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2018-12-22tracing: Simplify printf'ing in seq_print_symRasmus Villemoes
trace_seq_printf(..., "%s", ...) can be done with trace_seq_puts() instead, avoiding printf overhead. In the second instance, the string we're copying was just created from an snprintf() to a stack buffer, so we might as well do that printf directly. This naturally leads to moving the declaration of the str buffer inside the CONFIG_KALLSYMS guard, which in turn will make gcc inline the function for !CONFIG_KALLSYMS (it only has a single caller, but the huge stack frame seems to make gcc not inline it for CONFIG_KALLSYMS). Link: http://lkml.kernel.org/r/20181029223542.26175-4-linux@rasmusvillemoes.dk Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-12-22tracing: Avoid -Wformat-nonliteral warningRasmus Villemoes
Building with -Wformat-nonliteral, gcc complains kernel/trace/trace_output.c: In function ‘seq_print_sym’: kernel/trace/trace_output.c:356:3: warning: format not a string literal, argument types not checked [-Wformat-nonliteral] trace_seq_printf(s, fmt, name); But seq_print_sym only has a single caller which passes "%s" as fmt, so we might as well just use that directly. That also paves the way for further cleanups that will actually make that format string go away entirely. Link: http://lkml.kernel.org/r/20181029223542.26175-3-linux@rasmusvillemoes.dk Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-12-22tracing: Merge seq_print_sym_short() and seq_print_sym_offset()Rasmus Villemoes
These two functions are nearly identical, so we can avoid some code duplication by moving the conditional into a common implementation. Link: http://lkml.kernel.org/r/20181029223542.26175-2-linux@rasmusvillemoes.dk Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-08-16tracing: Add SPDX License format tags to tracing filesSteven Rostedt (VMware)
Add the SPDX License header to ease license compliance management. Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-07-12tracing: Reorder display of TGID to be after PIDJoel Fernandes (Google)
Currently ftrace displays data in trace output like so: _-----=> irqs-off / _----=> need-resched | / _---=> hardirq/softirq || / _--=> preempt-depth ||| / delay TASK-PID CPU TGID |||| TIMESTAMP FUNCTION | | | | |||| | | bash-1091 [000] ( 1091) d..2 28.313544: sched_switch: However Android's trace visualization tools expect a slightly different format due to an out-of-tree patch patch that was been carried for a decade, notice that the TGID and CPU fields are reversed: _-----=> irqs-off / _----=> need-resched | / _---=> hardirq/softirq || / _--=> preempt-depth ||| / delay TASK-PID TGID CPU |||| TIMESTAMP FUNCTION | | | | |||| | | bash-1091 ( 1091) [002] d..2 64.965177: sched_switch: From kernel v4.13 onwards, during which TGID was introduced, tracing with systrace on all Android kernels will break (most Android kernels have been on 4.9 with Android patches, so this issues hasn't been seen yet). From v4.13 onwards things will break. The chrome browser's tracing tools also embed the systrace viewer which uses the legacy TGID format and updates to that are known to be difficult to make. Considering this, I suggest we make this change to the upstream kernel and backport it to all Android kernels. I believe this feature is merged recently enough into the upstream kernel that it shouldn't be a problem. Also logically, IMO it makes more sense to group the TGID with the TASK-PID and the CPU after these. Link: http://lkml.kernel.org/r/20180626000822.113931-1-joel@joelfernandes.org Cc: jreck@google.com Cc: tkjos@google.com Cc: stable@vger.kernel.org Fixes: 441dae8f2f29 ("tracing: Add support for display of tgid in trace output") Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-10-10sched/debug: Rename task-state printing helpersPeter Zijlstra
Steve requested better names for the new task-state helper functions. So introduce the concept of task-state index for the printing and rename __get_task_state() to task_state_index() and __task_state_to_char() to task_index_to_char(). Requested-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Steven Rostedt <rostedt@goodmis.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20170929115016.pzlqc7ss3ccystyg@hirez.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-09-29sched/tracing: Use common task-state helpersPeter Zijlstra
