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Based on patches from Andi Kleen.
When printing PT instruction traces with perf script it is rather useful
to see some indentation for the call tree. This patch adds a new
callindent field to perf script that prints spaces for the function call
stack depth.
We already have code to track the function call stack for PT, that we
can reuse with minor modifications.
The resulting output is not quite as nice as ftrace yet, but a lot
better than what was there before.
Note there are some corner cases when the thread stack gets code
confused and prints incorrect indentation. Even with that it is fairly
useful.
When displaying kernel code traces it is recommended to run as root, as
otherwise perf doesn't understand the kernel addresses properly, and may
not reset the call stack correctly on kernel boundaries.
Example output:
sudo perf-with-kcore record eg2 -a -e intel_pt// -- sleep 1
sudo perf-with-kcore script eg2 --ns -F callindent,time,comm,pid,sym,ip,addr,flags,cpu --itrace=cre | less
...
swapper 0 [000] 5830.389116586: call irq_exit ffffffff8104d620 smp_call_function_single_interrupt+0x30 => ffffffff8107e720 irq_exit
swapper 0 [000] 5830.389116586: call idle_cpu ffffffff8107e769 irq_exit+0x49 => ffffffff810a3970 idle_cpu
swapper 0 [000] 5830.389116586: return idle_cpu ffffffff810a39b7 idle_cpu+0x47 => ffffffff8107e76e irq_exit
swapper 0 [000] 5830.389116586: call tick_nohz_irq_exit ffffffff8107e7bd irq_exit+0x9d => ffffffff810f2fc0 tick_nohz_irq_exit
swapper 0 [000] 5830.389116919: call __tick_nohz_idle_enter ffffffff810f2fe0 tick_nohz_irq_exit+0x20 => ffffffff810f28d0 __tick_nohz_idle_enter
swapper 0 [000] 5830.389116919: call ktime_get ffffffff810f28f1 __tick_nohz_idle_enter+0x21 => ffffffff810e9ec0 ktime_get
swapper 0 [000] 5830.389116919: call read_tsc ffffffff810e9ef6 ktime_get+0x36 => ffffffff81035070 read_tsc
swapper 0 [000] 5830.389116919: return read_tsc ffffffff81035084 read_tsc+0x14 => ffffffff810e9efc ktime_get
swapper 0 [000] 5830.389116919: return ktime_get ffffffff810e9f46 ktime_get+0x86 => ffffffff810f28f6 __tick_nohz_idle_enter
swapper 0 [000] 5830.389116919: call sched_clock_idle_sleep_event ffffffff810f290b __tick_nohz_idle_enter+0x3b => ffffffff810a7380 sched_clock_idle_sleep_event
swapper 0 [000] 5830.389116919: call sched_clock_cpu ffffffff810a738b sched_clock_idle_sleep_event+0xb => ffffffff810a72e0 sched_clock_cpu
swapper 0 [000] 5830.389116919: call sched_clock ffffffff810a734d sched_clock_cpu+0x6d => ffffffff81035750 sched_clock
swapper 0 [000] 5830.389116919: call native_sched_clock ffffffff81035754 sched_clock+0x4 => ffffffff81035640 native_sched_clock
swapper 0 [000] 5830.389116919: return native_sched_clock ffffffff8103568c native_sched_clock+0x4c => ffffffff81035759 sched_clock
swapper 0 [000] 5830.389116919: return sched_clock ffffffff8103575c sched_clock+0xc => ffffffff810a7352 sched_clock_cpu
swapper 0 [000] 5830.389116919: return sched_clock_cpu ffffffff810a7356 sched_clock_cpu+0x76 => ffffffff810a7390 sched_clock_idle_sleep_event
swapper 0 [000] 5830.389116919: return sched_clock_idle_sleep_event ffffffff810a7391 sched_clock_idle_sleep_event+0x11 => ffffffff810f2910 __tick_nohz_idle_enter
...
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Andi Kleen <ak@linux.intel.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lkml.kernel.org/r/1466689258-28493-4-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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This change allows python scripts to be able to utilize the recent
changes to the db export api allowing the export of call_paths derived
from sampled callchains. These call paths are also now associated with
the samples from which they were derived.
- This feature is enabled by setting "perf_db_export_callchains" to true
- When enabled, samples that have callchain information will have the
callchains exported via call_path_table
- The call_path_id field is added to sample_table to enable association of
samples with the corresponding callchain stored in the call paths
table. A call_path_id of 0 will be exported if there is no
corresponding callchain.
- When "perf_db_export_callchains" and "perf_db_export_calls" are both
set to True, the call path root data structure will be shared. This
prevents duplicating of data and call path ids that would result from
building two separate call path trees in memory.
- The call_return_processor structure definition was relocated to the header
file to make its contents visible to db-export.c. This enables the
sharing of call path trees between the two features, as mentioned
above.
This change is visible to python scripts using the python db export api.
The change is backwards compatible with scripts written against the
previous API, assuming that the scripts model the sample_table function
after the one in export-to-postgresql.py script by allowing for
additional arguments to be added in the future. ie. using *x as the
final argument of the sample_table function.
Signed-off-by: Chris Phlipot <cphlipot0@gmail.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1461831551-12213-6-git-send-email-cphlipot0@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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Move the call path handling code out of thread-stack.c and
thread-stack.h to allow other components that are not part of
thread-stack to create call paths.
Summary:
- Create call-path.c and call-path.h and add them to the build.
- Move all call path related code out of thread-stack.c and thread-stack.h
and into call-path.c and call-path.h.
- A small subset of structures and functions are now visible through
call-path.h, which is required for thread-stack.c to continue to
compile.
This change is a prerequisite for subsequent patches in this change set
and by itself contains no user-visible changes.
Signed-off-by: Chris Phlipot <cphlipot0@gmail.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1461831551-12213-3-git-send-email-cphlipot0@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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The thread-stack represents a thread's current stack. When a thread
exits there can still be many functions on the stack e.g. exit() can be
called many levels deep, so all the callers will never return. To get
that information output, the thread-stack must be flushed.
Previously it was assumed the thread-stack would be flushed when the
struct thread was deleted. With thread ref-counting it is no longer
clear when that will be, if ever. So instead explicitly flush all the
thread-stacks at the end of a session.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lkml.kernel.org/r/1432906425-9911-3-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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Enhance the thread stack to output detailed information about paired
calls and returns.
The enhanced processing consumes sample information via
thread_stack__process() and outputs information about paired calls /
returns via a call-back.
While the call-back makes it possible for the facility to be used by
arbitrary tools, a subsequent patch will provide the information to
Python scripting via the db-export interface.
An important part of the call/return information is the
call path which provides a structure that defines a context
sensitive call graph.
Note that there are now two ways to use the thread stack.
For simply providing a call stack (like you would get from the perf
record -g option) the interface consists of thread_stack__event() and
thread_stack__sample().
Whereas the enhanced interface consists of call_return_processor__new()
and thread_stack__process().
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1414678188-14946-5-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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Add a thread stack for synthesizing call chains from call and return
events.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1414678188-14946-2-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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Adrian Hunter
Chris Phlipot