + return 0; } -/* Put the first filled slot back to available pool */ -static inline void put_recv_comp_slot(struct netvsc_device *nvdev, u16 q_idx) +/* Count how many receive completions are outstanding */ +static void recv_comp_slot_avail(const struct netvsc_device *nvdev, + const struct multi_recv_comp *mrc, + u32 *filled, u32 *avail) { - struct multi_recv_comp *mrc = &nvdev->chan_table[q_idx].mrc; - int num_recv; + u32 count = nvdev->recv_completion_cnt; - mrc->first = (mrc->first + 1) % NETVSC_RECVSLOT_MAX; - - num_recv = atomic_dec_return(&nvdev->num_outstanding_recvs); + if (mrc->next >= mrc->first) + *filled = mrc->next - mrc->first; + else + *filled = (count - mrc->first) + mrc->next; - if (nvdev->destroy && num_recv == 0) - wake_up(&nvdev->wait_drain); + *avail = count - *filled - 1; } -/* Check and send pending recv completions */ -static void netvsc_chk_recv_comp(struct netvsc_device *nvdev, - struct vmbus_channel *channel, u16 q_idx) +/* Add receive complete to ring to send to host. */ +static void enq_receive_complete(struct net_device *ndev, + struct netvsc_device *nvdev, u16 q_idx, + u64 tid, u32 status) { + struct netvsc_channel *nvchan = &nvdev->chan_table[q_idx]; + struct multi_recv_comp *mrc = &nvchan->mrc; struct recv_comp_data *rcd; - int ret; - - while (true) { - rcd = read_recv_comp_slot(nvdev, q_idx); - if (!rcd) - break; + u32 filled, avail; - ret = netvsc_send_recv_completion(channel, rcd->tid, - rcd->status); - if (ret) - break; + recv_comp_slot_avail(nvdev, mrc, &filled, &avail); - put_recv_comp_slot(nvdev, q_idx); + if (unlikely(filled > NAPI_POLL_WEIGHT)) { + send_recv_completions(nvchan); + recv_comp_slot_avail(nvdev, mrc, &filled, &avail); } -} - -#define NETVSC_RCD_WATERMARK 80 -/* Get next available slot */ -static inline struct recv_comp_data *get_recv_comp_slot( - struct netvsc_device *nvdev, struct vmbus_channel *channel, u16 q_idx) -{ - struct multi_recv_comp *mrc = &nvdev->chan_table[q_idx].mrc; - u32 filled, avail, next; - struct recv_comp_data *rcd; - - if (unlikely(!nvdev->recv_section)) - return NULL; - - if (unlikely(!mrc->buf)) - return NULL; - - if (atomic_read(&nvdev->num_outstanding_recvs) > - nvdev->recv_section->num_sub_allocs * NETVSC_RCD_WATERMARK / 100) - netvsc_chk_recv_comp(nvdev, channel, q_idx); - - count_recv_comp_slot(nvdev, q_idx, &filled, &avail); - if (!avail) - return NULL; - - next = mrc->next; - rcd = mrc->buf + next * sizeof(struct recv_comp_data); - mrc->next = (next + 1) % NETVSC_RECVSLOT_MAX; + if (unlikely(!avail)) { + netdev_err(ndev, "Recv_comp full buf q:%hd, tid:%llx\n", + q_idx, tid); + return; + } - atomic_inc(&nvdev->num_outstanding_recvs); + rcd = mrc->slots + mrc->next; + rcd->tid = tid; + rcd->status = status; - return rcd; + if (++mrc->next == nvdev->recv_completion_cnt) + mrc->next = 0; } static int netvsc_receive(struct net_device *ndev, - struct netvsc_device *net_device, - struct net_device_context *net_device_ctx, - struct hv_device *device, - struct vmbus_channel *channel, - const struct vmpacket_descriptor *desc, - struct nvsp_message *nvsp) + struct netvsc_device *net_device, + struct net_device_context *net_device_ctx, + struct hv_device *device, + struct vmbus_channel *channel, + const struct vmpacket_descriptor *desc, + struct nvsp_message *nvsp) { const struct vmtransfer_page_packet_header *vmxferpage_packet = container_of(desc, const struct vmtransfer_page_packet_header, d); @@ -1083,7 +1051,6 @@ static int netvsc_receive(struct net_device *ndev, u32 status = NVSP_STAT_SUCCESS; int i; int count = 0; - int ret; /* Make sure this is a valid nvsp packet */ if (unlikely(nvsp->hdr.msg_type != NVSP_MSG1_TYPE_SEND_RNDIS_PKT)) { @@ -1114,25 +1081,9 @@ static int netvsc_receive(struct net_device *ndev, channel, data, buflen); } - if (net_device->chan_table[q_idx].mrc.buf) { - struct recv_comp_data *rcd; + enq_receive_complete(ndev, net_device, q_idx, + vmxferpage_packet->d.trans_id, status); - rcd = get_recv_comp_slot(net_device, channel, q_idx); - if (rcd) { - rcd->tid = vmxferpage_packet->d.trans_id; - rcd->status = status; - } else { - netdev_err(ndev, "Recv_comp full buf q:%hd, tid:%llx\n", - q_idx, vmxferpage_packet->d.trans_id); - } - } else { - ret = netvsc_send_recv_completion(channel, - vmxferpage_packet->d.trans_id, - status); - if (ret) - netdev_err(ndev, "Recv_comp q:%hd, tid:%llx, err:%d\n", - q_idx, vmxferpage_packet->d.trans_id, ret); - } return count; } @@ -1231,7 +1182,6 @@ int netvsc_poll(struct napi_struct *napi, int budget) struct netvsc_device *net_device = nvchan->net_device; struct vmbus_channel *channel = nvchan->channel; struct hv_device *device = netvsc_channel_to_device(channel); - u16 q_idx = channel->offermsg.offer.sub_channel_index; struct net_device *ndev = hv_get_drvdata(device); int work_done = 0; @@ -1245,17 +1195,18 @@ int netvsc_poll(struct napi_struct *napi, int budget) nvchan->desc = hv_pkt_iter_next(channel, nvchan->desc); } - /* If receive ring was exhausted - * and not doing busy poll - * then re-enable host interrupts - * and reschedule if ring is not empty. + /* If send of pending receive completions suceeded + * and did not exhaust NAPI budget + * and not doing busy poll + * then reschedule if more data has arrived from host */ - if (work_done < budget && + if (send_recv_completions(nvchan) == 0 && + work_done < budget && napi_complete_done(napi, work_done) && - hv_end_read(&channel->inbound) != 0) + hv_end_read(&channel->inbound)) { + hv_begin_read(&channel->inbound); napi_reschedule(napi); - - netvsc_chk_recv_comp(net_device, channel, q_idx); + } /* Driver may overshoot since multiple packets per descriptor */ return min(work_done, budget); -- cgit v1.2.3