Remove yet another task-state char instance. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-06-27tracing: Add support for display of tgid in trace outputJoel Fernandes
Earlier patches introduced ability to record the tgid using the 'record-tgid' option. Here we read the tgid and output it if the option is enabled. Link: http://lkml.kernel.org/r/20170626053844.5746-3-joelaf@google.com Cc: kernel-team@android.com Cc: Ingo Molnar <mingo@redhat.com> Tested-by: Michael Sartain <mikesart@gmail.com> Signed-off-by: Joel Fernandes <joelaf@google.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-06-22tracing: Show address when function names are not foundSteven Rostedt (VMware)
Currently, when a function is not found in kallsyms, instead of simply showing the function address, it shows nothing at all: # echo ':mod:kvm_intel' > /sys/kernel/tracing/set_ftrace_filter # echo function > /sys/kernel/tracing/set_ftrace_filter # qemu -enable-kvm /home/my-qemu-image <Ctrl-C> # rmmod kvm_intel # cat /sys/kernel/tracing/trace qemu-system-x86-2408 [001] d..2 135.013238: <-kvm_arch_hardware_enable qemu-system-x86-2408 [001] .... 135.014574: <-kvm_arch_vm_ioctl qemu-system-x86-2408 [001] .... 135.015420: <-kvm_vm_ioctl_check_extension qemu-system-x86-2408 [001] .... 135.045411: <-__do_cpuid_ent qemu-system-x86-2408 [001] .... 135.045412: <-__do_cpuid_ent qemu-system-x86-2408 [001] .... 135.045412: <-__do_cpuid_ent qemu-system-x86-2408 [001] .... 135.045412: <-__do_cpuid_ent qemu-system-x86-2408 [001] ...1 135.045413: <-__do_cpuid_ent qemu-system-x86-2408 [001] .... 135.045413: <-__do_cpuid_ent When it should show: qemu-system-x86-2408 [001] d..2 135.013238: 0xffffffffa02a39f0 <-kvm_arch_hardware_enable qemu-system-x86-2408 [001] .... 135.014574: 0xffffffffa02a2ba0 <-kvm_arch_vm_ioctl qemu-system-x86-2408 [001] .... 135.015420: 0xffffffffa029e4e0 <-kvm_vm_ioctl_check_extension qemu-system-x86-2408 [001] .... 135.045411: 0xffffffffa02a1380 <-__do_cpuid_ent qemu-system-x86-2408 [001] .... 135.045412: 0xffffffffa029e160 <-__do_cpuid_ent qemu-system-x86-2408 [001] .... 135.045412: 0xffffffffa029e180 <-__do_cpuid_ent qemu-system-x86-2408 [001] .... 135.045412: 0xffffffffa029e520 <-__do_cpuid_ent qemu-system-x86-2408 [001] ...1 135.045413: 0xffffffffa02a13b0 <-__do_cpuid_ent qemu-system-x86-2408 [001] .... 135.045413: 0xffffffffa02a1380 <-__do_cpuid_ent instead. Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-05-08trace: make trace_hwlat timestamp y2038 safeDeepa Dinamani
struct timespec is not y2038 safe on 32 bit machines and needs to be replaced by struct timespec64 in order to represent times beyond year 2038 on such machines. Fix all the timestamp representation in struct trace_hwlat and all the corresponding implementations. Link: http://lkml.kernel.org/r/1491613030-11599-3-git-send-email-deepa.kernel@gmail.com Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com> Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Cc: Ingo Molnar <mingo@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-03-02sched/headers: Prepare for new header dependencies before moving code to ↵Ingo Molnar
<linux/sched/mm.h> We are going to split <linux/sched/mm.h> out of <linux/sched.h>, which will have to be picked up from other headers and a couple of .c files. Create a trivial placeholder <linux/sched/mm.h> file that just maps to <linux/sched.h> to make this patch obviously correct and bisectable. The APIs that are going to be moved first are: mm_alloc() __mmdrop() mmdrop() mmdrop_async_fn() mmdrop_async() mmget_not_zero() mmput() mmput_async() get_task_mm() mm_access() mm_release() Include the new header in the files that are going to need it. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-02sched/headers: Prepare for new header dependencies before moving code to ↵Ingo Molnar
<linux/sched/clock.h> We are going to split <linux/sched/clock.h> out of <linux/sched.h>, which will have to be picked up from other headers and .c files. Create a trivial placeholder <linux/sched/clock.h> file that just maps to <linux/sched.h> to make this patch obviously correct and bisectable. Include the new header in the files that are going to need it. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-02-22tracing: add __print_flags_u64()Ross Zwisler
