kernel/include/linux/ftrace_event.h, branch linux-5.11.y

tracing: Rename ftrace_event.h to trace_events.h

2015-05-13T18:05:12Z

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

tracing: Remove unused prototype ftrace_event_define_field()

2015-05-13T18:03:51Z

ftrace_event_define_field() has a prototype defined but never used. Remove it. Signed-off-by: Steven Rostedt

tracing: remove unused ftrace_output_event() prototype

2015-05-12T19:56:54Z

The prototype of ftrace_output_event was added by commit 1d6bae966e90 ("tracing: Move raw output code from macro to standalone function") but this function was not defined anywhere, and is still nowhere to be found. Link: http://lkml.kernel.org/r/1430648282-25792-1-git-send-email-nicolas.iooss_linux@m4x.org Signed-off-by: Nicolas Iooss Signed-off-by: Steven Rostedt

tracing: Make ftrace_print_array_seq compute buf_len

2015-05-07T03:03:23Z

The only caller to this function (__print_array) was getting it wrong by passing the array length instead of buffer length. As the element size was already being passed for other reasons it seems reasonable to push the calculation of buffer length into the function. Link: http://lkml.kernel.org/r/1430320727-14582-1-git-send-email-alex.bennee@linaro.org Signed-off-by: Alex Bennée Signed-off-by: Steven Rostedt

Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2015-04-14T21:37:47Z

Pull perf changes from Ingo Molnar: "Core kernel changes: - One of the more interesting features in this cycle is the ability to attach eBPF programs (user-defined, sandboxed bytecode executed by the kernel) to kprobes. This allows user-defined instrumentation on a live kernel image that can never crash, hang or interfere with the kernel negatively. (Right now it's limited to root-only, but in the future we might allow unprivileged use as well.) (Alexei Starovoitov) - Another non-trivial feature is per event clockid support: this allows, amongst other things, the selection of different clock sources for event timestamps traced via perf. This feature is sought by people who'd like to merge perf generated events with external events that were measured with different clocks: - cluster wide profiling - for system wide tracing with user-space events, - JIT profiling events etc. Matching perf tooling support is added as well, available via the -k, --clockid parameter to perf record et al. (Peter Zijlstra) Hardware enablement kernel changes: - x86 Intel Processor Trace (PT) support: which is a hardware tracer on steroids, available on Broadwell CPUs. The hardware trace stream is directly output into the user-space ring-buffer, using the 'AUX' data format extension that was added to the perf core to support hardware constraints such as the necessity to have the tracing buffer physically contiguous. This patch-set was developed for two years and this is the result. A simple way to make use of this is to use BTS tracing, the PT driver emulates BTS output - available via the 'intel_bts' PMU. More explicit PT specific tooling support is in the works as well - will probably be ready by 4.2. (Alexander Shishkin, Peter Zijlstra) - x86 Intel Cache QoS Monitoring (CQM) support: this is a hardware feature of Intel Xeon CPUs that allows the measurement and allocation/partitioning of caches to individual workloads. These kernel changes expose the measurement side as a new PMU driver, which exposes various QoS related PMU events. (The partitioning change is work in progress and is planned to be merged as a cgroup extension.) (Matt Fleming, Peter Zijlstra; CPU feature detection by Peter P Waskiewicz Jr) - x86 Intel Haswell LBR call stack support: this is a new Haswell feature that allows the hardware recording of call chains, plus tooling support. To activate this feature you have to enable it via the new 'lbr' call-graph recording option: perf record --call-graph lbr perf report or: perf top --call-graph lbr This hardware feature is a lot faster than stack walk or dwarf based unwinding, but has some limitations: - It reuses the current LBR facility, so LBR call stack and branch record can not be enabled at the same time. - It is only available for user-space callchains. (Yan, Zheng) - x86 Intel Broadwell CPU support and various event constraints and event table fixes for earlier models. (Andi Kleen) - x86 Intel HT CPUs event scheduling workarounds. This is a complex CPU bug affecting the SNB,IVB,HSW families that results in counter value corruption. The mitigation code is automatically enabled and is transparent. (Maria Dimakopoulou, Stephane Eranian) The perf tooling side had a ton of changes in this cycle as well, so I'm only able to list the user visible changes here, in addition to the tooling changes outlined above: User visible changes affecting all tools: - Improve support of compressed kernel modules (Jiri Olsa) - Save DSO loading errno to better report errors (Arnaldo Carvalho de Melo) - Bash completion for subcommands (Yunlong Song) - Add 'I' event modifier for perf_event_attr.exclude_idle bit (Jiri Olsa) - Support missing -f to override perf.data file ownership. (Yunlong Song) - Show the first event with an invalid filter (David Ahern, Arnaldo Carvalho de Melo) User visible changes in individual tools: 'perf data': New tool for converting perf.data to other formats, initially for the CTF (Common Trace Format) from LTTng (Jiri Olsa, Sebastian Siewior) 'perf diff': Add --kallsyms option (David Ahern) 'perf list': Allow listing events with 'tracepoint' prefix (Yunlong Song) Sort the output of the command (Yunlong Song) 'perf kmem': Respect -i option (Jiri Olsa) Print big numbers using thousands' group (Namhyung Kim) Allow -v option (Namhyung Kim) Fix alignment of slab result table (Namhyung Kim) 'perf probe': Support multiple probes on different binaries on the same command line (Masami Hiramatsu) Support unnamed union/structure members data collection. (Masami Hiramatsu) Check kprobes blacklist when adding new events. (Masami Hiramatsu) 'perf record': Teach 'perf record' about perf_event_attr.clockid (Peter Zijlstra) Support recording running/enabled time (Andi Kleen) 'perf sched': Improve the performance of 'perf sched replay' on high CPU core count machines (Yunlong Song) 'perf report' and 'perf top': Allow annotating entries in callchains in the hists browser (Arnaldo Carvalho de Melo) Indicate which callchain entries are annotated in the TUI hists browser (Arnaldo Carvalho de Melo) Add pid/tid filtering to 'report' and 'script' commands (David Ahern) Consider PERF_RECORD_ events with cpumode == 0 in 'perf top', removing one cause of long term memory usage buildup, i.e. not processing PERF_RECORD_EXIT events (Arnaldo Carvalho de Melo) 'perf stat': Report unsupported events properly (Suzuki K. Poulose) Output running time and run/enabled ratio in CSV mode (Andi Kleen) 'perf trace': Handle legacy syscalls tracepoints (David Ahern, Arnaldo Carvalho de Melo) Only insert blank duration bracket when tracing syscalls (Arnaldo Carvalho de Melo) Filter out the trace pid when no threads are specified (Arnaldo Carvalho de Melo) Dump stack on segfaults (Arnaldo Carvalho de Melo) No need to explicitely enable evsels for workload started from perf, let it be enabled via perf_event_attr.enable_on_exec, removing some events that take place in the 'perf trace' before a workload is really started by it. (Arnaldo Carvalho de Melo) Allow mixing with tracepoints and suppressing plain syscalls. (Arnaldo Carvalho de Melo) There's also been a ton of infrastructure work done, such as the split-out of perf's build system into tools/build/ and other changes - see the shortlog and changelog for details" * 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (358 commits) perf/x86/intel/pt: Clean up the control flow in pt_pmu_hw_init() perf evlist: Fix type for references to data_head/tail perf probe: Check the orphaned -x option perf probe: Support multiple probes on different binaries perf buildid-list: Fix segfault when show DSOs with hits perf tools: Fix cross-endian analysis perf tools: Fix error path to do closedir() when synthesizing threads perf tools: Fix synthesizing fork_event.ppid for non-main thread perf tools: Add 'I' event modifier for exclude_idle bit perf report: Don't call map__kmap if map is NULL. perf tests: Fix attr tests perf probe: Fix ARM 32 building error perf tools: Merge all perf_event_attr print functions perf record: Add clockid parameter perf sched replay: Use replay_repeat to calculate the runavg of cpu usage instead of the default value 10 perf sched replay: Support using -f to override perf.data file ownership perf sched replay: Fix the EMFILE error caused by the limitation of the maximum open files perf sched replay: Handle the dead halt of sem_wait when create_tasks() fails for any task perf sched replay: Fix the segmentation fault problem caused by pr_err in threads perf sched replay: Realloc the memory of pid_to_task stepwise to adapt to the different pid_max configurations ...

tracing: Add TRACE_DEFINE_ENUM() macro to map enums to their values

2015-04-08T13:39:56Z

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 Cc: Tony Luck Cc: Xie XiuQi Acked-by: Namhyung Kim Reviewed-by: Masami Hiramatsu Tested-by: Masami Hiramatsu Signed-off-by: Steven Rostedt

tracing: Give system name a pointer

2015-04-08T13:39:55Z

Normally the compiler will use the same pointer for a string throughout the file. But there's no guarantee of that happening. Later changes will require that all events have the same pointer to the system string. Name the system string and have all events point to it. Testing this, it did not increases the size of the text, except for the notes section, which should not harm the real size any. Link: http://lkml.kernel.org/r/20150403013802.220157513@goodmis.org Reviewed-by: Masami Hiramatsu Tested-by: Masami Hiramatsu Signed-off-by: Steven Rostedt

