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?
