Age | Commit message (Collapse) | Author |
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sysfs_blk_trace_enable_show()/store() share most of code with
sysfs_blk_trace_attr_show()/store().
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <49C30EA3.1060004@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
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blk_trace_remove_queue() returns EINVAL if q->blk_trace == NULL,
but blk_trace_setup_queue() doesn't return EBUSY if
q->blk_trace != NULL.
# echo 0 > sdaX/trace/enable
# echo 0 > sdaX/trace/enable
bash: echo: write error: Invalid argument
# echo 1 > sdaX/trace/enable
# echo 1 > sdaX/trace/enable
(should return EBUSY)
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <49C2F614.2010101@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
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do_blk_trace_setup() may return EBUSY, but the current code
doesn't decrease blk_probes_ref in this case.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <49C2F5FF.80002@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
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blk_register_tracepoints() always returns 0, so make it return void,
thus we don't need to use blk_probe_mutex to protect blk_probes_ref.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <49C2F5EA.8060606@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
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It doesn't have to be a counter, and it can be a bool flag instead.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <49C2F5D3.8090104@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
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When we failed to create "block" debugfs dir, we should do some
cleanups.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <49C2F5B2.8000800@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
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'linus' into tracing/core
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Impact: fix warning with irqsoff tracer
The ring buffer allocates its buffers on pre-smp time (early_initcall).
It means that, at first, only the boot cpu buffer is allocated and
the ring-buffer cpumask only has the boot cpu set (cpu_online_mask).
Later, the secondary cpu will show up and the ring-buffer will be notified
about this event: the appropriate buffer will be allocated and the cpumask
will be updated.
Unfortunately, if !CONFIG_CPU_HOTPLUG, the ring-buffer will not be
notified about the secondary cpus, meaning that the cpumask will have
only the cpu boot set, and only one cpu buffer allocated.
We fix that by using cpu_possible_mask if !CONFIG_CPU_HOTPLUG.
This patch fixes the following warning with irqsoff tracer running:
[ 169.317794] WARNING: at kernel/trace/trace.c:466 update_max_tr_single+0xcc/0xf3()
[ 169.318002] Hardware name: AMILO Li 2727
[ 169.318002] Modules linked in:
[ 169.318002] Pid: 5624, comm: bash Not tainted 2.6.29-rc8-tip-02636-g6aafa6c #11
[ 169.318002] Call Trace:
[ 169.318002] [<ffffffff81036182>] warn_slowpath+0xea/0x13d
[ 169.318002] [<ffffffff8100b9d6>] ? ftrace_call+0x5/0x2b
[ 169.318002] [<ffffffff8100b9d6>] ? ftrace_call+0x5/0x2b
[ 169.318002] [<ffffffff8100b9d1>] ? ftrace_call+0x0/0x2b
[ 169.318002] [<ffffffff8101ef10>] ? ftrace_modify_code+0xa9/0x108
[ 169.318002] [<ffffffff8106e27f>] ? trace_hardirqs_off+0x25/0x27
[ 169.318002] [<ffffffff8149afe7>] ? _spin_unlock_irqrestore+0x1f/0x2d
[ 169.318002] [<ffffffff81064f52>] ? ring_buffer_reset_cpu+0xf6/0xfb
[ 169.318002] [<ffffffff8106637c>] ? ring_buffer_reset+0x36/0x48
[ 169.318002] [<ffffffff8106aeda>] update_max_tr_single+0xcc/0xf3
[ 169.318002] [<ffffffff8100bc17>] ? sysret_check+0x22/0x5d
[ 169.318002] [<ffffffff8106e3ea>] stop_critical_timing+0x142/0x204
[ 169.318002] [<ffffffff8106e4cf>] trace_hardirqs_on_caller+0x23/0x25
[ 169.318002] [<ffffffff8149ac28>] trace_hardirqs_on_thunk+0x3a/0x3c
[ 169.318002] [<ffffffff8100bc17>] ? sysret_check+0x22/0x5d
[ 169.318002] ---[ end trace db76cbf775a750cf ]---
Because this tracer may try to swap two cpu ring buffers for an
unregistered cpu on the ring buffer.
This patch might also fix a fair loss of traces due to unallocated buffers
for secondary cpus.
Reported-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-b: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <1237470453-5427-1-git-send-email-fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
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Zero-sized tracepoint sections can occur if tracing is enabled but
no tracepoint is defined. Do not emit a warning in that case.
