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* ring_buffer: Do no not complete benchmark reader too earlyPetr Mladek2015-11-031-9/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It seems that complete(&read_done) might be called too early in some situations. 1st scenario: ------------- CPU0 CPU1 ring_buffer_producer_thread() wake_up_process(consumer); wait_for_completion(&read_start); ring_buffer_consumer_thread() complete(&read_start); ring_buffer_producer() # producing data in # the do-while cycle ring_buffer_consumer(); # reading data # got error # set kill_test = 1; set_current_state( TASK_INTERRUPTIBLE); if (reader_finish) # false schedule(); # producer still in the middle of # do-while cycle if (consumer && !(cnt % wakeup_interval)) wake_up_process(consumer); # spurious wakeup while (!reader_finish && !kill_test) # leaving because # kill_test == 1 reader_finish = 0; complete(&read_done); 1st BANG: We might access uninitialized "read_done" if this is the the first round. # producer finally leaving # the do-while cycle because kill_test == 1; if (consumer) { reader_finish = 1; wake_up_process(consumer); wait_for_completion(&read_done); 2nd BANG: This will never complete because consumer already did the completion. 2nd scenario: ------------- CPU0 CPU1 ring_buffer_producer_thread() wake_up_process(consumer); wait_for_completion(&read_start); ring_buffer_consumer_thread() complete(&read_start); ring_buffer_producer() # CPU3 removes the module <--- difference from # and stops producer <--- the 1st scenario if (kthread_should_stop()) kill_test = 1; ring_buffer_consumer(); while (!reader_finish && !kill_test) # kill_test == 1 => we never go # into the top level while() reader_finish = 0; complete(&read_done); # producer still in the middle of # do-while cycle if (consumer && !(cnt % wakeup_interval)) wake_up_process(consumer); # spurious wakeup while (!reader_finish && !kill_test) # leaving because kill_test == 1 reader_finish = 0; complete(&read_done); BANG: We are in the same "bang" situations as in the 1st scenario. Root of the problem: -------------------- ring_buffer_consumer() must complete "read_done" only when "reader_finish" variable is set. It must not be skipped due to other conditions. Note that we still must keep the check for "reader_finish" in a loop because there might be spurious wakeups as described in the above scenarios. Solution: ---------- The top level cycle in ring_buffer_consumer() will finish only when "reader_finish" is set. The data will be read in "while-do" cycle so that they are not read after an error (kill_test == 1) or a spurious wake up. In addition, "reader_finish" is manipulated by the producer thread. Therefore we add READ_ONCE() to make sure that the fresh value is read in each cycle. Also we add the corresponding barrier to synchronize the sleep check. Next we set the state back to TASK_RUNNING for the situation where we did not sleep. Just from paranoid reasons, we initialize both completions statically. This is safer, in case there are other races that we are unaware of. As a side effect we could remove the memory barrier from ring_buffer_producer_thread(). IMHO, this was the reason for the barrier. ring_buffer_reset() uses spin locks that should provide the needed memory barrier for using the buffer. Link: http://lkml.kernel.org/r/1441629518-32712-2-git-send-email-pmladek@suse.com Signed-off-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* tracing: Remove redundant TP_ARGS redefiningDmitry Safonov2015-11-031-3/+0
| | | | | | | | | | TP_ARGS is not used anywhere in trace.h nor trace_entries.h Firstly, I left just #undef TP_ARGS and had no errors - remove it. Link: http://lkml.kernel.org/r/1446576560-14085-1-git-send-email-0x7f454c46@gmail.com Signed-off-by: Dmitry Safonov <0x7f454c46@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* tracing: Rename max_stack_lock to stack_trace_max_lockSteven Rostedt (Red Hat)2015-11-031-8/+8
| | | | | | | | Now that max_stack_lock is a global variable, it requires a naming convention that is unlikely to collide. Rename it to the same naming convention that the other stack_trace variables have. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* tracing: Allow arch-specific stack tracerAKASHI Takahiro2015-11-031-37/+43