Patch series "DAX tracepoints, mm argument simplification", v4. This contains both my DAX tracepoint code and Dave Jiang's MM argument simplifications. Dave's code was written with my tracepoint code as a baseline, so it seemed simplest to keep them together in a single series. This patch (of 7): Add __print_flags_u64() and the helper trace_print_flags_seq_u64() in the same spirit as __print_symbolic_u64() and trace_print_symbols_seq_u64(). These functions allow us to print symbols associated with flags that are 64 bits wide even on 32 bit machines. These will be used by the DAX code so that we can print the flags set in a pfn_t such as PFN_SG_CHAIN, PFN_SG_LAST, PFN_DEV and PFN_MAP. Without this new function I was getting errors like the following when compiling for i386: include/linux/pfn_t.h:13:22: warning: large integer implicitly truncated to unsigned type [-Woverflow] #define PFN_SG_CHAIN (1ULL << (BITS_PER_LONG_LONG - 1)) ^ Link: http://lkml.kernel.org/r/1484085142-2297-2-git-send-email-ross.zwisler@linux.intel.com Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> Reviewed-by: Steven Rostedt <rostedt@goodmis.org> Cc: Dave Chinner <david@fromorbit.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Jan Kara <jack@suse.cz> Cc: Matthew Wilcox <mawilcox@microsoft.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-03trace: rename trace_print_hex_seq arg and add kdocDaniel Borkmann
Steven suggested to improve trace_print_hex_seq() a bit after commit 2acae0d5b0f7 ("trace: add variant without spacing in trace_print_hex_seq") in two ways: i) by adding a kdoc comment for the helper function itself and ii) by renaming 'spacing' argument into 'concatenate' to better denote that we don't add spaces between each hex bytes. Suggested-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-25trace: add variant without spacing in trace_print_hex_seqDaniel Borkmann
For upcoming tracepoint support for BPF, we want to dump the program's tag. Format should be similar to __print_hex(), but without spacing. Add a __print_hex_str() variant for exactly that purpose that reuses trace_print_hex_seq(). Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-11-15tracing: Add new trace_marker_rawSteven Rostedt
A new file is created: /sys/kernel/debug/tracing/trace_marker_raw This allows for appications to create data structures and write the binary data directly into it, and then read the trace data out from trace_pipe_raw into the same type of data structure. This saves on converting numbers into ASCII that would be required by trace_marker. Suggested-by: Olof Johansson <olof@lixom.net> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-09-02tracing: Add NMI tracing in hwlat detectorSteven Rostedt (Red Hat)
As NMIs can also cause latency when interrupts are disabled, the hwlat detectory has no way to know if the latency it detects is from an NMI or an SMI or some other hardware glitch. As ftrace_nmi_enter/exit() funtions are no longer used (except for sh, which isn't supported anymore), I converted those to "arch_ftrace_nmi_enter/exit" and use ftrace_nmi_enter/exit() to check if hwlat detector is tracing or not, and if so, it calls into the hwlat utility. Since the hwlat detector only has a single kthread that is spinning with interrupts disabled, it marks what CPU it is on, and if the NMI callback happens on that CPU, it records the time spent in that NMI. This is added to the output that is generated by the hwlat detector as: #3 inner/outer(us): 9/9 ts:1470836488.206734548 #4 inner/outer(us): 0/8 ts:1470836497.140808588 #5 inner/outer(us): 0/6 ts:1470836499.140825168 nmi-total:5 nmi-count:1 #6 inner/outer(us): 9/9 ts:1470836501.140841748 All time is still tracked in microseconds. The NMI information is only shown when an NMI occurred during the sample. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-09-02tracing: Added hardware latency tracerSteven Rostedt (Red Hat)
