diff options
| author | David S. Miller <davem@davemloft.net> | 2013-02-14 15:57:38 -0500 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2013-02-14 15:57:38 -0500 |
| commit | 9754e293491e3a4e6c1ac020d25140b1ed3d9cd2 (patch) | |
| tree | 72273ca8e34846ac586a520b792c147bd95cd498 /net/core/dev.c | |
| parent | ba7797119b486bb5992beda74bdb26be9a291b46 (diff) | |
net: Don't write to current task flags on every packet received.
Even for non-pfmalloc SKBs, __netif_receive_skb() will do a
tsk_restore_flags() on current unconditionally.
Make __netif_receive_skb() a shim around the existing code, renamed to
__netif_receive_skb_core(). Let __netif_receive_skb() wrap the
__netif_receive_skb_core() call with the task flag modifications, if
necessary.
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/core/dev.c')
| -rw-r--r-- | net/core/dev.c | 46 |
1 files changed, 28 insertions, 18 deletions
diff --git a/net/core/dev.c b/net/core/dev.c index 2f31bf97ba65..f44473696b8b 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -3457,7 +3457,7 @@ static bool skb_pfmemalloc_protocol(struct sk_buff *skb) } } -static int __netif_receive_skb(struct sk_buff *skb) +static int __netif_receive_skb_core(struct sk_buff *skb, bool pfmemalloc) { struct packet_type *ptype, *pt_prev; rx_handler_func_t *rx_handler; @@ -3466,24 +3466,11 @@ static int __netif_receive_skb(struct sk_buff *skb) bool deliver_exact = false; int ret = NET_RX_DROP; __be16 type; - unsigned long pflags = current->flags; net_timestamp_check(!netdev_tstamp_prequeue, skb); trace_netif_receive_skb(skb); - /* - * PFMEMALLOC skbs are special, they should - * - be delivered to SOCK_MEMALLOC sockets only - * - stay away from userspace - * - have bounded memory usage - * - * Use PF_MEMALLOC as this saves us from propagating the allocation - * context down to all allocation sites. - */ - if (sk_memalloc_socks() && skb_pfmemalloc(skb)) - current->flags |= PF_MEMALLOC; - /* if we've gotten here through NAPI, check netpoll */ if (netpoll_receive_skb(skb)) goto out; @@ -3517,7 +3504,7 @@ another_round: } #endif - if (sk_memalloc_socks() && skb_pfmemalloc(skb)) + if (pfmemalloc) goto skip_taps; list_for_each_entry_rcu(ptype, &ptype_all, list) { @@ -3536,8 +3523,7 @@ skip_taps: ncls: #endif - if (sk_memalloc_socks() && skb_pfmemalloc(skb) - && !skb_pfmemalloc_protocol(skb)) + if (pfmemalloc && !skb_pfmemalloc_protocol(skb)) goto drop; if (vlan_tx_tag_present(skb)) { @@ -3607,7 +3593,31 @@ drop: unlock: rcu_read_unlock(); out: - tsk_restore_flags(current, pflags, PF_MEMALLOC); + return ret; +} + +static int __netif_receive_skb(struct sk_buff *skb) +{ + int ret; + + if (sk_memalloc_socks() && skb_pfmemalloc(skb)) { + unsigned long pflags = current->flags; + + /* + * PFMEMALLOC skbs are special, they should + * - be delivered to SOCK_MEMALLOC sockets only + * - stay away from userspace + * - have bounded memory usage + * + * Use PF_MEMALLOC as this saves us from propagating the allocation + * context down to all allocation sites. + */ + current->flags |= PF_MEMALLOC; + ret = __netif_receive_skb_core(skb, true); + tsk_restore_flags(current, pflags, PF_MEMALLOC); + } else + ret = __netif_receive_skb_core(skb, false); + return ret; } |