linux-toradex.git/kernel/trace/trace_syscalls.c, branch v4.12-rc1

tracing/syscalls: fix multiline in error message text

2016-09-29T08:25:23+00:00

pr_info message spans two lines and the literal string is missing
a white space between words. Add the white space.

Signed-off-by: Colin Ian King 
Acked-by: Ingo Molnar 
Acked-by: Steven Rostedt 
Signed-off-by: Jiri Kosina

perf: split perf_trace_buf_prepare into alloc and update parts

2016-04-08T01:04:26+00:00

split allows to move expensive update of 'struct trace_entry' to later phase.
Repurpose unused 1st argument of perf_tp_event() to indicate event type.

While splitting use temp variable 'rctx' instead of '*rctx' to avoid
unnecessary loads done by the compiler due to -fno-strict-aliasing

Signed-off-by: Alexei Starovoitov 
Acked-by: Peter Zijlstra (Intel) 
Signed-off-by: David S. Miller

Merge tag 'trace-v4.6' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

2016-03-24T17:52:25+00:00

Pull tracing updates from Steven Rostedt:
 "Nothing major this round.  Mostly small clean ups and fixes.

  Some visible changes:

   - A new flag was added to distinguish traces done in NMI context.

   - Preempt tracer now shows functions where preemption is disabled but
     interrupts are still enabled.

  Other notes:

   - Updates were done to function tracing to allow better performance
     with perf.

   - Infrastructure code has been added to allow for a new histogram
     feature for recording live trace event histograms that can be
     configured by simple user commands.  The feature itself was just
     finished, but needs a round in linux-next before being pulled.

     This only includes some infrastructure changes that will be needed"

* tag 'trace-v4.6' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (22 commits)
  tracing: Record and show NMI state
  tracing: Fix trace_printk() to print when not using bprintk()
  tracing: Remove redundant reset per-CPU buff in irqsoff tracer
  x86: ftrace: Fix the misleading comment for arch/x86/kernel/ftrace.c
  tracing: Fix crash from reading trace_pipe with sendfile
  tracing: Have preempt(irqs)off trace preempt disabled functions
  tracing: Fix return while holding a lock in register_tracer()
  ftrace: Use kasprintf() in ftrace_profile_tracefs()
  ftrace: Update dynamic ftrace calls only if necessary
  ftrace: Make ftrace_hash_rec_enable return update bool
  tracing: Fix typoes in code comment and printk in trace_nop.c
  tracing, writeback: Replace cgroup path to cgroup ino
  tracing: Use flags instead of bool in trigger structure
  tracing: Add an unreg_all() callback to trigger commands
  tracing: Add needs_rec flag to event triggers
  tracing: Add a per-event-trigger 'paused' field
  tracing: Add get_syscall_name()
  tracing: Add event record param to trigger_ops.func()
  tracing: Make event trigger functions available
  tracing: Make ftrace_event_field checking functions available
  ...

tracing: Add get_syscall_name()

2016-03-08T16:19:32+00:00

Add a utility function to grab the syscall name from the syscall
metadata, given a syscall id.

Link: http://lkml.kernel.org/r/be26a8dfe3f15e16a837799f1c1e2b4d62742843.1449767187.git.tom.zanussi@linux.intel.com

Signed-off-by: Tom Zanussi 
Tested-by: Masami Hiramatsu 
Reviewed-by: Namhyung Kim 
Signed-off-by: Steven Rostedt

tracing/syscalls: Rename "/format" tracepoint field name "nr" to "__syscall_nr:

2016-02-29T14:34:53+00:00

Some tracepoint have multiple fields with the same name, "nr", the first
one is a unique syscall ID, the other is a syscall argument:

  # cat /sys/kernel/debug/tracing/events/syscalls/sys_enter_io_getevents/format
  name: sys_enter_io_getevents
  ID: 747
  format:
 	field:unsigned short common_type;	offset:0;	size:2;	signed:0;
 	field:unsigned char common_flags;	offset:2;	size:1;	signed:0;
 	field:unsigned char common_preempt_count;	offset:3;	size:1;	signed:0;
 	field:int common_pid;	offset:4;	size:4;	signed:1;

 	field:int nr;	offset:8;	size:4;	signed:1;
 	field:aio_context_t ctx_id;	offset:16;	size:8;	signed:0;
 	field:long min_nr;	offset:24;	size:8;	signed:0;
 	field:long nr;	offset:32;	size:8;	signed:0;
 	field:struct io_event * events;	offset:40;	size:8;	signed:0;
 	field:struct timespec * timeout;	offset:48;	size:8;	signed:0;

  print fmt: "ctx_id: 0x%08lx, min_nr: 0x%08lx, nr: 0x%08lx, events: 0x%08lx, timeout: 0x%08lx", ((unsigned long)(REC->ctx_id)), ((unsigned long)(REC->min_nr)), ((unsigned long)(REC->nr)), ((unsigned long)(REC->events)), ((unsigned long)(REC->timeout))
  #

Fix it by renaming the "/format" common tracepoint field "nr" to "__syscall_nr".

Signed-off-by: Taeung Song 
[ Do not rename the struct member, just the '/format' field name ]
Signed-off-by: Steven Rostedt 
Acked-by: Peter Zijlstra 
Cc: Jiri Olsa 
Cc: Lai Jiangshan 
Cc: Namhyung Kim 
Cc: Thomas Gleixner 
Link: http://lkml.kernel.org/r/20160226132301.3ae065a4@gandalf.local.home
Signed-off-by: Arnaldo Carvalho de Melo

tracing: Move trace_flags from global to a trace_array field

2015-09-30T19:22:55+00:00

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

tracing: Rename ftrace_trigger_soft_disabled() to trace_trigger_soft_disabled()

2015-05-13T19:25:39+00:00

The name "ftrace" really refers to the function hook infrastructure. It
is not about the trace_events. The ftrace_trigger_soft_disabled() tests if a
trace_event is soft disabled (called but not traced), and returns true if
it is. It has nothing to do with function tracing and should be renamed.

Signed-off-by: Steven Rostedt

tracing: Rename ftrace_event_{call,class} to trace_event_{call,class}

2015-05-13T18:06:10+00:00

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

tracing: Rename ftrace_event_file to trace_event_file

2015-05-13T18:05:16+00:00

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

perf: Avoid horrible stack usage

2015-01-14T14:11:45+00:00

Both Linus (most recent) and Steve (a while ago) reported that perf
related callbacks have massive stack bloat.

The problem is that software events need a pt_regs in order to
properly report the event location and unwind stack. And because we
could not assume one was present we allocated one on stack and filled
it with minimal bits required for operation.

Now, pt_regs is quite large, so this is undesirable. Furthermore it
turns out that most sites actually have a pt_regs pointer available,
making this even more onerous, as the stack space is pointless waste.

This patch addresses the problem by observing that software events
have well defined nesting semantics, therefore we can use static
per-cpu storage instead of on-stack.

Linus made the further observation that all but the scheduler callers
of perf_sw_event() have a pt_regs available, so we change the regular
perf_sw_event() to require a valid pt_regs (where it used to be
optional) and add perf_sw_event_sched() for the scheduler.

We have a scheduler specific call instead of a more generic _noregs()
like construct because we can assume non-recursion from the scheduler
and thereby simplify the code further (_noregs would have to put the
recursion context call inline in order to assertain which __perf_regs
element to use).

One last note on the implementation of perf_trace_buf_prepare(); we
allow .regs = NULL for those cases where we already have a pt_regs
pointer available and do not need another.

Reported-by: Linus Torvalds 
Reported-by: Steven Rostedt 
Signed-off-by: Peter Zijlstra (Intel) 
Cc: Arnaldo Carvalho de Melo 
Cc: Javi Merino 
Cc: Linus Torvalds 
Cc: Mathieu Desnoyers 
Cc: Oleg Nesterov 
Cc: Paul Mackerras 
Cc: Petr Mladek 
Cc: Steven Rostedt 
Cc: Tom Zanussi 
Cc: Vaibhav Nagarnaik 
Link: http://lkml.kernel.org/r/20141216115041.GW3337@twins.programming.kicks-ass.net
Signed-off-by: Ingo Molnar