The hardware latency tracer has been in the PREEMPT_RT patch for some time. It is used to detect possible SMIs or any other hardware interruptions that the kernel is unaware of. Note, NMIs may also be detected, but that may be good to note as well. The logic is pretty simple. It simply creates a thread that spins on a single CPU for a specified amount of time (width) within a periodic window (window). These numbers may be adjusted by their cooresponding names in /sys/kernel/tracing/hwlat_detector/ The defaults are window = 1000000 us (1 second) width = 500000 us (1/2 second) The loop consists of: t1 = trace_clock_local(); t2 = trace_clock_local(); Where trace_clock_local() is a variant of sched_clock(). The difference of t2 - t1 is recorded as the "inner" timestamp and also the timestamp t1 - prev_t2 is recorded as the "outer" timestamp. If either of these differences are greater than the time denoted in /sys/kernel/tracing/tracing_thresh then it records the event. When this tracer is started, and tracing_thresh is zero, it changes to the default threshold of 10 us. The hwlat tracer in the PREEMPT_RT patch was originally written by Jon Masters. I have modified it quite a bit and turned it into a tracer. Based-on-code-by: Jon Masters <jcm@redhat.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-22tracing: Record and show NMI statePeter Zijlstra
The latency tracer format has a nice column to indicate IRQ state, but this is not able to tell us about NMI state. When tracing perf interrupt handlers (which often run in NMI context) it is very useful to see how the events nest. Link: http://lkml.kernel.org/r/20160318153022.105068893@infradead.org Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-09-30tracing: Move trace_flags from global to a trace_array fieldSteven Rostedt (Red Hat)
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>
2015-09-28tracing: Turn seq_print_user_ip() into a static functionSteven Rostedt (Red Hat)
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>
2015-09-28tracing: Inject seq_print_userip_objs() into its only userSteven Rostedt (Red Hat)
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>
2015-07-20tracing: Introduce two additional marks for delayJungseok Lee
A fine granulity support for delay would be very useful when profiling VM logics, such as page allocation including page reclaim and memory compaction with function graph. Thus, this patch adds two additional marks with two changes. - An equal sign in mark selection function is removed to align code behavior with comments and documentation. - The function graph example related to delay in ftrace.txt is updated to cover all supported marks. Link: http://lkml.kernel.org/r/1436626300-1679-3-git-send-email-jungseoklee85@gmail.com Cc: Byungchul Park <byungchul.park@lge.com> Signed-off-by: Jungseok Lee <jungseoklee85@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-05-13tracing: Rename ftrace_event_name() to trace_event_name()Steven Rostedt (Red Hat)
The name "ftrace" really refers to the function hook infrastructure. It is not about the trace_events. ftrace_event_name() returns the name of an event tracepoint, has nothing to do with function tracing. Rename it to trace_event_name(). Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-05-13tracing: Rename FTRACE_MAX_EVENT to TRACE_EVENT_TYPE_MAXSteven Rostedt (Red Hat)
The name "ftrace" really refers to the function hook infrastructure. It is not about the trace_events. Rename the max trace_event type size to something more descriptive and appropriate. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-05-13tracing: Rename ftrace_output functions to trace_outputSteven Rostedt (Red Hat)
The name "ftrace" really refers to the function hook infrastructure. It is not about the trace_events. The ftrace_output_*() and ftrace_raw_output_*() functions represent the trace_event code. Rename them to just trace_output or trace_raw_output. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-05-13tracing: Rename ftrace_event_{call,class} to trace_event_{call,class}Steven Rostedt (Red Hat)
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>
2015-05-13tracing: Rename (un)register_ftrace_event() to (un)register_trace_event()Steven Rostedt (Red Hat)
The name "ftrace" really refers to the function hook infrastructure. It is not about the trace_events. The functions (un)register_ftrace_event() is really about trace_events, and the name should be register_trace_event() instead. Also renamed ftrace_event_reg() to trace_event_reg() for the same reason. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-05-13tracing: Rename ftrace_print_*() functions ta trace_print_*()Steven Rostedt (Red Hat)
The name "ftrace" really refers to the function hook infrastructure. It is not about the trace_events. The functions ftrace_print_*() are not part of the function infrastructure, and the names can be confusing. Rename them to be trace_print_*(). Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-05-06tracing: Make ftrace_print_array_seq compute buf_lenAlex Bennée
