summaryrefslogtreecommitdiffstats
path: root/kernel/trace/trace.h
Commit message (Collapse)AuthorAgeFilesLines
* tracing: Remove unused ftrace_cpu_disabled per cpu variableDmitry Safonov2015-11-071-1/+0
| | | | | | | | | | | | | | | Since the ring buffer is lockless, there is no need to disable ftrace on CPU. And no one doing so: after commit 68179686ac67cb ("tracing: Remove ftrace_disable/enable_cpu()") ftrace_cpu_disabled stays the same after initialization, nothing changes it. ftrace_cpu_disabled shouldn't be used by any external module since it disables only function and graph_function tracers but not any other tracer. Link: http://lkml.kernel.org/r/1446836846-22239-1-git-send-email-0x7f454c46@gmail.com Signed-off-by: Dmitry Safonov <0x7f454c46@gmail.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: ftrace_event_is_function() can return booleanYaowei Bai2015-11-021-1/+1
| | | | | | | | | | | | | 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: Implement event pid filteringSteven Rostedt (Red Hat)2015-10-251-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | 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)2015-10-251-0/+7
| | | | | | | | | | | | | | 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>
* tracing: Add trace options for tracer options to instancesSteven Rostedt (Red Hat)2015-09-301-1/+8
| | | | | | | | | 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 a method to pass in trace_array descriptor to option filesSteven Rostedt (Red Hat)2015-09-301-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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)2015-09-301-3/+2
| | | | | | | | | | | | | | | | | 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)2015-09-301-6/+5
| | | | | | | | | 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)2015-09-301-0/+1
| | | | | | | | | | 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)2015-09-301-1/+5
| | | | | | | | | 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)2015-09-301-0/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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)2015-09-291-1/+8
| | | | | | | | | | 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)2015-09-291-1/+10
| | | | | | | | | 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)2015-09-291-3/+17
| | | | | | | 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)2015-09-291-57/+45
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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)2015-09-291-17/+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)2015-09-291-0/+1
| | | | | | | | | | | | 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: Make ftrace_trace_stack() staticSteven Rostedt (Red Hat)2015-09-281-8/+0
| | | | | | | ftrace_trace_stack() is not called outside of trace.c. Make it a static function. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* tracing: Remove ftrace_trace_stack_regs()Steven Rostedt (Red Hat)2015-09-251-9/+0
| | | | | | | | ftrace_trace_stack_regs() is used in only one place, and because that is such a simple function, just move its code into the location that it was used in (trace_buffer_unlock_commit_regs()). Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* tracing: Have branch tracer use recursive field of task structSteven Rostedt (Red Hat)2015-07-081-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fengguang Wu's tests triggered a bug in the branch tracer's start up test when CONFIG_DEBUG_PREEMPT set. This was because that config adds some debug logic in the per cpu field, which calls back into the branch tracer. The branch tracer has its own recursive checks, but uses a per cpu variable to implement it. If retrieving the per cpu variable calls back into the branch tracer, you can see how things will break. Instead of using a per cpu variable, use the trace_recursion field of the current task struct. Simply set a bit when entering the branch tracing and clear it when leaving. If the bit is set on entry, just don't do the tracing. There's also the case with lockdep, as the local_irq_save() called before the recursion can also trigger code that can call back into the function. Changing that to a raw_local_irq_save() will protect that as well. This prevents the recursion and the inevitable crash that follows. Link: http://lkml.kernel.org/r/20150630141803.GA28071@wfg-t540p.sh.intel.com Cc: stable@vger.kernel.org # 3.10+ Reported-by: Fengguang Wu <fengguang.wu@intel.com> Tested-by: Fengguang Wu <fengguang.wu@intel.