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Commit 976673ee authored by Chris Mason's avatar Chris Mason Committed by Andy Grover
Browse files

rds: switch to rwlock on bind_lock 



The bind_lock is almost entirely readonly, but it gets
hammered during normal operations and is a major bottleneck.

This commit changes it to an rwlock, which takes it from 80%
of the system time on a big numa machine down to much lower
numbers.

A better fix would involve RCU, which is done in a later commit

Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
parent ce47f52f

net/rds/bind.c

+7 −7
Original line number Diff line number Diff line
@@ -43,7 +43,7 @@ 
 * This is now called for every incoming frame so we arguably care much more

 * about it than we used to.

 */

static DEFINE_SPINLOCK(rds_bind_lock);

static DEFINE_RWLOCK(rds_bind_lock);

static struct rb_root rds_bind_tree = RB_ROOT;



static struct rds_sock *rds_bind_tree_walk(__be32 addr, __be16 port,
@@ -88,13 +88,13 @@ struct rds_sock *rds_find_bound(__be32 addr, __be16 port) 
	struct rds_sock *rs;

	unsigned long flags;



	spin_lock_irqsave(&rds_bind_lock, flags);

	read_lock_irqsave(&rds_bind_lock, flags);

	rs = rds_bind_tree_walk(addr, port, NULL);

	if (rs && !sock_flag(rds_rs_to_sk(rs), SOCK_DEAD))

		rds_sock_addref(rs);

	else

		rs = NULL;

	spin_unlock_irqrestore(&rds_bind_lock, flags);

	read_unlock_irqrestore(&rds_bind_lock, flags);



	rdsdebug("returning rs %p for %pI4:%u\n", rs, &addr,

		ntohs(port));
@@ -116,7 +116,7 @@ static int rds_add_bound(struct rds_sock *rs, __be32 addr, __be16 *port) 
		last = rover - 1;

	}



	spin_lock_irqsave(&rds_bind_lock, flags);

	write_lock_irqsave(&rds_bind_lock, flags);



	do {

		if (rover == 0)
@@ -137,7 +137,7 @@ static int rds_add_bound(struct rds_sock *rs, __be32 addr, __be16 *port) 
		  rs, &addr, (int)ntohs(*port));

	}



	spin_unlock_irqrestore(&rds_bind_lock, flags);

	write_unlock_irqrestore(&rds_bind_lock, flags);



	return ret;

}
@@ -146,7 +146,7 @@ void rds_remove_bound(struct rds_sock *rs) 
{

	unsigned long flags;



	spin_lock_irqsave(&rds_bind_lock, flags);

	write_lock_irqsave(&rds_bind_lock, flags);



	if (rs->rs_bound_addr) {

		rdsdebug("rs %p unbinding from %pI4:%d\n",
@@ -158,7 +158,7 @@ void rds_remove_bound(struct rds_sock *rs) 
		rs->rs_bound_addr = 0;

	}



	spin_unlock_irqrestore(&rds_bind_lock, flags);

	write_unlock_irqrestore(&rds_bind_lock, flags);

}



int rds_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)