From: Jakub Kicinski <kuba@kernel.org>
To: Eric Dumazet <edumazet@google.com>
Cc: "David S . Miller" <davem@davemloft.net>,
Paolo Abeni <pabeni@redhat.com>, Simon Horman <horms@kernel.org>,
Kuniyuki Iwashima <kuniyu@google.com>,
netdev@vger.kernel.org, eric.dumazet@gmail.com
Subject: Re: [PATCH v4 net-next 0/5] rtnetlink: RTNL avoidance in rtnl_getlink() and rtnl_dump_ifinfo()
Date: Fri, 22 May 2026 14:29:42 -0700 [thread overview]
Message-ID: <20260522142942.36973ef6@kernel.org> (raw)
In-Reply-To: <20260522173002.2181677-1-edumazet@google.com>
On Fri, 22 May 2026 17:29:57 +0000 Eric Dumazet wrote:
> Many shell scripts invoke iproute2 commands specifying a device by
> its name.
>
> This series improves their performance avoiding RTNL acquisition
> for their (repeated) name->index conversion.
>
> v3: insert patch 2/3 in the series (Jakub reported a KASAN splat)
> v4: Addressed Sashiko's feedback.
> added 2 patches for rtnl_dump_ifinfo().
The CI looks fried, various errors:
# 0.02 [+0.02] RTNETLINK answers: File exists
# 0.02 [+0.00] Failed to create netif
# CMD: ip -d -j link show dev eth8
# EXIT: 1
# STDOUT: []
# STDERR: RTNETLINK answers: Message too long
# Cannot send link get request: Message too long
At boot we hit:
[ 0.661578] ------------[ cut here ]------------
[ 0.661608] WARNING: net/core/rtnetlink.c:4296 at rtnl_getlink+0x457/0x5e0, CPU#3: ip/71
[ 0.661656] Modules linked in:
[ 0.661681] CPU: 3 UID: 0 PID: 71 Comm: ip Tainted: G W 7.1.0-rc4-virtme #1 PREEMPT(lazy)
[ 0.661735] Tainted: [W]=WARN
[ 0.661756] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[ 0.661795] RIP: 0010:rtnl_getlink+0x457/0x5e0
[ 0.661831] Code: ff ff 89 c3 48 83 c4 38 e8 76 44 fe ff 85 db 48 8b 7c 24 08 0f 84 2c 01 00 00 48 89 fe ba 02 00 00 00 31 ff e8 4a b7 fb ff 90 <0f> 0b 90 b8 a6 ff ff ff 49 8b 94 24 40 05 00 00 65 ff 0a 80 7c 24
[ 0.661928] RSP: 0018:ff87a370c027b7a8 EFLAGS: 00010296
[ 0.661956] RAX: 0000000000000010 RBX: 00000000ffffffa6 RCX: ff368f1541d3ef00
[ 0.661998] RDX: ff368f157edadda0 RSI: 0000000000000011 RDI: ff368f15411ffa00
[ 0.662041] RBP: ff368f1541e60b00 R08: ff368f1541845810 R09: ffffffff9ec3bbe6
[ 0.662076] R10: ffd7c3a340079800 R11: ff368f15411ffa00 R12: ff368f1541e31000
[ 0.662126] R13: ffffffff9fe4f700 R14: 0000000000000009 R15: ffffffff9fe4f700
[ 0.662176] FS: 00007fa9d67e0600(0000) GS:ff368f15df00c000(0000) knlGS:0000000000000000
[ 0.662219] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 0.662253] CR2: 00007fff3c059c78 CR3: 000000000190f005 CR4: 0000000000771ef0
[ 0.662294] PKRU: 55555554
[ 0.662307] Call Trace:
[ 0.662319] <TASK>
[ 0.662338] ? rtnl_fill_ifinfo.isra.0+0x1670/0x1670