tracing, perf: Implement BPF programs attached to kprobes

2015-04-02T11:25:49Z

BPF programs, attached to kprobes, provide a safe way to execute user-defined BPF byte-code programs without being able to crash or hang the kernel in any way. The BPF engine makes sure that such programs have a finite execution time and that they cannot break out of their sandbox. The user interface is to attach to a kprobe via the perf syscall: struct perf_event_attr attr = { .type = PERF_TYPE_TRACEPOINT, .config = event_id, ... }; event_fd = perf_event_open(&attr,...); ioctl(event_fd, PERF_EVENT_IOC_SET_BPF, prog_fd); 'prog_fd' is a file descriptor associated with BPF program previously loaded. 'event_id' is an ID of the kprobe created. Closing 'event_fd': close(event_fd); ... automatically detaches BPF program from it. BPF programs can call in-kernel helper functions to: - lookup/update/delete elements in maps - probe_read - wraper of probe_kernel_read() used to access any kernel data structures BPF programs receive 'struct pt_regs *' as an input ('struct pt_regs' is architecture dependent) and return 0 to ignore the event and 1 to store kprobe event into the ring buffer. Note, kprobes are a fundamentally _not_ a stable kernel ABI, so BPF programs attached to kprobes must be recompiled for every kernel version and user must supply correct LINUX_VERSION_CODE in attr.kern_version during bpf_prog_load() call. Signed-off-by: Alexei Starovoitov Reviewed-by: Steven Rostedt Reviewed-by: Masami Hiramatsu Cc: Andrew Morton Cc: Arnaldo Carvalho de Melo Cc: Arnaldo Carvalho de Melo Cc: Daniel Borkmann Cc: David S. Miller Cc: Jiri Olsa Cc: Linus Torvalds Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/1427312966-8434-4-git-send-email-ast@plumgrid.com Signed-off-by: Ingo Molnar

tracing: Add kprobe flag

2015-04-02T11:25:49Z

add TRACE_EVENT_FL_KPROBE flag to differentiate kprobe type of tracepoints, since bpf programs can only be attached to kprobe type of PERF_TYPE_TRACEPOINT perf events. Signed-off-by: Alexei Starovoitov Reviewed-by: Steven Rostedt Reviewed-by: Masami Hiramatsu Cc: Andrew Morton Cc: Arnaldo Carvalho de Melo Cc: Arnaldo Carvalho de Melo Cc: Daniel Borkmann Cc: David S. Miller Cc: Jiri Olsa Cc: Linus Torvalds Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/1427312966-8434-3-git-send-email-ast@plumgrid.com Signed-off-by: Ingo Molnar

Merge tag 'trace-v3.20' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

2015-02-12T16:37:41Z

Pull tracing updates from Steven Rostedt: "The updates included in this pull request for ftrace are: o Several clean ups to the code One such clean up was to convert to 64 bit time keeping, in the ring buffer benchmark code. o Adding of __print_array() helper macro for TRACE_EVENT() o Updating the sample/trace_events/ to add samples of different ways to make trace events. Lots of features have been added since the sample code was made, and these features are mostly unknown. Developers have been making their own hacks to do things that are already available. o Performance improvements. Most notably, I found a performance bug where a waiter that is waiting for a full page from the ring buffer will see that a full page is not available, and go to sleep. The sched event caused by it going to sleep would cause it to wake up again. It would see that there was still not a full page, and go back to sleep again, and that would wake it up again, until finally it would see a full page. This change has been marked for stable. Other improvements include removing global locks from fast paths" * tag 'trace-v3.20' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: ring-buffer: Do not wake up a splice waiter when page is not full tracing: Fix unmapping loop in tracing_mark_write tracing: Add samples of DECLARE_EVENT_CLASS() and DEFINE_EVENT() tracing: Add TRACE_EVENT_FN example tracing: Add TRACE_EVENT_CONDITION sample tracing: Update the TRACE_EVENT fields available in the sample code tracing: Separate out initializing top level dir from instances tracing: Make tracing_init_dentry_tr() static trace: Use 64-bit timekeeping tracing: Add array printing helper tracing: Remove newline from trace_printk warning banner tracing: Use IS_ERR() check for return value of tracing_init_dentry() tracing: Remove unneeded includes of debugfs.h and fs.h tracing: Remove taking of trace_types_lock in pipe files tracing: Add ref count to tracer for when they are being read by pipe