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* Merge tag 'trace-v4.2' of ↵Linus Torvalds2015-06-261-21/+21
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing updates from Steven Rostedt: "This patch series contains several clean ups and even a new trace clock "monitonic raw". Also some enhancements to make the ring buffer even faster. But the biggest and most noticeable change is the renaming of the ftrace* files, structures and variables that have to deal with trace events. Over the years I've had several developers tell me about their confusion with what ftrace is compared to events. Technically, "ftrace" is the infrastructure to do the function hooks, which include tracing and also helps with live kernel patching. But the trace events are a separate entity altogether, and the files that affect the trace events should not be named "ftrace". These include: include/trace/ftrace.h -> include/trace/trace_events.h include/linux/ftrace_event.h -> include/linux/trace_events.h Also, functions that are specific for trace events have also been renamed: ftrace_print_*() -> trace_print_*() (un)register_ftrace_event() -> (un)register_trace_event() ftrace_event_name() -> trace_event_name() ftrace_trigger_soft_disabled() -> trace_trigger_soft_disabled() ftrace_define_fields_##call() -> trace_define_fields_##call() ftrace_get_offsets_##call() -> trace_get_offsets_##call() Structures have been renamed: ftrace_event_file -> trace_event_file ftrace_event_{call,class} -> trace_event_{call,class} ftrace_event_buffer -> trace_event_buffer ftrace_subsystem_dir -> trace_subsystem_dir ftrace_event_raw_##call -> trace_event_raw_##call ftrace_event_data_offset_##call-> trace_event_data_offset_##call ftrace_event_type_funcs_##call -> trace_event_type_funcs_##call And a few various variables and flags have also been updated. This has been sitting in linux-next for some time, and I have not heard a single complaint about this rename breaking anything. Mostly because these functions, variables and structures are mostly internal to the tracing system and are seldom (if ever) used by anything external to that" * tag 'trace-v4.2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (33 commits) ring_buffer: Allow to exit the ring buffer benchmark immediately ring-buffer-benchmark: Fix the wrong type ring-buffer-benchmark: Fix the wrong param in module_param ring-buffer: Add enum names for the context levels ring-buffer: Remove useless unused tracing_off_permanent() ring-buffer: Give NMIs a chance to lock the reader_lock ring-buffer: Add trace_recursive checks to ring_buffer_write() ring-buffer: Allways do the trace_recursive checks ring-buffer: Move recursive check to per_cpu descriptor ring-buffer: Add unlikelys to make fast path the default tracing: Rename ftrace_get_offsets_##call() to trace_event_get_offsets_##call() tracing: Rename ftrace_define_fields_##call() to trace_event_define_fields_##call() tracing: Rename ftrace_event_type_funcs_##call to trace_event_type_funcs_##call tracing: Rename ftrace_data_offset_##call to trace_event_data_offset_##call tracing: Rename ftrace_raw_##call event structures to trace_event_raw_##call tracing: Rename ftrace_trigger_soft_disabled() to trace_trigger_soft_disabled() tracing: Rename FTRACE_EVENT_FL_* flags to EVENT_FILE_FL_* tracing: Rename struct ftrace_subsystem_dir to trace_subsystem_dir tracing: Rename ftrace_event_name() to trace_event_name() tracing: Rename FTRACE_MAX_EVENT to TRACE_EVENT_TYPE_MAX ...