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 <alex.bennee@linaro.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-01-28tracing: Add array printing helperDave Martin
If a trace event contains an array, there is currently no standard way to format this for text output. Drivers are currently hacking around this by a) local hacks that use the trace_seq functionailty directly, or b) just not printing that information. For fixed size arrays, formatting of the elements can be open-coded, but this gets cumbersome for arrays of non-trivial size. These approaches result in non-standard content of the event format description delivered to userspace, so userland tools needs to be taught to understand and parse each array printing method individually. This patch implements a __print_array() helper that tracepoint implementations can use instead of reinventing it. A simple C-style syntax is used to delimit the array and its elements {like,this}. So that the helpers can be used with large static arrays as well as dynamic arrays, they take a pointer and element count: they can be used with __get_dynamic_array() for use with dynamic arrays. Link: http://lkml.kernel.org/r/1422449335-8289-2-git-send-email-javi.merino@arm.com Cc: Ingo Molnar <mingo@redhat.com> Signed-off-by: Dave Martin <Dave.Martin@arm.com> Signed-off-by: Javi Merino <javi.merino@arm.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-12-03tracing: Add additional marks to signal very large time deltasByungchul Park
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>
2014-11-19tracing: Fix return value of ftrace_raw_output_prep()Steven Rostedt (Red Hat)
If the trace_seq of ftrace_raw_output_prep() is full this function returns TRACE_TYPE_PARTIAL_LINE, otherwise it returns zero. The problem is that TRACE_TYPE_PARTIAL_LINE happens to be zero! The thing is, the caller of ftrace_raw_output_prep() expects a success to be zero. Change that to expect it to be TRACE_TYPE_HANDLED. Link: http://lkml.kernel.org/r/20141114112522.GA2988@dhcp128.suse.cz Reminded-by: Petr Mladek <pmladek@suse.cz> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-11-19tracing: Add trace_seq_has_overflowed() and trace_handle_return()Steven Rostedt (Red Hat)
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>
2014-11-11tracing: Add entry->next_cpu to trace_ctxwake_bin()Jiang Liu
Function trace_ctxwake_bin() misses ctx_switch_entry->next_cpu field, so user will get stale value for "next_cpu". Link: http://lkml.kernel.org/p/1377176379-27908-1-git-send-email-liuj97@gmail.com Signed-off-by: Jiang Liu <jiang.liu@huawei.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-07-01tracing: Add trace_seq_buffer_ptr() helper functionSteven Rostedt (Red Hat)
There's several locations in the kernel that open code the calculation of the next location in the trace_seq buffer. This is usually done with p->buffer + p->len Instead of having this open coded, supply a helper function in the header to do it for them. This function is called trace_seq_buffer_ptr(). Link: http://lkml.kernel.org/p/20140626220129.452783019@goodmis.org Acked-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-07-01tracing: Move the trace_seq_* functions into its own trace_seq.c fileSteven Rostedt (Red Hat)
The trace_seq_*() functions are a nice utility that allows users to manipulate buffers with printf() like formats. It has its own trace_seq.h header in include/linux and should be in its own file. Being tied with trace_output.c is rather awkward. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-05-15tracing: Add __bitmask() macro to trace events to cpumasks and other bitmasksSteven Rostedt (Red Hat)
