Commit 3c689b73 authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
Browse files

inet: cleanup of local_port_range 



I noticed sysctl_local_port_range[] and its associated seqlock
sysctl_local_port_range_lock were on separate cache lines.
Moreover, sysctl_local_port_range[] was close to unrelated
variables, highly modified, leading to cache misses.

Moving these two variables in a structure can help data
locality and moving this structure to read_mostly section
helps sharing of this data among cpus.

Cleanup of extern declarations (moved in include file where
they belong), and use of inet_get_local_port_range()
accessor instead of direct access to ports values.

Signed-off-by: default avatarEric Dumazet <dada1@cosmosbay.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 9088c560

include/net/ip.h

+4 −0
Original line number Diff line number Diff line
@@ -178,6 +178,10 @@ extern unsigned long snmp_fold_field(void *mib[], int offt); 
extern int snmp_mib_init(void *ptr[2], size_t mibsize);

extern void snmp_mib_free(void *ptr[2]);



extern struct local_ports {

	seqlock_t	lock;

	int		range[2];

} sysctl_local_ports;

extern void inet_get_local_port_range(int *low, int *high);



extern int sysctl_ip_default_ttl;

net/ipv4/inet_connection_sock.c

+9 −7
Original line number Diff line number Diff line
@@ -30,20 +30,22 @@ EXPORT_SYMBOL(inet_csk_timer_bug_msg); 
#endif



/*

 * This array holds the first and last local port number.

 * This struct holds the first and last local port number.

 */

int sysctl_local_port_range[2] = { 32768, 61000 };

DEFINE_SEQLOCK(sysctl_port_range_lock);

struct local_ports sysctl_local_ports __read_mostly = {

	.lock = SEQLOCK_UNLOCKED,

	.range = { 32768, 61000 },

};



void inet_get_local_port_range(int *low, int *high)

{

	unsigned seq;

	do {

		seq = read_seqbegin(&sysctl_port_range_lock);

		seq = read_seqbegin(&sysctl_local_ports.lock);



		*low = sysctl_local_port_range[0];

		*high = sysctl_local_port_range[1];

	} while (read_seqretry(&sysctl_port_range_lock, seq));

		*low = sysctl_local_ports.range[0];

		*high = sysctl_local_ports.range[1];

	} while (read_seqretry(&sysctl_local_ports.lock, seq));

}

EXPORT_SYMBOL(inet_get_local_port_range);

net/ipv4/sysctl_net_ipv4.c

+10 −13
Original line number Diff line number Diff line
@@ -26,16 +26,13 @@ static int tcp_retr1_max = 255; 
static int ip_local_port_range_min[] = { 1, 1 };

static int ip_local_port_range_max[] = { 65535, 65535 };



extern seqlock_t sysctl_port_range_lock;

extern int sysctl_local_port_range[2];



/* Update system visible IP port range */

static void set_local_port_range(int range[2])

{

	write_seqlock(&sysctl_port_range_lock);

	sysctl_local_port_range[0] = range[0];

	sysctl_local_port_range[1] = range[1];

	write_sequnlock(&sysctl_port_range_lock);

	write_seqlock(&sysctl_local_ports.lock);

	sysctl_local_ports.range[0] = range[0];

	sysctl_local_ports.range[1] = range[1];

	write_sequnlock(&sysctl_local_ports.lock);

}



/* Validate changes from /proc interface. */
@@ -44,8 +41,7 @@ static int ipv4_local_port_range(ctl_table *table, int write, struct file *filp, 
				 size_t *lenp, loff_t *ppos)

{

	int ret;

	int range[2] = { sysctl_local_port_range[0],

			 sysctl_local_port_range[1] };

	int range[2];

	ctl_table tmp = {

		.data = &range,

		.maxlen = sizeof(range),
@@ -54,6 +50,7 @@ static int ipv4_local_port_range(ctl_table *table, int write, struct file *filp, 
		.extra2 = &ip_local_port_range_max,

	};



	inet_get_local_port_range(range, range + 1);

	ret = proc_dointvec_minmax(&tmp, write, filp, buffer, lenp, ppos);



	if (write && ret == 0) {
@@ -73,8 +70,7 @@ static int ipv4_sysctl_local_port_range(ctl_table *table, int __user *name, 
					void __user *newval, size_t newlen)

{

	int ret;

	int range[2] = { sysctl_local_port_range[0],

			 sysctl_local_port_range[1] };

	int range[2];

	ctl_table tmp = {

		.data = &range,

		.maxlen = sizeof(range),
@@ -83,6 +79,7 @@ static int ipv4_sysctl_local_port_range(ctl_table *table, int __user *name, 
		.extra2 = &ip_local_port_range_max,

	};



	inet_get_local_port_range(range, range + 1);

	ret = sysctl_intvec(&tmp, name, nlen, oldval, oldlenp, newval, newlen);

	if (ret == 0 && newval && newlen) {

		if (range[1] < range[0])
@@ -396,8 +393,8 @@ static struct ctl_table ipv4_table[] = { 
	{

		.ctl_name	= NET_IPV4_LOCAL_PORT_RANGE,

		.procname	= "ip_local_port_range",

		.data		= &sysctl_local_port_range,

		.maxlen		= sizeof(sysctl_local_port_range),

		.data		= &sysctl_local_ports.range,

		.maxlen		= sizeof(sysctl_local_ports.range),

		.mode		= 0644,

		.proc_handler	= &ipv4_local_port_range,

		.strategy	= &ipv4_sysctl_local_port_range,

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