From: Frederic Weisbecker <fweisbec@gmail.com>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@elte.hu>,
linux-kernel@vger.kernel.org,
Andrew Morton <akpm@linux-foundation.org>
Subject: Re: [PATCH 0/4] [GIT PULL] tracing: recursion and compile fixes
Date: Mon, 20 Apr 2009 21:48:54 +0200 [thread overview]
Message-ID: <20090420194853.GC5974@nowhere> (raw)
In-Reply-To: <alpine.DEB.2.00.0904201540400.26147@gandalf.stny.rr.com>
On Mon, Apr 20, 2009 at 03:43:21PM -0400, Steven Rostedt wrote:
>
> On Mon, 20 Apr 2009, Ingo Molnar wrote:
> > Running tests on all trace events:
> > Testing all events: <4>Tracing recursion: HC[0]:SC[0]:NMI[0]
>
> Recursion is wrong :-/
>
> > ------------[ cut here ]------------
> > WARNING: at kernel/trace/ring_buffer.c:1510 ring_buffer_lock_reserve+0xf7/0x1ce()
> > Hardware name: To Be Filled By O.E.M.
> > Pid: 1, comm: swapper Not tainted 2.6.30-rc2-tip-01538-ge8201b9-dirty #37740
> > Call Trace:
> > <IRQ> [<ffffffff80268a01>] warn_slowpath+0xcc/0x114
> > [<ffffffff80299ed3>] ? trace_hardirqs_on_caller+0x11d/0x179
> > [<ffffffff80299ba6>] ? mark_held_locks+0x60/0x95
> > [<ffffffff802ca335>] ring_buffer_lock_reserve+0xf7/0x1ce
> > [<ffffffff802ceb60>] trace_buffer_lock_reserve+0x34/0x7e
> > [<ffffffff810c8f97>] ? do_IRQ+0xf/0xe8
> > [<ffffffff802cf949>] trace_current_buffer_lock_reserve+0x36/0x4c
> > [<ffffffff802d9da4>] function_test_events_call+0x7e/0xe2
> > [<ffffffff80216313>] ? ret_from_intr+0x0/0x16
> > [<ffffffff80215616>] ftrace_call+0x5/0x2b
> > [<ffffffff8021630e>] ? common_interrupt+0xe/0x13
> > [<ffffffff810c8f9c>] ? do_IRQ+0x14/0xe8
>
> The function tracer was called before we updated the hardirq_count :-/
Oh! I feared about such racy situation. That's really a pity, this context count
is so useful :-/
Frederic.
> I liked the fact that we can detect same level recursion. Perhaps I'll
> just make a depth test instead. Have a max of 16? times we can recurse
> (should be plenty) and then bug if we hit it?
>
> -- Steve
>
>
> > [<ffffffff8021630e>] ? common_interrupt+0xe/0x13
> > [<ffffffff80216313>] ret_from_intr+0x0/0x16
> > <EOI> [<ffffffff802c311c>] ? trace_clock_local+0x37/0x57
> > [<ffffffff80254b27>] ? __wake_up+0x57/0x7a
> > [<ffffffff802c9e60>] ? rb_reserve_next_event+0x73/0x319
> > [<ffffffff802f6106>] ? ftrace_raw_event_kmalloc+0x11/0xdd
> > [<ffffffff802d0ac8>] ? trace_wake_up+0x41/0x57
> > [<ffffffff802ca3ab>] ? ring_buffer_lock_reserve+0x16d/0x1ce
> > [<ffffffff802ceb60>] ? trace_buffer_lock_reserve+0x34/0x7e
> > [<ffffffff802c278d>] ? tracepoint_entry_add_probe+0xb3/0x12b
> > [<ffffffff802c278d>] ? tracepoint_entry_add_probe+0xb3/0x12b
> > [<ffffffff802cf949>] ? trace_current_buffer_lock_reserve+0x36/0x4c
> > [<ffffffff802c278d>] ? tracepoint_entry_add_probe+0xb3/0x12b
> > [<ffffffff802f615d>] ? ftrace_raw_event_kmalloc+0x68/0xdd
> > [<ffffffff802c278d>] ? tracepoint_entry_add_probe+0xb3/0x12b
> > [<ffffffff8031e265>] ? __kmalloc+0x268/0x298
> > [<ffffffff802969c6>] ? ftrace_event_lock_acquire+0x0/0x89
> > [<ffffffff802c278d>] ? tracepoint_entry_add_probe+0xb3/0x12b
> > [<ffffffff802c1e5f>] ? get_tracepoint+0x12/0x274
