Commit 243bbcaa authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller

[IPV4]: Optimize inet_getpeer()

1) Some sysctl vars are declared __read_mostly

2) We can avoid updating stack[] when doing an AVL lookup only.

    lookup() macro is extended to receive a second parameter, that may be NULL
in case of a pure lookup (no need to save the AVL path). This removes
unnecessary instructions, because compiler knows if this _stack parameter is
NULL or not.

    text size of net/ipv4/inetpeer.o is 2063 bytes instead of 2107 on x86_64
Signed-off-by: default avatarEric Dumazet <dada1@cosmosbay.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 43e68392
...@@ -87,10 +87,12 @@ static DEFINE_RWLOCK(peer_pool_lock); ...@@ -87,10 +87,12 @@ static DEFINE_RWLOCK(peer_pool_lock);
static int peer_total; static int peer_total;
/* Exported for sysctl_net_ipv4. */ /* Exported for sysctl_net_ipv4. */
int inet_peer_threshold = 65536 + 128; /* start to throw entries more int inet_peer_threshold __read_mostly = 65536 + 128; /* start to throw entries more
* aggressively at this stage */ * aggressively at this stage */
int inet_peer_minttl = 120 * HZ; /* TTL under high load: 120 sec */ int inet_peer_minttl __read_mostly = 120 * HZ; /* TTL under high load: 120 sec */
int inet_peer_maxttl = 10 * 60 * HZ; /* usual time to live: 10 min */ int inet_peer_maxttl __read_mostly = 10 * 60 * HZ; /* usual time to live: 10 min */
int inet_peer_gc_mintime __read_mostly = 10 * HZ;
int inet_peer_gc_maxtime __read_mostly = 120 * HZ;
static struct inet_peer *inet_peer_unused_head; static struct inet_peer *inet_peer_unused_head;
static struct inet_peer **inet_peer_unused_tailp = &inet_peer_unused_head; static struct inet_peer **inet_peer_unused_tailp = &inet_peer_unused_head;
...@@ -99,9 +101,6 @@ static DEFINE_SPINLOCK(inet_peer_unused_lock); ...@@ -99,9 +101,6 @@ static DEFINE_SPINLOCK(inet_peer_unused_lock);
static void peer_check_expire(unsigned long dummy); static void peer_check_expire(unsigned long dummy);
static DEFINE_TIMER(peer_periodic_timer, peer_check_expire, 0, 0); static DEFINE_TIMER(peer_periodic_timer, peer_check_expire, 0, 0);
/* Exported for sysctl_net_ipv4. */
int inet_peer_gc_mintime = 10 * HZ,
inet_peer_gc_maxtime = 120 * HZ;
/* Called from ip_output.c:ip_init */ /* Called from ip_output.c:ip_init */
void __init inet_initpeers(void) void __init inet_initpeers(void)
...@@ -151,20 +150,27 @@ static void unlink_from_unused(struct inet_peer *p) ...@@ -151,20 +150,27 @@ static void unlink_from_unused(struct inet_peer *p)
spin_unlock_bh(&inet_peer_unused_lock); spin_unlock_bh(&inet_peer_unused_lock);
} }
/* Called with local BH disabled and the pool lock held. */ /*
#define lookup(daddr) \ * Called with local BH disabled and the pool lock held.
* _stack is known to be NULL or not at compile time,
* so compiler will optimize the if (_stack) tests.
*/
#define lookup(_daddr,_stack) \
({ \ ({ \
struct inet_peer *u, **v; \ struct inet_peer *u, **v; \
stackptr = stack; \ if (_stack) { \
*stackptr++ = &peer_root; \ stackptr = _stack; \
*stackptr++ = &peer_root; \
} \
for (u = peer_root; u != peer_avl_empty; ) { \ for (u = peer_root; u != peer_avl_empty; ) { \
if (daddr == u->v4daddr) \ if (_daddr == u->v4daddr) \
break; \ break; \
if ((__force __u32)daddr < (__force __u32)u->v4daddr) \ if ((__force __u32)_daddr < (__force __u32)u->v4daddr) \
v = &u->avl_left; \ v = &u->avl_left; \
else \ else \
v = &u->avl_right; \ v = &u->avl_right; \
*stackptr++ = v; \ if (_stack) \
*stackptr++ = v; \
u = *v; \ u = *v; \
} \ } \
u; \ u; \
...@@ -288,7 +294,7 @@ static void unlink_from_pool(struct inet_peer *p) ...@@ -288,7 +294,7 @@ static void unlink_from_pool(struct inet_peer *p)
if (atomic_read(&p->refcnt) == 1) { if (atomic_read(&p->refcnt) == 1) {
struct inet_peer **stack[PEER_MAXDEPTH]; struct inet_peer **stack[PEER_MAXDEPTH];
struct inet_peer ***stackptr, ***delp; struct inet_peer ***stackptr, ***delp;
if (lookup(p->v4daddr) != p) if (lookup(p->v4daddr, stack) != p)
BUG(); BUG();
delp = stackptr - 1; /* *delp[0] == p */ delp = stackptr - 1; /* *delp[0] == p */
if (p->avl_left == peer_avl_empty) { if (p->avl_left == peer_avl_empty) {
...@@ -373,7 +379,7 @@ struct inet_peer *inet_getpeer(__be32 daddr, int create) ...@@ -373,7 +379,7 @@ struct inet_peer *inet_getpeer(__be32 daddr, int create)
/* Look up for the address quickly. */ /* Look up for the address quickly. */
read_lock_bh(&peer_pool_lock); read_lock_bh(&peer_pool_lock);
p = lookup(daddr); p = lookup(daddr, NULL);
if (p != peer_avl_empty) if (p != peer_avl_empty)
atomic_inc(&p->refcnt); atomic_inc(&p->refcnt);
read_unlock_bh(&peer_pool_lock); read_unlock_bh(&peer_pool_lock);
...@@ -400,7 +406,7 @@ struct inet_peer *inet_getpeer(__be32 daddr, int create) ...@@ -400,7 +406,7 @@ struct inet_peer *inet_getpeer(__be32 daddr, int create)
write_lock_bh(&peer_pool_lock); write_lock_bh(&peer_pool_lock);
/* Check if an entry has suddenly appeared. */ /* Check if an entry has suddenly appeared. */
p = lookup(daddr); p = lookup(daddr, stack);
if (p != peer_avl_empty) if (p != peer_avl_empty)
goto out_free; goto out_free;
......
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