Impact: added precaution on failure detection
Break out of the modifying loop as soon as a failure is detected.
This is just an added precaution found by code review and was not
found by any bug chasing.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
This patch creates the weak functions: ftrace_arch_code_modify_prepare
and ftrace_arch_code_modify_post_process that are called before and
after the stop machine is called to modify the kernel text.
If the arch needs to do pre or post processing, it only needs to define
these functions.
[ Update: Ingo Molnar suggested using the name ftrace_arch_code_modify_*
over using ftrace_arch_modify_* ]
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Impact: trace only functions matching a pattern
The set_graph_function file let one to trace only one or several
chosen functions and follow all their code flow.
Currently, only a constant function name is allowed so this patch
allows the ftrace_regex functions:
- matches all functions that end with "name":
echo *name > set_graph_function
- matches all functions that begin with "name":
echo name* > set_graph_function
- matches all functions that contains "name":
echo *name* > set_graph_function
Example:
echo mutex* > set_graph_function
0) | mutex_lock_nested() {
0) 0.563 us | __might_sleep();
0) 2.072 us | }
0) | mutex_unlock() {
0) 1.036 us | __mutex_unlock_slowpath();
0) 2.433 us | }
0) | mutex_unlock() {
0) 0.691 us | __mutex_unlock_slowpath();
0) 1.787 us | }
0) | mutex_lock_interruptible_nested() {
0) 0.548 us | __might_sleep();
0) 1.945 us | }
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
tracing: limit the number of loops the ring buffer self test can make
tracing: have function trace select kallsyms
tracing: disable tracing while testing ring buffer
tracing/function-graph-tracer: trace the idle tasks
Impact: prevent deadlock if ring buffer gets corrupted
This patch adds a paranoid check to make sure the ring buffer consumer
does not go into an infinite loop. Since the ring buffer has been set
to read only, the consumer should not loop for more than the ring buffer
size. A check is added to make sure the consumer does not loop more than
the ring buffer size.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Impact: fix output of function tracer to be useful
The function tracer is pretty useless if KALLSYMS is not configured.
Unless you are good at reading hex values, the function tracer should
select the KALLSYMS configuration.
Also, the dynamic function tracer will fail its self test if KALLSYMS
is not selected.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Impact: fix to prevent hard lockup on self tests
If one of the tracers are broken and is constantly filling the ring
buffer while the test of the ring buffer is running, it will hang
the box. The reason is that the test is a consumer that will not
stop till the ring buffer is empty. But if the tracer is broken and
is constantly producing input to the buffer, this test will never
end. The result is a lockup of the box.
This happened when KALLSYMS was not defined and the dynamic ftrace
test constantly filled the ring buffer, because the filter failed
and all functions were being traced. Something was being called
that constantly filled the buffer.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
* 'for-linus' of git://git.kernel.dk/linux-2.6-block:
block: fix deadlock in blk_abort_queue() for drivers that readd to timeout list
block: fix booting from partitioned md array
block: revert part of 18ce3751cc
cciss: PCI power management reset for kexec
paride/pg.c: xs(): &&/|| confusion
fs/bio: bio_alloc_bioset: pass right object ptr to mempool_free
block: fix bad definition of BIO_RW_SYNC
bsg: Fix sense buffer bug in SG_IO
Compilation of kprobes.c with CONFIG_PM unset is broken due to some broken
config dependncies. Fix that.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Reported-by: Ingo Molnar <mingo@elte.hu>
Tested-by: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Len Brown <lenb@kernel.org>
Acked-by: Pavel Machek <pavel@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In cgroup_kill_sb(), root is freed before sb is detached from the list, so
another sget() may find this sb and call cgroup_test_super(), which will
access the root that has been freed.
Reported-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Acked-by: Paul Menage <menage@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There is nothing really arch specific of the push and pop functions
used by the function graph tracer. This patch moves them to generic
code.
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
We can't OR shift values, so get rid of BIO_RW_SYNC and use BIO_RW_SYNCIO
and BIO_RW_UNPLUG explicitly. This brings back the behaviour from before
213d9417fe.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Impact: api and pipe waiting change
Currently, the waiting used in tracing_read_pipe() is done through a
100 msecs schedule_timeout() loop which periodically check if there
are traces on the buffer.
This can cause small latencies for programs which are reading the incoming
events.
This patch makes the reader waiting for the trace_wait waitqueue except
for few tracers such as the sched and functions tracers which might be
already hold the runqueue lock while waking up the reader.
