Commit 817913d8 authored by David Howells's avatar David Howells
Browse files

af_rxrpc: Expose more RxRPC parameters via sysctls 



Expose RxRPC parameters via sysctls to control the Rx window size, the Rx MTU
maximum size and the number of packets that can be glued into a jumbo packet.

More info added to Documentation/networking/rxrpc.txt.

Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
parent 9823f39a

Documentation/networking/rxrpc.txt

+19 −0
Original line number Diff line number Diff line
@@ -926,3 +926,22 @@ adjusted through sysctls in /proc/net/rxrpc/: 
     The amount of time in seconds after a transport was last used before we

     remove it from the transport list.  Whilst a transport is in existence, it

     serves to anchor the peer data and keeps the connection ID counter.



 (*) rxrpc_rx_window_size



     The size of the receive window in packets.  This is the maximum number of

     unconsumed received packets we're willing to hold in memory for any

     particular call.



 (*) rxrpc_rx_mtu



     The maximum packet MTU size that we're willing to receive in bytes.  This

     indicates to the peer whether we're willing to accept jumbo packets.



 (*) rxrpc_rx_jumbo_max



     The maximum number of packets that we're willing to accept in a jumbo

     packet.  Non-terminal packets in a jumbo packet must contain a four byte

     header plus exactly 1412 bytes of data.  The terminal packet must contain

     a four byte header plus any amount of data.  In any event, a jumbo packet

     may not exceed rxrpc_rx_mtu in size.

net/rxrpc/ar-ack.c

+23 −3
Original line number Diff line number Diff line
@@ -43,6 +43,26 @@ unsigned rxrpc_soft_ack_delay = 1 * HZ; 
 */

unsigned rxrpc_idle_ack_delay = 0.5 * HZ;



/*

 * Receive window size in packets.  This indicates the maximum number of

 * unconsumed received packets we're willing to retain in memory.  Once this

 * limit is hit, we should generate an EXCEEDS_WINDOW ACK and discard further

 * packets.

 */

unsigned rxrpc_rx_window_size = 32;



/*

 * Maximum Rx MTU size.  This indicates to the sender the size of jumbo packet

 * made by gluing normal packets together that we're willing to handle.

 */

unsigned rxrpc_rx_mtu = 5692;



/*

 * The maximum number of fragments in a received jumbo packet that we tell the

 * sender that we're willing to handle.

 */

unsigned rxrpc_rx_jumbo_max = 4;



static const char *rxrpc_acks(u8 reason)

{

	static const char *const str[] = {
@@ -1195,11 +1215,11 @@ void rxrpc_process_call(struct work_struct *work) 
	mtu = call->conn->trans->peer->if_mtu;

	mtu -= call->conn->trans->peer->hdrsize;

	ackinfo.maxMTU	= htonl(mtu);

	ackinfo.rwind	= htonl(32);

	ackinfo.rwind	= htonl(rxrpc_rx_window_size);



	/* permit the peer to send us jumbo packets if it wants to */

	ackinfo.rxMTU	= htonl(5692);

	ackinfo.jumbo_max = htonl(4);

	ackinfo.rxMTU	= htonl(rxrpc_rx_mtu);

	ackinfo.jumbo_max = htonl(rxrpc_rx_jumbo_max);



	hdr.serial = htonl(atomic_inc_return(&call->conn->serial));

	_proto("Tx ACK %%%u { m=%hu f=#%u p=#%u s=%%%u r=%s n=%u }",

net/rxrpc/ar-call.c

+1 −1
Original line number Diff line number Diff line
@@ -99,7 +99,7 @@ static struct rxrpc_call *rxrpc_alloc_call(gfp_t gfp) 
	call->rx_data_expect = 1;

	call->rx_data_eaten = 0;

	call->rx_first_oos = 0;

	call->ackr_win_top = call->rx_data_eaten + 1 + RXRPC_MAXACKS;

	call->ackr_win_top = call->rx_data_eaten + 1 + rxrpc_rx_window_size;

	call->creation_jif = jiffies;

	return call;

}

net/rxrpc/ar-internal.h

+3 −0
Original line number Diff line number Diff line
@@ -436,6 +436,9 @@ int rxrpc_reject_call(struct rxrpc_sock *); 
extern unsigned rxrpc_requested_ack_delay;

extern unsigned rxrpc_soft_ack_delay;

extern unsigned rxrpc_idle_ack_delay;

extern unsigned rxrpc_rx_window_size;

extern unsigned rxrpc_rx_mtu;

extern unsigned rxrpc_rx_jumbo_max;



void __rxrpc_propose_ACK(struct rxrpc_call *, u8, __be32, bool);

void rxrpc_propose_ACK(struct rxrpc_call *, u8, __be32, bool);

net/rxrpc/sysctl.c

+33 −0
Original line number Diff line number Diff line
@@ -17,6 +17,9 @@ 
static struct ctl_table_header *rxrpc_sysctl_reg_table;

static const unsigned zero = 0;

static const unsigned one = 1;

static const unsigned four = 4;

static const unsigned n_65535 = 65535;

static const unsigned n_max_acks = RXRPC_MAXACKS;



/*

 * RxRPC operating parameters.
@@ -94,6 +97,36 @@ static struct ctl_table rxrpc_sysctl_table[] = { 
		.proc_handler	= proc_dointvec_minmax,

		.extra1		= (void *)&one,

	},



	/* Non-time values */

	{

		.procname	= "rx_window_size",

		.data		= &rxrpc_rx_window_size,

		.maxlen		= sizeof(unsigned),

		.mode		= 0644,

		.proc_handler	= proc_dointvec_minmax,

		.extra1		= (void *)&one,

		.extra2		= (void *)&n_max_acks,

	},

	{

		.procname	= "rx_mtu",

		.data		= &rxrpc_rx_mtu,

		.maxlen		= sizeof(unsigned),

		.mode		= 0644,

		.proc_handler	= proc_dointvec_minmax,

		.extra1		= (void *)&one,

		.extra1		= (void *)&n_65535,

	},

	{

		.procname	= "rx_jumbo_max",

		.data		= &rxrpc_rx_jumbo_max,

		.maxlen		= sizeof(unsigned),

		.mode		= 0644,

		.proc_handler	= proc_dointvec_minmax,

		.extra1		= (void *)&one,

		.extra2		= (void *)&four,

	},



	{ }

};