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
LKML-Reference: <1237394936.3132.1.camel@localhost.localdomain>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
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Change this crash:
BUG: unable to handle kernel NULL pointer dereference at (null)
IP: [<ffffffff8107d4de>] tracepoint_update_probe_range+0x1f/0x9b
PGD 13d5fb067 PUD 13d688067 PMD 0
Oops: 0000 [#1] SMP
To a more debuggable WARN_ONCE().
Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <1237394936.3132.1.camel@localhost.localdomain>
[ moved the check outside the lock and added a WARN_ON(). ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
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Fix locking imbalance in kretprobes:
=====================================
[ BUG: bad unlock balance detected! ]
-------------------------------------
kthreadd/2 is trying to release lock (&rp->lock) at:
[<c06b3080>] pre_handler_kretprobe+0xea/0xf4
but there are no more locks to release!
other info that might help us debug this:
1 lock held by kthreadd/2:
#0: (rcu_read_lock){..--}, at: [<c06b2b24>] __atomic_notifier_call_chain+0x0/0x5a
stack backtrace:
Pid: 2, comm: kthreadd Not tainted 2.6.29-rc8 #1
Call Trace:
[<c06ae498>] ? printk+0xf/0x17
[<c06b3080>] ? pre_handler_kretprobe+0xea/0xf4
[<c044ce6c>] print_unlock_inbalance_bug+0xc3/0xce
[<c0444d4b>] ? clocksource_read+0x7/0xa
[<c04450a4>] ? getnstimeofday+0x5f/0xf6
[<c044a9ca>] ? register_lock_class+0x17/0x293
[<c044b72c>] ? mark_lock+0x1e/0x30b
[<c0448956>] ? tick_dev_program_event+0x4a/0xbc
[<c0498100>] ? __slab_alloc+0xa5/0x415
[<c06b2fbe>] ? pre_handler_kretprobe+0x28/0xf4
[<c06b3080>] ? pre_handler_kretprobe+0xea/0xf4
[<c044cf1b>] lock_release_non_nested+0xa4/0x1a5
[<c06b3080>] ? pre_handler_kretprobe+0xea/0xf4
[<c044d15d>] lock_release+0x141/0x166
[<c06b07dd>] _spin_unlock_irqrestore+0x19/0x50
[<c06b3080>] pre_handler_kretprobe+0xea/0xf4
[<c06b20b5>] kprobe_exceptions_notify+0x1c9/0x43e
[<c06b2b02>] notifier_call_chain+0x26/0x48
[<c06b2b5b>] __atomic_notifier_call_chain+0x37/0x5a
[<c06b2b24>] ? __atomic_notifier_call_chain+0x0/0x5a
[<c06b2b8a>] atomic_notifier_call_chain+0xc/0xe
[<c0442d0d>] notify_die+0x2d/0x2f
[<c06b0f9c>] do_int3+0x1f/0x71
[<c06b0e84>] int3+0x2c/0x34
[<c042d476>] ? do_fork+0x1/0x288
[<c040221b>] ? kernel_thread+0x71/0x79
[<c043ed1b>] ? kthread+0x0/0x60
[<c043ed1b>] ? kthread+0x0/0x60
[<c04040b8>] ? kernel_thread_helper+0x0/0x10
[<c043ec7f>] kthreadd+0xac/0x148
[<c043ebd3>] ? kthreadd+0x0/0x148
[<c04040bf>] kernel_thread_helper+0x7/0x10
Signed-off-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Tested-by: Bharata B Rao <bharata@linux.vnet.ibm.com>
Cc: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Jim Keniston <jkenisto@us.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: <stable@kernel.org> [2.6.29.x, 2.6.28.x, 2.6.27.x]
LKML-Reference: <20090318113621.GB4129@in.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
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Impact: fix a selftest warning
In some cases, it's possible to see the following warning on irqsoff
tracer selftest:
[ 4.640003] Testing tracer irqsoff: <4>------------[ cut here ]------------
[ 4.653562] WARNING: at kernel/trace/trace.c:458 update_max_tr_single+0x9a/0xc4()
[ 4.660000] Hardware name: System Product Name
[ 4.660000] Modules linked in:
[ 4.660000] Pid: 301, comm: kstop/1 Not tainted 2.6.29-rc8-tip #35837
[ 4.660000] Call Trace:
[ 4.660000] [<4014b588>] warn_slowpath+0x79/0x8f
