linux/net/core
Shaohua Li fb05e7a89f net: don't wait for order-3 page allocation
We saw excessive direct memory compaction triggered by skb_page_frag_refill.
This causes performance issues and add latency. Commit 5640f76858
introduces the order-3 allocation. According to the changelog, the order-3
allocation isn't a must-have but to improve performance. But direct memory
compaction has high overhead. The benefit of order-3 allocation can't
compensate the overhead of direct memory compaction.

This patch makes the order-3 page allocation atomic. If there is no memory
pressure and memory isn't fragmented, the alloction will still success, so we
don't sacrifice the order-3 benefit here. If the atomic allocation fails,
direct memory compaction will not be triggered, skb_page_frag_refill will
fallback to order-0 immediately, hence the direct memory compaction overhead is
avoided. In the allocation failure case, kswapd is waken up and doing
compaction, so chances are allocation could success next time.

alloc_skb_with_frags is the same.

The mellanox driver does similar thing, if this is accepted, we must fix
the driver too.

V3: fix the same issue in alloc_skb_with_frags as pointed out by Eric
V2: make the changelog clearer

Cc: Eric Dumazet <edumazet@google.com>
Cc: Chris Mason <clm@fb.com>
Cc: Debabrata Banerjee <dbavatar@gmail.com>
Signed-off-by: Shaohua Li <shli@fb.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-06-11 17:33:44 -07:00
..
datagram.c new helper: msg_data_left() 2015-04-11 15:53:35 -04:00
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
dev.c net: replace last open coded skb_orphan_frags with function call 2015-06-08 12:15:13 -07:00
drop_monitor.c net: Replace get_cpu_var through this_cpu_ptr 2014-08-26 13:45:47 -04:00
dst.c dst: no need to take reference on DST_NOCACHE dsts 2014-12-09 16:08:17 -05:00
ethtool.c Revert "net: core: 'ethtool' issue with querying phy settings" 2015-06-01 14:43:50 -07:00
fib_rules.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2015-04-06 22:34:15 -04:00
filter.c bpf: fix bpf helpers to use skb->mac_header relative offsets 2015-04-16 14:08:49 -04:00
flow_dissector.c xps: fix xps for stacked devices 2015-02-04 13:02:54 -08:00
flow.c flowcache: Fix kernel panic in flow_cache_flush_task 2015-02-05 14:38:53 -08:00
gen_estimator.c net: sched: make bstats per cpu and estimator RCU safe 2014-09-30 01:02:26 -04:00
gen_stats.c gen_stats.c: Duplicate xstats buffer for later use 2015-02-19 15:45:53 -05:00
link_watch.c dev: introduce dev_get_iflink() 2015-04-02 14:04:59 -04:00
Makefile net: bury net/core/iovec.c - nothing in there is used anymore 2015-02-04 01:34:15 -05:00
neighbour.c net: neighbour: Add mcast_resolicit to configure the number of multicast resolicitations in PROBE state. 2015-03-20 21:47:40 -04:00
net_namespace.c netns: return RTM_NEWNSID instead of RTM_GETNSID on a get 2015-05-12 18:53:25 -04:00
net-procfs.c
net-sysfs.c dev: introduce dev_get_iflink() 2015-04-02 14:04:59 -04:00
net-sysfs.h
net-traces.c
netclassid_cgroup.c cgroup: rename cgroup_subsys->base_cftypes to ->legacy_cftypes 2014-07-15 11:05:09 -04:00
netevent.c
netpoll.c net: rename vlan_tx_* helpers since "tx" is misleading there 2015-01-13 17:51:08 -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: disable xmit_clone on virtual devices 2015-02-22 22:43:20 -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 net: convert syn_wait_lock to a spinlock 2015-03-23 16:52:26 -04:00
rtnetlink.c rtnl/bond: don't send rtnl msg for unregistered iface 2015-05-17 22:43:07 -04:00
scm.c net: introduce helper macro for_each_cmsghdr 2014-12-10 22:41:55 -05:00
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: don't wait for order-3 page allocation 2015-06-11 17:33:44 -07:00
sock_diag.c net: add real socket cookies 2015-03-11 21:55:28 -04:00
sock.c net: don't wait for order-3 page allocation 2015-06-11 17:33:44 -07:00
stream.c
sysctl_net_core.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2015-03-20 18:51:09 -04:00
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