linux/Documentation/networking
David Arinzon a087d4b502 net: ena: Add dynamic recycling mechanism for rx buffers
[ Upstream commit f7d625adeb ]

The current implementation allocates page-sized rx buffers.
As traffic may consist of different types and sizes of packets,
in various cases, buffers are not fully used.

This change (Dynamic RX Buffers - DRB) uses part of the allocated rx
page needed for the incoming packet, and returns the rest of the
unused page to be used again as an rx buffer for future packets.
A threshold of 2K for unused space has been set in order to declare
whether the remainder of the page can be reused again as an rx buffer.

As a page may be reused, dma_sync_single_for_cpu() is added in order
to sync the memory to the CPU side after it was owned by the HW.
In addition, when the rx page can no longer be reused, it is being
unmapped using dma_page_unmap(), which implicitly syncs and then
unmaps the entire page. In case the kernel still handles the skbs
pointing to the previous buffers from that rx page, it may access
garbage pointers, caused by the implicit sync overwriting them.
The implicit dma sync is removed by replacing dma_page_unmap() with
dma_unmap_page_attrs() with DMA_ATTR_SKIP_CPU_SYNC flag.

The functionality is disabled for XDP traffic to avoid handling
several descriptors per packet.

Signed-off-by: Arthur Kiyanovski <akiyano@amazon.com>
Signed-off-by: Shay Agroskin <shayagr@amazon.com>
Signed-off-by: David Arinzon <darinzon@amazon.com>
Link: https://lore.kernel.org/r/20230612121448.28829-1-darinzon@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Stable-dep-of: 2dc8b1e717 ("net: ena: Fix redundant device NUMA node override")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-06-16 13:39:52 +02:00
..
caif tty: cumulate and document tty_struct::flow* members 2021-05-13 16:57:16 +02:00
device_drivers net: ena: Add dynamic recycling mechanism for rx buffers 2024-06-16 13:39:52 +02:00
devlink ice: Print the api_patch as part of the fw.mgmt.api 2021-10-14 10:14:46 -07:00
dsa docs: net: dsa: sja1105: fix reference to sja1105.txt 2021-09-19 12:45:03 +01:00
mac80211_hwsim docs: net: convert two README files to ReST format 2019-07-31 13:31:56 -06:00
6lowpan.rst docs: networking: convert 6lowpan.txt to ReST 2020-02-28 14:52:36 +01:00
6pack.rst docs: networking: convert 6pack.txt to ReST 2020-04-28 14:38:38 -07:00
af_xdp.rst xsk: Honor SO_BINDTODEVICE on bind 2023-07-23 13:47:29 +02:00
alias.rst
arcnet-hardware.rst docs: networking: arcnet-hardware.rst: don't duplicate chapter names 2020-05-01 12:24:43 -07:00
arcnet.rst Documentation: networking: arcnet: drop doubled word 2020-07-04 17:46:21 -07:00
atm.rst docs: networking: convert atm.txt to ReST 2020-04-28 14:38:38 -07:00
ax25.rst Documentation: networking: ax25: drop doubled word 2020-07-04 17:46:21 -07:00
bareudp.rst Documentation: bareudp: Corrected description of bareudp module. 2020-07-28 17:53:03 -07:00
batman-adv.rst batman-adv: Move IRC channel to hackint.org 2021-08-08 20:05:46 +02:00
bonding.rst Bonding: add arp_missed_max option 2023-06-05 09:21:19 +02:00
bridge.rst
can_ucan_protocol.rst Documentation: networking: can_ucan_protocol: drop doubled words 2020-07-04 17:46:21 -07:00
can.rst can: add a note that RECV_OWN_MSGS frames are subject to filtering 2021-04-24 14:36:51 +02:00
cdc_mbim.rst docs: networking: convert cdc_mbim.txt to ReST 2020-04-28 14:38:39 -07:00
checksum-offloads.rst docs: networking: convert netdev-features.txt to ReST 2020-04-30 12:56:36 -07:00
dccp.rst net: dccp: Add SIOCOUTQ IOCTL support (send buffer fill) 2020-07-22 17:00:37 -07:00
dctcp.rst docs: networking: convert dctcp.txt to ReST 2020-04-28 14:38:39 -07:00
dns_resolver.rst docs: networking: convert dns_resolver.txt to ReST 2020-04-28 14:39:46 -07:00
