linux-stable/net/core
Eric Dumazet 6ffe75eb53 net: avoid two atomic operations in fast clones
Commit ce1a4ea3f1 ("net: avoid one atomic operation in skb_clone()")
took the wrong way to save one atomic operation.

It is actually possible to avoid two atomic operations, if we
do not change skb->fclone values, and only rely on clone_ref
content to signal if the clone is available or not.

skb_clone() can simply use the fast clone if clone_ref is 1.

kfree_skbmem() can avoid the atomic_dec_and_test() if clone_ref is 1.

Note that because we usually free the clone before the original skb,
this particular attempt is only done for the original skb to have better
branch prediction.

SKB_FCLONE_FREE is removed.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Chris Mason <clm@fb.com>
Cc: Sabrina Dubroca <sd@queasysnail.net>
Cc: Vijay Subramanian <subramanian.vijay@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-12-09 13:40:20 -05:00
..
datagram.c switch AF_PACKET and AF_UNIX to skb_copy_datagram_from_iter() 2014-11-24 05:16:39 -05:00
dev.c rtnetlink: delay RTM_DELLINK notification until after ndo_uninit() 2014-12-09 13:36:57 -05:00
dev_addr_lists.c net: fix spelling for synchronized 2014-11-18 15:26:32 -05:00
dev_ioctl.c dev_ioctl: use sizeof(x) instead of sizeof x 2014-11-18 15:27:32 -05:00
drop_monitor.c net: Replace get_cpu_var through this_cpu_ptr 2014-08-26 13:45:47 -04:00
dst.c ipv4: fix dst race in sk_dst_get() 2014-06-25 17:41:44 -07:00
ethtool.c ethtool: Support for configurable RSS hash function 2014-12-08 21:07:10 -05:00
fib_rules.c net: fix 'ip rule' iif/oif device rename 2014-02-09 19:02:52 -08:00
filter.c net: sock: allow eBPF programs to be attached to sockets 2014-12-05 21:47:32 -08:00
flow.c CPU hotplug notifiers registration fixes for 3.15-rc1 2014-04-07 14:55:46 -07:00
flow_dissector.c flow-dissector: Fix alignment issue in __skb_flow_get_ports 2014-10-10 15:33:47 -04:00
gen_estimator.c net: sched: make bstats per cpu and estimator RCU safe 2014-09-30 01:02:26 -04:00
gen_stats.c net_sched: fix unused variables in __gnet_stats_copy_basic_cpu() 2014-10-07 00:10:49 -04:00
iovec.c fold verify_iovec() into copy_msghdr_from_user() 2014-11-19 16:23:49 -05:00
link_watch.c net/core: include linux/types.h instead of asm/types.h 2014-11-18 15:26:32 -05:00
Makefile dmaengine-3.17 2014-10-07 20:39:25 -04:00
neighbour.c neigh: remove dynamic neigh table registration support 2014-11-11 15:23:54 -05:00
net-procfs.c rps: selective flow shedding during softnet overflow 2013-05-20 13:48:04 -07:00
net-sysfs.c net-sysfs: expose physical switch id for particular device 2014-12-02 20:01:22 -08:00
net-sysfs.h net: netdev_kobject_init: annotate with __init 2014-01-05 20:27:54 -05:00
net-traces.c net: Add export.h for EXPORT_SYMBOL/THIS_MODULE to non-modules 2011-10-31 19:30:30 -04:00
net_namespace.c netns: remove one sparse warning 2014-09-09 20:10:45 -07:00
netclassid_cgroup.c cgroup: rename cgroup_subsys->base_cftypes to ->legacy_cftypes 2014-07-15 11:05:09 -04:00
netevent.c net: Add export.h for EXPORT_SYMBOL/THIS_MODULE to non-modules 2011-10-31 19:30:30 -04:00
netpoll.c vlan: introduce *vlan_hwaccel_push_inside helpers 2014-11-21 14:20:17 -05:00
netprio_cgroup.c cgroup: rename cgroup_subsys->base_cftypes to ->legacy_cftypes 2014-07-15 11:05:09 -04:00
pktgen.c net: pktgen: Deletion of an unnecessary check before the function call "proc_remove" 2014-11-19 15:20:15 -05:00
ptp_classifier.c net: filter: split 'struct sk_filter' into socket and bpf parts 2014-08-02 15:03:58 -07:00
request_sock.c inet: reduce TLB pressure for listeners 2014-06-25 16:37:24 -07:00
rtnetlink.c rtnetlink: delay RTM_DELLINK notification until after ndo_uninit() 2014-12-09 13:36:57 -05:00
scm.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2013-09-07 14:35:32 -07:00
secure_seq.c net: use ktime_get_ns() and ktime_get_real_ns() helpers 2014-08-22 19:57:23 -07:00
skbuff.c net: avoid two atomic operations in fast clones 2014-12-09 13:40:20 -05:00
sock.c net: sock: allow eBPF programs to be attached to sockets 2014-12-05 21:47:32 -08:00
sock_diag.c net: filter: split 'struct sk_filter' into socket and bpf parts 2014-08-02 15:03:58 -07:00
stream.c net: replace macros net_random and net_srandom with direct calls to prandom 2014-01-14 15:15:25 -08:00
sysctl_net_core.c net: provide a per host RSS key generic infrastructure 2014-11-16 15:59:11 -05:00
timestamping.c net-timestamp: Make the clone operation stand-alone from phy timestamping 2014-09-05 17:43:45 -07:00
tso.c net: tso: fix unaligned access to crafted TCP header in helper API 2014-10-22 12:52:55 -04:00
utils.c net: Convert LIMIT_NETDEBUG to net_dbg_ratelimited 2014-11-11 14:10:31 -05:00