| | | | | | | | | | | | | | | | | A stack frame may be used in a different way depending on cpu architecture. Thus it is not always appropriate to slurp the stack contents, as current check_stack() does, in order to calcurate a stack index (height) at a given function call. At least not on arm64. In addition, there is a possibility that we will mistakenly detect a stale stack frame which has not been overwritten. This patch makes check_stack() a weak function so as to later implement arch-specific version. Link: http://lkml.kernel.org/r/1446182741-31019-5-git-send-email-takahiro.akashi@linaro.org Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* tracing: ftrace_event_is_function() can return booleanYaowei Bai2015-11-022-2/+2
| | | | | | | | | | | | | Make ftrace_event_is_function() return bool to improve readability due to this particular function only using either one or zero as its return value. No functional change. Link: http://lkml.kernel.org/r/1443537816-5788-9-git-send-email-bywxiaobai@163.com Signed-off-by: Yaowei Bai <bywxiaobai@163.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* tracing: is_legal_op() can return booleanYaowei Bai2015-11-021-4/+4
| | | | | | | | | | | | Make is_legal_op() return bool to improve readability due to this particular function only using either one or zero as its return value. No functional change. Link: http://lkml.kernel.org/r/1443537816-5788-8-git-send-email-bywxiaobai@163.com Signed-off-by: Yaowei Bai <bywxiaobai@163.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* ring-buffer: rb_event_is_commit() can return booleanYaowei Bai2015-11-021-2/+2
| | | | | | | | | | | | | Make rb_event_is_commit() return bool to improve readability due to this particular function only using either one or zero as its return value. No functional change. Link: http://lkml.kernel.org/r/1443537816-5788-7-git-send-email-bywxiaobai@163.com Signed-off-by: Yaowei Bai <bywxiaobai@163.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* ring-buffer: rb_per_cpu_empty() can return booleanYaowei Bai2015-11-021-2/+2
| | | | | | | | | | | Makes rb_per_cpu_empty() return bool to improve readability. No functional change. Link: http://lkml.kernel.org/r/1443537816-5788-6-git-send-email-bywxiaobai@163.com Signed-off-by: Yaowei Bai <bywxiaobai@163.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* ring_buffer: ring_buffer_empty{cpu}() can return booleanYaowei Bai2015-11-021-5/+5
| | | | | | | | | | | Make ring_buffer_empty() and ring_buffer_empty_cpu() return bool. No functional change. Link: http://lkml.kernel.org/r/1443537816-5788-5-git-send-email-bywxiaobai@163.com Signed-off-by: Yaowei Bai <bywxiaobai@163.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* ring-buffer: rb_is_reader_page() can return booleanYaowei Bai2015-11-021-1/+1
| | | | | | | | | | | | Make rb_is_reader_page() return bool to improve readability due to this particular function only using either true or false as its return value. No functional change. Link: http://lkml.kernel.org/r/1443537816-5788-4-git-send-email-bywxiaobai@163.com Signed-off-by: Yaowei Bai <bywxiaobai@163.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* tracing: report_latency() in trace_irqsoff.c can return booleanYaowei Bai2015-11-021-4/+4
| | | | | | | | | | | | | This patch makes report_latency return bool due to this particular function only using either one or zero as its return value. No functional change. Link: http://lkml.kernel.org/r/1443537816-5788-3-git-send-email-bywxiaobai@163.com Signed-off-by: Yaowei Bai <bywxiaobai@163.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* tracing: report_latency() in trace_sched_wakeup.c can return booleanYaowei Bai2015-11-021-4/+4
| | | | | | | | | | | | This patch makes report_latency return bool to improve readability, indicating whether this new latency should be reported/recorded. No functional change. Link: http://lkml.kernel.org/r/1443537816-5788-2-git-send-email-bywxiaobai@163.com Signed-off-by: Yaowei Bai <bywxiaobai@163.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* tracing: Update instance_rmdir() to use tracefs_remove_recursiveJiaxing Wang2015-11-021-1/+1
| | | | | | | | | | | | | Update instancd_rmdir to use tracefs_remove_recursive instead of debugfs_remove_recursive.This was left in the transition from debugfs to tracefs. Link: http://lkml.kernel.org/r/1445169490-18315-2-git-send-email-hello.wjx@gmail.com Cc: stable@vger.kernel.org # 4.1+ Fixes: 8434dc9340cd2 ("tracing: Convert the tracing facility over to use tracefs") Signed-off-by: Jiaxing Wang <hello.wjx@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* tracing: Only benchmark the time tracepoints take if tracing is onChunyan Zhang2015-11-021-1/+1
