From: Lee Revell <rlrevell@joe-job.com>
To: Florian Schmidt <mista.tapas@gmx.net>
Cc: Ingo Molnar <mingo@elte.hu>,
Paul Davis <paul@linuxaudiosystems.com>,
Thomas Gleixner <tglx@linutronix.de>,
LKML <linux-kernel@vger.kernel.org>,
mark_h_johnson@raytheon.com, Bill Huey <bhuey@lnxw.com>,
Adam Heath <doogie@debian.org>,
Michal Schmidt <xschmi00@stud.feec.vutbr.cz>,
Fernando Pablo Lopez-Lezcano <nando@ccrma.stanford.edu>,
Karsten Wiese <annabellesgarden@yahoo.de>,
jackit-devel <jackit-devel@lists.sourceforge.net>,
Rui Nuno Capela <rncbc@rncbc.org>
Subject: Re: [Fwd: Re: [patch] Real-Time Preemption, -RT-2.6.9-mm1-V0.4]
Date: Fri, 29 Oct 2004 23:36:03 -0400 [thread overview]
Message-ID: <1099107364.1551.7.camel@krustophenia.net> (raw)
In-Reply-To: <20041030003122.03bcf01b@mango.fruits.de>
On Sat, 2004-10-30 at 00:31 +0200, Florian Schmidt wrote:
> On Fri, 29 Oct 2004 23:25:45 +0200
> Ingo Molnar <mingo@elte.hu> wrote:
>
> > > will do so. btw: i think i'm a bit confused right now. What debugging
> > > features should i have enabled for this test?
> >
> > this particular one (atomicity-checking) is always-enabled if you have
> > the -RT patch applied (it's a really cheap check).
> >
> > for the 'application-triggered tracing' facility we talked about earlier
> > is only active if LATENCY_TRACING is enabled. In that case to turn the
> > tracer on, call:
> [snip]
>
> Ok,
>
> .config attached,
>
> running the patched jackd -R -P 60 -d alsa -p64 for a bit and provoking
> xruns via window wiggling :)
>
Ingo, here are some of my traces with the same settings. These do seem
to correspond to the xruns. Many of them look tty related - could the
recent changes to the tty layer be responsible? Possibly this has
nothing to do with RT preempt, but is an unrelated bug in -mm? The
xruns do seem to correspond to display activity such as switching tabs
in gnome-terminal.
jackd:1507 userspace BUG: scheduling in user-atomic context!
[<c01069fc>] dump_stack+0x1c/0x20 (20)
[<c02834d0>] schedule+0x70/0x100 (24)
[<c010639b>] work_resched+0x6/0x17 (-8124)
---------------------------
| preempt count: 00000001 ]
| 1-level deep critical section nesting:
----------------------------------------
.. [<c012e5d3>] .... print_traces+0x13/0x50
.....[<c01069fc>] .. ( <= dump_stack+0x1c/0x20)
jackd:1507 userspace BUG: scheduling in user-atomic context!
[<c01069fc>] dump_stack+0x1c/0x20 (20)
[<c02834d0>] schedule+0x70/0x100 (24)
[<c028465d>] down_write_mutex+0xbd/0x180 (36)
[<c012cbf6>] __mutex_lock+0x36/0x40 (16)
[<c012cc75>] _mutex_lock_irqsave+0x15/0x20 (16)
[<c01f1237>] tty_ldisc_try+0x17/0x50 (20)
[<c01f1287>] tty_ldisc_ref_wait+0x17/0xc0 (88)
[<c01f21fd>] tty_write+0x7d/0x230 (68)
[<c01546ac>] vfs_write+0xbc/0x110 (36)
[<c01547b1>] sys_write+0x41/0x70 (44)
[<c0106367>] syscall_call+0x7/0xb (-8124)
---------------------------
| preempt count: 00000001 ]
| 1-level deep critical section nesting:
----------------------------------------
.. [<c012e5d3>] .... print_traces+0x13/0x50
.....[<c01069fc>] .. ( <= dump_stack+0x1c/0x20)
jackd:1507 userspace BUG: scheduling in user-atomic context!
