linux/kernel/trace/Kconfig, branch v3.16

tracing: Add tracepoint benchmark tracepoint

2014-05-30T02:49:54Z

In order to help benchmark the time tracepoints take, a new config option is added called CONFIG_TRACEPOINT_BENCHMARK. When this option is set a tracepoint is created called "benchmark:benchmark_event". When the tracepoint is enabled, it kicks off a kernel thread that goes into an infinite loop (calling cond_sched() to let other tasks run), and calls the tracepoint. Each iteration will record the time it took to write to the tracepoint and the next iteration that data will be passed to the tracepoint itself. That is, the tracepoint will report the time it took to do the previous tracepoint. The string written to the tracepoint is a static string of 128 bytes to keep the time the same. The initial string is simply a write of "START". The second string records the cold cache time of the first write which is not added to the rest of the calculations. As it is a tight loop, it benchmarks as hot cache. That's fine because we care most about hot paths that are probably in cache already. An example of the output: START first=3672 [COLD CACHED] last=632 first=3672 max=632 min=632 avg=316 std=446 std^2=199712 last=278 first=3672 max=632 min=278 avg=303 std=316 std^2=100337 last=277 first=3672 max=632 min=277 avg=296 std=258 std^2=67064 last=273 first=3672 max=632 min=273 avg=292 std=224 std^2=50411 last=273 first=3672 max=632 min=273 avg=288 std=200 std^2=40389 last=281 first=3672 max=632 min=273 avg=287 std=183 std^2=33666 Signed-off-by: Steven Rostedt

uprobes: Kconfig dependency fix

2014-03-18T20:39:33Z

Suggested change from Oleg Nesterov. Fixes incomplete dependencies for uprobes feature. Signed-off-by: David A. Long Acked-by: Oleg Nesterov

ring-buffer: Select IRQ_WORK

2013-05-03T23:24:17Z

As the wake up logic for waiters on the buffer has been moved from the tracing code to the ring buffer, it requires also adding IRQ_WORK as the wake up code is performed via irq_work. This fixes compile breakage when a user of the ring buffer is selected but tracing and irq_work are not. Link http://lkml.kernel.org/r/20130503115332.GT8356@rric.localhost Cc: Arnd Bergmann Reported-by: Robert Richter Signed-off-by: Steven Rostedt

Merge tag 'trace-3.10' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

2013-04-29T20:55:38Z

Pull tracing updates from Steven Rostedt: "Along with the usual minor fixes and clean ups there are a few major changes with this pull request. 1) Multiple buffers for the ftrace facility This feature has been requested by many people over the last few years. I even heard that Google was about to implement it themselves. I finally had time and cleaned up the code such that you can now create multiple instances of the ftrace buffer and have different events go to different buffers. This way, a low frequency event will not be lost in the noise of a high frequency event. Note, currently only events can go to different buffers, the tracers (ie function, function_graph and the latency tracers) still can only be written to the main buffer. 2) The function tracer triggers have now been extended. The function tracer had two triggers. One to enable tracing when a function is hit, and one to disable tracing. Now you can record a stack trace on a single (or many) function(s), take a snapshot of the buffer (copy it to the snapshot buffer), and you can enable or disable an event to be traced when a function is hit. 3) A perf clock has been added. A "perf" clock can be chosen to be used when tracing. This will cause ftrace to use the same clock as perf uses, and hopefully this will make it easier to interleave the perf and ftrace data for analysis." * tag 'trace-3.10' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (82 commits) tracepoints: Prevent null probe from being added tracing: Compare to 1 instead of zero for is_signed_type() tracing: Remove obsolete macro guard _TRACE_PROFILE_INIT ftrace: Get rid of ftrace_profile_bits tracing: Check return value of tracing_init_dentry() tracing: Get rid of unneeded key calculation in ftrace_hash_move() tracing: Reset ftrace_graph_filter_enabled if count is zero tracing: Fix off-by-one on allocating stat->pages kernel: tracing: Use strlcpy instead of strncpy tracing: Update debugfs README file tracing: Fix ftrace_dump() tracing: Rename trace_event_mutex to trace_event_sem tracing: Fix comment about prefix in arch_syscall_match_sym_name() tracing: Convert trace_destroy_fields() to static tracing: Move find_event_field() into trace_events.c tracing: Use TRACE_MAX_PRINT instead of constant tracing: Use pr_warn_once instead of open coded implementation ring-buffer: Add ring buffer startup selftest tracing: Bring Documentation/trace/ftrace.txt up to date tracing: Add "perf" trace_clock ... Conflicts: kernel/trace/ftrace.c kernel/trace/trace.c

ring-buffer: Add ring buffer startup selftest

2013-03-15T17:21:16Z

When testing my large changes to the ftrace system, there was a bug that looked like the ring buffer was dropping events. I wrote up a quick integrity checker of the ring buffer to see if it was. Although the bug ended up being something stupid I did in ftrace, and had nothing to do with the ring buffer, I figured if I spent the time to write up this test, I might as well include it in the kernel. I cleaned it up a bit, as the original version was rather ugly. Not saying this version is pretty, but it's a beauty queen compared to what I original wrote. To enable the start up test, set CONFIG_RING_BUFFER_STARTUP_TEST. Note, it runs for 10 seconds, so it will slow your boot time by at least 10 more seconds. What it does is documented in both the comments and the Kconfig help. Signed-off-by: Steven Rostedt