This is performed through a new callback wait_pipe() on struct tracer.
If none is implemented on a specific tracer, the default waiting for
trace_wait queue is attached.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
doc: mmiotrace.txt, buffer size control change
trace: mmiotrace to the tracer menu in Kconfig
mmiotrace: count events lost due to not recording
Impact: clean up
The traceon and traceoff function probes are confusing to developers
to what happens when a counter is not specified. This should help
clear things up.
# echo "*:traceoff" > set_ftrace_filter
# cat /debug/tracing/set_ftrace_filter
#### all functions enabled ####
do_fork:traceoff:unlimited
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Impact: cleanup
Fix incorrect hint message in code and typos in comments.
Signed-off-by: Wenji Huang <wenji.huang@oracle.com>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
This patch is to fix the return value of trace_selftest_startup_sysprof
and trace_selftest_startup_branch on failure.
Signed-off-by: Wenji Huang <wenji.huang@oracle.com>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Pass tsk to tracing_record_cmdline instead of current.
Signed-off-by: Wenji Huang <wenji.huang@oracle.com>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Impact: clean up
Ingo Molnar did not like the _hook naming convention used by the
select function tracer. Luis Claudio R. Goncalves suggested using
the "_probe" extension. This patch implements the change of
calling the functions and variables "_hook" and replacing them
with "_probe".
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Ingo Molnar pointed out some coding style issues with the recent ftrace
updates. This patch cleans them up.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
This patch adds a pretty print version of traceon and traceoff
output for set_ftrace_filter.
# echo 'sys_open:traceon:4' > set_ftrace_filter
# cat set_ftrace_filter
#### all functions enabled ####
sys_open:traceon:count=4
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
This patch adds a call back for the tracers that have hooks to
selected functions. This allows the tracer to show better output
in the set_ftrace_filter file.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
This patch adds output to show what functions have tracer hooks
attached to them.
# echo 'sys_open:traceon:4' > /debug/tracing/set_ftrace_filter
# cat set_ftrace_filter
#### all functions enabled ####
sys_open:ftrace_traceon:0000000000000004
# echo 'do_fork:traceoff:' > set_ftrace_filter
# cat set_ftrace_filter
#### all functions enabled ####
sys_open:ftrace_traceon:0000000000000002
do_fork:ftrace_traceoff:ffffffffffffffff
Note the 4 changed to a 2. This is because The code was executed twice
since the traceoff was added. If a cat is done again:
#### all functions enabled ####
sys_open:ftrace_traceon
do_fork:ftrace_traceoff:ffffffffffffffff
The number disappears. That is because it will not print a NULL.
Callbacks to allow the tracer to pretty print will be implemented soon.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
This patch adds the new function selection commands traceon and
traceoff. traceon sets the function to enable the ring buffers
while traceoff disables the ring buffers. You can pass in the
number of times you want the command to be executed when the function
is hit. It will only execute if the state of the buffers are not
already in that state.
Example:
# echo do_fork:traceon:4
Will enable the ring buffers if they are disabled every time it
hits do_fork, up to 4 times.
# echo sys_close:traceoff
This will disable the ring buffers every time (unlimited) when
sys_close is called.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Impact: new feature
Currently, the function tracer only gives you an ability to hook
a tracer to all functions being traced. The dynamic function trace
allows you to pick and choose which of those functions will be
traced, but all functions being traced will call all tracers that
registered with the function tracer.
This patch adds a new feature that allows a tracer to hook to specific
functions, even when all functions are being traced. It allows for
different functions to call different tracer hooks.
The way this is accomplished is by a special function that will hook
to the function tracer and will set up a hash table knowing which
tracer hook to call with which function. This is the most general
and easiest method to accomplish this. Later, an arch may choose
to supply their own method in changing the mcount call of a function
to call a different tracer. But that will be an exercise for the
future.
To register a function:
struct ftrace_hook_ops {
void (*func)(unsigned long ip,
unsigned long parent_ip,
void **data);
int (*callback)(unsigned long ip, void **data);
void (*free)(void **data);
};
int register_ftrace_function_hook(char *glob, struct ftrace_hook_ops *ops,
void *data);
glob is a simple glob to search for the functions to hook.
ops is a pointer to the operations (listed below)
data is the default data to be passed to the hook functions when traced
ops:
func is the hook function to call when the functions are traced
callback is a callback function that is called when setting up the hash.
