According to PEP 394 recommendation [1], it's more portable to use
python2 rather than plain python to refer python binary version 2.
Since there're distros using python3 by default like Arch, and we don't
support python3 (yet), it'd be better using python2 explicitly.
But older versions (prior to 2.7) seem not to provide python2 but just
python. Given that it's only old version, try python2 first and then
fallback to python. It'll ensure that it always points to python 2.x.
I tested (compiles and perf script runs) with the combinations:
1) python -> python2.x, python-config -> python2.x-config
python2 N/A, python2-config N/A
2) python -> python3.x, python-config -> python3.x-config
python2 -> python2.x, python2-config -> python2.x-config
3) python -> python2.x, python-config -> python2.x-config
python2 -> python2.x, python2-config -> python2.x-config
4) python -> python2.x, python-config -> python2.x-config
python2 -> python2.x, python2-config N/A
Based on / replaces the patch 2/2 by Namhyung Kim.
[1] https://www.python.org/dev/peps/pep-0394
Based-on-patch-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Thomas Ilsche <thomas.ilsche@tu-dresden.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/53DF8493.6070206@tu-dresden.de
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
When saving the callchain on Power, the kernel conservatively saves excess
entries in the callchain. A few of these entries are needed in some cases
but not others. We should use the DWARF debug information to determine
when the entries are needed.
Eg: the value in the link register (LR) is needed only when it holds the
return address of a function. At other times it must be ignored.
If the unnecessary entries are not ignored, we end up with duplicate arcs
in the call-graphs.
Use the DWARF debug information to determine if any callchain entries
should be ignored when building call-graphs.
Callgraph before the patch:
14.67% 2234 sprintft libc-2.18.so [.] __random
|
--- __random
|
|--61.12%-- __random
| |
| |--97.15%-- rand
| | do_my_sprintf
| | main
| | generic_start_main.isra.0
| | __libc_start_main
| | 0x0
| |
| --2.85%-- do_my_sprintf
| main
| generic_start_main.isra.0
| __libc_start_main
| 0x0
|
--38.88%-- rand
|
|--94.01%-- rand
| do_my_sprintf
| main
| generic_start_main.isra.0
| __libc_start_main
| 0x0
|
--5.99%-- do_my_sprintf
main
generic_start_main.isra.0
__libc_start_main
0x0
Callgraph after the patch:
14.67% 2234 sprintft libc-2.18.so [.] __random
|
--- __random
|
|--95.93%-- rand
| do_my_sprintf
| main
| generic_start_main.isra.0
| __libc_start_main
| 0x0
|
--4.07%-- do_my_sprintf
main
generic_start_main.isra.0
__libc_start_main
0x0
TODO: For split-debug info objects like glibc, we can only determine
the call-frame-address only when both .eh_frame and .debug_info
sections are available. We should be able to determin the CFA
even without the .eh_frame section.
Fix suggested by Anton Blanchard.
Thanks to valuable input on DWARF debug information from Ulrich Weigand.
Reported-by: Maynard Johnson <maynard@us.ibm.com>
Tested-by: Maynard Johnson <maynard@us.ibm.com>
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/20140625154903.GA29607@us.ibm.com
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Currently 'make help' message has such hint:
use "make prefix=<path> <install target>" to install to a particular
path like make prefix=/usr/local install install-doc
But this is misleading, when I specify "prefix=/usr/local", it has got no
respect at all.
This is because that, "DESTDIR" is considered first. In this case, "DESTDIR"
has an empty value, so "prefix" is honored. However, "prefix" is unconditionally
assigned to $HOME, regardless of what it is set to from command line. So our
"prefix" setting got no respect and the actual destination falls back to $HOME.
This patch fixes this issue and corrects the help message.
Signed-off-by: Jianyu Zhan <nasa4836@gmail.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/r/1401727474-19370-1-git-send-email-nasa4836@gmail.com
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Pull perf/core improvements and fixes from Jiri Olsa:
* Wire up perf_regs and unwind support for ARM64 (Jean Pihet)
* Move u64_swap union to its single user's header, evsel.h (Borislav Petkov)
* Fix for s390 to properly parse tracepoints plus test code (Alexander Yarygin)
* Handle EINTR error for readn/writen (Namhyung Kim)
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
arch/x86/tests/regs_load.S is missing the linker note about the stack
requirements, therefore making the linker fall back to an executable
stack. As this object gets linked against the final perf binary, it'll
needlessly end up with an executable stack. Fix this by adding the
appropriate linker note.
Also add a global linker flag to prevent future regressions, as
suggested by Jiri. This way perf won't get an executable stack even if
we fail to add the .GNU-stack linker note to future assembler files.
Though, doing so might create regressions the other way around, when
(statically) linking against libraries needing an executable stack.
But, apparently, regressing in that direction is wanted as it is an
indicator of poor code quality -- or just missing linker notes.
Fixes: 3c8b06f981 ("perf tests x86: Introduce perf_regs_load function")
Signed-off-by: Mathias Krause <minipli@googlemail.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1398617466-22749-1-git-send-email-minipli@googlemail.com
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
I.e. do the same as when NO_LIBELF is explicitely passed in the 'make'
command line, fixing this:
Auto-detecting system features:
... dwarf: [ OFF ]
... glibc: [ on ]
... gtk2: [ OFF ]
... libaudit: [ OFF ]
... libbfd: [ OFF ]
... libelf: [ OFF ]
... libunwind: [ OFF ]
... libdw-dwarf-unwind: [ OFF ]
... DWARF post unwind library: libdw
<SNIP>
CC /tmp/build/perf/util/symbol-minimal.o
CC /tmp/build/perf/util/unwind-libdw.o
arch/x86/util/unwind-libdw.c:1:30: fatal error: elfutils/libdwfl.h: No such file or directory
compilation terminated.
CC /tmp/build/perf/tests/keep-tracking.o
util/unwind-libdw.c:2:28: fatal error: elfutils/libdw.h: No such file or directory
compilation terminated.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-e39j1yxanltjx4t0msse63ax@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Pull arch/tile updates from Chris Metcalf:
"These fix a few stray build issues seen in linux-next, and also add
the minimal required support for perf to tilegx"
* git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile:
arch/tile: remove unused variable 'devcap'
tile: Fix vDSO compilation issue with allyesconfig
perf tools: Allow building for tile
tile/perf: Support perf_events on tilegx and tilepro
tile: Enable NMIs on return from handle_nmi() without errors
tile: Add support for handling PMC hardware
tile: don't use __get_cpu_var() with structure-typed arguments
tile: avoid overflow in ns2cycles
Tested by building perf:
- Cross-compiled for tile on x86_64
- Built natively on tile
Signed-off-by: Zhigang Lu <zlu@tilera.com>
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
