OpenCloudOS-Kernel/tools/perf/util/unwind-libunwind.c

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License cleanup: add SPDX GPL-2.0 license identifier to files with no license Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-01 22:07:57 +08:00
// SPDX-License-Identifier: GPL-2.0
#include "unwind.h"
#include "map.h"
#include "thread.h"
perf unwind: Check the target platform before assigning unwind methods Currently, 'perf script' uses host unwind methods to parse perf.data callchain info without taking the target architecture into account, i.e. assuming the perf.data file was generated on the same machine where the analysis is being performed. So we get wrong result without any warnings when unwinding callchains of x86(32-bit) on x86(64-bit) machine. This patch adds an extra step that checks the target platform before assigning unwind methods. In later patches in this series, we can use this info to assign the right unwind methods for supported platforms. Committer note: After fixing it to register the local unwinder for live mode tools ('perf trace', 'perf top'), i.e. tools that don't use a perf.data file, it works as intended and passes the 'perf test unwind' test: # perf trace -e nanosleep --call dwarf usleep 1 0.328 ( 0.058 ms): usleep/11115 nanosleep(rqtp: 0x7fff083fa480) = 0 __nanosleep_nocancel+0x7 (/usr/lib64/libc-2.22.so) usleep+0x34 (/usr/lib64/libc-2.22.so) main+0x1eb (/usr/bin/usleep) __libc_start_main+0xf0 (/usr/lib64/libc-2.22.so) _start+0x29 (/usr/bin/usleep) # perf test 48 48: Test dwarf unwind : Ok # Signed-off-by: He Kuang <hekuang@huawei.com> Acked-by: Jiri Olsa <jolsa@kernel.org> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Ekaterina Tumanova <tumanova@linux.vnet.ibm.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Kan Liang <kan.liang@intel.com> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Pekka Enberg <penberg@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com> Cc: Wang Nan <wangnan0@huawei.com> Link: http://lkml.kernel.org/r/1464924803-22214-11-git-send-email-hekuang@huawei.com [ Fixed exit path for 'live' mode tools, where we need to default to local unwinding ] Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-06-03 11:33:19 +08:00
#include "session.h"
#include "debug.h"
#include "env.h"
perf tools: Speed up report for perf compiled with linwunwind When compiled with libunwind, perf does some preparatory work when processing side-band events. This is not needed when report actually don't unwind dwarf callchains, so it's disabled with dwarf_callchain_users bool. However we could move that check to higher level and shield more unwanted code for normal report processing, giving us following speed up on kernel build profile: Before: $ perf record make -j40 ... $ ll ../../perf.data -rw-------. 1 jolsa jolsa 461783932 Apr 26 09:11 perf.data $ perf stat -e cycles:u,instructions:u perf report -i perf.data > out Performance counter stats for 'perf report -i perf.data': 78,669,920,155 cycles:u 99,076,431,951 instructions:u # 1.26 insn per cycle 55.382823668 seconds time elapsed 27.512341000 seconds user 27.712871000 seconds sys After: $ perf stat -e cycles:u,instructions:u perf report -i perf.data > out Performance counter stats for 'perf report -i perf.data': 59,626,798,904 cycles:u 88,583,575,849 instructions:u # 1.49 insn per cycle 21.296935559 seconds time elapsed 20.010191000 seconds user 1.202935000 seconds sys The speed is higher with profile having many side-band events, because these trigger libunwind preparatory code. This does not apply for perf compiled with libdw for dwarf unwind, only for build with libunwind. Signed-off-by: Jiri Olsa <jolsa@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20190426073804.17238-1-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2019-04-26 15:38:04 +08:00
#include "callchain.h"
struct unwind_libunwind_ops __weak *local_unwind_libunwind_ops;
struct unwind_libunwind_ops __weak *x86_32_unwind_libunwind_ops;
struct unwind_libunwind_ops __weak *arm64_unwind_libunwind_ops;
static void unwind__register_ops(struct thread *thread,
struct unwind_libunwind_ops *ops)
{
thread->unwind_libunwind_ops = ops;
}
int unwind__prepare_access(struct thread *thread, struct map *map,
bool *initialized)
{