That is, if the tracer needs to do something special for each
function, that is being traced, and wants to give each function
its own data. The address of the entry data is passed to this
callback, so that the callback may wish to update the entry to
whatever it would like.
free is a callback for when the entry is freed. In case the tracer
allocated any data, it is give the chance to free it.
To unregister we have three functions:
void
unregister_ftrace_function_hook(char *glob, struct ftrace_hook_ops *ops,
void *data)
This will unregister all hooks that match glob, point to ops, and
have its data matching data. (note, if glob is NULL, blank or '*',
all functions will be tested).
void
unregister_ftrace_function_hook_func(char *glob,
struct ftrace_hook_ops *ops)
This will unregister all functions matching glob that has an entry
pointing to ops.
void unregister_ftrace_function_hook_all(char *glob)
This simply unregisters all funcs.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Impact: clean up
Now that ftrace_lock is a mutex, there is no reason to have three
different mutexes protecting similar data. All the mutex paths
are not in hot paths, so having a mutex to cover more data is
not a problem.
This patch removes the ftrace_sysctl_lock and ftrace_start_lock
and uses the ftrace_lock to protect the locations that were protected
by these locks. By doing so, this change also removes some of
the lock nesting that was taking place.
There are still more mutexes in ftrace.c that can probably be
consolidated, but they can be dealt with later. We need to be careful
about the way the locks are nested, and by consolidating, we can cause
a recursive deadlock.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Impact: clean up
The older versions of ftrace required doing the ftrace list
search under atomic context. Now all the calls are in non-atomic
context. There is no reason to keep the ftrace_lock as a spinlock.
This patch converts it to a mutex.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Allow for other tracers to add their own commands for function
selection. This interface gives a trace the ability to name a
command for function selection. Right now it is pretty limited
in what it offers, but this is a building step for more features.
The :mod: command is converted to this interface and also serves
as a template for other implementations.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Impact: fix to prevent empty set_ftrace_filter and no ftrace output
The function filter is used to only trace a given set of functions.
The filter is enabled when a function name is echoed into the
set_ftrace_filter file. But if the name has a typo and the function
is not found, the filter is enabled, but no function is listed.
This makes a confusing situation where set_ftrace_filter is empty
but no functions ever get enabled for tracing.
For example:
# cat /debug/tracing/set_ftrace_filter
#### all functions enabled ####
# echo bad_name > set_ftrace_filter
# cat /debug/tracing/set_ftrace_filter
# echo function > current_tracer
# cat trace
# tracer: nop
#
# TASK-PID CPU# TIMESTAMP FUNCTION
# | | | | |
This patch changes that to only enable filtering if a function
is set to be filtered on. Now, the filter is not enabled if
a bad name is echoed into set_ftrace_filter.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
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>
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>
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>
Impact: clean up
While reviewing the ring buffer code, I thougth I saw a bug with
if (!__raw_spin_trylock(&cpu_buffer->lock))
goto out_unlock;
But I forgot that we use a variable "lock_taken" that is set if
the spinlock is taken, and only unlock it if that variable is set.
To avoid further confusion from other reviewers, this patch
renames the label out_unlock with out_reset, which is the more
appropriate name.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
I enabled all cgroup subsystems when compiling kernel, and then:
# mount -t cgroup -o net_cls xxx /mnt
# mkdir /mnt/0
This showed up immediately:
BUG: MAX_LOCKDEP_SUBCLASSES too low!
turning off the locking correctness validator.
It's caused by the cgroup hierarchy lock:
for (i = 0; i < CGROUP_SUBSYS_COUNT; i++) {
struct cgroup_subsys *ss = subsys[i];
if (ss->root == root)
mutex_lock_nested(&ss->hierarchy_mutex, i);
}
Now we have 9 cgroup subsystems, and the above 'i' for net_cls is 8, but
MAX_LOCKDEP_SUBCLASSES is 8.
This patch uses different lockdep keys for different subsystems.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Acked-by: Paul Menage <menage@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We need to pass an unsigned long as the minimum, because it gets casted
to an unsigned long in the sysctl handler. If we pass an int, we'll
access four more bytes on 64bit arches, resulting in a random minimum
value.
[rientjes@google.com: fix type of `old_bytes']
Signed-off-by: Sven Wegener <sven.wegener@stealer.net>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Catalin noticed that (38d47c1b70: futex: rely on get_user_pages() for
shared futexes) caused an mm_struct leak.
Some tracing with the function graph tracer quickly pointed out that
futex_wait() has exit paths with unbalanced reference counts.
This regression was discovered by kmemleak.
