Re: b44: regression in 2.6.22 (resend)

Stephen Hemminger
2007-06-04T16:22:47Z

On Mon, 04 Jun 2007 08:39:48 +0200
Thomas Gleixner <tglx@linutronix.de> wrote:

> On Sun, 2007-06-03 at 18:26 +0200, Maximilian Engelhardt wrote:
> > > Is there any other strange behavior of the high res enabled kernel than
> > > the b44 problem ?
> >
> > I didn't notice anything in the past (as I wrote). But today I did some tests
> > for an updated version of the p54 mac80211 wlan driver and I noticed exactly
> > the same problem:
> >
> > when booting with highres=off everything is fine.
> > But when I boot an highres enabled kernel and I do the iperf-test with the p54
> > driver, my systems becomes unresponsive during the test. It seems to be
> > exactly the same problem I have with the b44 driver.
> > So this might not be a bug in the b44 code but a bug somewhere in the linux
> > networking code.
> >
> > I did the test with an 2.6.22-rc3-git4 kernel and the p54 driver built
> > external as module.
>
> Can you look at iperf to figure out, whether it does some weird timer
> stuff (high frequency interval timer or such) ? Either check the code or
> strace it.
>
> tglx
>
>

It is the receiver doing a tight loop doing gettimeofday/recv calls.

sendto(-1227715616, 0xc, 3085438964, 0, {...}, 3067249832) = 0
gettimeofday({1180973726, 981615}, NULL) = 0
gettimeofday({1180973726, 981751}, NULL) = 0
futex(0x8055c64, 0x5 /* FUTEX_??? */, 1) = 1
futex(0x8055c90, FUTEX_WAKE, 1) = 0
recv(4, "\0\0\0\0\0\0\0\1\0\0\23\211\0\0\0\0\0\0\0\0\377\377\364"..., 8192, 0) = 8192
gettimeofday({1180973726, 982754}, NULL) = 0
recv(4, "\0\0\0\0\0\0\0\1\0\0\23\211\0\0\0\0\0\0\0\0\377\377\364"..., 8192, 0) = 8192
gettimeofday({1180973726, 983790}, NULL) = 0
recv(4, "\0\0\0\0\0\0\0\1\0\0\23\211\0\0\0\0\0\0\0\0\377\377\364"..., 8192, 0) = 8192
gettimeofday({1180973726, 984355}, NULL) = 0
recv(4, "\0\0\0\0\0\0\0\1\0\0\23\211\0\0\0\0\0\0\0\0\377\377\364"..., 8192, 0) = 8192
gettimeofday({1180973726, 984706}, NULL) = 0
recv(4, "\0\0\0\0\0\0\0\1\0\0\23\211\0\0\0\0\0\0\0\0\377\377\364"..., 8192, 0) = 8192
gettimeofday({1180973726, 985111}, NULL) = 0
recv(4, "\0\0\0\0\0\0\0\1\0\0\23\211\0\0\0\0\0\0\0\0\377\377\364"..., 8192, 0) = 8192
gettimeofday({1180973726, 985499}, NULL) = 0
recv(4, "\0\0\0\0\0\0\0\1\0\0\23\211\0\0\0\0\0\0\0\0\377\377\364"..., 8192, 0) = 8192
gettimeofday({1180973726, 986088}, NULL) = 0
recv(4, "\0\0\0\0\0\0\0\1\0\0\23\211\0\0\0\0\0\0\0\0\377\377\364"..., 8192, 0) = 8192
gettimeofday({1180973726, 986436}, NULL) = 0
recv(4, "\0\0\0\0\0\0\0\1\0\0\23\211\0\0\0\0\0\0\0\0\377\377\364"..., 8192, 0) = 8192
gettimeofday({1180973726, 986916}, NULL) = 0
recv(4, "\0\0\0\0\0\0\0\1\0\0\23\211\0\0\0\0\0\0\0\0\377\377\364"..., 8192, 0) = 8192
gettimeofday({1180973726, 987397}, NULL) = 0
recv(4, "\0\0\0\0\0\0\0\1\0\0\23\211\0\0\0\0\0\0\0\0\377\377\364"..., 8192, 0) = 8192
gettimeofday({1180973726, 987872}, NULL) = 0
recv(4, "\0\0\0\0\0\0\0\1\0\0\23\211\0\0\0\0\0\0\0\0\377\377\364"..., 8192, 0) = 8192
gettimeofday({1180973726, 988440}, NULL) = 0
recv(4, "\0\0\0\0\0\0\0\1\0\0\23\211\0\0\0\0\0\0\0\0\377\377\364"..., 8192, 0) = 8192
gettimeofday({1180973726, 988823}, NULL) = 0
recv(4, "\0\0\0\0\0\0\0\1\0\0\23\211\0\0\0\0\0\0\0\0\377\377\364"..., 8192, 0) = 8192
gettimeofday({1180973726, 989314}, NULL) = 0
recv(4, "\0\0\0\0\0\0\0\1\0\0\23\211\0\0\0\0\0\0\0\0\377\377\364"..., 8192, 0) = 8192
gettimeofday({1180973726, 990029}, NULL) = 0
recv(4, "\0\0\0\0\0\0\0\1\0\0\23\211\0\0\0\0\0\0\0\0\377\377\364"..., 8192, 0) = 8192
gettimeofday({1180973726, 990890}, NULL) = 0
recv(4, "\0\0\0\0\0\0\0\1\0\0\23\211\0\0\0\0\0\0\0\0\377\377\364"..., 8192, 0) = 8192
gettimeofday({1180973726, 991803}, NULL) = 0
recv(4, "\0\0\0\0\0\0\0\1\0\0\23\211\0\0\0\0\0\0\0\0\377\377\364"..., 8192, 0) = 8192
gettimeofday({1180973726, 992616}, NULL) = 0
recv(4, "\0\0\0\0\0\0\0\1\0\0\23\211\0\0\0\0\0\0\0\0\377\377\364"..., 8192, 0) = 8192
gettimeofday({1180973726, 993105}, NULL) = 0
recv(4, "\0\0\0\0\0\0\0\1\0\0\23\211\0\0\0\0\0\0\0\0\377\377\364"..., 8192, 0) = 8192
gettimeofday({1180973726, 993585}, NULL) = 0
recv(4, "\0\0\0\0\0\0\0\1\0\0\23\211\0\0\0\0\0\0\0\0\377\377\364"..., 8192, 0) = 8192
gettimeofday({1180973726, 994014}, NULL) = 0
...

recv(4, "45678901234567890123456789012345"..., 8192, 0) = 1448
gettimeofday({1180973757, 172437}, NULL) = 0
recv(4, "23456789012345678901234567890123"..., 8192, 0) = 1448
gettimeofday({1180973757, 172576}, NULL) = 0
recv(4, "01234567890123456789012345678901"..., 8192, 0) = 1632
gettimeofday({1180973757, 172752}, NULL) = 0
recv(4, "", 8192, 0) = 0
gettimeofday({1180973757, 172797}, NULL) = 0
gettimeofday({1180973757, 172817}, NULL) = 0
nanosleep({0, 0}, NULL) = 0
nanosleep({0, 0}, NULL) = 0
close(4) = 0
futex(0x8055d04, 0x5 /* FUTEX_??? */, 1) = 1
futex(0x8055d30, FUTEX_WAKE, 1) = 0
_exit(0)

--
Stephen Hemminger <shemminger@linux-foundation.org>