user/sven/linux.git/drivers/net/loopback.c, branch v6.0-rc2

net: loopback: enable BIG TCP packets

2022-05-16T09:18:56Z

Set the driver limit to GSO_MAX_SIZE (512 KB). This allows the admin/user to set a GSO limit up to this value. Tested: ip link set dev lo gso_max_size 200000 netperf -H ::1 -t TCP_RR -l 100 -- -r 80000,80000 & tcpdump shows : 18:28:42.962116 IP6 ::1 > ::1: HBH 40051 > 63780: Flags [P.], seq 3626480001:3626560001, ack 3626560001, win 17743, options [nop,nop,TS val 3771179265 ecr 3771179265], length 80000 18:28:42.962138 IP6 ::1.63780 > ::1.40051: Flags [.], ack 3626560001, win 17743, options [nop,nop,TS val 3771179265 ecr 3771179265], length 0 18:28:42.962152 IP6 ::1 > ::1: HBH 63780 > 40051: Flags [P.], seq 3626560001:3626640001, ack 3626560001, win 17743, options [nop,nop,TS val 3771179265 ecr 3771179265], length 80000 18:28:42.962157 IP6 ::1.40051 > ::1.63780: Flags [.], ack 3626640001, win 17743, options [nop,nop,TS val 3771179265 ecr 3771179265], length 0 18:28:42.962180 IP6 ::1 > ::1: HBH 40051 > 63780: Flags [P.], seq 3626560001:3626640001, ack 3626640001, win 17743, options [nop,nop,TS val 3771179265 ecr 3771179265], length 80000 18:28:42.962214 IP6 ::1.63780 > ::1.40051: Flags [.], ack 3626640001, win 17743, options [nop,nop,TS val 3771179266 ecr 3771179265], length 0 18:28:42.962228 IP6 ::1 > ::1: HBH 63780 > 40051: Flags [P.], seq 3626640001:3626720001, ack 3626640001, win 17743, options [nop,nop,TS val 3771179266 ecr 3771179265], length 80000 18:28:42.962233 IP6 ::1.40051 > ::1.63780: Flags [.], ack 3626720001, win 17743, options [nop,nop,TS val 3771179266 ecr 3771179266], length 0 Signed-off-by: Eric Dumazet Acked-by: Alexander Duyck Signed-off-by: David S. Miller

net: Add skb_clear_tstamp() to keep the mono delivery_time

2022-03-03T14:38:48Z

Right now, skb->tstamp is reset to 0 whenever the skb is forwarded. If skb->tstamp has the mono delivery_time, clearing it can hurt the performance when it finally transmits out to fq@phy-dev. The earlier patch added a skb->mono_delivery_time bit to flag the skb->tstamp carrying the mono delivery_time. This patch adds skb_clear_tstamp() helper which keeps the mono delivery_time and clears everything else. The delivery_time clearing will be postponed until the stack knows the skb will be delivered locally. It will be done in a latter patch. Signed-off-by: Martin KaFai Lau Signed-off-by: David S. Miller

net: dev: Makes sure netif_rx() can be invoked in any context.

2022-02-14T13:38:35Z

Dave suggested a while ago (eleven years by now) "Let's make netif_rx() work in all contexts and get rid of netif_rx_ni()". Eric agreed and pointed out that modern devices should use netif_receive_skb() to avoid the overhead. In the meantime someone added another variant, netif_rx_any_context(), which behaves as suggested. netif_rx() must be invoked with disabled bottom halves to ensure that pending softirqs, which were raised within the function, are handled. netif_rx_ni() can be invoked only from process context (bottom halves must be enabled) because the function handles pending softirqs without checking if bottom halves were disabled or not. netif_rx_any_context() invokes on the former functions by checking in_interrupts(). netif_rx() could be taught to handle both cases (disabled and enabled bottom halves) by simply disabling bottom halves while invoking netif_rx_internal(). The local_bh_enable() invocation will then invoke pending softirqs only if the BH-disable counter drops to zero. Eric is concerned about the overhead of BH-disable+enable especially in regard to the loopback driver. As critical as this driver is, it will receive a shortcut to avoid the additional overhead which is not needed. Add a local_bh_disable() section in netif_rx() to ensure softirqs are handled if needed. Provide __netif_rx() which does not disable BH and has a lockdep assert to ensure that interrupts are disabled. Use this shortcut in the loopback driver and in drivers/net/*.c. Make netif_rx_ni() and netif_rx_any_context() invoke netif_rx() so they can be removed once they are no more users left. Link: https://lkml.kernel.org/r/20100415.020246.218622820.davem@davemloft.net Signed-off-by: Sebastian Andrzej Siewior Reviewed-by: Eric Dumazet Reviewed-by: Toke Høiland-Jørgensen Signed-off-by: David S. Miller

