The current perf scripting facility only supports tracepoints. This
patch implements a generic perl handler to support other events than
tracepoints too.
This patch introduces a function process_event() that is called by perf
for each sample. The function is called with byte streams as arguments
containing information about the event, its attributes, the sample and
raw data. Perl's unpack() function can easily be used for byte decoding.
The following is the default implementation for process_event() that can
also be generated with perf script:
# Packed byte string args of process_event():
#
# $event: union perf_event util/event.h
# $attr: struct perf_event_attr linux/perf_event.h
# $sample: struct perf_sample util/event.h
# $raw_data: perf_sample->raw_data util/event.h
sub process_event
{
my ($event, $attr, $sample, $raw_data) = @_;
my @event = unpack("LSS", $event);
my @attr = unpack("LLQQQQQLLQQ", $attr);
my @sample = unpack("QLLQQQQQLL", $sample);
my @raw_data = unpack("C*", $raw_data);
use Data::Dumper;
print Dumper \@event, \@attr, \@sample, \@raw_data;
}
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1323969824-9711-4-git-send-email-robert.richter@amd.com
Signed-off-by: Robert Richter <robert.richter@amd.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The features HEADER_TRACE_INFO and HEADER_BUILD_ID are handled
different when writing the feature section. All other features are
simply disabled on failure and writing the section goes on without
returning an error. There is no reason for these special cases. This
patch unifies handling of the features.
This should be ok since all features can be parsed independently.
Offset and size of a feature's block is stored in struct perf_file_
section right after the data block of perf.data (see perf_session__
write_header()). Thus, if a feature does not exist then other features
can be processed anyway.
Also moving special code for HEADER_BUILD_ID out to write_build_id().
v2:
* perf record throws an error now if buildids may not be generated,
which can be disabled with the --no-buildid option.
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1323248577-11268-6-git-send-email-robert.richter@amd.com
Signed-off-by: Robert Richter <robert.richter@amd.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The default input file for perf report is not handled the same way as
perf record does it for its output file. This leads to unexpected
behavior of perf report, etc. E.g.:
# perf record -a -e cpu-cycles sleep 2 | perf report | cat
failed to open perf.data: No such file or directory (try 'perf record' first)
While perf record writes to a fifo, perf report expects perf.data to be
read. This patch changes this to accept fifos as input file.
Applies to the following commands:
perf annotate
perf buildid-list
perf evlist
perf kmem
perf lock
perf report
perf sched
perf script
perf timechart
Also fixes char const* -> const char* type declaration for filename
strings.
v2:
* Prevent potential null pointer access to input_name in
builtin-report.c. Needed due to removal of patch "perf report: Setup
browser if stdout is a pipe"
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1323248577-11268-5-git-send-email-robert.richter@amd.com
Signed-off-by: Robert Richter <robert.richter@amd.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
I get such truncated annotation results in 'perf top':
: Disassembly of section .text: â–’
: â–’
: ffffffff810966a8 <nr_iowait_cpu>: â–’
4.94 : ffffffff810966a8: movslq %edi,%rdi â–’
3.70 : ffffffff810966ab: mov $0x13700,%rax â–’
0.00 : ffffffff810966b2: add -0x7e32cb00(,%rdi,8),%rax â–’
8.64 : ffffffff810966ba: mov 0x7e0(%rax),%eax â–’
82.72 : ffffffff810966c0: cltq â–’
Note the missing 'retq' which is there in the original function:
ffffffff810966a8 <nr_iowait_cpu>:
ffffffff810966a8: 48 63 ff movslq %edi,%rdi
ffffffff810966ab: 48 c7 c0 00 37 01 00 mov $0x13700,%rax
ffffffff810966b2: 48 03 04 fd 00 35 cd add -0x7e32cb00(,%rdi,8),%rax
ffffffff810966b9: 81
ffffffff810966ba: 8b 80 e0 07 00 00 mov 0x7e0(%rax),%eax
ffffffff810966c0: 48 98 cltq
ffffffff810966c2: c3 retq
ffffffff810966c3 <this_cpu_load>:
I'm using a fairly recent binutils:
GNU objdump version 2.21.51.0.6-2.fc16 20110118
AFAICS the bug is simply that sym->end points to the last byte
of the symbol in question - while objdump's --stop-address
expects the last byte plus 1 to disassemble the full range.
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20111223130804.GA24305@elte.hu
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
perf does not properly handle monitoring of processes with named threads.
For example:
$ ps -C myapp -L
PID LWP TTY TIME CMD
25118 25118 ? 00:00:00 myapp
25118 25119 ? 00:00:00 myapp:worker
perf record -e cs -c 1 -fo /tmp/perf.data -p 25118 -- sleep 10
perf report --stdio -i /tmp/perf.data
100.00% myapp:worker [kernel.kallsyms] [k] perf_event_task_sched_out
The process name is set to the name of the last thread it finds for the
process.
The Problem:
perf-top and perf-record both create a thread_map of threads to be
monitored. That map is used in perf_event__synthesize_thread_map which
loops over the entries in thread_map and calls __event__synthesize_thread
to generate COMM and MMAP events.
__event__synthesize_thread calls perf_event__synthesize_comm which opens
/proc/pid/status, reads the name of the task and its thread group id.
That's all fine. The problem is that it then reads /proc/pid/task and
generates COMM events for each task it finds - but using the name found
in /proc/pid/status where pid is the thread of interest.
The end result (looping over thread_map + synthesizing comm events for
each thread each time) means the name of the last thread processed sets
the name for all threads in the process - which is not good for
multithreaded processes with named threads.
The Fix:
perf_event__synthesize_comm has an input argument (full) that decides
whether to process task entries for each pid it is passed. It currently
never set to 0 (perf_event__synthesize_comm has a single caller and it
always passes the value 1). Let's fix that.
Add the full input argument to __event__synthesize_thread which passes
it to perf_event__synthesize_comm. For thread/process monitoring set full
to 0 which means COMM and MMAP events are only generated for the pid
passed to it. For system wide monitoring set full to 1 so that COMM events
are generated for all threads in a process.
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1324578603-12762-2-git-send-email-dsahern@gmail.com
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Robert Richter
Nelson Elhage
Ingo Molnar
David Ahern
Namhyung Kim
Stephane Eranian
Jiri Olsa