Date: Sat, 6 May 2006 14:55:30 -0400 From: =?ISO-8859-1?Q?Lodewijk_V=F6ge?= <lvoege@gmail.com> To: freebsd-stable@freebsd.org Subject: dhclient taking up all CPU Message-ID: <82912730-AD0E-4AE0-AA7C-FDD321F00B57@gmail.com>
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hello,
a while ago someone reported the same problem I had been seeing, that =20=
dhclient starts taking up 100% CPU. it's probably something comcast =20
is doing.
I couldn't get the requested coredump then, if I set kern.corefile =20
to /tmp/%N.core and kill -QUIT it, it doesn't seem to produce a =20
coredump. but it happened again just now, and I was able to attach =20
gdb. this is where it's spinning, in receive_packet() in bpf.c:
(gdb)
285 if (interface->rbuf_offset =3D=3D interface-=20
>rbuf_len) {
(gdb)
299 if (interface->rbuf_len - interface-=20
>rbuf_offset <
(gdb)
306 memcpy(&hdr, &interface->rbuf[interface-=20
>rbuf_offset],
(gdb)
313 if (interface->rbuf_offset + hdr.bh_hdrlen + =20
hdr.bh_caplen >
(gdb)
320 interface->rbuf_offset +=3D hdr.bh_hdrlen;
(gdb)
327 if (hdr.bh_caplen !=3D hdr.bh_datalen) {
(gdb)
328 interface->rbuf_offset =3D
(gdb)
331 continue;
(gdb)
385 } while (!length);
and then it goes back to line 285. interesting variables are:
(gdb) p *interface
$1 =3D {next =3D 0x0, hw_address =3D {htype =3D 1 '\001', hlen =3D 6 =
'\006',
haddr =3D "\000\021=D8=A0\223?\000\000\000\000\000\000\000\000\000"},=
=20
primary_address =3D {s_addr =3D 0},
name =3D "vr0", '\0' <repeats 12 times>, rfdesc =3D 7, wfdesc =3D 7, =20=
rbuf =3D 0x807d000 "\022?\\Dk\214", rbuf_max =3D 4096,
rbuf_offset =3D 416, rbuf_len =3D 415, ifp =3D 0x806f160, client =3D =20=
0x8075000, noifmedia =3D 0, errors =3D 0, dead =3D 0, index =3D 2}
(gdb) p length
$2 =3D 0
(gdb) p hdr
$3 =3D {bh_tstamp =3D {tv_sec =3D 0, tv_usec =3D 0}, bh_caplen =3D =
4294901760, =20
bh_datalen =3D 4294901778, bh_hdrlen =3D 65535}
this is FreeBSD/i386 6.1-RC as of about two weeks ago.
Lodewijk
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