[ 4.660000] [<402d6949>] ? put_dec+0x64/0x6b
[ 4.660000] [<40162b56>] ? getnstimeofday+0x58/0xdd
[ 4.660000] [<40162210>] ? clocksource_read+0x3/0xf
[ 4.660000] [<4015eb44>] ? ktime_set+0x8/0x34
[ 4.660000] [<4014101a>] ? balance_runtime+0x8/0x56
[ 4.660000] [<405f6f11>] ? _spin_lock+0x3/0x10
[ 4.660000] [<4011f643>] ? ftrace_call+0x5/0x8
[ 4.660000] [<4015d0f1>] ? task_cputime_zero+0x3/0x27
[ 4.660000] [<40190ee7>] ? cpupri_set+0x90/0xcb
[ 4.660000] [<405f7208>] ? _spin_lock_irqsave+0x22/0x34
[ 4.660000] [<40190f12>] ? cpupri_set+0xbb/0xcb
[ 4.660000] [<405f7151>] ? _spin_unlock_irqrestore+0x23/0x35
[ 4.660000] [<4018493f>] ? ring_buffer_reset_cpu+0x27/0x51
[ 4.660000] [<405f7208>] ? _spin_lock_irqsave+0x22/0x34
[ 4.660000] [<40184962>] ? ring_buffer_reset_cpu+0x4a/0x51
[ 4.660000] [<405f7151>] ? _spin_unlock_irqrestore+0x23/0x35
[ 4.660000] [<4018cc29>] ? trace_hardirqs_off+0x1a/0x1c
[ 4.660000] [<405f7151>] ? _spin_unlock_irqrestore+0x23/0x35
[ 4.660000] [<40184962>] ? ring_buffer_reset_cpu+0x4a/0x51
[ 4.660000] [<401850f3>] ? cpumask_next+0x15/0x18
[ 4.660000] [<4018a41f>] update_max_tr_single+0x9a/0xc4
[ 4.660000] [<4014e5fe>] ? exit_notify+0x16/0xf2
[ 4.660000] [<4018cd13>] check_critical_timing+0xcc/0x11e
[ 4.660000] [<4014e5fe>] ? exit_notify+0x16/0xf2
[ 4.660000] [<4014e5fe>] ? exit_notify+0x16/0xf2
[ 4.660000] [<4018cdf1>] stop_critical_timing+0x8c/0x9f
[ 4.660000] [<4014e5c4>] ? forget_original_parent+0xac/0xd0
[ 4.660000] [<4018ce3a>] trace_hardirqs_on+0x1a/0x1c
[ 4.660000] [<4014e5c4>] forget_original_parent+0xac/0xd0
[ 4.660000] [<4014e5fe>] exit_notify+0x16/0xf2
[ 4.660000] [<4014e8a5>] do_exit+0x1cb/0x225
[ 4.660000] [<4015c72b>] ? kthread+0x0/0x69
[ 4.660000] [<4011f61d>] kernel_thread_helper+0xd/0x10
[ 4.660000] ---[ end trace a7919e7f17c0a725 ]---
[ 4.660164] .. no entries found ..FAILED!
During the selftest of irqsoff tracer, we do that:
/* disable interrupts for a bit */
local_irq_disable();
udelay(100);
local_irq_enable();
/* stop the tracing. */
tracing_stop();
/* check both trace buffers */
ret = trace_test_buffer(tr, NULL);
If a callsite performs a new max delay with irqs off just after
tracing_stop, update_max_tr_single() -> ring_buffer_swap_cpu()
will be called with the buffers disabled by tracing_stop(), hence
the warning, then ring_buffer_swap_cpu() return -EAGAIN and
update_max_tr_single() complains.
Fix it by also stopping the tracer before stopping the tracing globally.
A similar situation can happen with preemptoff and preemptirqsoff tracers
where we apply the same fix.
Reported-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <1237325938-5240-1-git-send-email-fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
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Impact: fix command line to pid mapping
map_cmdline_to_pid[] is checked in trace_save_cmdline(), but never
updated. This results in stale pid to command line mappings and the
tracer output will associate the wrong comm string.
Signed-off-by: Carsten Emde <Carsten.Emde@osadl.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Steven Rostedt <srostedt@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
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Impact: prevent stale command line output
In case there is no valid command line mapping for a pid
trace_find_cmdline() returns without updating the comm buffer. The
trace dump keeps the previous entry which results in confusing trace
output:
<idle>-0 [000] 280.702056 ....
