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Message-Id: <20170728155947.10062-6-sthemmin@microsoft.com>
Date: Fri, 28 Jul 2017 08:59:45 -0700
From: Stephen Hemminger <stephen@...workplumber.org>
To: kys@...rosoft.com, haiyangz@...rosoft.com, sthemmin@...rosoft.com
Cc: devel@...uxdriverproject.org, netdev@...r.kernel.org
Subject: [PATCH net-next v3 5/7] 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 <sthemmin@...rosoft.com>
---
drivers/net/hyperv/hyperv_net.h | 14 +-
drivers/net/hyperv/netvsc.c | 267 ++++++++++++++++----------------------
drivers/net/hyperv/rndis_filter.c | 20 +--
3 files changed, 126 insertions(+), 175 deletions(-)
diff --git a/drivers/net/hyperv/hyperv_net.h b/drivers/net/hyperv/hyperv_net.h
index 9ca3ed692d73..f2cef5aaed1f 100644
--- a/drivers/net/hyperv/hyperv_net.h
+++ b/drivers/net/hyperv/hyperv_net.h
@@ -186,6 +186,7 @@ struct net_device_context;
struct netvsc_device *netvsc_device_add(struct hv_device *device,
const struct netvsc_device_info *info);
+int netvsc_alloc_recv_comp_ring(struct netvsc_device *net_device, u32 q_idx);
void netvsc_device_remove(struct hv_device *device);
int netvsc_send(struct net_device_context *ndc,
struct hv_netvsc_packet *packet,
@@ -657,13 +658,10 @@ struct recv_comp_data {
u32 status;
};
-/* Netvsc Receive Slots Max */
-#define NETVSC_RECVSLOT_MAX (NETVSC_RECEIVE_BUFFER_SIZE / ETH_DATA_LEN + 1)
-
struct multi_recv_comp {
- void *buf; /* queued receive completions */
- u32 first; /* first data entry */
- u32 next; /* next entry for writing */
+ struct recv_comp_data *slots;
+ u32 first; /* first data entry */
+ u32 next; /* next entry for writing */
};
struct netvsc_stats {
@@ -750,7 +748,7 @@ struct netvsc_device {
u32 recv_buf_size;
u32 recv_buf_gpadl_handle;
u32 recv_section_cnt;
- struct nvsp_1_receive_buffer_section *recv_section;
+ u32 recv_completion_cnt;
/* Send buffer allocated by us */
void *send_buf;
@@ -778,8 +776,6 @@ struct netvsc_device {
u32 max_pkt; /* max number of pkt in one send, e.g. 8 */
u32 pkt_align; /* alignment bytes, e.g. 8 */
- atomic_t num_outstanding_recvs;
-
atomic_t open_cnt;
struct netvsc_channel chan_table[VRSS_CHANNEL_MAX];
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 @@ int netvsc_send(struct net_device_context *ndev_ctx,
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);
diff --git a/drivers/net/hyperv/rndis_filter.c b/drivers/net/hyperv/rndis_filter.c
index d80e9e3f433e..44165fe328a4 100644
--- a/drivers/net/hyperv/rndis_filter.c
+++ b/drivers/net/hyperv/rndis_filter.c
@@ -928,12 +928,12 @@ static bool netvsc_device_idle(const struct netvsc_device *nvdev)
{
int i;
- if (atomic_read(&nvdev->num_outstanding_recvs) > 0)
- return false;
-
for (i = 0; i < nvdev->num_chn; i++) {
const struct netvsc_channel *nvchan = &nvdev->chan_table[i];
+ if (nvchan->mrc.first != nvchan->mrc.next)
+ return false;
+
if (atomic_read(&nvchan->queue_sends) > 0)
return false;
}
@@ -1031,11 +1031,6 @@ static void netvsc_sc_open(struct vmbus_channel *new_sc)
return;
nvchan = nvscdev->chan_table + chn_index;
- nvchan->mrc.buf
- = vzalloc(NETVSC_RECVSLOT_MAX * sizeof(struct recv_comp_data));
-
- if (!nvchan->mrc.buf)
- return;
/* Because the device uses NAPI, all the interrupt batching and
* control is done via Net softirq, not the channel handling
@@ -1225,6 +1220,15 @@ struct netvsc_device *rndis_filter_device_add(struct hv_device *dev,
if (num_rss_qs == 0)
return net_device;
+ for (i = 1; i < net_device->num_chn; i++) {
+ ret = netvsc_alloc_recv_comp_ring(net_device, i);
+ if (ret) {
+ while (--i != 0)
+ vfree(net_device->chan_table[i].mrc.slots);
+ goto out;
+ }
+ }
+
refcount_set(&net_device->sc_offered, num_rss_qs);
vmbus_set_sc_create_callback(dev->channel, netvsc_sc_open);
--
2.11.0
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