This patch adds a "command" syntax to the function filtering files:
/debugfs/tracing/set_ftrace_filter
/debugfs/tracing/set_ftrace_notrace
Of the format: <function>:<command>:<parameter>
The command is optional, and dependent on the command, so are
the parameters.
echo do_fork > set_ftrace_filter
Will only trace 'do_fork'.
echo 'sched_*' > set_ftrace_filter
Will only trace functions starting with the letters 'sched_'.
echo '*:mod:ext3' > set_ftrace_filter
Will trace only the ext3 module functions.
echo '*write*:mod:ext3' > set_ftrace_notrace
Will prevent the ext3 functions with the letters 'write' in
the name from being traced.
echo '!*_allocate:mod:ext3' > set_ftrace_filter
Will remove the functions in ext3 that end with the letters
'_allocate' from the ftrace filter.
Although this patch implements the 'command' format, only the
'mod' command is supported. More commands to follow.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Impact: clean up
ftrace_match_records does a lot of things that other features
can use. This patch breaks up ftrace_match_records and pulls
out ftrace_setup_glob and ftrace_match_record.
ftrace_setup_glob prepares a simple glob expression for use with
ftrace_match_record. ftrace_match_record compares a single record
with a glob type.
Breaking this up will allow for more features to run on individual
records.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Impact: clean up
ftrace_match is too generic of a name. What it really does is
search all records and matches the records with the given string,
and either sets or unsets the functions to be traced depending
on if the parameter 'enable' is set or not.
This allows us to make another function called ftrace_match that
can be used to test a single record.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Impact: clean up
To iterate over all the functions that dynamic trace knows about
it requires two for loops. One to iterate over the pages and the
other to iterate over the records within the page.
There are several duplications of these loops in ftrace.c. This
patch creates the macros do_for_each_ftrace_rec and
while_for_each_ftrace_rec to handle this logic, and removes the
duplicate code.
While making this change, I also discovered and fixed a small
bug that one of the iterations should exit the loop after it found the
record it was searching for. This used a break when it should have
used a goto, since there were two loops it needed to break out
from. No real harm was done by this bug since it would only continue
to search the other records, and the code was in a slow path anyway.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Impact: clean up, make set_ftrace_filter less confusing
The set_ftrace_filter shows only the functions that will be traced.
But when it is empty, it will trace all functions. This can be a bit
confusing.
This patch makes set_ftrace_filter show:
#### all functions enabled ####
When all functions will be traced, and we do not filter only a select
few.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
#define TASK_NICE(p) PRIO_TO_NICE((p)->static_prio)
So it's better to use TASK_NICE here.
Signed-off-by: WANG Cong <wangcong@zeuux.org>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Mapping from a struct timecounter to a time returned by functions like
ktime_get_real() is implemented. This is sufficient to use this code
in a network device driver which wants to support hardware time
stamping and transformation of hardware time stamps to system time.
The interface could have been made more versatile by not depending on
a time counter, but this wasn't done to avoid writing glue code
elsewhere.
The method implemented here is the one used and analyzed under the name
"assisted PTP" in the LCI PTP paper:
http://www.linuxclustersinstitute.org/conferences/archive/2008/PDF/Ohly_92221.pdf
Acked-by: John Stultz <johnstul@us.ibm.com>
Signed-off-by: Patrick Ohly <patrick.ohly@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
So far struct clocksource acted as the interface between time/timekeeping.c
and hardware. This patch generalizes the concept so that a similar
interface can also be used in other contexts. For that it introduces
new structures and related functions *without* touching the existing
struct clocksource.
The reasons for adding these new structures to clocksource.[ch] are
* the APIs are clearly related
* struct clocksource could be cleaned up to use the new structs
* avoids proliferation of files with similar names (timesource.h?
timecounter.h?)
As outlined in the discussion with John Stultz, this patch adds
* struct cyclecounter: stateless API to hardware which counts clock cycles
* struct timecounter: stateful utility code built on a cyclecounter which
provides a nanosecond counter
* only the function to read the nanosecond counter; deltas are used internally
and not exposed to users of timecounter
The code does no locking of the shared state. It must be called at least
as often as the cycle counter wraps around to detect these wrap arounds.
Both is the responsibility of the timecounter user.
Acked-by: John Stultz <johnstul@us.ibm.com>
Signed-off-by: Patrick Ohly <patrick.ohly@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Impact: struct rq size optimization
The idle_at_tick in struct rq is only used in SMP settings
and it does not make sense to have this in the rq in an UP setup.
Signed-off-by: Henrik Austad <henrik@austad.us>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The function bts_trace_init() references a variable
bts_hotcpu_notifier which is marked
as __cpuinitdata. Thus causes section mismatch. This patch fixes it.
LD kernel/trace/built-in.o
WARNING: kernel/trace/built-in.o(.text+0xc90c): Section mismatch in
reference from the function bts_trace_init() to the variable
.cpuinit.data:bts_hotcpu_notifier
The function bts_trace_init() references
the variable __cpuinitdata bts_hotcpu_notifier.