Being able to show a cpumask of events can be useful as some events may affect only some CPUs. There is no standard way to record the cpumask and converting it to a string is rather expensive during the trace as traces happen in hotpaths. It would be better to record the raw event mask and be able to parse it at print time. The following macros were added for use with the TRACE_EVENT() macro: __bitmask() __assign_bitmask() __get_bitmask() To test this, I added this to the sched_migrate_task event, which looked like this: TRACE_EVENT(sched_migrate_task, TP_PROTO(struct task_struct *p, int dest_cpu, const struct cpumask *cpus), TP_ARGS(p, dest_cpu, cpus), TP_STRUCT__entry( __array( char, comm, TASK_COMM_LEN ) __field( pid_t, pid ) __field( int, prio ) __field( int, orig_cpu ) __field( int, dest_cpu ) __bitmask( cpumask, num_possible_cpus() ) ), TP_fast_assign( memcpy(__entry->comm, p->comm, TASK_COMM_LEN); __entry->pid = p->pid; __entry->prio = p->prio; __entry->orig_cpu = task_cpu(p); __entry->dest_cpu = dest_cpu; __assign_bitmask(cpumask, cpumask_bits(cpus), num_possible_cpus()); ), TP_printk("comm=%s pid=%d prio=%d orig_cpu=%d dest_cpu=%d cpumask=%s", __entry->comm, __entry->pid, __entry->prio, __entry->orig_cpu, __entry->dest_cpu, __get_bitmask(cpumask)) ); With the output of: ksmtuned-3613 [003] d..2 485.220508: sched_migrate_task: comm=ksmtuned pid=3615 prio=120 orig_cpu=3 dest_cpu=2 cpumask=00000000,0000000f migration/1-13 [001] d..5 485.221202: sched_migrate_task: comm=ksmtuned pid=3614 prio=120 orig_cpu=1 dest_cpu=0 cpumask=00000000,0000000f awk-3615 [002] d.H5 485.221747: sched_migrate_task: comm=rcu_preempt pid=7 prio=120 orig_cpu=0 dest_cpu=1 cpumask=00000000,000000ff migration/2-18 [002] d..5 485.222062: sched_migrate_task: comm=ksmtuned pid=3615 prio=120 orig_cpu=2 dest_cpu=3 cpumask=00000000,0000000f Link: http://lkml.kernel.org/r/1399377998-14870-6-git-send-email-javi.merino@arm.com Link: http://lkml.kernel.org/r/20140506132238.22e136d1@gandalf.local.home Suggested-by: Javi Merino <javi.merino@arm.com> Tested-by: Javi Merino <javi.merino@arm.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-04-08tracepoint: Use struct pointer instead of name hash for reg/unreg tracepointsMathieu Desnoyers
Register/unregister tracepoint probes with struct tracepoint pointer rather than tracepoint name. This change, which vastly simplifies tracepoint.c, has been proposed by Steven Rostedt. It also removes 8.8kB (mostly of text) to the vmlinux size. From this point on, the tracers need to pass a struct tracepoint pointer to probe register/unregister. A probe can now only be connected to a tracepoint that exists. Moreover, tracers are responsible for unregistering the probe before the module containing its associated tracepoint is unloaded. text data bss dec hex filename 10443444 4282528 10391552 25117524 17f4354 vmlinux.orig 10434930 4282848 10391552 25109330 17f2352 vmlinux Link: http://lkml.kernel.org/r/1396992381-23785-2-git-send-email-mathieu.desnoyers@efficios.com CC: Ingo Molnar <mingo@kernel.org> CC: Frederic Weisbecker <fweisbec@gmail.com> CC: Andrew Morton <akpm@linux-foundation.org> CC: Frank Ch. Eigler <fche@redhat.com> CC: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> [ SDR - fixed return val in void func in tracepoint_module_going() ] Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-03-21Revert "tracing: Move event storage for array from macro to standalone function"Steven Rostedt (Red Hat)
I originally wrote commit 35bb4399bd0e to shrink the size of the overhead of tracepoints by several kilobytes. Later, I received a patch from Vaibhav Nagarnaik that fixed a bug in the same code that this commit touches. Not only did it fix a bug, it also removed code and shrunk the size of the overhead of trace events even more than this commit did. Since this commit is scheduled for 3.15 and Vaibhav's patch is already in mainline, I need to revert this patch in order to keep it from conflicting with Vaibhav's patch. Not to mention, Vaibhav's patch makes this patch obsolete. Link: http://lkml.kernel.org/r/20140320225637.0226041b@gandalf.local.home Cc: Vaibhav Nagarnaik <vnagarnaik@google.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-03-07tracing: Move event storage for array from macro to standalone functionSteven Rostedt
The code that shows array fields for events is defined for all events. This can add up quite a bit when you have over 500 events. By making helper functions in the core kernel to do the work instead, we can shrink the size of the kernel down a bit. With a kernel configured with 502 events, the change in size was: text data bss dec hex filename 12990946 1913568 9785344 24689858 178bcc2 /tmp/vmlinux 12987390 1913504 9785344 24686238 178ae9e /tmp/vmlinux.patched That's a total of 3556 bytes, which comes down to 7 bytes per event. Although it's not much, this code is just called at initialization of the events. Link: http://lkml.kernel.org/r/20120810034708.084036335@goodmis.org Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-03-07tracing: Move raw output code from macro to standalone functionSteven Rostedt