| | | | | | | | | | | | | | | | | | There's no need to record the time tracepoints take when tracing is off. This is because: 1) We cannot see these records since ring_buffer record is off at that moment. 2) If tracing is off and benchmark tracepoint is enabled, the time tracepoint takes is fewer than the same situation when tracing is on, since the tracepoints need to be wrote into ring_buffer, it would take more time. If turn on tracing at this moment, the average and standard deviation cannot exactly present the time that tracepoints take to write data into ring_buffer. Link: http://lkml.kernel.org/r/1445947933-27955-1-git-send-email-zhang.chunyan@linaro.org Signed-off-by: Chunyan Zhang <zhang.chunyan@linaro.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* tracing: Call on_each_cpu() when adding or removing single pids from ↵Steven Rostedt (Red Hat)2015-11-021-6/+7
| | | | | | | | | | | | | | | | | | | | | set_event_pid For the case where pids are already in set_event_pid, and one is added or removed then each CPU should be checked to make sure that the new or old pid is on or not on a CPU. For example: # echo 123 >> set_event_pid or # echo '!123' >> set_event_pid Link: http://lkml.kernel.org/r/20151030061643.GA19480@cac Suggested-by: Jiaxing Wang <hello.wjx@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* tracing: Fix sparse RCU warningSteven Rostedt (Red Hat)2015-10-261-0/+2
| | | | | | | | | p_start() and p_stop() are seq_file functions that match. Teach sparse to know that rcu_read_lock_sched() that is taken by p_start() is released by p_stop. Reported-by: kbuild test robot <fengguang.wu@intel.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* tracing: Check all tasks on each CPU when filtering pidsSteven Rostedt (Red Hat)2015-10-251-0/+22
| | | | | | | | | | My tests found that if a task is running but not filtered when set_event_pid is modified, then it can still be traced. Call on_each_cpu() to check if the current running task should be filtered and update the per cpu flags of tr->data appropriately. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* tracing: Implement event pid filteringSteven Rostedt (Red Hat)2015-10-252-3/+147
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Add the necessary hooks to use the pids loaded in set_event_pid to filter all the events enabled in the tracing instance that match the pids listed. Two probes are added to both sched_switch and sched_wakeup tracepoints to be called before other probes are called and after the other probes are called. The first is used to set the necessary flags to let the probes know to test if they should be traced or not. The sched_switch pre probe will set the "ignore_pid" flag if neither the previous or next task has a matching pid. The sched_switch probe will set the "ignore_pid" flag if the next task does not match the matching pid. The pre probe allows for probes tracing sched_switch to be traced if necessary. The sched_wakeup pre probe will set the "ignore_pid" flag if neither the current task nor the wakee task has a matching pid. The sched_wakeup post probe will set the "ignore_pid" flag if the current task does not have a matching pid. Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* tracing: Add set_event_pid directory for future useSteven Rostedt (Red Hat)2015-10-252-0/+294
| | | | | | | | | | | | | | Create a tracing directory called set_event_pid, which currently has no function, but will be used to filter all events for the tracing instance or the pids that are added to the file. The reason no functionality is added with this commit is that this commit focuses on the creation and removal of the pids in a safe manner. And tests can be made against this change to make sure things are correct before hooking features to the list of pids. Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* tracepoint: Give priority to probes of tracepointsSteven Rostedt (Red Hat)2015-10-251-11/+50
| | | | | | | | | | | | | | | | | | | | | | | In order to guarantee that a probe will be called before other probes that are attached to a tracepoint, there needs to be a mechanism to provide priority of one probe over the others. Adding a prio field to the struct tracepoint_func, which lets the probes be sorted by the priority set in the structure. If no priority is specified, then a priority of 10 is given (this is a macro, and perhaps may be changed in the future). Now probes may be added to affect other probes that are attached to a tracepoint with a guaranteed order. One use case would be to allow tracing of tracepoints be able to filter by pid. A special (higher priority probe) may be added to the sched_switch tracepoint and set the necessary flags of the other tracepoints to notify them if they should be traced or not. In case a tracepoint is enabled at the sched_switch tracepoint too, the order of the two are not random. Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* tracing: Remove {start,stop}_branch_traceDmitry Safonov2015-10-211-13/+2