[<c01069fc>] dump_stack+0x1c/0x20 (20)
[<c02834d0>] schedule+0x70/0x100 (24)
[<c010639b>] work_resched+0x6/0x17 (-8124)
---------------------------
| preempt count: 00000001 ]
| 1-level deep critical section nesting:
----------------------------------------
.. [<c012e5d3>] .... print_traces+0x13/0x50
.....[<c01069fc>] .. ( <= dump_stack+0x1c/0x20)
jackd:1507 userspace BUG: scheduling in user-atomic context!
[<c01069fc>] dump_stack+0x1c/0x20 (20)
[<c02834d0>] schedule+0x70/0x100 (24)
[<c028465d>] down_write_mutex+0xbd/0x180 (36)
[<c012cbf6>] __mutex_lock+0x36/0x40 (16)
[<c012cc75>] _mutex_lock_irqsave+0x15/0x20 (16)
[<c01f1237>] tty_ldisc_try+0x17/0x50 (20)
[<c01f1287>] tty_ldisc_ref_wait+0x17/0xc0 (88)
[<c01f21fd>] tty_write+0x7d/0x230 (68)
[<c01546ac>] vfs_write+0xbc/0x110 (36)
[<c01547b1>] sys_write+0x41/0x70 (44)
[<c0106367>] syscall_call+0x7/0xb (-8124)
---------------------------
| preempt count: 00000001 ]
| 1-level deep critical section nesting:
----------------------------------------
.. [<c012e5d3>] .... print_traces+0x13/0x50
.....[<c01069fc>] .. ( <= dump_stack+0x1c/0x20)
jackd:1507 userspace BUG: scheduling in user-atomic context!
[<c01069fc>] dump_stack+0x1c/0x20 (20)
[<c02834d0>] schedule+0x70/0x100 (24)
[<c028449c>] _down_write+0xcc/0x170 (32)
[<c01131d3>] lock_kernel+0x23/0x30 (16)
[<c01f22f0>] tty_write+0x170/0x230 (64)
[<c01546ac>] vfs_write+0xbc/0x110 (36)
[<c01547b1>] sys_write+0x41/0x70 (44)
[<c0106367>] syscall_call+0x7/0xb (-8124)
---------------------------
| preempt count: 00000001 ]
| 1-level deep critical section nesting:
----------------------------------------
.. [<c012e5d3>] .... print_traces+0x13/0x50
.....[<c01069fc>] .. ( <= dump_stack+0x1c/0x20)
jackd:1507 userspace BUG: scheduling in user-atomic context!
