Re: n_tty_write() going into schedule but NOT coming out

2013-04-06 Thread Vineet Gupta
On 04/06/2013 01:22 AM, Peter Hurley wrote: > I'll see if I can reproduce this over the weekend on an old single-core > laptop I > still have. TIA for doing this. > There were some race conditions in the N_TTY line discipline which I > recently fixed. Those changes are in linux-next. Can you

Re: n_tty_write() going into schedule but NOT coming out

2013-04-06 Thread Vineet Gupta
On 04/06/2013 01:22 AM, Peter Hurley wrote: I'll see if I can reproduce this over the weekend on an old single-core laptop I still have. TIA for doing this. There were some race conditions in the N_TTY line discipline which I recently fixed. Those changes are in linux-next. Can you test if

Re: n_tty_write() going into schedule but NOT coming out

2013-04-05 Thread Peter Hurley
[ --cc Ingo and Peter Z. as this is not scheduler-related] On Tue, 2013-04-02 at 18:56 +0530, Vineet Gupta wrote: > On 04/01/2013 08:40 PM, Peter Hurley wrote: > > On Mon, 2013-04-01 at 19:27 +0530, Vineet Gupta wrote: > >> Hi, > >> > >> Any thoughts: I observe the same issue even with

Re: n_tty_write() going into schedule but NOT coming out

2013-04-05 Thread Peter Hurley
[ --cc Ingo and Peter Z. as this is not scheduler-related] On Tue, 2013-04-02 at 18:56 +0530, Vineet Gupta wrote: On 04/01/2013 08:40 PM, Peter Hurley wrote: On Mon, 2013-04-01 at 19:27 +0530, Vineet Gupta wrote: Hi, Any thoughts: I observe the same issue even with CONFIG_PREEMPT and

Re: n_tty_write() going into schedule but NOT coming out

2013-04-03 Thread Vineet Gupta
Hi Ilya On 04/03/2013 11:14 AM, Ilya Zykov wrote: > Please, try this patch maybe it can help localize your problem. > > drivers/tty/n_tty.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c > index 05e72be..28f15d0 100644 > ---

Re: n_tty_write() going into schedule but NOT coming out

2013-04-03 Thread Vineet Gupta
Hi Ilya On 04/03/2013 11:14 AM, Ilya Zykov wrote: Please, try this patch maybe it can help localize your problem. drivers/tty/n_tty.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c index 05e72be..28f15d0 100644 --- a/drivers/tty/n_tty.c +++

Re: n_tty_write() going into schedule but NOT coming out

2013-04-02 Thread Ilya Zykov
Please, try this patch maybe it can help localize your problem. drivers/tty/n_tty.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c index 05e72be..28f15d0 100644 --- a/drivers/tty/n_tty.c +++ b/drivers/tty/n_tty.c @@ -230,6 +230,7 @@ static void

Re: n_tty_write() going into schedule but NOT coming out

2013-04-02 Thread Peter Hurley
On Tue, 2013-04-02 at 18:56 +0530, Vineet Gupta wrote: > On 04/01/2013 08:40 PM, Peter Hurley wrote: > > On Mon, 2013-04-01 at 19:27 +0530, Vineet Gupta wrote: > >> On 03/30/2013 06:05 PM, Vineet Gupta wrote: > >>> Hung find task is sitting in the schedule() call in n_tty_write() > >>> > >>>

Re: n_tty_write() going into schedule but NOT coming out

2013-04-02 Thread Vineet Gupta
On 04/01/2013 08:40 PM, Peter Hurley wrote: > On Mon, 2013-04-01 at 19:27 +0530, Vineet Gupta wrote: >> Hi, >> >> Any thoughts: I observe the same issue even with CONFIG_PREEMPT and >> CONFIG_PREEMPT_COUNT >> >> -Vineet >> >> On 03/30/2013 06:05 PM, Vineet Gupta wrote: >>> Hi, >>> >>> I've been

Re: n_tty_write() going into schedule but NOT coming out

2013-04-02 Thread Vineet Gupta
Hi Peter, On 04/01/2013 08:40 PM, Peter Hurley wrote: > On Mon, 2013-04-01 at 19:27 +0530, Vineet Gupta wrote: >> Hi, >> >> Any thoughts: I observe the same issue even with CONFIG_PREEMPT and >> CONFIG_PREEMPT_COUNT >> >> -Vineet >> >> On 03/30/2013 06:05 PM, Vineet Gupta wrote: >>> Hi, >>> >>>