| | | | | | | | | | | Both start_branch_trace() and stop_branch_trace() are used in only one location, and are both static. As they are small functions there is no need to keep them separated out. Link: http://lkml.kernel.org/r/1445000689-32596-1-git-send-email-0x7f454c46@gmail.com Signed-off-by: Dmitry Safonov <0x7f454c46@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* tracing: gpio: Add Kconfig option for enabling/disabling trace eventsTal Shorer2015-10-201-0/+7
| | | | | | | | | | | Add a new options to trace Kconfig, CONFIG_TRACING_EVENTS_GPIO, that is used for enabling/disabling compilation of gpio function trace events. Link: http://lkml.kernel.org/r/1438432079-11704-4-git-send-email-tal.shorer@gmail.com Acked-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Tal Shorer <tal.shorer@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* ftrace: add module globbingDmitry Safonov2015-10-201-15/+36
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Extend module command for function filter selection with globbing. It uses the same globbing as function filter. sh# echo '*alloc*:mod:*' > set_ftrace_filter Will trace any function with the letters 'alloc' in the name in any module but not in kernel. sh# echo '!*alloc*:mod:ipv6' >> set_ftrace_filter Will prevent from tracing functions with 'alloc' in the name from module ipv6 (do not forget to append to set_ftrace_filter file). sh# echo '*alloc*:mod:!ipv6' > set_ftrace_filter Will trace functions with 'alloc' in the name from kernel and any module except ipv6. sh# echo '*alloc*:mod:!*' > set_ftrace_filter Will trace any function with the letters 'alloc' in the name only from kernel, but not from any module. sh# echo '*:mod:!*' > set_ftrace_filter or sh# echo ':mod:!' > set_ftrace_filter Will trace every function in the kernel, but will not trace functions from any module. sh# echo '*:mod:*' > set_ftrace_filter or sh# echo ':mod:' > set_ftrace_filter As the opposite will trace all functions from all modules, but not from kernel. sh# echo '*:mod:*snd*' > set_ftrace_filter Will trace your sound drivers only (if any). Link: http://lkml.kernel.org/r/1443545176-3215-4-git-send-email-0x7f454c46@gmail.com Signed-off-by: Dmitry Safonov <0x7f454c46@gmail.com> [ Made format changes ] Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* ftrace: Introduce ftrace_glob structureDmitry Safonov2015-10-201-38/+46
| | | | | | | | | | | | | ftrace_match parameters are very related and I reduce the number of local variables & parameters with it. This is also preparation for module globbing as it would introduce more realated variables & parameters. Link: http://lkml.kernel.org/r/1443545176-3215-3-git-send-email-0x7f454c46@gmail.com Signed-off-by: Dmitry Safonov <0x7f454c46@gmail.com> [ Made some formatting changes ] Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* ftrace: Clarify code for mod commandDmitry Safonov2015-10-161-27/+10
| | | | | | | | | | | | | "Not" is too abstract variable name - changed to clear_filter. Removed ftrace_match_module_records function: comparison with !* or * not does the general code in filter_parse_regex() as it works without mod command for sh# echo '!*' > /sys/kernel/debug/tracing/set_ftrace_filter Link: http://lkml.kernel.org/r/1443545176-3215-2-git-send-email-0x7f454c46@gmail.com Signed-off-by: Dmitry Safonov <0x7f454c46@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* ftrace: Remove redundant strsep in mod_callbackDmitry Safonov2015-10-131-10/+5
| | | | | | | | | | | | | | | | | | | By now there isn't any subcommand for mod. Before: sh$ echo '*:mod:ipv6:a' > set_ftrace_filter sh$ echo '*:mod:ipv6' > set_ftrace_filter had the same results, but now first will result in: sh$ echo '*:mod:ipv6:a' > set_ftrace_filter -bash: echo: write error: Invalid argument Also, I clarified ftrace_mod_callback code a little. Link: http://lkml.kernel.org/r/1443545176-3215-1-git-send-email-0x7f454c46@gmail.com Signed-off-by: Dmitry Safonov <0x7f454c46@gmail.com> [ converted 'if (ret == 0)' to 'if (!ret)' ] Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* ftrace: Remove redundant swap functionRasmus Villemoes2015-10-011-12/+1