The code for trace events to format the raw recorded event data into human readable format in the 'trace' file is repeated for every event in the system. When you have over 500 events, this can add up quite a bit. By making helper functions in the core kernel to do the work instead, we can shrink the size of the kernel down a bit. With a kernel configured with 502 events, the change in size was: text data bss dec hex filename 12991007 1913568 9785344 24689919 178bcff /tmp/vmlinux.orig 12990946 1913568 9785344 24689858 178bcc2 /tmp/vmlinux.patched Note, this version does not save as much as the version of this patch I had a few years ago. That is because in the mean time, commit f71130de5c7f ("tracing: Add a helper function for event print functions") did a lot of the work my original patch did. But this change helps slightly, and is part of a larger clean up to reduce the size much further. Link: http://lkml.kernel.org/r/20120810034707.378538034@goodmis.org Cc: Li Zefan <lizefan@huawei.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-11-11ftrace, sched: Add TRACE_FLAG_PREEMPT_RESCHEDPeter Zijlstra
Since the introduction of PREEMPT_NEED_RESCHED in: f27dde8deef3 ("sched: Add NEED_RESCHED to the preempt_count") we need to be able to look at both TIF_NEED_RESCHED and PREEMPT_NEED_RESCHED to understand the full preemption behaviour. Add it to the trace output. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Steven Rostedt <rostedt@goodmis.org> Cc: Fengguang Wu <fengguang.wu@intel.com> Cc: Huang Ying <ying.huang@intel.com> Cc: Yuanhan Liu <yuanhan.liu@linux.intel.com> Link: http://lkml.kernel.org/r/20131004152826.GP3081@twins.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-07-18tracing: Use trace_seq_puts()/trace_seq_putc() where possiblezhangwei(Jovi)
For string without format specifiers, use trace_seq_puts() or trace_seq_putc(). Link: http://lkml.kernel.org/r/51E3B3AC.1000605@huawei.com Signed-off-by: zhangwei(Jovi) <jovi.zhangwei@huawei.com> [ fixed a trace_seq_putc(s, " ") to trace_seq_putc(s, ' ') ] Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-04-29Merge tag 'trace-3.10' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace 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
2013-03-15tracing: Rename trace_event_mutex to trace_event_semzhangwei(Jovi)
trace_event_mutex is an rw semaphore now, not a mutex, change the name. Link: http://lkml.kernel.org/r/513D843B.40109@huawei.com Signed-off-by: zhangwei(Jovi) <jovi.zhangwei@huawei.com> [ Forward ported to my new code ] Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-03-15tracing: Add trace_puts() for even faster trace_printk() tracingSteven Rostedt (Red Hat)
The trace_printk() is extremely fast and is very handy as it can be used in any context (including NMIs!). But it still requires scanning the fmt string for parsing the args. Even the trace_bprintk() requires a scan to know what args will be saved, although it doesn't copy the format string itself. Several times trace_printk() has no args, and wastes cpu cycles scanning the fmt string. Adding trace_puts() allows the developer to use an even faster tracing method that only saves the pointer to the string in the ring buffer without doing any format parsing at all. This will help remove even more of the "Heisenbug" effect, when debugging. Also fixed up the F_printk()s for the ftrace internal bprint and print events. Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-03-15tracing: Consolidate max_tr into main trace_array structureSteven Rostedt (Red Hat)
Currently, the way the latency tracers and snapshot feature works is to have a separate trace_array called "max_tr" that holds the snapshot buffer. For latency tracers, this snapshot buffer is used to swap the running buffer with this buffer to save the current max latency. The only items needed for the max_tr is really just a copy of the buffer itself, the per_cpu data pointers, the time_start timestamp that states when the max latency was triggered, and the cpu that the max latency was triggered on. All other fields in trace_array are unused by the max_tr, making the max_tr mostly bloat. This change removes the max_tr completely, and adds a new structure called trace_buffer, that holds the buffer pointer, the per_cpu data pointers, the time_start timestamp, and the cpu where the latency occurred. The trace_array, now has two trace_buffers, one for the normal trace and one for the max trace or snapshot. By doing this, not only do we remove the bloat from the max_trace but the instances of traces can now use their own snapshot feature and not have just the top level global_trace have the snapshot feature and latency tracers for itself. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-03-15tracing: Add a helper function for event print functionsLi Zefan