| * tracing: Rename struct ftrace_subsystem_dir to trace_subsystem_dirSteven Rostedt (Red Hat)2015-05-131-2/+2
| | | | | | | | | | | | | | | | | | The name "ftrace" really refers to the function hook infrastructure. It is not about the trace_events. The structure ftrace_subsystem_dir holds the information about trace event subsystems. It should not be named ftrace, rename it to trace_subsystem_dir. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * tracing: Rename ftrace_event_{call,class} to trace_event_{call,class}Steven Rostedt (Red Hat)2015-05-131-5/+5
| | | | | | | | | | | | | | | | | | The name "ftrace" really refers to the function hook infrastructure. It is not about the trace_events. The structures ftrace_event_call and ftrace_event_class have nothing to do with the function hooks, and are really trace_event structures. Rename ftrace_event_* to trace_event_*. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * tracing: Rename ftrace_event_file to trace_event_fileSteven Rostedt (Red Hat)2015-05-131-12/+12
| | | | | | | | | | | | | | | | The name "ftrace" really refers to the function hook infrastructure. It is not about the trace_events. The structure ftrace_event_file is really about trace events and not "ftrace". Rename it to trace_event_file. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * tracing: Rename ftrace_event.h to trace_events.hSteven Rostedt (Red Hat)2015-05-131-2/+2
| | | | | | | | | | | | | | | | | | The term "ftrace" is really the infrastructure of the function hooks, and not the trace events. Rename ftrace_event.h to trace_events.h to represent the trace_event infrastructure and decouple the term ftrace from it. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | tracing: Fix typo from "static inlin" to "static inline"Steven Rostedt (Red Hat)2015-06-251-1/+1
|/ | | | | | | | | The trace.h header when called without CONFIG_EVENT_TRACING enabled (seldom done), will not compile because of a typo in the protocol of trace_event_enum_update(). Cc: stable@vger.kernel.org # 4.1+ Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* Merge tag 'trace-v4.1' of ↵Linus Torvalds2015-04-141-0/+2
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing updates from Steven Rostedt: "Some clean ups and small fixes, but the biggest change is the addition of the TRACE_DEFINE_ENUM() macro that can be used by tracepoints. Tracepoints have helper functions for the TP_printk() called __print_symbolic() and __print_flags() that lets a numeric number be displayed as a a human comprehensible text. What is placed in the TP_printk() is also shown in the tracepoint format file such that user space tools like perf and trace-cmd can parse the binary data and express the values too. Unfortunately, the way the TRACE_EVENT() macro works, anything placed in the TP_printk() will be shown pretty much exactly as is. The problem arises when enums are used. That's because unlike macros, enums will not be changed into their values by the C pre-processor. Thus, the enum string is exported to the format file, and this makes it useless for user space tools. The TRACE_DEFINE_ENUM() solves this by converting the enum strings in the TP_printk() format into their number, and that is what is shown to user space. For example, the tracepoint tlb_flush currently has this in its format file: __print_symbolic(REC->reason, { TLB_FLUSH_ON_TASK_SWITCH, "flush on task switch" }, { TLB_REMOTE_SHOOTDOWN, "remote shootdown" }, { TLB_LOCAL_SHOOTDOWN, "local shootdown" }, { TLB_LOCAL_MM_SHOOTDOWN, "local mm shootdown" }) After adding: TRACE_DEFINE_ENUM(TLB_FLUSH_ON_TASK_SWITCH); TRACE_DEFINE_ENUM(TLB_REMOTE_SHOOTDOWN); TRACE_DEFINE_ENUM(TLB_LOCAL_SHOOTDOWN); TRACE_DEFINE_ENUM(TLB_LOCAL_MM_SHOOTDOWN); Its format file will contain this: __print_symbolic(REC->reason, { 0, "flush on task switch" }, { 1, "remote shootdown" }, { 2, "local shootdown" }, { 3, "local mm shootdown" })" * tag 'trace-v4.1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (27 commits) tracing: Add enum_map file to show enums that have been mapped writeback: Export enums used by tracepoint to user space v4l: Export enums used by tracepoints to user space SUNRPC: Export enums in tracepoints to user space mm: tracing: Export enums in tracepoints to user space irq/tracing: Export enums in tracepoints to user space f2fs: Export the enums in the tracepoints to userspace net/9p/tracing: Export enums in tracepoints to userspace x86/tlb/trace: Export enums in used by tlb_flush tracepoint tracing/samples: Update the trace-event-sample.h with TRACE_DEFINE_ENUM() tracing: Allow for modules to convert their enums to values tracing: Add TRACE_DEFINE_ENUM() macro to map enums to their values tracing: Update trace-event-sample with TRACE_SYSTEM_VAR documentation tracing: Give system name a pointer brcmsmac: Move each system tracepoints to their own header iwlwifi: Move each system tracepoints to their own header mac80211: Move message tracepoints to their own header tracing: Add TRACE_SYSTEM_VAR to xhci-hcd tracing: Add TRACE_SYSTEM_VAR to kvm-s390 tracing: Add TRACE_SYSTEM_VAR to intel-sst ...