> > [<ffffffff802969c6>] ? ftrace_event_lock_acquire+0x0/0x89
> > [<ffffffff802c2875>] ? tracepoint_add_probe+0x70/0xf6
> > [<ffffffff802c2cf0>] ? tracepoint_probe_register+0x40/0xbc
> > [<ffffffff802968dd>] ? ftrace_reg_event_lock_acquire+0x2b/0x5c
> > [<ffffffff802d886f>] ? ftrace_event_enable_disable+0x43/0x59
> > [<ffffffff802d8cb4>] ? ftrace_set_clr_event+0x10c/0x15b
> > [<ffffffff81b70aa3>] ? event_trace_self_tests+0x39b/0x3e6
> > [<ffffffff81b70c52>] ? event_trace_self_tests_init+0x0/0x5f
> > [<ffffffff81b70c8d>] ? event_trace_self_tests_init+0x3b/0x5f
> > [<ffffffff8020a0b6>] ? do_one_initcall+0x84/0x1ad
> > [<ffffffff8029c513>] ? __lock_acquire+0x851/0x8d3
> > [<ffffffff8037d3de>] ? get_inode_number+0x61/0xc2
> > [<ffffffff8037d4f1>] ? proc_register+0xb2/0x139
> > [<ffffffff8037d553>] ? proc_register+0x114/0x139
> > [<ffffffff8021df9e>] ? native_sched_clock+0x25/0x9c
> > [<ffffffff8021df73>] ? sched_clock+0x33/0x39
> > [<ffffffff80297ccf>] ? lock_release_holdtime+0x2f/0x19d
> > [<ffffffff8037d553>] ? proc_register+0x114/0x139
> > [<ffffffff8029d44b>] ? __lock_release+0x177/0x196
> > [<ffffffff8037d4f1>] ? proc_register+0xb2/0x139
> > [<ffffffff80637f3e>] ? _raw_spin_unlock+0x14f/0x16e
> > [<ffffffff810c7e43>] ? _spin_unlock+0x3a/0x55
> > [<ffffffff8037d553>] ? proc_register+0x114/0x139
> > [<ffffffff8037d6de>] ? create_proc_entry+0x92/0xbe
> > [<ffffffff802b95a1>] ? register_irq_proc+0xc2/0xf2
> > [<ffffffff81b53140>] ? early_idt_handler+0x0/0x71
> > [<ffffffff81b53140>] ? early_idt_handler+0x0/0x71
> > [<ffffffff81b53aa8>] ? kernel_init+0xb2/0x11a
> > [<ffffffff81b53140>] ? early_idt_handler+0x0/0x71
> > [<ffffffff80216a4a>] ? child_rip+0xa/0x20
> > [<ffffffff802163d0>] ? restore_args+0x0/0x30
> > [<ffffffff81b539f6>] ? kernel_init+0x0/0x11a
> > [<ffffffff80216a40>] ? child_rip+0x0/0x20
> > ---[ end trace 0d52030ff90bb47d ]---
next prev parent reply other threads:[~2009-04-20 19:49 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-04-20 17:38 [PATCH 0/4] [GIT PULL] tracing: recursion and compile fixes Steven Rostedt
2009-04-20 17:38 ` [PATCH 1/4] tracing/events: call the correct event trace selftest init function Steven Rostedt
2009-04-20 17:38 ` [PATCH 2/4] tracing: remove dangling semicolon Steven Rostedt
2009-04-20 17:38 ` [PATCH 3/4] tracing: fix recursive test level calculation Steven Rostedt
2009-04-20 19:30 ` Andrew Morton
2009-04-20 17:38 ` [PATCH 4/4] tracing: remove recursive test from ring_buffer_event_discard Steven Rostedt
2009-04-20 17:55 ` [PATCH 0/4] [GIT PULL] tracing: recursion and compile fixes Ingo Molnar
2009-04-20 19:28 ` Ingo Molnar
2009-04-20 19:45 ` Frederic Weisbecker
2009-04-20 19:53 ` Steven Rostedt
2009-04-20 20:17 ` Steven Rostedt
2009-04-20 20:33 ` Frederic Weisbecker
2009-04-20 20:44 ` Steven Rostedt
2009-04-20 21:01 ` Frederic Weisbecker
2009-04-20 21:14 ` Steven Rostedt
2009-04-20 21:25 ` Frederic Weisbecker
2009-04-20 19:29 ` Ingo Molnar
2009-04-20 19:43 ` Steven Rostedt
2009-04-20 19:48 ` Frederic Weisbecker [this message]
2009-04-20 19:55 ` Steven Rostedt
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