On Wed, Oct 14, 2026 at 07:56:40PM +0800, Jia Jia wrote:
An RX batch can make a socket readable while the worker still holds its
socket lock. Waking a blocking reader then only moves it to waiting for
the same lock.
Record the existing low-watermark condition and notify once after
release_sock(). Move the coalesced write-space notification after the
unlock as well, since both callbacks wake sk_sleep(sk). Deliver
write-space before data-ready and keep the lookup reference until both
callbacks complete.
As with write-space, save the initial sk_data_ready callback and batch only
while both saved callbacks remain installed. Sockets with replaced
callbacks retain their per-packet behavior.
The existing psock-marker check also covers a concurrent sockmap attach:
at most the already admitted packet completes on the native path, and the
next packet ends the batch.
Signed-off-by: Jia Jia <[email protected]>
---
include/linux/virtio_vsock.h | 1 +
include/net/af_vsock.h | 5 ++--
net/vmw_vsock/af_vsock.c | 1 +
net/vmw_vsock/virtio_transport_common.c | 35 ++++++++++++++++++-------
4 files changed, 31 insertions(+), 11 deletions(-)
diff --git a/include/linux/virtio_vsock.h b/include/linux/virtio_vsock.h
index bf077ee0ded88..f1396ca3ad9b5 100644
--- a/include/linux/virtio_vsock.h
+++ b/include/linux/virtio_vsock.h
@@ -288,6 +288,7 @@ struct virtio_transport_rx_batch {
unsigned int pkts;
size_t bytes;
bool write_space_pending;
+ bool data_ready_pending;
};
void virtio_transport_recv_pkt_batch(struct virtio_transport *t,
diff --git a/include/net/af_vsock.h b/include/net/af_vsock.h
index 9a40960d10cbe..78bab5820f528 100644
--- a/include/net/af_vsock.h
+++ b/include/net/af_vsock.h
@@ -64,9 +64,10 @@ struct vsock_sock {
bool sent_request;
bool ignore_connecting_rst;
/*
- * Initial callback, used to identify replacements and deliver deferred
- * write-space notifications.
+ * Initial callbacks, used to identify replacements and deliver deferred
+ * notifications.
*/
+ void (*default_data_ready)(struct sock *sk);
void (*default_write_space)(struct sock *sk);
/* Protected by lock_sock(sk) */
diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c
index fe7f49da6c4bc..f40659ec29df0 100644
--- a/net/vmw_vsock/af_vsock.c
+++ b/net/vmw_vsock/af_vsock.c
@@ -958,6 +958,7 @@ static struct sock *__vsock_create(struct net *net,
sk->sk_type = type;
vsk = vsock_sk(sk);
+ vsk->default_data_ready = sk->sk_data_ready;
vsk->default_write_space = sk->sk_write_space;
vsock_addr_init(&vsk->local_addr, VMADDR_CID_ANY, VMADDR_PORT_ANY);
vsock_addr_init(&vsk->remote_addr, VMADDR_CID_ANY, VMADDR_PORT_ANY);
diff --git a/net/vmw_vsock/virtio_transport_common.c
b/net/vmw_vsock/virtio_transport_common.c
index f4b5f0230493e..8b62b789b71c5 100644
--- a/net/vmw_vsock/virtio_transport_common.c
+++ b/net/vmw_vsock/virtio_transport_common.c
@@ -1588,7 +1588,8 @@ virtio_transport_recv_enqueue(struct vsock_sock *vsk,
static int
virtio_transport_recv_connected(struct sock *sk,
- struct sk_buff *skb)
+ struct sk_buff *skb,
+ bool *data_ready_pending)
{
struct virtio_vsock_hdr *hdr = virtio_vsock_hdr(skb);
struct vsock_sock *vsk = vsock_sk(sk);
@@ -1607,7 +1608,13 @@ virtio_transport_recv_connected(struct sock *sk,
vsock_remove_sock(vsk);
break;
}
- vsock_data_ready(sk);
+ if (!data_ready_pending) {
+ vsock_data_ready(sk);
+ } else if (!*data_ready_pending &&
+ (vsock_stream_has_data(vsk) >= sk->sk_rcvlowat ||
+ sock_flag(sk, SOCK_DONE))) {
+ *data_ready_pending = true;
+ }
return err;
case VIRTIO_VSOCK_OP_CREDIT_REQUEST:
virtio_transport_send_credit_update(vsk);
@@ -1820,6 +1827,7 @@ virtio_transport_recv_pkt_batchable(struct
virtio_transport *t,
return sk->sk_state == TCP_ESTABLISHED &&
sk->sk_type == SOCK_STREAM &&
READ_ONCE(sk->sk_prot) == sk->sk_prot_creator &&
+ READ_ONCE(sk->sk_data_ready) == vsk->default_data_ready &&
READ_ONCE(sk->sk_write_space) == vsk->default_write_space &&
!sock_flag(sk, SOCK_DONE) &&
vsk->transport == &t->transport &&
@@ -1830,8 +1838,9 @@ virtio_transport_recv_pkt_batchable(struct
virtio_transport *t,
/*
* The caller holds sk's socket lock. Set @batchable if the socket can remain
* locked for another ordinary STREAM/RW packet. When @batch is non-NULL,
- * record a default write-space notification for batch finish instead of
- * delivering it immediately. Return true if the caller must free @skb.
+ * record default write-space and data-ready notifications for batch finish
+ * instead of delivering them immediately. Return true if the caller must
+ * free @skb.
*/
static bool
virtio_transport_recv_pkt_locked(struct virtio_transport *t,
@@ -1883,7 +1892,9 @@ virtio_transport_recv_pkt_locked(struct virtio_transport
*t,
kfree_skb(skb);
break;
case TCP_ESTABLISHED:
- virtio_transport_recv_connected(sk, skb);
+ virtio_transport_recv_connected(sk, skb,
+ batch ?
+ &batch->data_ready_pending :
NULL);
break;
case TCP_CLOSING:
virtio_transport_recv_disconnecting(sk, skb);
@@ -1957,27 +1968,33 @@ EXPORT_SYMBOL_GPL(virtio_transport_recv_pkt);
/*
* Finish the RX batch.
* For a non-empty batch, the caller holds the socket lock acquired with
- * lock_sock(). Deliver any deferred write-space notification while the lock
- * is held, then release the lock and the batch's lookup reference.
- * An empty batch is a no-op.
+ * lock_sock(). Release the lock, deliver any deferred write-space and
+ * data-ready notifications in that order, then drop the batch's lookup
+ * reference. An empty batch is a no-op.
*/
void virtio_transport_rx_batch_finish(struct virtio_transport_rx_batch *batch)
{
bool write_space_pending = batch->write_space_pending;
+ bool data_ready_pending = batch->data_ready_pending;
struct sock *sk = batch->sk;
batch->sk = NULL;
batch->pkts = 0;
batch->bytes = 0;
batch->write_space_pending = false;
+ batch->data_ready_pending = false;
if (!sk)
return;
+ release_sock(sk);
+
Why in the previous patch we release the socket after calling
default_write_space() and now we are moving before?
if (write_space_pending)
vsock_sk(sk)->default_write_space(sk);
- release_sock(sk);
+ if (data_ready_pending)
+ vsock_sk(sk)->default_data_ready(sk);
+
sock_put(sk);
}
EXPORT_SYMBOL_GPL(virtio_transport_rx_batch_finish);
--
2.53.0