[<c01069fc>] dump_stack+0x1c/0x20 (20)
[<c02834d0>] schedule+0x70/0x100 (24)
[<c0119cba>] do_exit+0x29a/0x500 (24)
[<c0119f56>] sys_exit+0x16/0x20 (12)
[<c0106367>] syscall_call+0x7/0xb (-8124)
---------------------------
| preempt count: 00000001 ]
| 1-level deep critical section nesting:
----------------------------------------
.. [<c012e5d3>] .... print_traces+0x13/0x50
.....[<c01069fc>] .. ( <= dump_stack+0x1c/0x20)
However the longest latency recorded during all these xruns is 40-150 usecs:
preemption latency trace v1.0.7 on 2.6.9-mm1-RT-V0.5.14
-------------------------------------------------------
latency: 48 us, entries: 26 (26) | [VP:0 KP:1 SP:1 HP:1 #CPUS:1]
-----------------
| task: jackd/1629, uid:1000 nice:0 policy:1 rt_prio:10
-----------------
=> started at: try_to_wake_up+0x4c/0x100 <c01126ec>
=> ended at: finish_task_switch+0x27/0xb0 <c0112b77>
=======>
1101 80000000 0.000ms (+0.000ms): (89) ((116))
1101 80000000 0.000ms (+0.000ms): (1629) ((1101))
1101 80000000 0.000ms (+0.000ms): preempt_schedule (try_to_wake_up)
1101 80000000 0.001ms (+0.000ms): preempt_schedule (__up_write)
1101 00000000 0.001ms (+0.000ms): preempt_schedule (up_write_mutex)
1101 80000000 0.002ms (+0.000ms): __schedule (preempt_schedule)
1101 80000000 0.002ms (+0.000ms): profile_hit (__schedule)
1101 80000000 0.003ms (+0.002ms): sched_clock (__schedule)
1629 80000000 0.005ms (+0.000ms): __switch_to (__schedule)
1629 80000000 0.006ms (+0.000ms): (1101) ((1629))
1629 80000000 0.006ms (+0.000ms): (116) ((89))
1629 80000000 0.006ms (+0.000ms): finish_task_switch (__schedule)
1629 80000000 0.007ms (+0.000ms): trace_stop_sched_switched (finish_task_switch)
1629 80000000 0.007ms (+0.002ms): (1629) ((89))
1629 00000000 0.010ms (+0.000ms): bad_range (free_pages_bulk)
1629 00000000 0.010ms (+0.000ms): bad_range (free_pages_bulk)
1629 00000000 0.011ms (+0.000ms): _mutex_unlock_irqrestore (free_pages_bulk)
1629 00000000 0.011ms (+0.000ms): up_mutex (free_pages_bulk)
1629 00000000 0.011ms (+0.000ms): up_write_mutex (free_pages_bulk)
1629 00000000 0.012ms (+0.004ms): __up_write (up_write_mutex)
1629 00000000 0.016ms (+0.000ms): sys_gettimeofday (syscall_call)
1629 00000000 0.016ms (+0.000ms): user_trace_stop (sys_gettimeofday)
1629 80000000 0.017ms (+0.000ms): user_trace_stop (sys_gettimeofday)
1629 80000000 0.017ms (+0.000ms): update_max_trace (user_trace_stop)
1629 80000000 0.018ms (+0.000ms): _mmx_memcpy (update_max_trace)
1629 80000000 0.018ms (+0.000ms): kernel_fpu_begin (_mmx_memcpy)
We know that jackd prints from the realtime thread, and that in theory
this could be a problem, in practice it works OK. Maybe some recent
changes to the tty layer made this problematic.
I think there was a patch posted to the JACK mailing list to print from
