net/packet: convert po->pressure to an atomic flag

Not only this removes some READ_ONCE()/WRITE_ONCE(),
this also removes one integer.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Eric Dumazet 2023-03-16 01:10:14 +00:00 committed by David S. Miller
parent 61edf47981
commit 791a3e9f1a
2 changed files with 9 additions and 7 deletions

View File

@ -1307,22 +1307,23 @@ static int __packet_rcv_has_room(const struct packet_sock *po,
static int packet_rcv_has_room(struct packet_sock *po, struct sk_buff *skb)
{
int pressure, ret;
bool pressure;
int ret;
ret = __packet_rcv_has_room(po, skb);
pressure = ret != ROOM_NORMAL;
if (READ_ONCE(po->pressure) != pressure)
WRITE_ONCE(po->pressure, pressure);
if (packet_sock_flag(po, PACKET_SOCK_PRESSURE) != pressure)
packet_sock_flag_set(po, PACKET_SOCK_PRESSURE, pressure);
return ret;
}
static void packet_rcv_try_clear_pressure(struct packet_sock *po)
{
if (READ_ONCE(po->pressure) &&
if (packet_sock_flag(po, PACKET_SOCK_PRESSURE) &&
__packet_rcv_has_room(po, NULL) == ROOM_NORMAL)
WRITE_ONCE(po->pressure, 0);
packet_sock_flag_set(po, PACKET_SOCK_PRESSURE, false);
}
static void packet_sock_destruct(struct sock *sk)
@ -1409,7 +1410,8 @@ static unsigned int fanout_demux_rollover(struct packet_fanout *f,
i = j = min_t(int, po->rollover->sock, num - 1);
do {
po_next = pkt_sk(rcu_dereference(f->arr[i]));
if (po_next != po_skip && !READ_ONCE(po_next->pressure) &&
if (po_next != po_skip &&
!packet_sock_flag(po_next, PACKET_SOCK_PRESSURE) &&
packet_rcv_has_room(po_next, skb) == ROOM_NORMAL) {
if (i != j)
po->rollover->sock = i;

View File

@ -117,7 +117,6 @@ struct packet_sock {
spinlock_t bind_lock;
struct mutex pg_vec_lock;
unsigned long flags;
int pressure;
int ifindex; /* bound device */
__be16 num;
struct packet_rollover *rollover;
@ -146,6 +145,7 @@ enum packet_sock_flags {
PACKET_SOCK_TP_LOSS,
PACKET_SOCK_HAS_VNET_HDR,
PACKET_SOCK_RUNNING,
PACKET_SOCK_PRESSURE,
};
static inline void packet_sock_flag_set(struct packet_sock *po,