| | | | | | | | | | | | | | To cover the common case of sorting an array of pointers, Daniel Wagner recently modified the library sort() to use a specific swap function for size==8, in addition to the size==4 case which was already handled. Since sizeof(long) is either 4 or 8, ftrace_swap_ips() is redundant and we can just let sort() pick an appropriate and fast swap callback. Link: http://lkml.kernel.org/r/1441834023-13130-1-git-send-email-linux@rasmusvillemoes.dk Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* tracing: Use kstrdup_const instead of private implementationRasmus Villemoes2015-10-011-16/+8
| | | | | | | | | | | | | | | | | | | The kernel now has kstrdup_const/kfree_const for reusing .rodata (typically string literals) when possible; there's no reason to duplicate that logic in the tracing system. Moreover, as the comment above core_kernel_data states, it may not always return true for .rodata - that is for example the case on x86_64, where we thus end up kstrdup'ing all the passed-in strings. Arguably, testing for .rodata explicitly (as kstrdup_const does) is also more correct: I don't think one is supposed to be able to change the name after creating the event_subsystem by passing the address of a static char (but non-const) array. Link: http://lkml.kernel.org/r/1441833841-12955-1-git-send-email-linux@rasmusvillemoes.dk Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* tracing: Add trace options for tracer options to instancesSteven Rostedt (Red Hat)2015-09-302-22/+67
| | | | | | | | | Add the tracer options to instances options directory as well. Only add the options for tracers that are allowed to be enabled by an instance. But note, that tracer options are global. That is, tracer options enabled in an instance, also take affect at the top level and in other instances. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* tracing: Add trace options for core options to instancesSteven Rostedt (Red Hat)2015-09-301-5/+14
| | | | | | | | | Allow instances to have their own options, at least for the core options (non tracer specific ones). There are a few global options that should not be added to instances, like enabling of trace_printk, and the sched comm recording, which do not have a specific trace instance associated to them. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* tracing: Make ftrace_trace_stack() depend on general trace_array flagSteven Rostedt (Red Hat)2015-09-302-13/+16
| | | | | | | | In preparation for the multi buffer instances to have their own trace_flags, the check in ftrace_trace_stack() needs to test the trace_array descriptor flag that is for the current event, not the global_trace descriptor. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* tracing: Add a method to pass in trace_array descriptor to option filesSteven Rostedt (Red Hat)2015-09-302-7/+63
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | In preparation of having the multi buffer instances having their own trace option flags, the trace option files needs a way to not only pass in the flag they represent, but also the trace_array descriptor. A new field is added to the trace_array descriptor called trace_flags_index, which is a 32 byte character array representing a bit. This array is simply filled with the index of the array, where index_array[n] = n; Then the address of this array is passed to the file callbacks instead of the index of the flag index. Then to retrieve both the flag index and the trace_array descriptor: data is the passed in argument. index = *(unsigned char *)data; data -= index; /* Now data points to the address of the array in the trace_array */ tr = container_of(data, struct trace_array, trace_flags_index); Suggested-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* tracing: Move trace_flags from global to a trace_array fieldSteven Rostedt (Red Hat)2015-09-3010-101/+135
| | | | | | | | | | | | | | | | | In preparation to make trace options per instance, the global trace_flags needs to be moved from being a global variable to a field within the trace instance trace_array structure. There's still more work to do, as there's some functions that use trace_flags without passing in a way to get to the current_trace array. For those, the global_trace is used directly (from trace.c). This includes setting and clearing the trace_flags. This means that when a new instance is created, it just gets the trace_flags of the global_trace and will not be able to modify them. Depending on the functions that have access to the trace_array, the flags of an instance may not affect parts of its trace, where the global_trace is used. These will be fixed in future changes. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* tracing: Move sleep-time and graph-time options out of the core trace_flagsSteven Rostedt (Red Hat)2015-09-304-10/+35