| * tracing: Add TRACE_DEFINE_ENUM() macro to map enums to their valuesSteven Rostedt (Red Hat)2015-04-081-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Several tracepoints use the helper functions __print_symbolic() or __print_flags() and pass in enums that do the mapping between the binary data stored and the value to print. This works well for reading the ASCII trace files, but when the data is read via userspace tools such as perf and trace-cmd, the conversion of the binary value to a human string format is lost if an enum is used, as userspace does not have access to what the ENUM is. For example, the tracepoint trace_tlb_flush() has: __print_symbolic(REC->reason, { TLB_FLUSH_ON_TASK_SWITCH, "flush on task switch" }, { TLB_REMOTE_SHOOTDOWN, "remote shootdown" }, { TLB_LOCAL_SHOOTDOWN, "local shootdown" }, { TLB_LOCAL_MM_SHOOTDOWN, "local mm shootdown" }) Which maps the enum values to the strings they represent. But perf and trace-cmd do no know what value TLB_LOCAL_MM_SHOOTDOWN is, and would not be able to map it. With TRACE_DEFINE_ENUM(), developers can place these in the event header files and ftrace will convert the enums to their values: By adding: TRACE_DEFINE_ENUM(TLB_FLUSH_ON_TASK_SWITCH); TRACE_DEFINE_ENUM(TLB_REMOTE_SHOOTDOWN); TRACE_DEFINE_ENUM(TLB_LOCAL_SHOOTDOWN); TRACE_DEFINE_ENUM(TLB_LOCAL_MM_SHOOTDOWN); $ cat /sys/kernel/debug/tracing/events/tlb/tlb_flush/format [...] __print_symbolic(REC->reason, { 0, "flush on task switch" }, { 1, "remote shootdown" }, { 2, "local shootdown" }, { 3, "local mm shootdown" }) The above is what userspace expects to see, and tools do not need to be modified to parse them. Link: http://lkml.kernel.org/r/20150403013802.220157513@goodmis.org Cc: Guilherme Cox <cox@computer.org> Cc: Tony Luck <tony.luck@gmail.com> Cc: Xie XiuQi <xiexiuqi@huawei.com> Acked-by: Namhyung Kim <namhyung@kernel.org> Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | tracing: Convert the tracing facility over to use tracefsSteven Rostedt (Red Hat)2015-02-031-1/+1
|/ | | | | | | | | | | | | | | | | | | debugfs was fine for the tracing facility as a quick way to get an interface. Now that tracing has matured, it should separate itself from debugfs such that it can be mounted separately without needing to mount all of debugfs with it. That is, users resist using tracing because it requires mounting debugfs. Having tracing have its own file system lets users get the features of tracing without needing to bring in the rest of the kernel's debug infrastructure. Another reason for tracefs is that debubfs does not support mkdir. Currently, to create instances, one does a mkdir in the tracing/instance directory. This is implemented via a hack that forces debugfs to do something it is not intended on doing. By converting over to tracefs, this hack can be removed and mkdir can be properly implemented. This patch does not address this yet, but it lays the ground work for that to be done. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* tracing: Make tracing_init_dentry_tr() staticSteven Rostedt (Red Hat)2015-02-021-1/+0
| | | | | | | tracing_init_dentry_tr() is not used outside of trace.c, it should be static. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* tracing: Add ref count to tracer for when they are being read by pipeSteven Rostedt (Red Hat)2014-12-221-0/+1
| | | | | | | | | | | | When one of the trace pipe files are being read (by either the trace_pipe or trace_pipe_raw), do not allow the current_trace to change. By adding a ref count that is incremented when the pipe files are opened, will prevent the current_trace from being changed. This will allow for the removal of the global trace_types_lock from reading the pipe buffers (which is currently a bottle neck). Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* tracing: Add tp_printk cmdline to have tracepoints go to printk()Steven Rostedt (Red Hat)2014-12-151-0/+1