Reported-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Tested-by: "Pallipadi, Venkatesh" <venkatesh.pallipadi@intel.com>
Tested-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
timers: fix TIMER_ABSTIME for process wide cpu timers
timers: split process wide cpu clocks/timers, fix
x86: clean up hpet timer reinit
timers: split process wide cpu clocks/timers, remove spurious warning
timers: split process wide cpu clocks/timers
signal: re-add dead task accumulation stats.
x86: fix hpet timer reinit for x86_64
sched: fix nohz load balancer on cpu offline
* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
ptrace, x86: fix the usage of ptrace_fork()
i8327: fix outb() parameter order
x86: fix math_emu register frame access
x86: math_emu info cleanup
x86: include correct %gs in a.out core dump
x86, vmi: put a missing paravirt_release_pmd in pgd_dtor
x86: find nr_irqs_gsi with mp_ioapic_routing
x86: add clflush before monitor for Intel 7400 series
x86: disable intel_iommu support by default
x86: don't apply __supported_pte_mask to non-present ptes
x86: fix grammar in user-visible BIOS warning
x86/Kconfig.cpu: make Kconfig help readable in the console
x86, 64-bit: print DMI info in the oops trace
Intel reported a 10% regression (mysql+sysbench) on a 16-way machine
with these patches:
1596e29: sched: symmetric sync vs avg_overlap
d942fb6: sched: fix sync wakeups
Revert them.
Reported-by: "Zhang, Yanmin" <yanmin_zhang@linux.intel.com>
Bisected-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The POSIX timer interface allows for absolute time expiry values through the
TIMER_ABSTIME flag, therefore we have to synchronize the timer to the clock
every time we start it.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
To decrease the chance of a missed enable, always enable the timer when we
sample it, we'll always disable it when we find that there are no active timers
in the jiffy tick.
This fixes a flood of warnings reported by Mike Galbraith.
Reported-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Add the missing pair tracing_{start,stop}_record_cmdline() to record well
the cmdline associated with pid.
Changes in v2:
- fix a build error, the sched_switch tracer is needed to record the
cmdline.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
I noticed by pure accident we have ptrace_fork() and friends. This was
added by "x86, bts: add fork and exit handling", commit
bf53de907d.
I can't test this, ds_request_bts() returns -EOPNOTSUPP, but I strongly
believe this needs the fix. I think something like this program
int main(void)
{
int pid = fork();
if (!pid) {
ptrace(PTRACE_TRACEME, 0, NULL, NULL);
kill(getpid(), SIGSTOP);
fork();
} else {
struct ptrace_bts_config bts = {
.flags = PTRACE_BTS_O_ALLOC,
.size = 4 * 4096,
};
wait(NULL);
ptrace(PTRACE_SETOPTIONS, pid, NULL, PTRACE_O_TRACEFORK);
ptrace(PTRACE_BTS_CONFIG, pid, &bts, sizeof(bts));
ptrace(PTRACE_CONT, pid, NULL, NULL);
sleep(1);
}
return 0;
}
should crash the kernel.
If the task is traced by its natural parent ptrace_reparented() returns 0
but we should clear ->btsxxx anyway.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Markus Metzger <markus.t.metzger@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Fix these sparse warnings:
kernel/trace/ring_buffer.c:70:37: warning: incorrect type in argument 2 (different signedness)
kernel/trace/ring_buffer.c:84:39: warning: incorrect type in argument 2 (different signedness)
kernel/trace/ring_buffer.c:96:43: warning: incorrect type in argument 2 (different signedness)
kernel/trace/ring_buffer.c:2475:13: warning: incorrect type in argument 2 (different signedness)
kernel/trace/ring_buffer.c:2475:13: warning: incorrect type in argument 2 (different signedness)
kernel/trace/ring_buffer.c:2478:42: warning: incorrect type in argument 2 (different signedness)
kernel/trace/ring_buffer.c:2478:42: warning: incorrect type in argument 2 (different signedness)
kernel/trace/ring_buffer.c:2500:40: warning: incorrect type in argument 3 (different signedness)
kernel/trace/ring_buffer.c:2505:44: warning: incorrect type in argument 2 (different signedness)
kernel/trace/ring_buffer.c:2507:46: warning: incorrect type in argument 2 (different signedness)
kernel/trace/trace.c:2130:40: warning: incorrect type in argument 3 (different signedness)
kernel/trace/trace.c:2280:40: warning: incorrect type in argument 3 (different signedness)
Signed-off-by: Hannes Eder <hannes@hanneseder.net>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: make global variables and a global function static
The function '__trace_userstack' does not seem to have a caller, so it
is commented out.