| | | | | | | | | The sleep-time and graph-time options are only for the function graph tracer and are not used by anything else. As tracer options are now visible when the tracer is not activated, its better to move the function graph specific tracer options into the function graph tracer. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* tracing: Remove access to trace_flags in trace_printk.cSteven Rostedt (Red Hat)2015-09-303-5/+14
| | | | | | | | | | In the effort to move the global trace_flags to the tracing instances, the direct access to trace_flags must be removed from trace_printk.c Instead, add a new trace_printk_enabled boolean that is set by a new access function trace_printk_control(), that will enable or disable trace_printk. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* tracing: Add build bug if we have more trace_flags than bitsSteven Rostedt (Red Hat)2015-09-302-1/+11
| | | | | | | | | Add a enum that denotes the last bit of the trace_flags and have a BUILD_BUG_ON(last_bit > 32). If we add more bits than we have in trace_flags, the kernel wont build. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* tracing: Always show all tracer options in the options directorySteven Rostedt (Red Hat)2015-09-302-34/+27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There are options that are unique to a specific tracer (like function and function graph). Currently, these options are only visible in the options directory when the tracer is enabled. This has been a pain, especially for something like the func_stack_trace option that if used inappropriately, could bring the system to a crawl. But the only way to see it, is to enable the function tracer. For example, if one had done: # cd /sys/kernel/tracing # echo __schedule > set_ftrace_filter # echo 1 > options/func_stack_trace # echo function > current_tracer The __schedule call will be traced and a stack trace will also be recorded there. Now when you were done, you may do... # echo nop > current_tracer # echo > set_ftrace_filter But you forgot to disable the func_stack_trace. The only way to disable it is to re-enable function tracing first. If you do not add a filter to set_ftrace_filter and just do: # echo function > current_tracer Now you would be performing a stack trace on *every* function! On some systems, that causes a live lock. Others may take a few minutes to fix your mistake. Having the func_stack_trace option visible allows you to check it and disable it before enabling the funtion tracer. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* tracing: Only create stacktrace option when STACKTRACE is configuredSteven Rostedt (Red Hat)2015-09-292-14/+23
| | | | | | | | | | Only create the stacktrace trace option when CONFIG_STACKTRACE is configured. Cleaned up the ftrace_trace_stack() function call a little to allow better encapsulation of the stacktrace trace flag. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* tracing: Do not create function tracer options when not compiled inSteven Rostedt (Red Hat)2015-09-294-22/+63
| | | | | | | | | When the function tracer is not compiled in, do not create the option files for it. Fix up both the sched_wakeup and irqsoff tracers to handle the change. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* tracing: Only create branch tracer options when compiled inSteven Rostedt (Red Hat)2015-09-291-2/+9
| | | | | | | When the branch tracer is not compiled in, do not create the option files associated to it. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* tracing: Only create function graph options when it is compiled inSteven Rostedt (Red Hat)2015-09-294-11/+32
| | | | | | | Do not create fuction graph tracer options when function graph tracer is not even compiled in. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* tracing: Use TRACE_FLAGS macro to keep enums and strings matchedSteven Rostedt (Red Hat)2015-09-292-83/+55