| | | | | | | | | | | | | | | | | | | | | Add the kernel command line tp_printk option that will have tracepoints that are active sent to printk() as well as to the trace buffer. Passing "tp_printk" will activate this. To turn it off, the sysctl /proc/sys/kernel/tracepoint_printk can have '0' echoed into it. Note, this only works if the cmdline option is used. Echoing 1 into the sysctl file without the cmdline option will have no affect. Note, this is a dangerous option. Having high frequency tracepoints send their data to printk() can possibly cause a live lock. This is another reason why this is only active if the command line option is used. Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1412121539300.16494@nanos Suggested-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* tracing: Move enabling tracepoints to just after rcu_init()Steven Rostedt (Red Hat)2014-12-151-0/+13
| | | | | | | | | | | | | | | | | | | | Enabling tracepoints at boot up can be very useful. The tracepoint can be initialized right after RCU has been. There's no need to wait for the early_initcall() to be called. That's too late for some things that can use tracepoints for debugging. Move the logic to enable tracepoints out of the initcalls and into init/main.c to right after rcu_init(). This also allows trace_printk() to be used early too. Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1412121539300.16494@nanos Link: http://lkml.kernel.org/r/20141214164104.307127356@goodmis.org Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Suggested-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* tracing: Add additional marks to signal very large time deltasByungchul Park2014-12-031-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, function graph tracer prints "!" or "+" just before function execution time to signal a function overhead, depending on the time. And some tracers tracing latency also print "!" or "+" just after time to signal overhead, depending on the interval between events. Even it is usually enough to do that, we sometimes need to signal for bigger execution time than 100 micro seconds. For example, I used function graph tracer to detect if there is any case that exit_mm() takes too much time. I did following steps in /sys/kernel/debug/tracing. It was easier to detect very large excution time with patched kernel than with original kernel. $ echo exit_mm > set_graph_function $ echo function_graph > current_tracer $ echo > trace $ cat trace_pipe > $LOGFILE ... (do something and terminate logging) $ grep "\\$" $LOGFILE 3) $ 22082032 us | } /* kernel_map_pages */ 3) $ 22082040 us | } /* free_pages_prepare */ 3) $ 22082113 us | } /* free_hot_cold_page */ 3) $ 22083455 us | } /* free_hot_cold_page_list */ 3) $ 22083895 us | } /* release_pages */ 3) $ 22177873 us | } /* free_pages_and_swap_cache */ 3) $ 22178929 us | } /* unmap_single_vma */ 3) $ 22198885 us | } /* unmap_vmas */ 3) $ 22206949 us | } /* exit_mmap */ 3) $ 22207659 us | } /* mmput */ 3) $ 22207793 us | } /* exit_mm */ And then, it was easy to find out that a schedule-out occured by sub_preempt_count() within kernel_map_pages(). To detect very large function exection time caused by either problematic function implementation or scheduling issues, this patch can be useful. Link: http://lkml.kernel.org/r/1416789259-24038-1-git-send-email-byungchul.park@lge.com Signed-off-by: Byungchul Park <byungchul.park@lge.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* tracing: Have function_graph use trace_seq_has_overflowed()Steven Rostedt (Red Hat)2014-11-191-1/+1
