From 791a3e9f1a86fe8eb09173c9788493b8b5c957f4 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Thu, 16 Mar 2023 01:10:14 +0000 Subject: [PATCH] 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 Signed-off-by: David S. Miller --- net/packet/af_packet.c | 14 ++++++++------ net/packet/internal.h | 2 +- 2 files changed, 9 insertions(+), 7 deletions(-) diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index ec446452bbe8..7b9367b233d3 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -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; diff --git a/net/packet/internal.h b/net/packet/internal.h index 58f042c63172..680703dbce5e 100644 --- a/net/packet/internal.h +++ b/net/packet/internal.h @@ -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,