This is often because bts_trace_init lacks a __cpuinitdata
annotation or the annotation of bts_hotcpu_notifier is wrong.
WARNING: kernel/trace/built-in.o(.text+0xc92a): Section mismatch in
reference from the function bts_trace_reset() to the variable
.cpuinit.data:bts_hotcpu_notifier
The function bts_trace_reset() references
the variable __cpuinitdata bts_hotcpu_notifier.
This is often because bts_trace_reset lacks a __cpuinitdata
annotation or the annotation of bts_hotcpu_notifier is wrong.
Signed-off-by: Rakib Mullick <rakib.mullick@gmail.com>
Cc: markus.t.metzger@gmail.com
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: cosmetic change in Kconfig menu layout
This patch was originally suggested by Peter Zijlstra, but seems it
was forgotten.
CONFIG_MMIOTRACE and CONFIG_MMIOTRACE_TEST were selectable
directly under the Kernel hacking / debugging menu in the kernel
configuration system. They were present only for x86 and x86_64.
Other tracers that use the ftrace tracing framework are in their own
sub-menu. This patch moves the mmiotrace configuration options there.
Since the Kconfig file, where the tracer menu is, is not architecture
specific, HAVE_MMIOTRACE_SUPPORT is introduced and provided only by
x86/x86_64. CONFIG_MMIOTRACE now depends on it.
Signed-off-by: Pekka Paalanen <pq@iki.fi>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: enhances lost events counting in mmiotrace
The tracing framework, or the ring buffer facility it uses, has a switch
to stop recording data. When recording is off, the trace events will be
lost. The framework does not count these, so mmiotrace has to count them
itself.
Signed-off-by: Pekka Paalanen <pq@iki.fi>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: cleanup
- separate out the loop from the actual freeing logic, this wins us
two indentation levels allowing a number of followup prettifications
- turn the WARN_ON() into a more informative WARN().
- clean up the comments and the code flow some more
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The __GFP_FS annotations fail to build with CONFIG_LOCKDEP=y,
CONFIG_PROVE_LOCKING=n, ammend that.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Arnd pointed out we have the stringify macro magic already in-kernel.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
CC: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
re-add some of the comments that got lost in the refactoring.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Now that we have nice numerical relations for the states, remove the macro
magics.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Now what its only two functions, they again look rather similar.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Generate the state bit definitions from the lockdep_states.h file.
Also, move LOCK_USED to last, so that the
USED_IN
USED_IN_READ
ENABLED
ENABLED_READ
states are nicely bit aligned -- we're going to use that property
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Introduce a header file to generate all the states from.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
s/HELD_OVER/ENABLED/g
so that its similar to the hard and soft-irq names.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
s/\(LOCKF\?_ENABLED_[^ ]*\)S\(_READ\)\?\>/\1\2/g
So that the USED_IN and ENABLED have the same names.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Here is another version, with the incremental patch rolled up, and
added reclaim context annotation to kswapd, and allocation tracing
to slab allocators (which may only ever reach the page allocator
in rare cases, so it is good to put annotations here too).
Haven't tested this version as such, but it should be getting closer
to merge worthy ;)
--
After noticing some code in mm/filemap.c accidentally perform a __GFP_FS
allocation when it should not have been, I thought it might be a good idea to
try to catch this kind of thing with lockdep.
I coded up a little idea that seems to work. Unfortunately the system has to
actually be in __GFP_FS page reclaim, then take the lock, before it will mark
it. But at least that might still be some orders of magnitude more common
(and more debuggable) than an actual deadlock condition, so we have some
improvement I hope (the concept is no less complete than discovery of a lock's
interrupt contexts).
I guess we could even do the same thing with __GFP_IO (normal reclaim), and
even GFP_NOIO locks too... but filesystems will have the most locks and fiddly
code paths, so let's start there and see how it goes.
It *seems* to work. I did a quick test.
=================================
[ INFO: inconsistent lock state ]
2.6.28-rc6-00007-ged31348-dirty #26
---------------------------------
inconsistent {in-reclaim-W} -> {ov-reclaim-W} usage.