Re: n_tty_write() going into schedule but NOT coming out

2013-04-02 Thread Vineet Gupta
Hi Peter, On 04/01/2013 08:40 PM, Peter Hurley wrote: On Mon, 2013-04-01 at 19:27 +0530, Vineet Gupta wrote: Hi, Any thoughts: I observe the same issue even with CONFIG_PREEMPT and CONFIG_PREEMPT_COUNT -Vineet On 03/30/2013 06:05 PM, Vineet Gupta wrote: Hi, I've been stress testing

Re: n_tty_write() going into schedule but NOT coming out

2013-04-02 Thread Vineet Gupta
On 04/01/2013 08:40 PM, Peter Hurley wrote: On Mon, 2013-04-01 at 19:27 +0530, Vineet Gupta wrote: Hi, Any thoughts: I observe the same issue even with CONFIG_PREEMPT and CONFIG_PREEMPT_COUNT -Vineet On 03/30/2013 06:05 PM, Vineet Gupta wrote: Hi, I've been stress testing ARC Linux 3.8

Re: n_tty_write() going into schedule but NOT coming out

2013-04-02 Thread Peter Hurley
On Tue, 2013-04-02 at 18:56 +0530, Vineet Gupta wrote: On 04/01/2013 08:40 PM, Peter Hurley wrote: On Mon, 2013-04-01 at 19:27 +0530, Vineet Gupta wrote: On 03/30/2013 06:05 PM, Vineet Gupta wrote: Hung find task is sitting in the schedule() call in n_tty_write() [ARCLinux]$ cat

Re: n_tty_write() going into schedule but NOT coming out

2013-04-02 Thread Ilya Zykov
Please, try this patch maybe it can help localize your problem. drivers/tty/n_tty.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c index 05e72be..28f15d0 100644 --- a/drivers/tty/n_tty.c +++ b/drivers/tty/n_tty.c @@ -230,6 +230,7 @@ static void

Re: n_tty_write() going into schedule but NOT coming out

2013-04-01 Thread Peter Hurley
On Mon, 2013-04-01 at 19:27 +0530, Vineet Gupta wrote: > Hi, > > Any thoughts: I observe the same issue even with CONFIG_PREEMPT and > CONFIG_PREEMPT_COUNT > > -Vineet > > On 03/30/2013 06:05 PM, Vineet Gupta wrote: > > Hi, > > > > I've been stress testing ARC Linux 3.8 (same happens for

Re: n_tty_write() going into schedule but NOT coming out

2013-04-01 Thread Vineet Gupta
Hi, Any thoughts: I observe the same issue even with CONFIG_PREEMPT and CONFIG_PREEMPT_COUNT -Vineet On 03/30/2013 06:05 PM, Vineet Gupta wrote: > Hi, > > I've been stress testing ARC Linux 3.8 (same happens for 3.9-rc3 as well). The > setup has 3 telnet sessions, each running find . -name "*"

Re: n_tty_write() going into schedule but NOT coming out

2013-04-01 Thread Vineet Gupta
Hi, Any thoughts: I observe the same issue even with CONFIG_PREEMPT and CONFIG_PREEMPT_COUNT -Vineet On 03/30/2013 06:05 PM, Vineet Gupta wrote: Hi, I've been stress testing ARC Linux 3.8 (same happens for 3.9-rc3 as well). The setup has 3 telnet sessions, each running find . -name * in a

Re: n_tty_write() going into schedule but NOT coming out

2013-04-01 Thread Peter Hurley
On Mon, 2013-04-01 at 19:27 +0530, Vineet Gupta wrote: Hi, Any thoughts: I observe the same issue even with CONFIG_PREEMPT and CONFIG_PREEMPT_COUNT -Vineet On 03/30/2013 06:05 PM, Vineet Gupta wrote: Hi, I've been stress testing ARC Linux 3.8 (same happens for 3.9-rc3 as well).

n_tty_write() going into schedule but NOT coming out

2013-03-30 Thread Vineet Gupta
Hi, I've been stress testing ARC Linux 3.8 (same happens for 3.9-rc3 as well). The setup has 3 telnet sessions, each running find . -name "*" in a loop. The platform is a FPGA @ 80 MHz, running a single core ARC700 so kernel .config has !SMP and PREEMPT_NONE. After ~10 mins of run, I see that

n_tty_write() going into schedule but NOT coming out

2013-03-30 Thread Vineet Gupta
Hi, I've been stress testing ARC Linux 3.8 (same happens for 3.9-rc3 as well). The setup has 3 telnet sessions, each running find . -name * in a loop. The platform is a FPGA @ 80 MHz, running a single core ARC700 so kernel .config has !SMP and PREEMPT_NONE. After ~10 mins of run, I see that one