In perf_event__parse_sample(), the array variable was not incremented
by the amount of data used by the raw_data.
That was okay until we added PERF_SAMPLE_BRANCH_STACK which depends on
the array variable pointing to the beginning of the branch stack data.
But that was not the case if branch stack was combined with raw mode
sampling. That led to bogus branch stack addresses and count.
The bug would show up with:
$ perf record -R -b foo
This patch fixes the problem by correctly moving the array pointer
forward for RAW samples.
Signed-off-by: Stephane Eranian <eranian@google.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20120317222317.GA8803@quad
[ committer note: Fix also later submitted by Jiri Olsa ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The callchain stdio mode display was written using a sorted by symbol
report. In this mode we have only one callchain root per hist so we
forgot to handle cases where we have multiple callchain root, as in per
dso sorting for example.
Fix this by handling these roots like any other branch, with the hist as
the parent.
Before:
1.97% libpthread-2.12.1.so
|
--- __libc_write
create_worker
bench_sched_messaging
cmd_bench
run_builtin
main
__libc_start_main
|
--- __libc_read
create_worker
bench_sched_messaging
cmd_bench
run_builtin
main
__libc_start_main
After:
1.97% libpthread-2.12.1.so
|
|--36.97%-- __libc_write
| create_worker
| bench_sched_messaging
| cmd_bench
| run_builtin
| main
| __libc_start_main
|
|--31.47%-- __libc_read
| create_worker
| bench_sched_messaging
| cmd_bench
| run_builtin
| main
| __libc_start_main
...
Single roots keep their entry without percentage because they have
the same overhead than the hist they refer to. ie: 100% in fractal
mode and the percentage of the hist in graph mode:
0.00% [k] reschedule_interrupt
|
--- default_idle
amd_e400_idle
cpu_idle
start_secondary
Reported-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1332526010-15400-1-git-send-email-fweisbec@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The perf diff command is broken since:
perf hists: Threaded addition and sorting of entries
commit 1980c2ebd7
Several places were broken:
- hists data need to be collected into opened sessions instead
of into events
- session's hists data need to be initialized properly when the
session is created
- hist_entry__pcnt_snprintf: the percentage and displacement
buffer preparation must not use 'ret' because it's used
as a pointer to the final buffer
Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20120322133726.GB1601@m.brq.redhat.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Pull perf events changes for v3.4 from Ingo Molnar:
- New "hardware based branch profiling" feature both on the kernel and
the tooling side, on CPUs that support it. (modern x86 Intel CPUs
with the 'LBR' hardware feature currently.)
This new feature is basically a sophisticated 'magnifying glass' for
branch execution - something that is pretty difficult to extract from
regular, function histogram centric profiles.
The simplest mode is activated via 'perf record -b', and the result
looks like this in perf report:
$ perf record -b any_call,u -e cycles:u branchy
$ perf report -b --sort=symbol
52.34% [.] main [.] f1
24.04% [.] f1 [.] f3
23.60% [.] f1 [.] f2
0.01% [k] _IO_new_file_xsputn [k] _IO_file_overflow
0.01% [k] _IO_vfprintf_internal [k] _IO_new_file_xsputn
0.01% [k] _IO_vfprintf_internal [k] strchrnul
0.01% [k] __printf [k] _IO_vfprintf_internal
0.01% [k] main [k] __printf
This output shows from/to branch columns and shows the highest
percentage (from,to) jump combinations - i.e. the most likely taken
branches in the system. "branches" can also include function calls
and any other synchronous and asynchronous transitions of the
instruction pointer that are not 'next instruction' - such as system
calls, traps, interrupts, etc.
This feature comes with (hopefully intuitive) flat ascii and TUI
support in perf report.
- Various 'perf annotate' visual improvements for us assembly junkies.
It will now recognize function calls in the TUI and by hitting enter
you can follow the call (recursively) and back, amongst other
improvements.
- Multiple threads/processes recording support in perf record, perf
stat, perf top - which is activated via a comma-list of PIDs:
perf top -p 21483,21485
perf stat -p 21483,21485 -ddd
perf record -p 21483,21485
- Support for per UID views, via the --uid paramter to perf top, perf
report, etc. For example 'perf top --uid mingo' will only show the
tasks that I am running, excluding other users, root, etc.
- Jump label restructurings and improvements - this includes the
factoring out of the (hopefully much clearer) include/linux/static_key.h
generic facility:
struct static_key key = STATIC_KEY_INIT_FALSE;
...
if (static_key_false(&key))
do unlikely code
else
do likely code
...
static_key_slow_inc();
...
static_key_slow_inc();
...
The static_key_false() branch will be generated into the code with as
little impact to the likely code path as possible. the
static_key_slow_*() APIs flip the branch via live kernel code patching.
This facility can now be used more widely within the kernel to
micro-optimize hot branches whose likelihood matches the static-key
usage and fast/slow cost patterns.
- SW function tracer improvements: perf support and filtering support.
- Various hardenings of the perf.data ABI, to make older perf.data's
smoother on newer tool versions, to make new features integrate more
smoothly, to support cross-endian recording/analyzing workflows
better, etc.
- Restructuring of the kprobes code, the splitting out of 'optprobes',
and a corner case bugfix.
- Allow the tracing of kernel console output (printk).
- Improvements/fixes to user-space RDPMC support, allowing user-space
self-profiling code to extract PMU counts without performing any
system calls, while playing nice with the kernel side.
- 'perf bench' improvements
- ... and lots of internal restructurings, cleanups and fixes that made
these features possible. And, as usual this list is incomplete as
there were also lots of other improvements
* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (120 commits)
perf report: Fix annotate double quit issue in branch view mode
perf report: Remove duplicate annotate choice in branch view mode
perf/x86: Prettify pmu config literals
perf report: Enable TUI in branch view mode
perf report: Auto-detect branch stack sampling mode
perf record: Add HEADER_BRANCH_STACK tag
perf record: Provide default branch stack sampling mode option
perf tools: Make perf able to read files from older ABIs
perf tools: Fix ABI compatibility bug in print_event_desc()
perf tools: Enable reading of perf.data files from different ABI rev
perf: Add ABI reference sizes
perf report: Add support for taken branch sampling
perf record: Add support for sampling taken branch
perf tools: Add code to support PERF_SAMPLE_BRANCH_STACK
x86/kprobes: Split out optprobe related code to kprobes-opt.c
x86/kprobes: Fix a bug which can modify kernel code permanently
x86/kprobes: Fix instruction recovery on optimized path
perf: Add callback to flush branch_stack on context switch
perf: Disable PERF_SAMPLE_BRANCH_* when not supported
perf/x86: Add LBR software filter support for Intel CPUs
...
This patch adds a simple GTK2-based browser to 'perf report' that's
based on the TTY-based browser in builtin-report.c.
To launch "perf report" using the new GTK interface just type:
$ perf report --gtk
The interface is somewhat limited in features at the moment:
- No callgraph support
- No KVM guest profiling support
- No color coding for percentages
- No sorting from the UI
- ..and many, many more!
That said, I think this patch a reasonable start to build future features on.
Signed-off-by: Pekka Enberg <penberg@kernel.org>
Cc: Colin Walters <walters@verbum.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ingo Molnar <mingo@kernel.org>
Link: http://lkml.kernel.org/r/alpine.LFD.2.02.1202231952410.6689@tux.localdomain
[ committer note: Added #pragma to make gtk no strict prototype problem go
away as suggested by Colin Walters modulo avoiding push/pop ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