modprobe/8526 [HC0[0]:SC0[0]:HE1:SE1] takes:
(testlock){--..}, at: [<ffffffffa0020055>] brd_init+0x55/0x216 [brd]
{in-reclaim-W} state was registered at:
[<ffffffff80267bdb>] __lock_acquire+0x75b/0x1a60
[<ffffffff80268f71>] lock_acquire+0x91/0xc0
[<ffffffff8070f0e1>] mutex_lock_nested+0xb1/0x310
[<ffffffffa002002b>] brd_init+0x2b/0x216 [brd]
[<ffffffff8020903b>] _stext+0x3b/0x170
[<ffffffff80272ebf>] sys_init_module+0xaf/0x1e0
[<ffffffff8020c3fb>] system_call_fastpath+0x16/0x1b
[<ffffffffffffffff>] 0xffffffffffffffff
irq event stamp: 3929
hardirqs last enabled at (3929): [<ffffffff8070f2b5>] mutex_lock_nested+0x285/0x310
hardirqs last disabled at (3928): [<ffffffff8070f089>] mutex_lock_nested+0x59/0x310
softirqs last enabled at (3732): [<ffffffff8061f623>] sk_filter+0x83/0xe0
softirqs last disabled at (3730): [<ffffffff8061f5b6>] sk_filter+0x16/0xe0
other info that might help us debug this:
1 lock held by modprobe/8526:
#0: (testlock){--..}, at: [<ffffffffa0020055>] brd_init+0x55/0x216 [brd]
stack backtrace:
Pid: 8526, comm: modprobe Not tainted 2.6.28-rc6-00007-ged31348-dirty #26
Call Trace:
[<ffffffff80265483>] print_usage_bug+0x193/0x1d0
[<ffffffff80266530>] mark_lock+0xaf0/0xca0
[<ffffffff80266735>] mark_held_locks+0x55/0xc0
[<ffffffffa0020000>] ? brd_init+0x0/0x216 [brd]
[<ffffffff802667ca>] trace_reclaim_fs+0x2a/0x60
[<ffffffff80285005>] __alloc_pages_internal+0x475/0x580
[<ffffffff8070f29e>] ? mutex_lock_nested+0x26e/0x310
[<ffffffffa0020000>] ? brd_init+0x0/0x216 [brd]
[<ffffffffa002006a>] brd_init+0x6a/0x216 [brd]
[<ffffffffa0020000>] ? brd_init+0x0/0x216 [brd]
[<ffffffff8020903b>] _stext+0x3b/0x170
[<ffffffff8070f8b9>] ? mutex_unlock+0x9/0x10
[<ffffffff8070f83d>] ? __mutex_unlock_slowpath+0x10d/0x180
[<ffffffff802669ec>] ? trace_hardirqs_on_caller+0x12c/0x190
[<ffffffff80272ebf>] sys_init_module+0xaf/0x1e0
[<ffffffff8020c3fb>] system_call_fastpath+0x16/0x1b
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This modifies the timer code in a way to allow lockdep to detect
deadlocks resulting from a lock being taken in the timer function
as well as around the del_timer_sync() call.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
uids in namespaces other than init don't get a sysfs entry.
For those in the init namespace, while we're waiting to remove
the sysfs entry for the uid the uid is still hashed, and
alloc_uid() may re-grab that uid without getting a new
reference to the user_ns, which we've already put in free_user
before scheduling remove_user_sysfs_dir().
Reported-and-tested-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Serge E. Hallyn <serue@us.ibm.com>
Acked-by: David Howells <dhowells@redhat.com>
Tested-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Convert the c/p state "power" tracer to use tracepoints. Avoids a
function call when the tracer is disabled.
Signed-off-by: Jason Baron <jbaron@redhat.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
While reviewing the manpages, I noticed I'd missed some clock vs timer sites.
Make sure that all timer functions call cpu_timer_sample_group() and not
cpu_clock_sample_group(). This ensures that we enable the process wide timer
in time, and therefore pay the O(n) thread group cost from the syscall.
Not doing it here, will result in the first jiffy tick after setting the timer
doing this, resulting in a very expensive tick (but only once) and a delay in
actually starting the timer.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Jaswinder Singh Rajput reported that commit 23a185ca8a caused the
context switch and migration software counters to report zero always.
With that commit, the software counters only count events that occur
between sched-in and sched-out for a task. This is necessary for the
counter enable/disable prctls and ioctls to work. However, the
context switch and migration counts are incremented after sched-out
for one task and before sched-in for the next. Since the increment
doesn't occur while a task is scheduled in (as far as the software
counters are concerned) it doesn't count towards any counter.
Thus the context switch and migration counters need to count events
that occur at any time, provided the counter is enabled, not just
those that occur while the task is scheduled in (from the perf_counter
subsystem's point of view). The problem though is that the software
counter code can't tell the difference between being enabled and being
scheduled in, and between being disabled and being scheduled out,
since we use the one pair of enable/disable entry points for both.
That is, the high-level disable operation simply arranges for the
counter to not be scheduled in any more, and the high-level enable
operation arranges for it to be scheduled in again.
One way to solve this would be to have sched_in/out operations in the
hw_perf_counter_ops struct as well as enable/disable. However, this
takes a simpler approach: it adds a 'prev_state' field to the
perf_counter struct that allows a counter's enable method to know
whether the counter was previously disabled or just inactive
(scheduled out), and therefore whether the enable method is being
called as a result of a high-level enable or a schedule-in operation.
This then allows the context switch, migration and page fault counters
to reset their hw.prev_count value in their enable functions only if
they are called as a result of a high-level enable operation.
Although page faults would normally only occur while the counter is
scheduled in, this changes the page fault counter code too in case
there are ever circumstances where page faults get counted against a
task while its counters are not scheduled in.
Reported-by: Jaswinder Singh Rajput <jaswinder@kernel.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
request_irq() calls into proc code via __setup_irq() which is not safe
in an atomic context, so request_irq() can itself use the more
reliable GFP_KERNEL allocation for the action descriptor.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
