kernel/linux.git/drivers/net/veth.c, branch v5.6.17

veth: ignore peer tx_dropped when counting local rx_dropped

2020-03-06T01:33:57+00:00

When local NET_RX backlog is full due to traffic overrun, peer veth tx_dropped counter increases. At that time, list local veth stats, rx_dropped has double value of peer tx_dropped, even bigger than transmit packets by peer. In NET_RX softirq process, if any packet drop case happens, it increases dev's rx_dropped counter and returns NET_RX_DROP. At veth tx side, it records any error returned from peer netif_rx into local dev tx_dropped counter. In veth get stats process, it puts local dev rx_dropped and peer dev tx_dropped into together as local rx_drpped value. So that it shows double value of real dropped packets number in this case. This patch ignores peer tx_dropped when counting local rx_dropped, since peer tx_dropped is duplicated to local rx_dropped at most cases. Signed-off-by: Jiang Lidong Signed-off-by: David S. Miller

bpf, xdp: Remove no longer required rcu_read_{un}lock()

2020-01-27T10:16:25+00:00

Now that we depend on rcu_call() and synchronize_rcu() to also wait for preempt_disabled region to complete the rcu read critical section in __dev_map_flush() is no longer required. Except in a few special cases in drivers that need it for other reasons. These originally ensured the map reference was safe while a map was also being free'd. And additionally that bpf program updates via ndo_bpf did not happen while flush updates were in flight. But flush by new rules can only be called from preempt-disabled NAPI context. The synchronize_rcu from the map free path and the rcu_call from the delete path will ensure the reference there is safe. So lets remove the rcu_read_lock and rcu_read_unlock pair to avoid any confusion around how this is being protected. If the rcu_read_lock was required it would mean errors in the above logic and the original patch would also be wrong. Now that we have done above we put the rcu_read_lock in the driver code where it is needed in a driver dependent way. I think this helps readability of the code so we know where and why we are taking read locks. Most drivers will not need rcu_read_locks here and further XDP drivers already have rcu_read_locks in their code paths for reading xdp programs on RX side so this makes it symmetric where we don't have half of rcu critical sections define in driver and the other half in devmap. Signed-off-by: John Fastabend Signed-off-by: Daniel Borkmann Acked-by: Jesper Dangaard Brouer Link: https://lore.kernel.org/bpf/1580084042-11598-4-git-send-email-john.fastabend@gmail.com

xdp: Use bulking for non-map XDP_REDIRECT and consolidate code paths

2020-01-17T04:03:34+00:00

Since the bulk queue used by XDP_REDIRECT now lives in struct net_device, we can re-use the bulking for the non-map version of the bpf_redirect() helper. This is a simple matter of having xdp_do_redirect_slow() queue the frame on the bulk queue instead of sending it out with __bpf_tx_xdp(). Unfortunately we can't make the bpf_redirect() helper return an error if the ifindex doesn't exit (as bpf_redirect_map() does), because we don't have a reference to the network namespace of the ingress device at the time the helper is called. So we have to leave it as-is and keep the device lookup in xdp_do_redirect_slow(). Since this leaves less reason to have the non-map redirect code in a separate function, so we get rid of the xdp_do_redirect_slow() function entirely. This does lose us the tracepoint disambiguation, but fortunately the xdp_redirect and xdp_redirect_map tracepoints use the same tracepoint entry structures. This means both can contain a map index, so we can just amend the tracepoint definitions so we always emit the xdp_redirect(_err) tracepoints, but with the map ID only populated if a map is present. This means we retire the xdp_redirect_map(_err) tracepoints entirely, but keep the definitions around in case someone is still listening for them. With this change, the performance of the xdp_redirect sample program goes from 5Mpps to 8.4Mpps (a 68% increase). Since the flush functions are no longer map-specific, rename the flush() functions to drop _map from their names. One of the renamed functions is the xdp_do_flush_map() callback used in all the xdp-enabled drivers. To keep from having to update all drivers, use a #define to keep the old name working, and only update the virtual drivers in this patch. Signed-off-by: Toke Høiland-Jørgensen Signed-off-by: Alexei Starovoitov Acked-by: John Fastabend Link: https://lore.kernel.org/bpf/157918768505.1458396.17518057312953572912.stgit@toke.dk

veth: use standard dev_lstats_add() and dev_lstats_read()