Move duplicate code in event print functions to a helper function. This shrinks the size of the kernel by ~13K. text data bss dec hex filename 6596137 1743966 10138672 18478775 119f6b7 vmlinux.o.old 6583002 1743849 10138672 18465523 119c2f3 vmlinux.o.new Link: http://lkml.kernel.org/r/51258746.2060304@huawei.com Signed-off-by: Li Zefan <lizefan@huawei.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-02-27hlist: drop the node parameter from iteratorsSasha Levin
I'm not sure why, but the hlist for each entry iterators were conceived list_for_each_entry(pos, head, member) The hlist ones were greedy and wanted an extra parameter: hlist_for_each_entry(tpos, pos, head, member) Why did they need an extra pos parameter? I'm not quite sure. Not only they don't really need it, it also prevents the iterator from looking exactly like the list iterator, which is unfortunate. Besides the semantic patch, there was some manual work required: - Fix up the actual hlist iterators in linux/list.h - Fix up the declaration of other iterators based on the hlist ones. - A very small amount of places were using the 'node' parameter, this was modified to use 'obj->member' instead. - Coccinelle didn't handle the hlist_for_each_entry_safe iterator properly, so those had to be fixed up manually. The semantic patch which is mostly the work of Peter Senna Tschudin is here: @@ iterator name hlist_for_each_entry, hlist_for_each_entry_continue, hlist_for_each_entry_from, hlist_for_each_entry_rcu, hlist_for_each_entry_rcu_bh, hlist_for_each_entry_continue_rcu_bh, for_each_busy_worker, ax25_uid_for_each, ax25_for_each, inet_bind_bucket_for_each, sctp_for_each_hentry, sk_for_each, sk_for_each_rcu, sk_for_each_from, sk_for_each_safe, sk_for_each_bound, hlist_for_each_entry_safe, hlist_for_each_entry_continue_rcu, nr_neigh_for_each, nr_neigh_for_each_safe, nr_node_for_each, nr_node_for_each_safe, for_each_gfn_indirect_valid_sp, for_each_gfn_sp, for_each_host; type T; expression a,c,d,e; identifier b; statement S; @@ -T b; <+... when != b ( hlist_for_each_entry(a, - b, c, d) S | hlist_for_each_entry_continue(a, - b, c) S | hlist_for_each_entry_from(a, - b, c) S | hlist_for_each_entry_rcu(a, - b, c, d) S | hlist_for_each_entry_rcu_bh(a, - b, c, d) S | hlist_for_each_entry_continue_rcu_bh(a, - b, c) S | for_each_busy_worker(a, c, - b, d) S | ax25_uid_for_each(a, - b, c) S | ax25_for_each(a, - b, c) S | inet_bind_bucket_for_each(a, - b, c) S | sctp_for_each_hentry(a, - b, c) S | sk_for_each(a, - b, c) S | sk_for_each_rcu(a, - b, c) S | sk_for_each_from -(a, b) +(a) S + sk_for_each_from(a) S | sk_for_each_safe(a, - b, c, d) S | sk_for_each_bound(a, - b, c) S | hlist_for_each_entry_safe(a, - b, c, d, e) S | hlist_for_each_entry_continue_rcu(a, - b, c) S | nr_neigh_for_each(a, - b, c) S | nr_neigh_for_each_safe(a, - b, c, d) S | nr_node_for_each(a, - b, c) S | nr_node_for_each_safe(a, - b, c, d) S | - for_each_gfn_sp(a, c, d, b) S + for_each_gfn_sp(a, c, d) S | - for_each_gfn_indirect_valid_sp(a, c, d, b) S + for_each_gfn_indirect_valid_sp(a, c, d) S | for_each_host(a, - b, c) S | for_each_host_safe(a, - b, c, d) S | for_each_mesh_entry(a, - b, c, d) S ) ...+> [akpm@linux-foundation.org: drop bogus change from net/ipv4/raw.c] [akpm@linux-foundation.org: drop bogus hunk from net/ipv6/raw.c] [akpm@linux-foundation.org: checkpatch fixes] [akpm@linux-foundation.org: fix warnings] [akpm@linux-foudnation.org: redo intrusive kvm changes] Tested-by: Peter Senna Tschudin <peter.senna@gmail.com> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Sasha Levin <sasha.levin@oracle.com> Cc: Wu Fengguang <fengguang.wu@intel.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Gleb Natapov <gleb@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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