<idle>-23456 [000] 280.702080 ....
Update the comm buffer with "<...>" when no mapping is found.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Steven Rostedt <srostedt@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
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Impact: cleanup
The command line recorder uses (unsigned) -1 to mark non mapped
entries in the pid to command line maps. The validity check is
completely unintuitive: idx >= SAVED_CMDLINES
There is no need for such casting games. Use a constant to mark
unmapped entries and check for that constant to make the code readable
and understandable.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Steven Rostedt <srostedt@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
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Impact: prevent overwrite of command line entries
When the tracer is stopped the command line recording continues to
record. The check for tracing_is_on() is not sufficient here as the
ringbuffer status is not affected by setting
debug/tracing/tracing_enabled to 0. On a non idle system this can
result in the loss of the command line information for the stopped
trace, which makes the trace harder to read and analyse.
Check tracer_enabled to allow further recording.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Steven Rostedt <srostedt@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
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git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into tracing/ftrace
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The start/stop methods of a tracer should be able to be executed
in all contexts. This patch converts the power tracer to do so.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
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The stopping and starting of a tracer should be light weight and
be able to be called in all contexts. The sched_switch grabbed
mutexes in the start/stop functions. This patch changes it to a
simple variable, on/off.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
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Impact: feature to allow better serialized clock
This patch adds an option called "global-clock" that will allow
the tracer to switch to a slower but more accurate (across CPUs)
clock.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
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This patch adds a new function called ring_buffer_set_clock that
allows a tracer to assign its own clock source to the buffer.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
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Impact: fix ref-after-free crash on failed module load
Fix refptr bug: Change refptr allocation and release order not to access a module
data structure pointed by 'mod' after freeing mod->module_core.
This bug will cause kernel panic(e.g. failed to find undefined symbols).
This bug was reported on systemtap bugzilla.
http://sources.redhat.com/bugzilla/show_bug.cgi?id=9927
Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
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git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into tracing/ftrace
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Impact: fix memory leak
If event_format_read() exits early due to nonzero ppos, the
previous kmalloc doesn't get freed - might as well do the
check before the kmalloc and avoid the problem.
Signed-off-by: Tom Zanussi <tzanussi@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: =?ISO-8859-1?Q?Fr=E9d=E9ric?= Weisbecker <fweisbec@gmail.com>
LKML-Reference: <1237270859.8033.141.camel@charm-linux>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
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Impact: fix for losing comms in trace
The command lines of tasks are cached at sched switch to not need
to record them at every trace point. Disabling the tracing on stops
the recording of traces, but does not stop the caching of command lines.
When the tracing is off the cache may overflow and cause the tracing
to show incorrect tasks matching the PIDs.
This patch disables prevents updates to the comm cache when the ring buffer
is off.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
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Impact: fix to one cause of incorrect comm outputs in trace
The spinlock only protected the creation of a comm <=> pid pair.
But it was possible that a reader could look up a pid, and get the
wrong comm because it had no locking.
This also required changing trace_find_cmdline to copy the comm cache
and not just send back a pointer to it.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
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Impact: fix a dynamic tracing failure
Recently, the function and function graph tracers failed to use dynamic
tracing after the following commit:
fa9d13cf135efbd454453a53b6299976bea245a9
(ftrace: don't try to __ftrace_replace_code on !FTRACE_FL_CONVERTED rec)
The patch is right except a mistake on the check for the FTRACE_FL_CONVERTED
flag. The code patching is aborted in case of successfully nopped sites.
What we want is the opposite: ignore the callsites that haven't been nopped.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
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Impact: fix crashes when tracing cpumasks
While ring-buffer allocation, the cpumasks are allocated too,
including the tracing cpumask and the per-cpu file mask handler.
But these cpumasks are freed accidentally just after.
Fix it.
Reported-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <1237164303-11476-1-git-send-email-fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
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Impact: fix a warning during preemptirqsoff selftests
When the preemptirqsoff selftest fails, we see the following
warning:
[ 6.050000] Testing tracer preemptirqsoff: .. no entries found ..
