From: Steven Rostedt <rostedt@goodmis.org>
To: Tom Zanussi <tom.zanussi@linux.intel.com>
Cc: tglx@linutronix.de, mhiramat@kernel.org, namhyung@kernel.org,
linux-kernel@vger.kernel.org, linux-rt-users@vger.kernel.org
Subject: Re: [RFC][PATCH 00/21] tracing: Inter-event (e.g. latency) support
Date: Wed, 8 Feb 2017 15:01:09 -0500 [thread overview]
Message-ID: <20170208150109.5919a2ea@gandalf.local.home> (raw)
In-Reply-To: <cover.1486569306.git.tom.zanussi@linux.intel.com>
On Wed, 8 Feb 2017 11:24:56 -0600
Tom Zanussi <tom.zanussi@linux.intel.com> wrote:
> # echo 'wakeup_latency lat=sched_switch:wakeup_lat \
> pid=sched_switch:woken_pid \
> prio=sched_switch:woken_prio' >> \
> /sys/kernel/debug/tracing/synthetic_events
I applied all your patches, did the above and then:
BUG: unable to handle kernel NULL pointer dereference at 0000000000000034
IP: free_synthetic_event+0x46/0xb0
PGD 0
Oops: 0000 [#1] SMP
Modules linked in: ip6table_filter ip6_tables x86_pkg_temp_thermal kvm_intel kvm snd_hda_codec_hdmi snd_hda_codec_realtek snd_hda_codec_generic snd_hda_intel snd_hda_codec snd_hwdep snd_hda_core irqbypass snd_seq snd_seq_device snd_pcm snd_timer snd i2c_i801 soundcore wmi i915 i2c_algo_bit drm_kms_helper e1000e syscopyarea sysfillrect sysimgblt fb_sys_fops ptp drm pps_core i2c_core video
CPU: 0 PID: 1389 Comm: bash Not tainted 4.10.0-rc2-test+ #36
Hardware name: Hewlett-Packard HP Compaq Pro 6300 SFF/339A, BIOS K01 v02.05 05/07/2012
task: ffff8800c8c48000 task.stack: ffffc90000a00000
RIP: 0010:free_synthetic_event+0x46/0xb0
RSP: 0018:ffffc90000a03cf8 EFLAGS: 00010282
RAX: 0000000015675b00 RBX: ffff8800ccf4bcd0 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90000a03d18 R08: 0000000000000000 R09: ffff8800ccea7c6c
R10: 000000000000003d R11: ffff8800c8c48000 R12: 0000000000000001
R13: ffff8800c8ca6000 R14: ffff8800ccea7d88 R15: 0000000000000001
FS: 00007fde7acdb700(0000) GS:ffff88011ea00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000034 CR3: 00000000ccc44000 CR4: 00000000001406f0
Call Trace:
create_synthetic_event+0xcb/0x580
? parse_var_ref+0x120/0x120
trace_run_command+0x5f/0x70
trace_parse_run_command+0x76/0x150
? parse_var_ref+0x120/0x120
synthetic_events_write+0x10/0x20
__vfs_write+0x28/0x140
? vmacache_find+0xcc/0x180
? rw_verify_area+0xd8/0x190
? _cond_resched+0x2e/0x50
? __sb_start_write+0x82/0xe0
vfs_write+0x138/0x260
SyS_write+0x4f/0xa0
entry_SYSCALL_64_fastpath+0x13/0x94
Anyway, I kinda like the approach. I'll go patch by patch to see what
you did and maybe even take a few now, if they seem appropriate as
helpers.
