Commit 420f8af5 authored by David Howells's avatar David Howells Committed by Jakub Kicinski
Browse files

rxrpc: Use a large kvec[] in rxrpc_local rather than every rxrpc_txbuf 



Use a single large kvec[] in the rxrpc_local struct rather than one in
every rxrpc_txbuf struct to build large packets to save on memory.

Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Link: https://patch.msgid.link/20241204074710.990092-9-dhowells@redhat.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 8b5823ea

net/rxrpc/ar-internal.h

+6 −0
Original line number Diff line number Diff line
@@ -320,6 +320,12 @@ struct rxrpc_local { 
	struct list_head	new_client_calls; /* Newly created client calls need connection */

	spinlock_t		client_call_lock; /* Lock for ->new_client_calls */

	struct sockaddr_rxrpc	srx;		/* local address */

	/* Provide a kvec table sufficiently large to manage either a DATA

	 * packet with a maximum set of jumbo subpackets or a PING ACK padded

	 * out to 64K with zeropages for PMTUD.

	 */

	struct kvec		kvec[RXRPC_MAX_NR_JUMBO > 3 + 16 ?

				     RXRPC_MAX_NR_JUMBO : 3 + 16];

};



/*

net/rxrpc/output.c

+33 −12
Original line number Diff line number Diff line
@@ -175,9 +175,11 @@ static void rxrpc_begin_rtt_probe(struct rxrpc_call *call, rxrpc_serial_t serial 
/*

 * Transmit an ACK packet.

 */

static void rxrpc_send_ack_packet(struct rxrpc_call *call, struct rxrpc_txbuf *txb)

static void rxrpc_send_ack_packet(struct rxrpc_call *call, struct rxrpc_txbuf *txb,

				  int nr_kv)

{

	struct rxrpc_wire_header *whdr = txb->kvec[0].iov_base;

	struct kvec *kv = call->local->kvec;

	struct rxrpc_wire_header *whdr = kv[0].iov_base;

	struct rxrpc_connection *conn;

	struct rxrpc_ackpacket *ack = (struct rxrpc_ackpacket *)(whdr + 1);

	struct msghdr msg;
@@ -206,8 +208,9 @@ static void rxrpc_send_ack_packet(struct rxrpc_call *call, struct rxrpc_txbuf *t 


	rxrpc_inc_stat(call->rxnet, stat_tx_ack_send);



	iov_iter_kvec(&msg.msg_iter, WRITE, txb->kvec, txb->nr_kvec, txb->len);

	iov_iter_kvec(&msg.msg_iter, WRITE, kv, nr_kv, txb->len);

	rxrpc_local_dont_fragment(conn->local, false);



	ret = do_udp_sendmsg(conn->local->socket, &msg, txb->len);

	call->peer->last_tx_at = ktime_get_seconds();

	if (ret < 0) {
@@ -233,6 +236,8 @@ void rxrpc_send_ACK(struct rxrpc_call *call, u8 ack_reason, 
		    rxrpc_serial_t serial, enum rxrpc_propose_ack_trace why)

{

	struct rxrpc_txbuf *txb;

	struct kvec *kv = call->local->kvec;

	int nr_kv;



	if (test_bit(RXRPC_CALL_DISCONNECTED, &call->flags))

		return;
@@ -248,12 +253,19 @@ void rxrpc_send_ACK(struct rxrpc_call *call, u8 ack_reason, 
	txb->ack_why = why;



	rxrpc_fill_out_ack(call, txb, ack_reason, serial);



	nr_kv = txb->nr_kvec;

	kv[0] = txb->kvec[0];

	kv[1] = txb->kvec[1];

	kv[2] = txb->kvec[2];

	// TODO: Extend a path MTU probe ACK



	call->ackr_nr_unacked = 0;

	atomic_set(&call->ackr_nr_consumed, 0);

	clear_bit(RXRPC_CALL_RX_IS_IDLE, &call->flags);



	trace_rxrpc_send_ack(call, why, ack_reason, serial);

	rxrpc_send_ack_packet(call, txb);

	rxrpc_send_ack_packet(call, txb, nr_kv);

	rxrpc_put_txbuf(txb, rxrpc_txbuf_put_ack_tx);

}
@@ -324,12 +336,15 @@ int rxrpc_send_abort_packet(struct rxrpc_call *call) 
/*

 * Prepare a (sub)packet for transmission.