perf unwind: Check the target platform before assigning unwind methods Currently, 'perf script' uses host unwind methods to parse perf.data callchain info without taking the target architecture into account, i.e. assuming the perf.data file was generated on the same machine where the analysis is being performed. So we get wrong result without any warnings when unwinding callchains of x86(32-bit) on x86(64-bit) machine. This patch adds an extra step that checks the target platform before assigning unwind methods. In later patches in this series, we can use this info to assign the right unwind methods for supported platforms. Committer note: After fixing it to register the local unwinder for live mode tools ('perf trace', 'perf top'), i.e. tools that don't use a perf.data file, it works as intended and passes the 'perf test unwind' test: # perf trace -e nanosleep --call dwarf usleep 1 0.328 ( 0.058 ms): usleep/11115 nanosleep(rqtp: 0x7fff083fa480) = 0 __nanosleep_nocancel+0x7 (/usr/lib64/libc-2.22.so) usleep+0x34 (/usr/lib64/libc-2.22.so) main+0x1eb (/usr/bin/usleep) __libc_start_main+0xf0 (/usr/lib64/libc-2.22.so) _start+0x29 (/usr/bin/usleep) # perf test 48 48: Test dwarf unwind : Ok # Signed-off-by: He Kuang <hekuang@huawei.com> Acked-by: Jiri Olsa <jolsa@kernel.org> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Ekaterina Tumanova <tumanova@linux.vnet.ibm.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Kan Liang <kan.liang@intel.com> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Pekka Enberg <penberg@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com> Cc: Wang Nan <wangnan0@huawei.com> Link: http://lkml.kernel.org/r/1464924803-22214-11-git-send-email-hekuang@huawei.com [ Fixed exit path for 'live' mode tools, where we need to default to local unwinding ] Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-06-03 11:33:19 +08:00
const char *arch;
enum dso_type dso_type;
struct unwind_libunwind_ops *ops = local_unwind_libunwind_ops;
int err;
perf unwind: Check the target platform before assigning unwind methods Currently, 'perf script' uses host unwind methods to parse perf.data callchain info without taking the target architecture into account, i.e. assuming the perf.data file was generated on the same machine where the analysis is being performed. So we get wrong result without any warnings when unwinding callchains of x86(32-bit) on x86(64-bit) machine. This patch adds an extra step that checks the target platform before assigning unwind methods. In later patches in this series, we can use this info to assign the right unwind methods for supported platforms. Committer note: After fixing it to register the local unwinder for live mode tools ('perf trace', 'perf top'), i.e. tools that don't use a perf.data file, it works as intended and passes the 'perf test unwind' test: # perf trace -e nanosleep --call dwarf usleep 1 0.328 ( 0.058 ms): usleep/11115 nanosleep(rqtp: 0x7fff083fa480) = 0 __nanosleep_nocancel+0x7 (/usr/lib64/libc-2.22.so) usleep+0x34 (/usr/lib64/libc-2.22.so) main+0x1eb (/usr/bin/usleep) __libc_start_main+0xf0 (/usr/lib64/libc-2.22.so) _start+0x29 (/usr/bin/usleep) # perf test 48 48: Test dwarf unwind : Ok # Signed-off-by: He Kuang <hekuang@huawei.com> Acked-by: Jiri Olsa <jolsa@kernel.org> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Ekaterina Tumanova <tumanova@linux.vnet.ibm.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Kan Liang <kan.liang@intel.com> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Pekka Enberg <penberg@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com> Cc: Wang Nan <wangnan0@huawei.com> Link: http://lkml.kernel.org/r/1464924803-22214-11-git-send-email-hekuang@huawei.com [ Fixed exit path for 'live' mode tools, where we need to default to local unwinding ] Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-06-03 11:33:19 +08:00