------------[ cut here ]------------
[ 6.060000] WARNING: at kernel/trace/trace.c:688 tracing_start+0x67/0xd3()
[ 6.060000] Modules linked in:
[ 6.060000] Pid: 1, comm: swapper Tainted: G
[ 6.060000] Call Trace:
[ 6.060000] [<ffffffff802460ff>] warn_slowpath+0xb1/0x100
[ 6.060000] [<ffffffff802a8f5b>] ? trace_preempt_on+0x35/0x4b
[ 6.060000] [<ffffffff802a37fb>] ? tracing_start+0x31/0xd3
[ 6.060000] [<ffffffff802a37fb>] ? tracing_start+0x31/0xd3
[ 6.060000] [<ffffffff80271e0b>] ? __lock_acquired+0xe6/0x1f2
[ 6.060000] [<ffffffff802a37fb>] ? tracing_start+0x31/0xd3
[ 6.060000] [<ffffffff802a3831>] tracing_start+0x67/0xd3
[ 6.060000] [<ffffffff802a8ace>] ? irqsoff_tracer_reset+0x2d/0x57
[ 6.060000] [<ffffffff802a4d1c>] trace_selftest_startup_preemptirqsoff+0x1c8/0x1f1
[ 6.060000] [<ffffffff802a4798>] register_tracer+0x12f/0x241
[ 6.060000] [<ffffffff810250d0>] ? init_irqsoff_tracer+0x0/0x53
[ 6.060000] [<ffffffff8102510b>] init_irqsoff_tracer+0x3b/0x53
This is because in fail case, the preemptirqsoff tracer selftest calls twice
the tracing_start() function:
int
trace_selftest_startup_preemptirqsoff(struct tracer *trace, struct trace_array *tr)
{
if (!ret && !count) {
printk(KERN_CONT ".. no entries found ..");
ret = -1;
tracing_start(); <-----
goto out;
}
[...]
out:
trace->reset(tr);
tracing_start(); <------
tracing_max_latency = save_max;
return ret;
}
Since it is well handled in the out path, we don't need the conditional one.
Reported-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <1237159961-7447-1-git-send-email-fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
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Impact: fix possible locking imbalance
In case of ring buffer resize failure, tracing_set_tracer forgot to
release trace_types_lock. Fix it.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <1237151439-6755-5-git-send-email-fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
|
|
Syscall tracing must select kallsysms.
The arch code builds a table to find the syscall metadata by syscall
number. It needs the syscalls names resolution from the symbol table
to know which name found on the syscalls metadatas match a function
pointer from the arch sys_call_table.
Reported-by: Andrew Morton <akpm@linux-foundation.org>
Reported-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <1237151439-6755-4-git-send-email-fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
|
|
Impact: fix syscall tracer enable/disable race
The current thread flag toggling is racy as shown in the following
scenario:
- task A is the last user of syscall tracing, it releases the
TIF_SYSCALL_FTRACE on each tasks
- at the same time task B start syscall tracing. refcount == 0 so
it sets up TIF_SYSCALL_FTRACE on each tasks.
The effect of the mixup is unpredictable.
So this fix adds a mutex on {start,stop}_syscall_tracing().
Reported-by: Andrew Morton <akpm@linux-foundation.org>
Reported-by: Ingo Molnar <mingo@elte.hu>
LKML-Reference: <1237151439-6755-3-git-send-email-fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
|
|
Impact: cleanup
- Drop unused cpu variable
- Fix some errors on comments
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <1237151439-6755-2-git-send-email-fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
|
|
Impact: fix 'stuck' syscall tracer
The syscall tracer uses a refcounter to enable several users
simultaneously.
But the refcounter did not behave correctly and always restored
its value to 0 after calling start_syscall_tracing(). Therefore,
stop_syscall_tracing() couldn't release correctly the tasks from
tracing.
Also the tracer forgot to reset the buffer when it is released.
Drop the pointless refcount decrement on start_syscall_tracing()
and reset the buffer when we release the tracer.
This fixes two reported issue:
- when we switch from syscall tracer to another tracer, syscall
tracing continued.
- incorrect use of the refcount.
Reported-by: Andrew Morton <akpm@linux-foundation.org>
Reported-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <1237151439-6755-1-git-send-email-fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
|
|
tracing/core
Conflicts:
arch/parisc/kernel/irq.c
|
|
Impact: new feature
This adds the generic support for syscalls tracing. This is
currently exploited through a devoted tracer but other tracing
engines can use it. (They just have to play with
{start,stop}_ftrace_syscalls() and use the display callbacks
unless they want to override them.)