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Use a cute little macro trick to keep the names of the trace flags file guaranteed to match the corresponding masks. The macro TRACE_FLAGS is defined as a serious of enum names followed by the string name of the file that matches it. For example: #define TRACE_FLAGS \ C(PRINT_PARENT, "print-parent"), \ C(SYM_OFFSET, "sym-offset"), \ C(SYM_ADDR, "sym-addr"), \ C(VERBOSE, "verbose"), Now we can define the following: #undef C #define C(a, b) TRACE_ITER_##a##_BIT enum trace_iterator_bits { TRACE_FLAGS }; The above creates: enum trace_iterator_bits { TRACE_ITER_PRINT_PARENT_BIT, TRACE_ITER_SYM_OFFSET_BIT, TRACE_ITER_SYM_ADDR_BIT, TRACE_ITER_VERBOSE_BIT, }; Then we can redefine C as: #undef C #define C(a, b) TRACE_ITER_##a = (1 << TRACE_ITER_##a##_BIT) enum trace_iterator_flags { TRACE_FLAGS }; Which creates: enum trace_iterator_flags { TRACE_ITER_PRINT_PARENT = (1 << TRACE_ITER_PRINT_PARENT_BIT), TRACE_ITER_SYM_OFFSET = (1 << TRACE_ITER_SYM_OFFSET_BIT), TRACE_ITER_SYM_ADDR = (1 << TRACE_ITER_SYM_ADDR_BIT), TRACE_ITER_VERBOSE = (1 << TRACE_ITER_VERBOSE_BIT), }; Then finally we can create the list of file names: #undef C #define C(a, b) b static const char *trace_options[] = { TRACE_FLAGS NULL }; Which creates: static const char *trace_options[] = { "print-parent", "sym-offset", "sym-addr", "verbose", NULL }; The importance of this is that the strings match the bit index. trace_options[TRACE_ITER_SYM_ADDR_BIT] == "sym-addr" Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* tracing: Use enums instead of hard coded bitmasks for TRACE_ITER flagsSteven Rostedt (Red Hat)2015-09-291-26/+55
| | | | | | | | Using enums with FLAG_BIT and then defining a FLAG = (1 << FLAG_BIT), is a bit more robust as we require that there are no bits out of order or skipped to match the file names that represent the bits. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* tracing: Remove unused tracing option "ftrace_preempt"Steven Rostedt (Red Hat)2015-09-292-18/+16
| | | | | | | | | | There was a time where the function tracing would disable interrupts unless specifically told not to, where it would only disable preemption. With the new lockless code, the function tracing never disalbes interrupts and just uses disabling of preemption. Remove the option "ftrace_preempt" as it does nothing anyway. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* tracing: Move "display-graph" option to main optionsSteven Rostedt (Red Hat)2015-09-294-64/+30
| | | | | | | | | | | | In order to facilitate making all tracer options visible even when the tracer is not active, we need to get rid of duplicate options. Any option that is shared between multiple tracers really should be a main option. As the wakeup and irqsoff tracers both use the "display-graph" option, and use it exactly the same way, move that option from the tracer options to the main options and consolidate them. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* tracing: Turn seq_print_user_ip() into a static functionSteven Rostedt (Red Hat)2015-09-282-4/+2
| | | | | | | | seq_print_user_ip() is used in only one location in one file. Turn it into a static function. We could inject its code into the caller, but that would make the code a bit too complex. Keep the code separate. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* tracing: Inject seq_print_userip_objs() into its only userSteven Rostedt (Red Hat)2015-09-282-47/+36
| | | | | | | | | seq_print_userip_objs() is used only in one location, in one file. Instead of having it as an external function, go one further than making it static, but inject is code into its only user. It doesn't make the calling function much more complex. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* tracing: Make ftrace_trace_stack() staticSteven Rostedt (Red Hat)2015-09-282-9/+9
| | | | | | | ftrace_trace_stack() is not called outside of trace.c. Make it a static function. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* tracing: Pass trace_array into trace_buffer_unlock_commit()Steven Rostedt (Red Hat)2015-09-255-20/+19
| | | | | | | | | | | | In preparation for having trace options be per instance, the trace_array needs to be passed to the trace_buffer_unlock_commit(). The trace_event_buffer_lock_reserve() already passes in the trace_event_file where the trace_array can be derived from. Also added a "__init" to the boot up test event plus function tracing function function_test_events_call(). Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* tracing: Remove unused function trace_current_buffer_lock_reserve()Steven Rostedt (Red Hat)2015-09-251-8/+0
| | | | | | | trace_current_buffer_lock_reserve() is not used by anything. Might as well get rid of it. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
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