inetpeer: reduce stack usage
On 64bit arches, we use 752 bytes of stack when cleanup_once() is called
from inet_getpeer().
Lets share the avl stack to save ~376 bytes.
Before patch :
# objdump -d net/ipv4/inetpeer.o | scripts/checkstack.pl
0x000006c3 unlink_from_pool [inetpeer.o]: 376
0x00000721 unlink_from_pool [inetpeer.o]: 376
0x00000cb1 inet_getpeer [inetpeer.o]: 376
0x00000e6d inet_getpeer [inetpeer.o]: 376
0x0004 inet_initpeers [inetpeer.o]: 112
# size net/ipv4/inetpeer.o
text data bss dec hex filename
5320 432 21 5773 168d net/ipv4/inetpeer.o
After patch :
objdump -d net/ipv4/inetpeer.o | scripts/checkstack.pl
0x00000c11 inet_getpeer [inetpeer.o]: 376
0x00000dcd inet_getpeer [inetpeer.o]: 376
0x00000ab9 peer_check_expire [inetpeer.o]: 328
0x00000b7f peer_check_expire [inetpeer.o]: 328
0x0004 inet_initpeers [inetpeer.o]: 112
# size net/ipv4/inetpeer.o
text data bss dec hex filename
5163 432 21 5616 15f0 net/ipv4/inetpeer.o
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Scot Doyle <lkml@scotdoyle.com>
Cc: Stephen Hemminger <shemminger@vyatta.com>
Cc: Hiroaki SHIMODA <shimoda.hiroaki@gmail.com>
Reviewed-by: Hiroaki SHIMODA <shimoda.hiroaki@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/inetpeer.c b/net/ipv4/inetpeer.c
index dd1b20e..9df4e63 100644
--- a/net/ipv4/inetpeer.c
+++ b/net/ipv4/inetpeer.c
@@ -354,7 +354,8 @@
}
/* May be called with local BH enabled. */
-static void unlink_from_pool(struct inet_peer *p, struct inet_peer_base *base)
+static void unlink_from_pool(struct inet_peer *p, struct inet_peer_base *base,
+ struct inet_peer __rcu **stack[PEER_MAXDEPTH])
{
int do_free;
@@ -368,7 +369,6 @@
* We use refcnt=-1 to alert lockless readers this entry is deleted.
*/
if (atomic_cmpxchg(&p->refcnt, 1, -1) == 1) {
- struct inet_peer __rcu **stack[PEER_MAXDEPTH];
struct inet_peer __rcu ***stackptr, ***delp;
if (lookup(&p->daddr, stack, base) != p)
BUG();
@@ -422,7 +422,7 @@
}
/* May be called with local BH enabled. */
-static int cleanup_once(unsigned long ttl)
+static int cleanup_once(unsigned long ttl, struct inet_peer __rcu **stack[PEER_MAXDEPTH])
{
struct inet_peer *p = NULL;
@@ -454,7 +454,7 @@
* happen because of entry limits in route cache. */
return -1;
- unlink_from_pool(p, peer_to_base(p));
+ unlink_from_pool(p, peer_to_base(p), stack);
return 0;
}
@@ -524,7 +524,7 @@
if (base->total >= inet_peer_threshold)
/* Remove one less-recently-used entry. */
- cleanup_once(0);
+ cleanup_once(0, stack);
return p;
}
@@ -540,6 +540,7 @@
{
unsigned long now = jiffies;
int ttl, total;
+ struct inet_peer __rcu **stack[PEER_MAXDEPTH];
total = compute_total();
if (total >= inet_peer_threshold)
@@ -548,7 +549,7 @@
ttl = inet_peer_maxttl
- (inet_peer_maxttl - inet_peer_minttl) / HZ *
total / inet_peer_threshold * HZ;
- while (!cleanup_once(ttl)) {
+ while (!cleanup_once(ttl, stack)) {
if (jiffies != now)
break;
}