| | | | | | | | | | | | | | Instead of doing individual checks all over the place that makes the code very messy. Just check trace_seq_has_overflowed() at the end or in strategic places. This makes the code much cleaner and also helps with getting closer to removing the return values of trace_seq_printf() and friends. Link: http://lkml.kernel.org/r/20141114011410.987913836@goodmis.org Reviewed-by: Petr Mladek <pmladek@suse.cz> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* tracing: Add trace_seq_has_overflowed() and trace_handle_return()Steven Rostedt (Red Hat)2014-11-191-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | Adding a trace_seq_has_overflowed() which returns true if the trace_seq had too much written into it allows us to simplify the code. Instead of checking the return value of every call to trace_seq_printf() and friends, they can all be called normally, and at the end we can return !trace_seq_has_overflowed() instead. Several functions also return TRACE_TYPE_PARTIAL_LINE when the trace_seq overflowed and TRACE_TYPE_HANDLED otherwise. Another helper function was created called trace_handle_return() which takes a trace_seq and returns these enums. Using this helper function also simplifies the code. This change also makes it possible to remove the return values of trace_seq_printf() and friends. They should instead just be void functions. Link: http://lkml.kernel.org/r/20141114011410.365183157@goodmis.org Reviewed-by: Petr Mladek <pmladek@suse.cz> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* tracing: Move tracing_sched_{switch,wakeup}() into wakeup tracerSteven Rostedt (Red Hat)2014-11-111-9/+0
| | | | | | | | | | | | The only code that references tracing_sched_switch_trace() and tracing_sched_wakeup_trace() is the wakeup latency tracer. Those two functions use to belong to the sched_switch tracer which has long been removed. These functions were left behind because the wakeup latency tracer used them. But since the wakeup latency tracer is the only one to use them, they should be static functions inside that code. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* tracing: Kill tracing_{start,stop}_sched_switch_record() and ↵Oleg Nesterov2014-11-111-3/+0
| | | | | | | | | | | | | | | tracing_sched_switch_assign_trace() tracing_{start,stop}_sched_switch_record() have no callers since 87d80de2800d "tracing: Remove obsolete sched_switch tracer". The last caller of tracing_sched_switch_assign_trace() was removed by 30dbb20e68e6 "tracing: Remove boot tracer". Link: http://lkml.kernel.org/p/20140723193501.GA30214@redhat.com Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* tracing: let user specify tracing_thresh after selecting function_graphStanislav Fomichev2014-07-181-0/+2
| | | | | | | | | | | | | | Currently, tracing_thresh works only if we specify it before selecting function_graph tracer. If we do the opposite, tracing_thresh will change it's value, but it will not be applied. To fix it, we add update_thresh callback which is called whenever tracing_thresh is updated and for function_graph tracer we register handler which reinitializes tracer depending on tracing_thresh. Link: http://lkml.kernel.org/p/20140718111727.GA3206@stfomichev-desktop.yandex.net Signed-off-by: Stanislav Fomichev <stfomichev@yandex-team.ru> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* tracing: Fix check of ftrace_trace_arrays list_empty() checkSteven Rostedt (Red Hat)2014-06-101-1/+1
| | | | | | | | | | | | | | | | | | | The check that tests if ftrace_trace_arrays is empty in top_trace_array(), uses the .prev pointer: if (list_empty(ftrace_trace_arrays.prev)) instead of testing the variable itself: if (list_empty(&ftrace_trace_arrays)) Although it is technically correct, it is awkward and confusing. Use the proper method. Link: http://lkml.kernel.org/r/87oay1bas8.fsf@sejong.aot.lge.com Reported-by: Namhyung Kim <namhyung@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* tracing: Return error if ftrace_trace_arrays list is emptyYoshihiro YUNOMAE2014-06-061-0/+3