[ 0.662366] rtnetlink_rcv_msg+0x39f/0x460
[ 0.662390] ? rtnl_calcit.isra.0+0x160/0x160
[ 0.662420] netlink_rcv_skb+0xca/0x140
[ 0.662445] netlink_unicast+0x26b/0x3a0
[ 0.662467] netlink_sendmsg+0x1e2/0x430
[ 0.662489] ____sys_sendmsg+0x14c/0x2b0
[ 0.662511] ___sys_sendmsg+0xe1/0x120
[ 0.662539] __sys_sendmsg+0xad/0x100
[ 0.662560] do_syscall_64+0x104/0xfc0
[ 0.662585] entry_SYSCALL_64_after_hwframe+0x4b/0x53
[ 0.662609] RIP: 0033:0x7fa9d6a1808e
[ 0.662631] Code: 4d 89 d8 e8 94 bd 00 00 4c 8b 5d f8 41 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 11 c9 c3 0f 1f 80 00 00 00 00 48 8b 45 10 0f 05 <c9> c3 83 e2 39 83 fa 08 75 e7 e8 03 ff ff ff 0f 1f 00 f3 0f 1e fa
[ 0.662733] RSP: 002b:00007fff3c059b50 EFLAGS: 00000202 ORIG_RAX: 000000000000002e
[ 0.662775] RAX: ffffffffffffffda RBX: 00007fff3c05ce1d RCX: 00007fa9d6a1808e
[ 0.662823] RDX: 0000000000000000 RSI: 00007fff3c059c00 RDI: 0000000000000004
[ 0.662864] RBP: 00007fff3c059b60 R08: 0000000000000000 R09: 0000000000000000
[ 0.662907] R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000
[ 0.662947] R13: 000000006a10c531 R14: 00007fff3c059ca0 R15: 00007fff3c05ce1d
[ 0.662982] </TASK>
[ 0.662998] ---[ end trace 0000000000000000 ]---
[ 0.663079] ------------[ cut here ]------------
[ 0.663110] WARNING: net/core/rtnetlink.c:4523 at rtmsg_ifinfo_build_skb+0xc8/0x110, CPU#3: ip/71
[ 0.663162] Modules linked in:
[ 0.663186] CPU: 3 UID: 0 PID: 71 Comm: ip Tainted: G W 7.1.0-rc4-virtme #1 PREEMPT(lazy)
[ 0.663235] Tainted: [W]=WARN
[ 0.663256] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[ 0.663289] RIP: 0010:rtmsg_ifinfo_build_skb+0xc8/0x110
[ 0.663319] Code: 80 00 00 00 e8 59 d9 ff ff 48 83 c4 38 85 c0 75 18 48 83 c4 08 4c 89 f8 5b 5d 41 5c 41 5d 41 5e 41 5f c3 44 8b 48 08 eb b4 90 <0f> 0b 90 ba 02 00 00 00 4c 89 fe 31 ff e8 36 ab fb ff b9 a6 ff ff
[ 0.663414] RSP: 0018:ff87a370c027b720 EFLAGS: 00010286
[ 0.663439] RAX: 00000000ffffffa6 RBX: 0000000000000001 RCX: 0000000000000000
[ 0.663485] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ff368f1541e60700
[ 0.663527] RBP: 0000000000000000 R08: ff368f1541845810 R09: ff368f154298f02c
[ 0.663569] R10: ff368f1541e31120 R11: fefefefefefefeff R12: 0000000000000000
[ 0.663612] R13: 0000000000000010 R14: ff368f1541e31000 R15: ff368f1541e60700
[ 0.663655] FS: 00007fa9d67e0600(0000) GS:ff368f15df00c000(0000) knlGS:0000000000000000
[ 0.663699] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 0.663730] CR2: 000055ed56288988 CR3: 000000000190f005 CR4: 0000000000771ef0
[ 0.663774] PKRU: 55555554
[ 0.663787] Call Trace:
[ 0.663803] <TASK>
[ 0.663821] rtmsg_ifinfo+0x3c/0xa0
[ 0.663845] __dev_notify_flags+0xb1/0xf0