perf tools: Speed up report for perf compiled with linwunwind When compiled with libunwind, perf does some preparatory work when processing side-band events. This is not needed when report actually don't unwind dwarf callchains, so it's disabled with dwarf_callchain_users bool. However we could move that check to higher level and shield more unwanted code for normal report processing, giving us following speed up on kernel build profile: Before: $ perf record make -j40 ... $ ll ../../perf.data -rw-------. 1 jolsa jolsa 461783932 Apr 26 09:11 perf.data $ perf stat -e cycles:u,instructions:u perf report -i perf.data > out Performance counter stats for 'perf report -i perf.data': 78,669,920,155 cycles:u 99,076,431,951 instructions:u # 1.26 insn per cycle 55.382823668 seconds time elapsed 27.512341000 seconds user 27.712871000 seconds sys After: $ perf stat -e cycles:u,instructions:u perf report -i perf.data > out Performance counter stats for 'perf report -i perf.data': 59,626,798,904 cycles:u 88,583,575,849 instructions:u # 1.49 insn per cycle 21.296935559 seconds time elapsed 20.010191000 seconds user 1.202935000 seconds sys The speed is higher with profile having many side-band events, because these trigger libunwind preparatory code. This does not apply for perf compiled with libdw for dwarf unwind, only for build with libunwind. Signed-off-by: Jiri Olsa <jolsa@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20190426073804.17238-1-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2019-04-26 15:38:04 +08:00
if (!dwarf_callchain_users)
return 0;
perf unwind: Check the target platform before assigning unwind methods Currently, 'perf script' uses host unwind methods to parse perf.data callchain info without taking the target architecture into account, i.e. assuming the perf.data file was generated on the same machine where the analysis is being performed. So we get wrong result without any warnings when unwinding callchains of x86(32-bit) on x86(64-bit) machine. This patch adds an extra step that checks the target platform before assigning unwind methods. In later patches in this series, we can use this info to assign the right unwind methods for supported platforms. Committer note: After fixing it to register the local unwinder for live mode tools ('perf trace', 'perf top'), i.e. tools that don't use a perf.data file, it works as intended and passes the 'perf test unwind' test: # perf trace -e nanosleep --call dwarf usleep 1 0.328 ( 0.058 ms): usleep/11115 nanosleep(rqtp: 0x7fff083fa480) = 0 __nanosleep_nocancel+0x7 (/usr/lib64/libc-2.22.so) usleep+0x34 (/usr/lib64/libc-2.22.so) main+0x1eb (/usr/bin/usleep) __libc_start_main+0xf0 (/usr/lib64/libc-2.22.so) _start+0x29 (/usr/bin/usleep) # perf test 48 48: Test dwarf unwind : Ok # Signed-off-by: He Kuang <hekuang@huawei.com> Acked-by: Jiri Olsa <jolsa@kernel.org> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Ekaterina Tumanova <tumanova@linux.vnet.ibm.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Kan Liang <kan.liang@intel.com> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Pekka Enberg <penberg@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com> Cc: Wang Nan <wangnan0@huawei.com> Link: http://lkml.kernel.org/r/1464924803-22214-11-git-send-email-hekuang@huawei.com [ Fixed exit path for 'live' mode tools, where we need to default to local unwinding ] Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-06-03 11:33:19 +08:00
if (thread->addr_space) {
pr_debug("unwind: thread map already set, dso=%s\n",
map->dso->name);
if (initialized)
*initialized = true;
perf unwind: Check the target platform before assigning unwind methods Currently, 'perf script' uses host unwind methods to parse perf.data callchain info without taking the target architecture into account, i.e. assuming the perf.data file was generated on the same machine where the analysis is being performed. So we get wrong result without any warnings when unwinding callchains of x86(32-bit) on x86(64-bit) machine. This patch adds an extra step that checks the target platform before assigning unwind methods. In later patches in this series, we can use this info to assign the right unwind methods for supported platforms. Committer note: After fixing it to register the local unwinder for live mode tools ('perf trace', 'perf top'), i.e. tools that don't use a perf.data file, it works as intended and passes the 'perf test unwind' test: # perf trace -e nanosleep --call dwarf usleep 1 0.328 ( 0.058 ms): usleep/11115 nanosleep(rqtp: 0x7fff083fa480) = 0 __nanosleep_nocancel+0x7 (/usr/lib64/libc-2.22.so) usleep+0x34 (/usr/lib64/libc-2.22.so) main+0x1eb (/usr/bin/usleep) __libc_start_main+0xf0 (/usr/lib64/libc-2.22.so) _start+0x29 (/usr/bin/usleep) # perf test 48 48: Test dwarf unwind : Ok # Signed-off-by: He Kuang <hekuang@huawei.com> Acked-by: Jiri Olsa <jolsa@kernel.org> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Ekaterina Tumanova <tumanova@linux.vnet.ibm.