tracing: Add config option to allow snapshot to swap per cpu

2013-03-15T04:35:47Z

When the preempt or irq latency tracers are enabled, they require the ring buffer to be able to swap the per cpu sub buffers between two main buffers. This adds a slight overhead to tracing as the trace recording needs to perform some checks to synchronize between recording and swaps that might be happening on other CPUs. The config RING_BUFFER_ALLOW_SWAP is set when a user of the ring buffer needs the "swap cpu" feature, otherwise the extra checks are not implemented and removed from the tracing overhead. The snapshot feature will swap per CPU if the RING_BUFFER_ALLOW_SWAP config is set. But that only gets set by things like OPROFILE and the irqs and preempt latency tracers. This config is added to let the user decide to include this feature with the snapshot agnostic from whether or not another user of the ring buffer sets this config. Signed-off-by: Steven Rostedt

tracing: Enable snapshot when any latency tracer is enabled

2013-03-15T04:34:57Z

The snapshot utility is extremely useful, and does not add any more overhead in memory when another latency tracer is enabled. They use the snapshot underneath. There's no reason to hide the snapshot file when a latency tracer has been enabled in the kernel. If any of the latency tracers (irq, preempt or wakeup) is enabled then also select the snapshot facility. Note, snapshot can be enabled without the latency tracers enabled. Signed-off-by: Steven Rostedt

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

2013-03-11T14:54:29Z

Pull perf fixes from Ingo Molnar: "Misc minor fixes mostly related to tracing" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: s390: Fix a header dependencies related build error tracing: update documentation of snapshot utility tracing: Do not return EINVAL in snapshot when not allocated tracing: Add help of snapshot feature when snapshot is empty ftrace: Update the kconfig for DYNAMIC_FTRACE

ftrace: Update the kconfig for DYNAMIC_FTRACE

2013-02-28T02:58:01Z

The prompt to enable DYNAMIC_FTRACE (the ability to nop and enable function tracing at run time) had a confusing statement: "enable/disable ftrace tracepoints dynamically" This was written before tracepoints were added to the kernel, but now that tracepoints have been added, this is very confusing and has confused people enough to give wrong information during presentations. Not only that, I looked at the help text, and it still references that dreaded daemon that use to wake up once a second to update the nop locations and brick NICs, that hasn't been around for over five years. Time to bring the text up to the current decade. Cc: stable@vger.kernel.org Reported-by: Ezequiel Garcia Signed-off-by: Steven Rostedt

Merge tag 'pm+acpi-3.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

2013-02-20T19:26:56Z

Pull ACPI and power management updates from Rafael Wysocki: - Rework of the ACPI namespace scanning code from Rafael J. Wysocki with contributions from Bjorn Helgaas, Jiang Liu, Mika Westerberg, Toshi Kani, and Yinghai Lu. - ACPI power resources handling and ACPI device PM update from Rafael J Wysocki. - ACPICA update to version 20130117 from Bob Moore and Lv Zheng with contributions from Aaron Lu, Chao Guan, Jesper Juhl, and Tim Gardner. - Support for Intel Lynxpoint LPSS from Mika Westerberg. - cpuidle update from Len Brown including Intel Haswell support, C1 state for intel_idle, removal of global pm_idle. - cpuidle fixes and cleanups from Daniel Lezcano. - cpufreq fixes and cleanups from Viresh Kumar and Fabio Baltieri with contributions from Stratos Karafotis and Rickard Andersson. - Intel P-states driver for Sandy Bridge processors from Dirk Brandewie. - cpufreq driver for Marvell Kirkwood SoCs from Andrew Lunn. - cpufreq fixes related to ordering issues between acpi-cpufreq and powernow-k8 from Borislav Petkov and Matthew Garrett. - cpufreq support for Calxeda Highbank processors from Mark Langsdorf and Rob Herring. - cpufreq driver for the Freescale i.MX6Q SoC and cpufreq-cpu0 update from Shawn Guo. - cpufreq Exynos fixes and cleanups from Jonghwan Choi, Sachin Kamat, and Inderpal Singh. - Support for "lightweight suspend" from Zhang Rui. - Removal of the deprecated power trace API from Paul Gortmaker. - Assorted updates from Andreas Fleig, Colin Ian King, Davidlohr Bueso, Joseph Salisbury, Kees Cook, Li Fei, Nishanth Menon, ShuoX Liu, Srinivas Pandruvada, Tejun Heo, Thomas Renninger, and Yasuaki Ishimatsu. * tag 'pm+acpi-3.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (267 commits) PM idle: remove global declaration of pm_idle unicore32 idle: delete stray pm_idle comment openrisc idle: delete pm_idle mn10300 idle: delete pm_idle microblaze idle: delete pm_idle m32r idle: delete pm_idle, and other dead idle code ia64 idle: delete pm_idle cris idle: delete idle and pm_idle ARM64 idle: delete pm_idle ARM idle: delete pm_idle blackfin idle: delete pm_idle sparc idle: rename pm_idle to sparc_idle sh idle: rename global pm_idle to static sh_idle x86 idle: rename global pm_idle to static x86_idle APM idle: register apm_cpu_idle via cpuidle cpufreq / intel_pstate: Add kernel command line option disable intel_pstate. cpufreq / intel_pstate: Change to disallow module build tools/power turbostat: display SMI count by default intel_idle: export both C1 and C1E ACPI / hotplug: Fix concurrency issues and memory leaks ...