driver.rst docs: networking: convert driver.txt to ReST 2020-04-28 14:39:46 -07:00
eql.rst docs: networking: convert eql.txt to ReST 2020-04-28 14:39:46 -07:00
ethtool-netlink.rst ethtool: add two coalesce attributes for CQE mode 2021-08-24 07:38:28 -07:00
failover.rst
fib_trie.rst docs: networking: convert fib_trie.txt to ReST 2020-04-28 14:39:46 -07:00
filter.rst bpf: Refactor BPF_PROG_RUN into a function 2021-08-17 00:45:07 +02:00
gen_stats.rst docs: networking: convert gen_stats.txt to ReST 2020-04-28 14:39:46 -07:00
generic_netlink.rst docs: networking: convert generic_netlink.txt to ReST 2020-04-28 14:39:46 -07:00
generic-hdlc.rst docs: networking: convert generic-hdlc.txt to ReST 2020-04-28 14:39:46 -07:00
gtp.rst docs: networking: convert gtp.txt to ReST 2020-04-28 14:39:46 -07:00
ieee802154.rst docs: net: ieee802154.rst: fix C expressions 2020-10-15 07:49:41 +02:00
ila.rst docs: networking: convert ila.txt to ReST 2020-04-28 14:39:47 -07:00
index.rst Remove DECnet support from kernel 2023-06-21 15:59:15 +02:00
ioam6-sysctl.rst ipv6: ioam: Documentation for new IOAM sysctls 2021-07-21 08:14:33 -07:00
ip_dynaddr.rst docs: networking: convert ip_dynaddr.txt to ReST 2020-04-28 14:39:47 -07:00
ip-sysctl.rst net: change accept_ra_min_rtr_lft to affect all RA lifetimes 2023-10-19 23:05:35 +02:00
ipddp.rst docs: networking: convert ipddp.txt to ReST 2020-04-28 14:39:47 -07:00
ipsec.rst docs: networking: convert ipsec.txt to ReST 2020-04-28 14:39:47 -07:00
ipv6.rst docs: networking: convert ipv6.txt to ReST 2020-04-28 14:40:18 -07:00
ipvlan.rst docs: networking: convert ipvlan.txt to ReST 2020-04-28 14:40:18 -07:00
ipvs-sysctl.rst netfilter: ipvs: Fix reuse connection if RS weight is 0 2021-12-01 09:04:45 +01:00
j1939.rst can: j1939: add tables for the CAN identifier and its fields 2020-11-20 09:43:29 +01:00
kapi.rst wimax: move out to staging 2020-10-29 19:27:45 +01:00
kcm.rst docs: networking: convert kcm.txt to ReST 2020-04-28 14:40:19 -07:00
l2tp.rst docs: networking: add tracepoint info to l2tp.rst 2020-08-22 12:44:37 -07:00
lapb-module.rst docs: networking: convert lapb-module.txt to ReST 2020-04-30 12:56:35 -07:00
mac80211-auth-assoc-deauth.txt
mac80211-injection.rst doc: networking: wireless: fix wiki website url 2020-06-08 10:05:53 +02:00
mctp.rst mctp: unify sockaddr_mctp types 2021-10-18 13:47:09 +01:00
mpls-sysctl.rst docs: networking: convert mpls-sysctl.txt to ReST 2020-04-30 12:56:36 -07:00
mptcp-sysctl.rst mptcp: faster active backup recovery 2021-08-14 11:37:25 +01:00
msg_zerocopy.rst
multiqueue.rst docs: networking: convert multiqueue.txt to ReST 2020-04-30 12:56:36 -07:00
net_dim.rst docs: networking: add full DIM API 2020-04-10 18:11:04 -07:00
net_failover.rst docs: networking: net_failover: Fix a few typos 2020-03-03 16:07:02 -08:00
netconsole.rst docs: networking: convert netconsole.txt to ReST 2020-04-30 12:56:36 -07:00
netdev-FAQ.rst docs: networking: netdevsim rules 2021-08-04 12:43:27 +01:00
netdev-features.rst net: hsr: add offloading support 2021-02-11 13:24:44 -08:00
netdevices.rst net: bonding: move ioctl handling to private ndo operation 2021-07-27 20:11:45 +01:00
netfilter-sysctl.rst docs: networking: convert netfilter-sysctl.txt to ReST 2020-04-30 12:56:36 -07:00
netif-msg.rst docs: networking: convert netif-msg.txt to ReST 2020-04-30 12:56:36 -07:00
nexthop-group-resilient.rst Documentation: net: Document resilient next-hop groups 2021-03-29 13:51:38 -07:00
nf_conntrack-sysctl.rst Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf 2021-09-03 16:20:37 -07:00
nf_flowtable.rst docs: nf_flowtable: fix compilation and warnings 2021-03-25 17:42:02 -07:00
nfc.rst docs: networking: nfc: change to rst format 2019-11-23 11:00:19 -08:00
openvswitch.rst docs: networking: convert openvswitch.txt to ReST 2020-04-30 12:56:36 -07:00