net: Don't include filter.h from net/sock.h

2021-12-29T16:48:14Z

sock.h is pretty heavily used (5k objects rebuilt on x86 after it's touched). We can drop the include of filter.h from it and add a forward declaration of struct sk_filter instead. This decreases the number of rebuilt objects when bpf.h is touched from ~5k to ~1k. There's a lot of missing includes this was masking. Primarily in networking tho, this time. Signed-off-by: Jakub Kicinski Signed-off-by: Alexei Starovoitov Acked-by: Marc Kleine-Budde Acked-by: Florian Fainelli Acked-by: Nikolay Aleksandrov Acked-by: Stefano Garzarella Link: https://lore.kernel.org/bpf/20211229004913.513372-1-kuba@kernel.org

net: use u64_stats_t in struct pcpu_lstats

2019-11-08T04:03:08Z

In order to fix the data-race found by KCSAN, we can use the new u64_stats_t type and its accessors instead of plain u64 fields. This will still generate optimal code for both 32 and 64 bit platforms. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

net: provide dev_lstats_add() helper

2019-11-08T04:03:08Z

Many network drivers need it and hand-coded the same function. In order to ease u64_stats_t adoption, it is time to factorize. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

net: provide dev_lstats_read() helper

2019-11-08T04:03:08Z

Many network drivers use hand-coded implementation of the same thing, let's factorize things so that u64_stats_t adoption is done once. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

loopback: fix lockdep splat

2019-07-03T18:24:38Z

dev_init_scheduler() and dev_activate() expect the caller to hold RTNL. Since we don't want blackhole device to be initialized per ns, we are initializing at init. [ 3.855027] Call Trace: [ 3.855034] dump_stack+0x67/0x95 [ 3.855037] lockdep_rcu_suspicious+0xd5/0x110 [ 3.855044] dev_init_scheduler+0xe3/0x120 [ 3.855048] ? net_olddevs_init+0x60/0x60 [ 3.855050] blackhole_netdev_init+0x45/0x6e [ 3.855052] do_one_initcall+0x6c/0x2fa [ 3.855058] ? rcu_read_lock_sched_held+0x8c/0xa0 [ 3.855066] kernel_init_freeable+0x1e5/0x288 [ 3.855071] ? rest_init+0x260/0x260 [ 3.855074] kernel_init+0xf/0x180 [ 3.855076] ? rest_init+0x260/0x260 [ 3.855078] ret_from_fork+0x24/0x30 Fixes: 4de83b88c66 ("loopback: create blackhole net device similar to loopack.") Reported-by: Geert Uytterhoeven Cc: Eric Dumazet Signed-off-by: Mahesh Bandewar Tested-by: Geert Uytterhoeven Signed-off-by: David S. Miller

loopback: create blackhole net device similar to loopack.

2019-07-02T02:34:46Z

Create a blackhole net device that can be used for "dead" dst entries instead of loopback device. This blackhole device differs from loopback in few aspects: (a) It's not per-ns. (b) MTU on this device is ETH_MIN_MTU (c) The xmit function is essentially kfree_skb(). and (d) since it's not registered it won't have ifindex. Lower MTU effectively make the device not pass the MTU check during the route check when a dst associated with the skb is dead. Signed-off-by: Mahesh Bandewar Signed-off-by: David S. Miller

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152

2019-05-30T18:26:32Z

Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 3029 file(s). Signed-off-by: Thomas Gleixner Reviewed-by: Allison Randal Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de Signed-off-by: Greg Kroah-Hartman