a separate thread, I will look into this.
Lee
next prev parent reply other threads:[~2004-10-30 3:37 UTC|newest]
Thread overview: 152+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <1099008264.4199.4.camel@krustophenia.net>
2004-10-29 0:57 ` [Fwd: Re: [patch] Real-Time Preemption, -RT-2.6.9-mm1-V0.4] Paul Davis
2004-10-29 2:10 ` Lee Revell
2004-10-29 8:02 ` Ingo Molnar
2004-10-29 8:21 ` Thomas Gleixner
2004-10-29 9:09 ` Ingo Molnar
2004-10-29 11:01 ` Paul Davis
2004-10-29 11:14 ` Ingo Molnar
2004-10-29 11:26 ` Paul Davis
2004-10-29 11:36 ` Ingo Molnar
2004-10-29 13:35 ` Paul Davis
2004-10-29 13:55 ` Ingo Molnar
2004-10-29 14:03 ` Paul Davis
2004-10-29 14:15 ` Ingo Molnar
2004-10-29 16:14 ` Ingo Molnar
2004-10-29 16:21 ` Ingo Molnar
2004-10-29 16:32 ` Florian Schmidt
2004-10-29 16:23 ` Ingo Molnar
2004-10-29 16:31 ` Ingo Molnar
2004-10-29 16:37 ` Ingo Molnar
2004-10-29 16:53 ` Ingo Molnar
2004-10-29 17:16 ` Florian Schmidt
2004-10-29 17:02 ` Ingo Molnar
2004-10-29 17:09 ` Ingo Molnar
2004-10-29 17:16 ` Ingo Molnar
2004-10-29 17:33 ` Florian Schmidt
2004-10-29 17:21 ` Ingo Molnar
2004-10-29 17:22 ` Ingo Molnar
2004-10-29 18:36 ` Florian Schmidt
2004-10-29 20:33 ` Ingo Molnar
2004-10-29 20:51 ` Paul Davis
2004-10-29 21:11 ` Ingo Molnar
2004-10-30 1:06 ` Paul Davis
2004-10-30 11:34 ` Ingo Molnar
2004-11-26 17:16 ` [Jackit-devel] " Jack O'Quin
2004-10-29 20:42 ` Ingo Molnar
2004-10-29 21:31 ` Florian Schmidt
2004-10-29 21:25 ` Ingo Molnar
2004-10-29 21:42 ` Lee Revell
2004-10-29 21:46 ` Ingo Molnar
2004-10-29 21:53 ` Lee Revell
2004-10-29 23:12 ` Lee Revell
2004-10-30 11:58 ` Ingo Molnar
2004-10-30 17:49 ` Lee Revell
2004-10-30 19:17 ` Ingo Molnar
2004-10-30 19:43 ` Lee Revell
2004-10-30 19:47 ` Florian Schmidt
2004-10-30 19:37 ` Ingo Molnar
2004-10-30 19:57 ` Florian Schmidt
2004-10-30 19:52 ` Lee Revell
2004-10-30 20:15 ` Florian Schmidt
2004-10-30 20:26 ` Lee Revell
2004-10-30 21:13 ` Florian Schmidt
2004-10-30 21:26 ` Lee Revell
2004-10-30 21:38 ` Florian Schmidt
2004-10-30 23:12 ` Lee Revell
2004-10-31 12:07 ` Ingo Molnar
2004-10-31 12:48 ` Ingo Molnar
2004-10-31 12:54 ` Lee Revell
2004-10-31 13:13 ` Ingo Molnar
2004-10-31 13:40 ` Ingo Molnar
2004-10-31 15:20 ` Florian Schmidt
2004-10-31 15:59 ` Florian Schmidt
2004-10-31 19:06 ` Florian Schmidt
2004-11-01 13:42 ` Ingo Molnar
2004-11-01 13:53 ` Ingo Molnar
2004-11-01 14:06 ` Ingo Molnar
2004-11-01 15:47 ` Thomas Gleixner
2004-11-01 17:55 ` Lee Revell
2004-11-01 17:58 ` Thomas Gleixner
2004-11-01 18:43 ` Ingo Molnar
2004-11-01 18:46 ` Ingo Molnar
2004-11-01 22:30 ` Florian Schmidt
2004-11-01 22:40 ` Bill Huey
2004-11-01 22:51 ` Florian Schmidt
2004-11-01 22:59 ` Bill Huey
2004-11-02 8:02 ` Ingo Molnar
2004-11-02 8:07 ` Ingo Molnar