operstates.rst docs: operstates: document IF_OPER_TESTING 2021-08-02 15:16:04 +01:00
packet_mmap.rst docs: networking: Replace strncpy() with strscpy() 2021-06-04 11:21:43 -06:00
page_pool.rst net: page_pool: Add page_pool_put_page_bulk() to page_pool.rst 2020-11-24 14:56:54 -08:00
phonet.rst docs: networking: convert phonet.txt to ReST 2020-04-30 12:56:37 -07:00
phy.rst net: phy: Add 25G BASE-R interface mode 2021-06-12 13:08:57 -07:00
pktgen.rst pktgen: document the latest pktgen usage options 2021-08-25 13:44:30 +01:00
plip.rst docs: networking: convert PLIP.txt to ReST 2020-04-30 12:56:37 -07:00
ppp_generic.rst docs: update ppp_generic.rst to document new ioctls 2020-12-10 13:57:36 -08:00
proc_net_tcp.rst docs: networking: convert proc_net_tcp.txt to ReST 2020-04-30 12:56:37 -07:00
radiotap-headers.rst docs: networking: convert radiotap-headers.txt to ReST 2020-04-30 12:56:37 -07:00
rds.rst docs: networking: convert rds.txt to ReST 2020-04-30 12:56:37 -07:00
regulatory.rst doc: networking: wireless: fix wiki website url 2020-06-08 10:05:53 +02:00
rxrpc.rst Documentation: networking: rxrpc: drop doubled word 2020-07-04 17:46:21 -07:00
scaling.rst docs: networking: update XPS to account for netif_set_xps_queue 2020-10-13 16:21:54 -07:00
sctp.rst docs: networking: convert sctp.txt to ReST 2020-04-30 12:56:38 -07:00
secid.rst docs: networking: convert secid.txt to ReST 2020-04-30 12:56:38 -07:00
seg6-sysctl.rst doc: move seg6_flowlabel to seg6-sysctl.rst 2021-04-14 13:13:15 -07:00
segmentation-offloads.rst
sfp-phylink.rst net: mdio: Remove of_phy_attach() 2021-02-17 13:17:49 -08:00
snmp_counter.rst net-next: docs: Fix typos in snmp_counter.rst 2021-01-05 17:07:38 -08:00
statistics.rst docs: networking: extend the statistics documentation 2021-04-16 16:59:20 -07:00
strparser.rst docs: networking: convert strparser.txt to ReST 2020-04-30 12:56:38 -07:00
switchdev.rst Documentation: networking: switchdev: add missing "and" word 2021-03-17 12:34:34 -07:00
sysfs-tagging.rst Documentation: better locations for sysfs-pci, sysfs-tagging 2020-10-09 09:33:23 -06:00
tc-actions-env-rules.rst docs: networking: convert tc-actions-env-rules.txt to ReST 2020-04-30 12:56:38 -07:00
tcp-thin.rst docs: networking: convert tcp-thin.txt to ReST 2020-04-30 12:56:38 -07:00
team.rst docs: networking: convert team.txt to ReST 2020-04-30 12:56:38 -07:00
timestamping.rst dev_ioctl: split out ndo_eth_ioctl 2021-07-27 20:11:45 +01:00
tipc.rst Documentation: add more details in tipc.rst 2021-07-01 13:18:18 -07:00
tls-offload-layers.svg
tls-offload-reorder-bad.svg
tls-offload-reorder-good.svg
tls-offload.rst net: Disable NETIF_F_HW_TLS_RX when RXCSUM is disabled 2021-01-19 15:58:05 -08:00
tls.rst net/tls: add TlsDeviceRxResync statistic 2019-10-05 16:29:00 -07:00
tproxy.rst docs: networking: convert tproxy.txt to ReST 2020-04-30 12:56:38 -07:00
tuntap.rst docs: networking: Replace strncpy() with strscpy() 2021-06-04 11:21:43 -06:00
udplite.rst docs: networking: convert udplite.txt to ReST 2020-05-01 12:24:40 -07:00
vrf.rst doc: Document unexpected tcp_l3mdev_accept=1 behavior 2021-08-23 11:53:24 +01:00
vxlan.rst docs: vxlan: add info about device features 2020-09-28 12:50:12 -07:00
x25-iface.rst net: x25: Queue received packets in the drivers instead of per-CPU queues 2021-04-05 11:42:12 -07:00
x25.rst net: x25: Remove unimplemented X.25-over-LLC code stubs 2020-12-12 17:15:33 -08:00
xfrm_device.rst docs: networking: Fix a typo 2021-03-20 19:02:42 -07:00
xfrm_proc.rst docs: networking: convert xfrm_proc.txt to ReST 2020-05-01 12:24:40 -07:00
xfrm_sync.rst docs: networking: convert xfrm_sync.txt to ReST 2020-05-01 12:24:41 -07:00
xfrm_sysctl.rst docs: networking: convert xfrm_sysctl.txt to ReST 2020-05-01 12:24:41 -07:00