-- Steve
next prev parent reply other threads:[~2017-02-08 20:01 UTC|newest]
Thread overview: 56+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-02-08 17:24 Tom Zanussi
2017-02-08 17:24 ` [RFC][PATCH 01/21] tracing: Add hist_field_name() accessor Tom Zanussi
2017-02-08 20:09 ` Steven Rostedt
2017-02-08 17:24 ` [RFC][PATCH 02/21] tracing: Reimplement log2 Tom Zanussi
2017-02-08 20:13 ` Steven Rostedt
2017-02-08 20:25 ` Tom Zanussi
2017-02-08 17:24 ` [RFC][PATCH 03/21] ring-buffer: Add TIME_EXTEND_ABS ring buffer type Tom Zanussi
2017-02-08 20:32 ` Steven Rostedt
2017-02-08 20:55 ` Tom Zanussi
2017-02-09 14:54 ` Steven Rostedt
2017-02-10 6:04 ` Namhyung Kim
2017-02-10 14:28 ` Steven Rostedt
2017-02-08 17:25 ` [RFC][PATCH 04/21] tracing: Give event triggers access to ring_buffer_event Tom Zanussi
2017-02-08 17:25 ` [RFC][PATCH 05/21] tracing: Add ring buffer event param to hist field functions Tom Zanussi
2017-02-08 17:25 ` [RFC][PATCH 06/21] tracing: Increase tracing map KEYS_MAX size Tom Zanussi
2017-02-08 17:25 ` [RFC][PATCH 07/21] tracing: Break out hist trigger assignment parsing Tom Zanussi
2017-02-08 17:25 ` [RFC][PATCH 08/21] tracing: Make traceprobe parsing code reusable Tom Zanussi
2017-02-09 20:40 ` Steven Rostedt
2017-02-08 17:25 ` [RFC][PATCH 09/21] tracing: Add hist trigger timestamp support Tom Zanussi
2017-02-10 6:14 ` Namhyung Kim
2017-02-08 17:25 ` [RFC][PATCH 10/21] tracing: Add per-element variable support to tracing_map Tom Zanussi
2017-02-08 17:25 ` [RFC][PATCH 11/21] tracing: Add variable support to hist triggers Tom Zanussi
2017-02-13 6:03 ` Namhyung Kim
2017-02-14 15:25 ` Tom Zanussi
2017-02-08 17:25 ` [RFC][PATCH 12/21] tracing: Account for variables in named trigger compatibility Tom Zanussi
2017-02-13 6:04 ` Namhyung Kim
2017-02-14 15:26 ` Tom Zanussi
2017-02-08 17:25 ` [RFC][PATCH 13/21] tracing: Add simple expression support to hist triggers Tom Zanussi
2017-02-14 2:37 ` Namhyung Kim
2017-02-14 15:29 ` Tom Zanussi
2017-02-08 17:25 ` [RFC][PATCH 14/21] tracing: Add variable reference handling " Tom Zanussi
2017-02-08 17:25 ` [RFC][PATCH 15/21] tracing: Add usecs modifier for hist trigger timestamps Tom Zanussi
2017-02-08 17:25 ` [RFC][PATCH 16/21] tracing: Add support for dynamic tracepoints Tom Zanussi
2017-02-08 17:25 ` [RFC][PATCH 17/21] tracing: Add hist trigger action hook Tom Zanussi
2017-02-08 17:25 ` [RFC][PATCH 18/21] tracing: Add support for 'synthetic' events Tom Zanussi
2017-02-08 17:25 ` [RFC][PATCH 19/21] tracing: Add 'onmatch' hist trigger action support Tom Zanussi
2017-02-08 17:25 ` [RFC][PATCH 20/21] tracing: Add 'onmax' " Tom Zanussi
2017-02-08 17:25 ` [RFC][PATCH 21/21] tracing: Add inter-event hist trigger Documentation Tom Zanussi
2017-02-08 20:01 ` Steven Rostedt [this message]
2017-02-08 20:19 ` [RFC][PATCH 00/21] tracing: Inter-event (e.g. latency) support Tom Zanussi
2017-02-08 23:28 ` Tom Zanussi
2017-02-09 2:14 ` Steven Rostedt
2017-02-08 23:13 ` Masami Hiramatsu
2017-02-09 1:14 ` Tom Zanussi
2017-02-09 14:18 ` Masami Hiramatsu
2017-02-09 17:18 ` Tom Zanussi
2017-02-09 19:57 ` Steven Rostedt
2017-02-09 14:46 ` Frank Ch. Eigler
2017-02-09 18:43 ` Tom Zanussi
2017-02-10 4:16 ` Namhyung Kim
2017-02-10 9:34 ` Masami Hiramatsu
2017-02-10 18:58 ` Tom Zanussi
2017-02-13 1:04 ` Namhyung Kim
2017-02-14 9:37 ` Masami Hiramatsu
2017-02-14 15:27 ` Tom Zanussi
2017-02-10 18:43 ` Tom Zanussi
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