2004-11-02 15:06 ` [patch] Real-Time Preemption, -RT-2.6.9-mm1-V0.6.8 Ingo Molnar
2004-11-02 17:52 ` K.R. Foley
2004-11-02 19:37 ` Ingo Molnar
2004-11-02 19:40 ` K.R. Foley
2004-11-02 19:24 ` Norberto Bensa
2004-11-02 19:35 ` Ingo Molnar
2004-11-02 23:09 ` Karsten Wiese
2004-11-03 1:12 ` Ingo Molnar
2004-11-03 10:15 ` Karsten Wiese
2004-11-01 17:04 ` [Fwd: Re: [patch] Real-Time Preemption, -RT-2.6.9-mm1-V0.4] Rui Nuno Capela
2004-11-01 17:08 ` Thomas Gleixner
2004-11-01 20:00 ` Rui Nuno Capela
2004-11-01 17:24 ` K.R. Foley
2004-11-02 0:22 ` Michal Schmidt
2004-11-01 13:54 ` Paul Davis
2004-11-01 14:30 ` Ingo Molnar
2004-11-01 19:30 ` Paul Davis
2004-11-02 8:17 ` Ingo Molnar
2004-11-01 14:03 ` Florian Schmidt
2004-11-01 14:12 ` Ingo Molnar
2004-11-01 15:29 ` K.R. Foley
2004-11-02 23:41 ` [Fwd: Re: [patch] Real-Time Preemption, -RT-2.6.9-mm1-V0.6] Remi Colinet
2004-11-03 1:04 ` Remi Colinet
2004-11-01 11:55 ` [Fwd: Re: [patch] Real-Time Preemption, -RT-2.6.9-mm1-V0.4] Ingo Molnar
2004-11-01 12:37 ` Ingo Molnar
2004-11-01 12:35 ` Thomas Gleixner
2004-11-01 12:51 ` Ingo Molnar
2004-11-01 13:15 ` Ingo Molnar
2004-11-01 13:40 ` Florian Schmidt
2004-11-01 13:48 ` Ingo Molnar
2004-11-01 16:47 ` Rui Nuno Capela
2004-10-31 23:16 ` Michal Schmidt
2004-11-01 0:05 ` Magnus Määttä
2004-10-31 13:11 ` Ingo Molnar
2004-10-31 14:11 ` Florian Schmidt
2004-10-31 13:22 ` Ingo Molnar
2004-10-31 14:28 ` Florian Schmidt
2004-10-31 13:30 ` Ingo Molnar
2004-10-31 21:58 ` Rui Nuno Capela
2004-10-31 22:11 ` K.R. Foley
2004-10-31 2:20 ` Lee Revell
2004-10-31 10:00 ` Florian Schmidt
2004-10-31 12:09 ` Lee Revell
2004-10-31 12:19 ` Ingo Molnar
2004-10-31 12:35 ` Lee Revell
2004-10-31 12:39 ` Ingo Molnar
2004-10-30 20:05 ` Lee Revell
2004-10-30 20:29 ` Florian Schmidt
2004-10-30 0:15 ` Lee Revell
2004-10-29 22:31 ` Florian Schmidt
2004-10-29 22:50 ` Florian Schmidt
2004-10-30 13:15 ` Ingo Molnar
2004-10-30 17:53 ` Florian Schmidt
2004-10-30 3:36 ` Lee Revell [this message]
2004-10-30 3:48 ` Lee Revell
2004-10-30 11:16 ` Ingo Molnar
2004-10-30 17:44 ` Lee Revell
2004-10-30 11:28 ` Ingo Molnar
2004-10-30 11:33 ` Ingo Molnar
2004-10-30 13:16 ` Florian Schmidt
2004-10-30 1:10 ` Lee Revell
2004-10-30 1:15 ` Lee Revell
2004-10-29 8:59 ` Ingo Molnar
2004-10-29 9:29 ` Ingo Molnar
2004-10-29 13:48 ` Ingo Molnar
2004-10-29 14:19 ` Paul Davis
2004-10-29 14:27 ` Ingo Molnar
2004-10-29 14:31 ` Ingo Molnar
2004-10-29 14:38 ` Paul Davis
2004-10-29 19:33 ` Lee Revell
2004-10-29 19:35 ` Thomas Gleixner
2004-11-01 14:32 Mark_H_Johnson
2004-11-01 14:36 ` Ingo Molnar
-- strict thread matches above, loose matches on Subject: below --
2004-11-01 16:34 Mark_H_Johnson
2004-11-01 18:48 ` Ingo Molnar
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