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Kan Liang <kan.liang@intel.com> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Pekka Enberg <penberg@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com> Cc: Wang Nan <wangnan0@huawei.com> Link: http://lkml.kernel.org/r/1464924803-22214-11-git-send-email-hekuang@huawei.com [ Fixed exit path for 'live' mode tools, where we need to default to local unwinding ] Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-06-03 11:33:19 +08:00
return 0;
}
/* env->arch is NULL for live-mode (i.e. perf top) */
if (!thread->mg->machine->env || !thread->mg->machine->env->arch)
goto out_register;
dso_type = dso__type(map->dso, thread->mg->machine);
if (dso_type == DSO__TYPE_UNKNOWN)
return 0;
arch = perf_env__arch(thread->mg->machine->env);
if (!strcmp(arch, "x86")) {
if (dso_type != DSO__TYPE_64BIT)
ops = x86_32_unwind_libunwind_ops;
} else if (!strcmp(arch, "arm64") || !strcmp(arch, "arm")) {
if (dso_type == DSO__TYPE_64BIT)
ops = arm64_unwind_libunwind_ops;
}
if (!ops) {
pr_err("unwind: target platform=%s is not supported\n", arch);
perf unwind: Do not fail due to missing unwind support We currently fail the MMAP event processing if we don't have the MMAP event's specific arch unwind support compiled in. That's wrong and can lead to unresolved mmaps in report output for 32bit binaries on 64bit server, like in this example on x86_64 server: $ cat ex.c int main(int argc, char **argv) { while (1) {} } $ gcc -o ex -m32 ex.c $ perf record ./ex ^C[ perf record: Woken up 2 times to write data ] [ perf record: Captured and wrote 0.371 MB perf.data (9322 samples) ] Before: $ perf report --stdio SNIP # Overhead Command Shared Object Symbol # ........ ....... ................ ...................... # 100.00% ex [unknown] [.] 0x00000000080483de 0.00% ex [unknown] [.] 0x00000000f76dba4f 0.00% ex [unknown] [.] 0x00000000f76e4c11 0.00% ex [unknown] [.] 0x00000000f76daa30 After: $ perf report --stdio SNIP # Overhead Command Shared Object Symbol # ........ ....... ............. ............... # 100.00% ex ex [.] main 0.00% ex ld-2.24.so [.] _dl_start 0.00% ex ld-2.24.so [.] do_lookup_x 0.00% ex ld-2.24.so [.] _start The fix is not to fail, just warn if there's not unwind support compiled in. Reported-by: Michael Lyle <mlyle@lyle.org> Signed-off-by: Jiri Olsa <jolsa@kernel.org> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: David Ahern <dsahern@gmail.com> Cc: He Kuang <hekuang@huawei.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20170704131131.27508-1-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2017-07-04 21:11:31 +08:00
return 0;
}
perf unwind: Check the target platform before assigning unwind methods Currently, 'perf script' uses host unwind methods to parse perf.data callchain info without taking the target architecture into account, i.e. assuming the perf.data file was generated on the same machine where the analysis is being performed. So we get wrong result without any warnings when unwinding callchains of x86(32-bit) on x86(64-bit) machine. This patch adds an extra step that checks the target platform before assigning unwind methods. In later patches in this series, we can use this info to assign the right unwind methods for supported platforms. Committer note: After fixing it to register the local unwinder for live mode tools ('perf trace', 'perf top'), i.e. tools that don't use a perf.data file, it works as intended and passes the 'perf test unwind' test: # perf trace -e nanosleep --call dwarf usleep 1 0.328 ( 0.058 ms): usleep/11115 nanosleep(rqtp: 0x7fff083fa480) = 0 __nanosleep_nocancel+0x7 (/usr/lib64/libc-2.22.so) usleep+0x34 (/usr/lib64/libc-2.22.so) main+0x1eb (/usr/bin/usleep) __libc_start_main+0xf0 (/usr/lib64/libc-2.22.so) _start+0x29 (/usr/bin/usleep) # perf test 48 48: Test dwarf unwind : Ok # Signed-off-by: He Kuang <hekuang@huawei.com> Acked-by: Jiri Olsa <jolsa@kernel.org> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Ekaterina Tumanova <tumanova@linux.vnet.ibm.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Kan Liang <kan.liang@intel.com> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Pekka Enberg <penberg@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com> Cc: Wang Nan <wangnan0@huawei.com> Link: http://lkml.kernel.org/r/1464924803-22214-11-git-send-email-hekuang@huawei.com [ Fixed exit path for 'live' mode tools, where we need to default to local unwinding ] Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-06-03 11:33:19 +08:00