Fix this sparse warnings:
kernel/trace/trace.c:82:5: warning: symbol 'tracing_disabled' was not declared. Should it be static?
kernel/trace/trace.c:600:10: warning: symbol 'trace_record_cmdline_disabled' was not declared. Should it be static?
kernel/trace/trace.c:957:6: warning: symbol '__trace_userstack' was not declared. Should it be static?
kernel/trace/trace.c:1694:5: warning: symbol 'tracing_release' was not declared. Should it be static?
Signed-off-by: Hannes Eder <hannes@hanneseder.net>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This patch is to make the function return early on failure, and give
correct return value on success.
Signed-off-by: Wenji Huang <wenji.huang@oracle.com>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
The C99 specification states in section 6.11.5:
The placement of a storage-class specifier other than at the beginning
of the declaration specifiers in a declaration is an obsolescent
feature.
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Impact: change API and init bpage when copy
ring_buffer_read_page()/rb_remove_entries() may be called for
a partially consumed page.
Add a parameter for rb_remove_entries() and make it update
cpu_buffer->entries correctly for partially consumed pages.
ring_buffer_read_page() now returns the offset to the next event.
Init the bpage's time_stamp when return value is 0.
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Impact: Fix bug
I found several very very curious line.
It's so curious that it may be brought by typing mistake.
When (cpu_buffer->reader_page == cpu_buffer->commit_page):
1) We haven't copied it for bpage is changed:
bpage = cpu_buffer->reader_page->page;
memcpy(bpage->data, cpu_buffer->reader_page->page->data + read ... )
2) We need update cpu_buffer->reader_page->read, but
"cpu_buffer->reader_page += read;" is not right.
[
This bug was a typo. The commit->reader_page is a page pointer
and not an index into the page. The line should have been
commit->reader_page->read += read. The other changes
by Lai are nice clean ups to the code. - SDR
]
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Impact: fix broken /proc/profile on UP machines
Commit c309b917ca "cpumask: convert
kernel/profile.c" broke profiling. prof_cpu_mask was previously
initialized to CPU_MASK_ALL, but left uninitialized in that commit.
We need to copy cpu_possible_mask (cpu_online_mask is not enough).
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Ingo Molnar suggested a series of clean ups for the splice code.
This patch implements those suggestions.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
This moves the pipe waiting code from tracing_read_pipe() into
tracing_wait_pipe(), which is useful to implement other fops, like
splice_read.
Signed-off-by: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Added and implemented tracing_pipe_fops->splice_read(). This allows
userspace programs to get tracing data more efficiently.
Signed-off-by: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
When one cats the trace file, the leaf functions are printed without brackets:
function();
whereas in the trace_pipe file we'll see the following:
function() {
}
This is because the ring_buffer handling is not the same between those two files.
On the trace file, when an entry is printed, the iterator advanced and then we can
check the next entry.
There is no iterator with trace_pipe, the current entry to print has been peeked
and not consumed. So checking the next entry will still return the current one while
we don't consume it.
This patch introduces a new value for the output callbacks to ask the tracing
core to not consume the current entry after printing it.
We need it because we will have to consume the current entry ourself to check
the next one.
Now the trace_pipe is able to handle well the leaf functions.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: build fix
The BLK_DEV_IO_TRACE entry used to be in block/Kconfig - which
file itself was dependent on CONFIG_BLOCK. But now the entry is
in kernel/trace/Kconfig - which is present even on !CONFIG_BLOCK.
So add a 'depends on BLOCK' to BLK_DEV_IO_TRACE.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: simplification
Instead of requiring that plugins have the sequence:
my_tracer_stop(my_trace_array);
unregister_tracer(my_tracer);
it should be possible just do a:
unregister_tracer(my_tracer);
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
When the function graph tracer picks a return address, it ensures this address
is really a kernel text one by calling __kernel_text_address()
Actually this path has never been taken.Its role was more likely to debug the tracer
on the beginning of its development but this function is wasteful since it is called
for every traced function.
The fault check is already sufficient.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: cleanup
Move the power tracer headers to trace/power.h to keep ftrace.h and power bits
more easy to maintain as separated topics.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Making it more easy to do a basic regression test for this tracer.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
list.h provides a dedicated primitive for
"list_del followed by list_add_tail"... list_move_tail.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