The syscalls prototypes definitions are abused here to steal
some metadata informations:
- syscall name, param types, param names, number of params
The syscall addr is not directly saved during this definition
because we don't know if its prototype is available in the
namespace. But we don't really need it. The arch has just to
build a function able to resolve the syscall number to its
metadata struct.
The current tracer prints the syscall names, parameters names
and values (and their types optionally). Currently the value is
a raw hex but higher level values diplaying is on my TODO list.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <1236955332-10133-2-git-send-email-fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
|
|
Impact: save memory
The struct dyn_ftrace table is very large, this patch will save
about 50%.
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Steven Rostedt <srostedt@redhat.com>
LKML-Reference: <49BA2C9F.8020009@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
|
|
Impact: cleanup
VFS layer has tested the file mode, we do not need test it.
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Steven Rostedt <srostedt@redhat.com>
LKML-Reference: <49BA2BAB.6010608@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
|
|
Do __ftrace_replace_code for !FTRACE_FL_CONVERTED rec will always
fail, we should ignore this rec.
Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Cc: "Steven Rostedt ;" <rostedt@goodmis.org>
LKML-Reference: <49BA2472.4060206@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
|
|
If dyn_ftrace is freed before ftrace_release(), ftrace_release()
will free it again and make ftrace_free_records wrong.
Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Cc: "Steven Rostedt ;" <rostedt@goodmis.org>
LKML-Reference: <49BA23D9.1050900@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
|
|
into tracing/core
|
|
Provide basic callbacks to do syscall tracing.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
LKML-Reference: <1236401580-5758-2-git-send-email-fweisbec@gmail.com>
[ simplified it to a trace_printk() for now. ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
|
|
Impact: clean up
It is redundant to have 'SOFTIRQ' in the softirq names.
Reported-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
|
|
The binary_buffers directory in /debugfs/tracing held the files
to read the trace buffers in a binary format. This held one file
per CPU buffer. But we also have a per_cpu directory that holds
a way to read the pretty-print formats.
This patch moves the binary buffers into the per_cpu_directory:
# ls /debug/tracing/per_cpu/cpu1/
trace trace_pipe trace_pipe_raw
The new name is called "trace_pipe_raw". The binary buffers always
acted similar to trace_pipe, except that they produce raw data.
Requested-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
|
|
Impact: documentation
The use of the double __builtin_contant_p checks in the event_trace_printk
can be confusing to developers and reviewers. This patch adds a comment
to explain why it is there.
Requested-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
LKML-Reference: <20090313122235.43EB.A69D9226@jp.fujitsu.com>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
|
|
Ingo Molnar suggested, instead of:
Depth Size Location (27 entries)
----- ---- --------
0) 2880 48 lock_timer_base+0x2b/0x4f
1) 2832 80 __mod_timer+0x33/0xe0
2) 2752 16 __ide_set_handler+0x63/0x65
To have it be:
Depth Size Location (27 entries)
----- ---- --------
0) 2880 48 lock_timer_base+0x2b/0x4f
1) 2832 80 __mod_timer+0x33/0xe0
2) 2752 16 __ide_set_handler+0x63/0x65
Requested-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
|
|
In a private email conversation I explained how the ring buffer
page worked by using silly ASCII art. Ingo suggested that I add
that to the comments of the code.
Here it is.
Requested-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
|
|
Unlike TRACE_FORMAT() macros, the TRACE_EVENT() macros do not show
the event name in the trace file. Knowing the event type in the trace
output is very useful.
Instead of:
task swapper:0 [140] ==> ntpd:3308 [120]
We now have:
sched_switch: task swapper:0 [140] ==> ntpd:3308 [120]
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
|
|
commit c3ffc7a40b7e94b094efe1c8ab4e24370a782b65
"Don't use tracing_record_cmdline() in workqueue tracer"
has a race window.
find_task_by_vpid() requires task_list_lock().
LKML-Reference: <20090313090042.43CD.A69D9226@jp.fujitsu.com>
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
|
|
Introduce softirq entry/exit tracepoints. These are useful for
augmenting existing tracers, and to figure out softirq frequencies and
timings.
[
s/irq_softirq_/softirq_/ for trace point names and
Fixed printf format in TRACE_FORMAT macro
- Steven Rostedt
]
LKML-Reference: <20090312183603.GC3352@redhat.com>
Signed-off-by: Jason Baron <jbaron@redhat.com>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
|