| | | | | | | | | | | | | | | | | | | ftrace_trace_arrays links global_trace.list. However, global_trace is not added to ftrace_trace_arrays if trace_alloc_buffers() failed. As the result, ftrace_trace_arrays becomes an empty list. If ftrace_trace_arrays is an empty list, current top_trace_array() returns an invalid pointer. As the result, the kernel can induce memory corruption or panic. Current implementation does not check whether ftrace_trace_arrays is empty list or not. So, in this patch, if ftrace_trace_arrays is empty list, top_trace_array() returns NULL. Moreover, this patch makes all functions calling top_trace_array() handle it appropriately. Link: http://lkml.kernel.org/p/20140605223517.32311.99233.stgit@yunodevel Signed-off-by: Yoshihiro YUNOMAE <yoshihiro.yunomae.ez@hitachi.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* tracing: Add funcgraph_tail option to print function name after closing bracesRobert Elliott2014-05-201-0/+1
| | | | | | | | | | | | | | | | | | | | In the function-graph tracer, add a funcgraph_tail option to print the function name on all } lines, not just functions whose first line is no longer in the trace buffer. If a function calls other traced functions, its total time appears on its } line. This change allows grep to be used to determine the function for which the line corresponds. Update Documentation/trace/ftrace.txt to describe this new option. Link: http://lkml.kernel.org/p/20140520221041.8359.6782.stgit@beardog.cce.hp.com Signed-off-by: Robert Elliott <elliott@hp.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* tracing: Eliminate duplicate TRACE_GRAPH_PRINT_xx definesRobert Elliott2014-05-201-0/+1
| | | | | | | | | | | | | | Eliminate duplicate TRACE_GRAPH_PRINT_xx defines in trace_functions_graph.c that are already in trace.h. Add TRACE_GRAPH_PRINT_IRQS to trace.h, which is the only one that is missing. Link: http://lkml.kernel.org/p/20140520221031.8359.24733.stgit@beardog.cce.hp.com Signed-off-by: Robert Elliott <elliott@hp.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* tracing: Remove mock up poll wait functionSteven Rostedt (Red Hat)2014-04-301-4/+0
| | | | | | | | | | | | | | | Now that the ring buffer has a built in way to wake up readers when there's data, using irq_work such that it is safe to do it in any context. But it was still using the old "poor man's" wait polling that checks every 1/10 of a second to see if it should wake up a waiter. This makes the latency for a wake up excruciatingly long. No need to do that anymore. Completely remove the different wait_poll types from the tracers and have them all use the default one now. Reported-by: Johannes Berg <johannes@sipsolutions.net> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* tracing/stack_trace: Skip 4 instead of 3 when using ftrace_ops_list_funcJiaxing Wang2014-04-241-0/+1
| | | | | | | | | | | | | | | | | | | | | | When using ftrace_ops_list_func, we should skip 4 instead of 3, to avoid ftrace_call+0x5/0xb appearing in the stack trace: Depth Size Location (110 entries) ----- ---- -------- 0) 2956 0 update_curr+0xe/0x1e0 1) 2956 68 ftrace_call+0x5/0xb 2) 2888 92 enqueue_entity+0x53/0xe80 3) 2796 80 enqueue_task_fair+0x47/0x7e0 4) 2716 28 enqueue_task+0x45/0x70 5) 2688 12 activate_task+0x22/0x30 Add a function using_ftrace_ops_list_func() to test for this while keeping ftrace_ops_list_func to remain static. Link: http://lkml.kernel.org/p/1398006644-5935-2-git-send-email-wangjiaxing@insigma.com.cn Signed-off-by: Jiaxing Wang <wangjiaxing@insigma.com.cn> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* tracing: Move ftrace_max_lock into trace_arraySteven Rostedt (Red Hat)2014-04-211-0/+14
| | | | | | | | In preparation for having tracers enabled in instances, the max_lock should be unique as updating the max for one tracer is a separate operation than updating it for another tracer using a different max. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* tracing: Move tracing_max_latency into trace_arraySteven Rostedt (Red Hat)2014-04-211-2/+1
| | | | | | | | In preparation for letting the latency tracers be used by instances, remove the global tracing_max_latency variable and add a max_latency field to the trace_array that the latency tracers will now use. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
OpenPOWER on IntegriCloud