2019-11-08T04:03:08+00:00

This cleanup will ease u64_stats_t adoption in a single location. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

veth: Support bulk XDP_TX

2019-06-25T12:26:54+00:00

XDP_TX is similar to XDP_REDIRECT as it essentially redirects packets to the device itself. XDP_REDIRECT has bulk transmit mechanism to avoid the heavy cost of indirect call but it also reduces lock acquisition on the destination device that needs locks like veth and tun. XDP_TX does not use indirect calls but drivers which require locks can benefit from the bulk transmit for XDP_TX as well. This patch introduces bulk transmit mechanism in veth using bulk queue on stack, and improves XDP_TX performance by about 9%. Here are single-core/single-flow XDP_TX test results. CPU consumptions are taken from "perf report --no-child". - Before: 7.26 Mpps _raw_spin_lock 7.83% veth_xdp_xmit 12.23% - After: 7.94 Mpps _raw_spin_lock 1.08% veth_xdp_xmit 6.10% v2: - Use stack for bulk queue instead of a global variable. Signed-off-by: Toshiaki Makita Acked-by: Jesper Dangaard Brouer Signed-off-by: Daniel Borkmann

veth: use xdp_release_frame for XDP_PASS

2019-06-19T15:23:13+00:00

Like cpumap use xdp_release_frame() when an xdp_frame got converted into an SKB and send towars the network stack. Signed-off-by: Jesper Dangaard Brouer Signed-off-by: David S. Miller

treewide: Add SPDX license identifier for more missed files

2019-05-21T08:50:45+00:00

Add SPDX license identifiers to all files which: - Have no license information of any form - Have MODULE_LICENCE("GPL*") inside which was used in the initial scan/conversion to ignore the file These files fall under the project license, GPL v2 only. The resulting SPDX license identifier is: GPL-2.0-only Signed-off-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman

net: veth: use generic helper to report timestamping info

2019-04-12T23:26:37+00:00

For reporting the common set of SW timestamping capabilities, use ethtool_op_get_ts_info() instead of re-implementing it. Signed-off-by: Julian Wiedmann Signed-off-by: David S. Miller

veth: Fix -Wformat-truncation

2019-02-23T21:44:58+00:00

Provide a precision hint to snprintf() in order to eliminate a -Wformat-truncation warning provided below. A maximum of 11 characters is allowed to reach a maximum of 32 - 1 characters given a possible maximum value of queues using up to UINT_MAX which occupies 10 characters. Incidentally 11 is the number of characters for "xdp_packets" which is the largest string we append. drivers/net/veth.c: In function 'veth_get_strings': drivers/net/veth.c:118:47: warning: '%s' directive output may be truncated writing up to 31 bytes into a region of size between 12 and 21 [-Wformat-truncation=] snprintf(p, ETH_GSTRING_LEN, "rx_queue_%u_%s", ^~ drivers/net/veth.c:118:5: note: 'snprintf' output between 12 and 52 bytes into a destination of size 32 snprintf(p, ETH_GSTRING_LEN, "rx_queue_%u_%s", ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ i, veth_rq_stats_desc[j].desc); ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Signed-off-by: Florian Fainelli Signed-off-by: David S. Miller

veth: Mark expected switch fall-throughs

2019-02-08T19:51:52+00:00

In preparation to enabling -Wimplicit-fallthrough, mark switch cases where we are expecting to fall through. Warning level 3 was used: -Wimplicit-fallthrough=3 This patch is part of the ongoing efforts to enabling -Wimplicit-fallthrough. Signed-off-by: Gustavo A. R. Silva Signed-off-by: David S. Miller