Re: Soft lockup in rt2x00usb_work_rxdone()

From: Richard Genoud
Date: Tue Nov 07 2017 - 06:14:08 EST


Le mardi 07 novembre 2017 Ã 11:13 +0100, Stanislaw Gruszka a ÃcritÂ:
> On Tue, Nov 07, 2017 at 11:06:39AM +0100, Richard Genoud wrote:
> > > 3 short articles how to configure and use ftrace are here:
> > > https://lwn.net/Articles/365835/
> > > https://lwn.net/Articles/366796/
> > > https://lwn.net/Articles/370423/
> > >
> >
> > I tried with ftrace, but I don't think there's a way to dump the
> > trace
> > when there's a soft lock-up
> > (I can't do anything after the unbind, even the heartbeat led
> > stopped blinking).
> > I saw the /proc/sys/kernel/ftrace_dump_on_oops file, but there's no
> > /proc/sys/kernel/ftrace_dump_on_soft_lock-up file :)
>
> You should configure function trace with rt2x* functions. After that
> start tracing, unbind the device, then stop tracing and provide trace
> output.
Here is another trace, with rt2* as function filter.
(sorry for the noise)

Dumping ftrace buffer:
---------------------------------
CPU:0 [LOST 3606923 EVENTS]
Â0)ÂÂÂ0.000 usÂÂÂÂ|ÂÂÂÂÂÂ} /* rt2x00usb_clear_entry */
Â0)ÂÂÂ0.000 usÂÂÂÂ|ÂÂÂÂ} /* rt2x00lib_rxdone */
Â0)ÂÂÂ0.000 usÂÂÂÂ|ÂÂÂÂrt2x00queue_get_entry();
Â0)ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ|ÂÂÂÂrt2x00lib_rxdone() {
Â0)ÂÂÂ0.000 usÂÂÂÂ|ÂÂÂÂÂÂrt2x00queue_index_inc();
Â0)ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ|ÂÂÂÂÂÂrt2x00usb_clear_entry() {
Â0)ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ|ÂÂÂÂÂÂÂÂrt2x00usb_kick_rx_entry() {
Â0)ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ|ÂÂÂÂÂÂÂÂÂÂrt2x00lib_dmastart() {
Â0)ÂÂÂ0.000 usÂÂÂÂ|ÂÂÂÂÂÂÂÂÂÂÂÂrt2x00queue_index_inc();
Â0)ÂÂÂ0.000 usÂÂÂÂ|ÂÂÂÂÂÂÂÂÂÂ}
Â0)ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ|ÂÂÂÂÂÂÂÂÂÂrt2x00lib_dmadone() {
Â0)ÂÂÂ0.000 usÂÂÂÂ|ÂÂÂÂÂÂÂÂÂÂÂÂrt2x00queue_index_inc();
Â0)ÂÂÂ0.000 usÂÂÂÂ|ÂÂÂÂÂÂÂÂÂÂ}
Â0)ÂÂÂ0.000 usÂÂÂÂ|ÂÂÂÂÂÂÂÂ}
Â0)ÂÂÂ0.000 usÂÂÂÂ|ÂÂÂÂÂÂ}
Â0)ÂÂÂ0.000 usÂÂÂÂ|ÂÂÂÂ}
Â0)ÂÂÂ0.000 usÂÂÂÂ|ÂÂÂÂrt2x00queue_get_entry();
Â0)ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ|ÂÂÂÂrt2x00lib_rxdone() {
Â0)ÂÂÂ0.000 usÂÂÂÂ|ÂÂÂÂÂÂrt2x00queue_index_inc();
Â0)ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ|ÂÂÂÂÂÂrt2x00usb_clear_entry() {
Â0)ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ|ÂÂÂÂÂÂÂÂrt2x00usb_kick_rx_entry() {
Â0)ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ|ÂÂÂÂÂÂÂÂÂÂrt2x00lib_dmastart() {
Â0)ÂÂÂ0.000 usÂÂÂÂ|ÂÂÂÂÂÂÂÂÂÂÂÂrt2x00queue_index_inc();
Â0)ÂÂÂ0.000 usÂÂÂÂ|ÂÂÂÂÂÂÂÂÂÂ}
Â0)ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ|ÂÂÂÂÂÂÂÂÂÂrt2x00lib_dmadone() {
Â0)ÂÂÂ0.000 usÂÂÂÂ|ÂÂÂÂÂÂÂÂÂÂÂÂrt2x00queue_index_inc();
Â0)ÂÂÂ0.000 usÂÂÂÂ|ÂÂÂÂÂÂÂÂÂÂ}
Â0)ÂÂÂ0.000 usÂÂÂÂ|ÂÂÂÂÂÂÂÂ}
Â0)ÂÂÂ0.000 usÂÂÂÂ|ÂÂÂÂÂÂ}
Â0)ÂÂÂ0.000 usÂÂÂÂ|ÂÂÂÂ}
Â0)ÂÂÂ0.000 usÂÂÂÂ|ÂÂÂÂrt2x00queue_get_entry();
Â0)ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ|ÂÂÂÂrt2x00lib_rxdone() {
Â0)ÂÂÂ0.000 usÂÂÂÂ|ÂÂÂÂÂÂrt2x00queue_index_inc();
Â0)ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ|ÂÂÂÂÂÂrt2x00usb_clear_entry() {
Â0)ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ|ÂÂÂÂÂÂÂÂrt2x00usb_kick_rx_entry() {
Â0)ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ|ÂÂÂÂÂÂÂÂÂÂrt2x00lib_dmastart() {
Â0)ÂÂÂ0.000 usÂÂÂÂ|ÂÂÂÂÂÂÂÂÂÂÂÂrt2x00queue_index_inc();
Â0)ÂÂÂ0.000 usÂÂÂÂ|ÂÂÂÂÂÂÂÂÂÂ}
Â0)ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ|ÂÂÂÂÂÂÂÂÂÂrt2x00lib_dmadone() {
Â0)ÂÂÂ0.000 usÂÂÂÂ|ÂÂÂÂÂÂÂÂÂÂÂÂrt2x00queue_index_inc();
Â0)ÂÂÂ0.000 usÂÂÂÂ|ÂÂÂÂÂÂÂÂÂÂ}
Â0)ÂÂÂ0.000 usÂÂÂÂ|ÂÂÂÂÂÂÂÂ}
Â0)ÂÂÂ0.000 usÂÂÂÂ|ÂÂÂÂÂÂ}
Â0)ÂÂÂ0.000 usÂÂÂÂ|ÂÂÂÂ}

>
> Thanks
> Stanislaw