 */

static void rxrpc_prepare_data_subpacket(struct rxrpc_call *call, struct rxrpc_txbuf *txb,

					 rxrpc_serial_t serial)

static size_t rxrpc_prepare_data_subpacket(struct rxrpc_call *call, struct rxrpc_txbuf *txb,

					   rxrpc_serial_t serial,

					   int subpkt)

{

	struct rxrpc_wire_header *whdr = txb->kvec[0].iov_base;

	enum rxrpc_req_ack_trace why;

	struct rxrpc_connection *conn = call->conn;

	struct kvec *kv = &call->local->kvec[subpkt];

	size_t len = txb->len;

	bool last, more;

	u8 flags;
@@ -385,8 +400,13 @@ static void rxrpc_prepare_data_subpacket(struct rxrpc_call *call, struct rxrpc_t 
	whdr->flags	= flags;

	whdr->serial	= htonl(txb->serial);

	whdr->cksum	= txb->cksum;

	whdr->serviceId	= htons(conn->service_id);

	kv->iov_base	= whdr;

	// TODO: Convert into a jumbo header for tail subpackets



	trace_rxrpc_tx_data(call, txb->seq, txb->serial, flags, false);

	kv->iov_len = len;

	return len;

}



/*
@@ -395,13 +415,15 @@ static void rxrpc_prepare_data_subpacket(struct rxrpc_call *call, struct rxrpc_t 
static size_t rxrpc_prepare_data_packet(struct rxrpc_call *call, struct rxrpc_txbuf *txb)

{

	rxrpc_serial_t serial;

	size_t len = 0;



	/* Each transmission of a Tx packet needs a new serial number */

	serial = rxrpc_get_next_serial(call->conn);



	rxrpc_prepare_data_subpacket(call, txb, serial);

	len += rxrpc_prepare_data_subpacket(call, txb, serial, 0);

	// TODO: Loop around adding tail subpackets



	return txb->len;

	return len;

}



/*
@@ -442,7 +464,6 @@ static void rxrpc_tstamp_data_packets(struct rxrpc_call *call, struct rxrpc_txbu 
 */

static int rxrpc_send_data_packet(struct rxrpc_call *call, struct rxrpc_txbuf *txb)

{

	struct rxrpc_wire_header *whdr = txb->kvec[0].iov_base;

	struct rxrpc_connection *conn = call->conn;

	enum rxrpc_tx_point frag;

	struct msghdr msg;
@@ -463,7 +484,7 @@ static int rxrpc_send_data_packet(struct rxrpc_call *call, struct rxrpc_txbuf *t 
		}

	}



	iov_iter_kvec(&msg.msg_iter, WRITE, txb->kvec, txb->nr_kvec, len);

	iov_iter_kvec(&msg.msg_iter, WRITE, call->local->kvec, 1, len);



	msg.msg_name	= &call->peer->srx.transport;

	msg.msg_namelen	= call->peer->srx.transport_len;
@@ -480,7 +501,7 @@ static int rxrpc_send_data_packet(struct rxrpc_call *call, struct rxrpc_txbuf *t 


	/* send the packet with the don't fragment bit set if we currently

	 * think it's small enough */

	if (txb->len >= call->peer->maxdata) {

	if (len >= sizeof(struct rxrpc_wire_header) + call->peer->maxdata) {

		rxrpc_local_dont_fragment(conn->local, false);

		frag = rxrpc_tx_point_call_data_frag;

	} else {
@@ -503,7 +524,7 @@ static int rxrpc_send_data_packet(struct rxrpc_call *call, struct rxrpc_txbuf *t 
		rxrpc_inc_stat(call->rxnet, stat_tx_data_send_fail);

		trace_rxrpc_tx_fail(call->debug_id, txb->serial, ret, frag);

	} else {

		trace_rxrpc_tx_packet(call->debug_id, whdr, frag);

		trace_rxrpc_tx_packet(call->debug_id, call->local->kvec[0].iov_base, frag);

	}



	rxrpc_tx_backoff(call, ret);