Date: Mon, 20 Apr 2026 10:26:56 +0200 From: Roger Pau =?utf-8?B?TW9ubsOp?= <royger@freebsd.org> To: Andrew Gallatin <gallatin@freebsd.org> Cc: src-committers@freebsd.org, dev-commits-src-all@freebsd.org, dev-commits-src-main@freebsd.org Subject: Re: git: 3fade68cfdf9 - main - iflib: accurately count bytes/segments for TSO Message-ID: <aeXjUNlDR029ijWB@macbook.local> In-Reply-To: <69e26f4a.346e1.31c510c2@gitrepo.freebsd.org>
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On Fri, Apr 17, 2026 at 05:35:06PM +0000, Andrew Gallatin wrote: > The branch main has been updated by gallatin: > > URL: https://cgit.FreeBSD.org/src/commit/?id=3fade68cfdf95ee0b517b5d69b270bd8da633404 > > commit 3fade68cfdf95ee0b517b5d69b270bd8da633404 > Author: Andrew Gallatin <gallatin@FreeBSD.org> > AuthorDate: 2026-04-17 15:45:22 +0000 > Commit: Andrew Gallatin <gallatin@FreeBSD.org> > CommitDate: 2026-04-17 17:34:27 +0000 > > iflib: accurately count bytes/segments for TSO > > When using software based ifnet counters, iflib has not factored > TSO into account when reporting the segments and bytes sent. > So it will underreport NIC bandwidth by a small percent, > and will undercount sent segments by a large factor. > Fix this by calculating the number of added segments the NIC > will send, and add header size multiplied by that number > to arrive at a correct accounting of segments and bytes sent. > This makes these software counters directly comparable to > hardware counters. > > Doing this requires moving the calculation into iflib_encap() where > we have already parsed the packet and know the header size, MSS, etc. Hello, This causes a reliable crash on my box when I attempt to ssh into it: panic: Assertion mp != NULL && *mp != NULL failed at /usr/src/sys/net/iflib.c:3922 cpuid = 11 time = 1776673321 KDB: stack backtrace: db_trace_self_wrapper() at db_trace_self_wrapper+0x2b/frame 0xfffffe0115bbf3e0 vpanic() at vpanic+0x136/frame 0xfffffe0115bbf510 panic() at panic+0x43/frame 0xfffffe0115bbf570 iflib_txq_drain() at iflib_txq_drain+0x429/frame 0xfffffe0115bbf5f0 drain_ring_lockless() at drain_ring_lockless+0x8a/frame 0xfffffe0115bbf640 ifmp_ring_enqueue() at ifmp_ring_enqueue+0x332/frame 0xfffffe0115bbf690 iflib_if_transmit() at iflib_if_transmit+0x273/frame 0xfffffe0115bbf710 bridge_enqueue() at bridge_enqueue+0x214/frame 0xfffffe0115bbf760 bridge_output() at bridge_output+0x10a/frame 0xfffffe0115bbf7b0 ether_output() at ether_output+0x689/frame 0xfffffe0115bbf840 ip_output() at ip_output+0x183d/frame 0xfffffe0115bbf960 tcp_default_output() at tcp_default_output+0x21d8/frame 0xfffffe0115bbfb30 tcp_usr_send() at tcp_usr_send+0x5d0/frame 0xfffffe0115bbfbe0 sosend_generic_locked() at sosend_generic_locked+0x59b/frame 0xfffffe0115bbfc90 sosend_generic() at sosend_generic+0x61/frame 0xfffffe0115bbfce0 sousrsend() at sousrsend+0x79/frame 0xfffffe0115bbfd40 dofilewrite() at dofilewrite+0x81/frame 0xfffffe0115bbfd90 sys_write() at sys_write+0x127/frame 0xfffffe0115bbfe00 amd64_syscall() at amd64_syscall+0x169/frame 0xfffffe0115bbff30 fast_syscall_common() at fast_syscall_common+0xf8/frame 0xfffffe0115bbff30 --- syscall (4, FreeBSD ELF64, write), rip = 0x297fd795023a, rsp = 0x297fccb77d98, rbp = 0x297fccb77dc0 --- KDB: enter: panic [ thread pid 3093 tid 100634 ] Stopped at kdb_enter+0x33: movq $0,0x15dd302(%rip) db> My network config is: ifconfig_igc0="DHCP" cloned_interfaces="bridge0" ifconfig_bridge0="addm igc0" Thanks, Roger.home | help
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