out_register:
unwind__register_ops(thread, ops);
err = thread->unwind_libunwind_ops->prepare_access(thread);
if (initialized)
*initialized = err ? false : true;
return err;
}
void unwind__flush_access(struct thread *thread)
{
perf tools: Speed up report for perf compiled with linwunwind When compiled with libunwind, perf does some preparatory work when processing side-band events. This is not needed when report actually don't unwind dwarf callchains, so it's disabled with dwarf_callchain_users bool. However we could move that check to higher level and shield more unwanted code for normal report processing, giving us following speed up on kernel build profile: Before: $ perf record make -j40 ... $ ll ../../perf.data -rw-------. 1 jolsa jolsa 461783932 Apr 26 09:11 perf.data $ perf stat -e cycles:u,instructions:u perf report -i perf.data > out Performance counter stats for 'perf report -i perf.data': 78,669,920,155 cycles:u 99,076,431,951 instructions:u # 1.26 insn per cycle 55.382823668 seconds time elapsed 27.512341000 seconds user 27.712871000 seconds sys After: $ perf stat -e cycles:u,instructions:u perf report -i perf.data > out Performance counter stats for 'perf report -i perf.data': 59,626,798,904 cycles:u 88,583,575,849 instructions:u # 1.49 insn per cycle 21.296935559 seconds time elapsed 20.010191000 seconds user 1.202935000 seconds sys The speed is higher with profile having many side-band events, because these trigger libunwind preparatory code. This does not apply for perf compiled with libdw for dwarf unwind, only for build with libunwind. Signed-off-by: Jiri Olsa <jolsa@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20190426073804.17238-1-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2019-04-26 15:38:04 +08:00
if (!dwarf_callchain_users)
return;
if (thread->unwind_libunwind_ops)
thread->unwind_libunwind_ops->flush_access(thread);
}
void unwind__finish_access(struct thread *thread)
{
perf tools: Speed up report for perf compiled with linwunwind When compiled with libunwind, perf does some preparatory work when processing side-band events. This is not needed when report actually don't unwind dwarf callchains, so it's disabled with dwarf_callchain_users bool. However we could move that check to higher level and shield more unwanted code for normal report processing, giving us following speed up on kernel build profile: Before: $ perf record make -j40 ... $ ll ../../perf.data -rw-------. 1 jolsa jolsa 461783932 Apr 26 09:11 perf.data $ perf stat -e cycles:u,instructions:u perf report -i perf.data > out Performance counter stats for 'perf report -i perf.data': 78,669,920,155 cycles:u 99,076,431,951 instructions:u # 1.26 insn per cycle 55.382823668 seconds time elapsed 27.512341000 seconds user 27.712871000 seconds sys After: $ perf stat -e cycles:u,instructions:u perf report -i perf.data > out Performance counter stats for 'perf report -i perf.data': 59,626,798,904 cycles:u 88,583,575,849 instructions:u # 1.49 insn per cycle 21.296935559 seconds time elapsed 20.010191000 seconds user 1.202935000 seconds sys The speed is higher with profile having many side-band events, because these trigger libunwind preparatory code. This does not apply for perf compiled with libdw for dwarf unwind, only for build with libunwind. Signed-off-by: Jiri Olsa <jolsa@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20190426073804.17238-1-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2019-04-26 15:38:04 +08:00
if (!dwarf_callchain_users)
return;
if (thread->unwind_libunwind_ops)
thread->unwind_libunwind_ops->finish_access(thread);
}
int unwind__get_entries(unwind_entry_cb_t cb, void *arg,
struct thread *thread,
struct perf_sample *data, int max_stack)
{
if (thread->unwind_libunwind_ops)
return thread->unwind_libunwind_ops->get_entries(cb, arg, thread, data, max_stack);
return 0;
}