[ 0.663867] ? rtnl_getlink+0x456/0x5e0
[ 0.663887] netif_change_flags+0x54/0x70
[ 0.663913] do_setlink.isra.0+0x3a2/0x1500
[ 0.663939] ? __nla_validate_parse+0x76/0xf20
[ 0.663970] rtnl_newlink+0x9d3/0xd90
[ 0.663993] ? do_setlink.isra.0+0x1500/0x1500
[ 0.664015] rtnetlink_rcv_msg+0x39f/0x460
[ 0.664035] ? get_page_from_freelist+0x157a/0x16a0
[ 0.664068] ? rtnl_calcit.isra.0+0x160/0x160
[ 0.664091] netlink_rcv_skb+0xca/0x140
[ 0.664118] netlink_unicast+0x26b/0x3a0
[ 0.664140] netlink_sendmsg+0x1e2/0x430
[ 0.664162] ____sys_sendmsg+0x14c/0x2b0
[ 0.664182] ___sys_sendmsg+0xe1/0x120
[ 0.664204] __sys_sendmsg+0xad/0x100
[ 0.664226] do_syscall_64+0x104/0xfc0
[ 0.664248] entry_SYSCALL_64_after_hwframe+0x4b/0x53
[ 0.664275] RIP: 0033:0x7fa9d6a1808e
[ 0.664295] Code: 4d 89 d8 e8 94 bd 00 00 4c 8b 5d f8 41 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 11 c9 c3 0f 1f 80 00 00 00 00 48 8b 45 10 0f 05 <c9> c3 83 e2 39 83 fa 08 75 e7 e8 03 ff ff ff 0f 1f 00 f3 0f 1e fa
[ 0.664397] RSP: 002b:00007fff3c05b1b0 EFLAGS: 00000202 ORIG_RAX: 000000000000002e
[ 0.664437] RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007fa9d6a1808e
[ 0.664478] RDX: 0000000000000000 RSI: 00007fff3c05b260 RDI: 0000000000000003
[ 0.664520] RBP: 00007fff3c05b1c0 R08: 0000000000000000 R09: 0000000000000000
[ 0.664559] R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000003
[ 0.664604] R13: 000000006a10c531 R14: 000055ed1cfb1040 R15: 0000000000000000
[ 0.664645] </TASK>
[ 0.664658] ---[ end trace 0000000000000000 ]---
next prev parent reply other threads:[~2026-05-22 21:29 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-05-22 17:29 [PATCH v4 net-next 0/5] rtnetlink: RTNL avoidance in rtnl_getlink() and rtnl_dump_ifinfo() Eric Dumazet
2026-05-22 17:29 ` [PATCH v4 net-next 1/5] rtnetlink: use nla_nest_end_safe() in rtnl_fill_prop_list() Eric Dumazet
2026-05-22 17:29 ` [PATCH v4 net-next 2/5] net: defer netdev_name_node_alt_flush() call to netdev_run_todo() Eric Dumazet
2026-05-22 17:30 ` [PATCH v4 net-next 3/5] rtnetlink: do not acquire RTNL in rtnl_getlink() with RTEXT_FILTER_NAME_ONLY Eric Dumazet
2026-05-22 17:30 ` [PATCH v4 net-next 4/5] rtnetlink: do not assume RTNL is held in link_master_filtered() Eric Dumazet
2026-05-22 17:30 ` [PATCH v4 net-next 5/5] rtnetlink: add RTEXT_FILTER_NAME_ONLY support to rtnl_dump_ifinfo() Eric Dumazet
2026-05-22 21:29 ` Jakub Kicinski [this message]
2026-05-23 4:48 ` [PATCH v4 net-next 0/5] rtnetlink: RTNL avoidance in rtnl_getlink() and rtnl_dump_ifinfo() Eric Dumazet
2026-05-23 7:00 ` [syzbot ci] " syzbot ci
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