kernel/tools/perf/util/callchain.c, branch linux-4.17.y

perf unwind: Do not look just at the global callchain_param.record_mode

2018-01-17T13:23:32Z

When setting up DWARF callchains on specific events, without using 'record' or 'trace' --call-graph, but instead doing it like: perf trace -e cycles/call-graph=dwarf/ The unwind__prepare_access() call in thread__insert_map() when we process PERF_RECORD_MMAP(2) metadata events were not being performed, precluding us from using per-event DWARF callchains, handling them just when we asked for all events to be DWARF, using "--call-graph dwarf". We do it in the PERF_RECORD_MMAP because we have to look at one of the executable maps to figure out the executable type (64-bit, 32-bit) of the DSO laid out in that mmap. Also to look at the architecture where the perf.data file was recorded. All this probably should be deferred to when we process a sample for some thread that has callchains, so that we do this processing only for the threads with samples, not for all of them. For now, fix using DWARF on specific events. Before: # perf trace --no-syscalls -e probe_libc:inet_pton/call-graph=dwarf/ ping -6 -c 1 ::1 PING ::1(::1) 56 data bytes 64 bytes from ::1: icmp_seq=1 ttl=64 time=0.048 ms --- ::1 ping statistics --- 1 packets transmitted, 1 received, 0% packet loss, time 0ms rtt min/avg/max/mdev = 0.048/0.048/0.048/0.000 ms 0.000 probe_libc:inet_pton:(7fe9597bb350)) Problem processing probe_libc:inet_pton callchain, skipping... # After: # perf trace --no-syscalls -e probe_libc:inet_pton/call-graph=dwarf/ ping -6 -c 1 ::1 PING ::1(::1) 56 data bytes 64 bytes from ::1: icmp_seq=1 ttl=64 time=0.060 ms --- ::1 ping statistics --- 1 packets transmitted, 1 received, 0% packet loss, time 0ms rtt min/avg/max/mdev = 0.060/0.060/0.060/0.000 ms 0.000 probe_libc:inet_pton:(7fd4aa930350)) __inet_pton (inlined) gaih_inet.constprop.7 (/usr/lib64/libc-2.26.so) __GI_getaddrinfo (inlined) [0xffffaa804e51af3f] (/usr/bin/ping) __libc_start_main (/usr/lib64/libc-2.26.so) [0xffffaa804e51b379] (/usr/bin/ping) # # perf trace --call-graph=dwarf --no-syscalls -e probe_libc:inet_pton/call-graph=dwarf/ ping -6 -c 1 ::1 PING ::1(::1) 56 data bytes 64 bytes from ::1: icmp_seq=1 ttl=64 time=0.057 ms --- ::1 ping statistics --- 1 packets transmitted, 1 received, 0% packet loss, time 0ms rtt min/avg/max/mdev = 0.057/0.057/0.057/0.000 ms 0.000 probe_libc:inet_pton:(7f9363b9e350)) __inet_pton (inlined) gaih_inet.constprop.7 (/usr/lib64/libc-2.26.so) __GI_getaddrinfo (inlined) [0xffffa9e8a14e0f3f] (/usr/bin/ping) __libc_start_main (/usr/lib64/libc-2.26.so) [0xffffa9e8a14e1379] (/usr/bin/ping) # # perf trace --call-graph=fp --no-syscalls -e probe_libc:inet_pton/call-graph=dwarf/ ping -6 -c 1 ::1 PING ::1(::1) 56 data bytes 64 bytes from ::1: icmp_seq=1 ttl=64 time=0.077 ms --- ::1 ping statistics --- 1 packets transmitted, 1 received, 0% packet loss, time 0ms rtt min/avg/max/mdev = 0.077/0.077/0.077/0.000 ms 0.000 probe_libc:inet_pton:(7f4947e1c350)) __inet_pton (inlined) gaih_inet.constprop.7 (/usr/lib64/libc-2.26.so) __GI_getaddrinfo (inlined) [0xffffaa716d88ef3f] (/usr/bin/ping) __libc_start_main (/usr/lib64/libc-2.26.so) [0xffffaa716d88f379] (/usr/bin/ping) # # perf trace --no-syscalls -e probe_libc:inet_pton/call-graph=fp/ ping -6 -c 1 ::1 PING ::1(::1) 56 data bytes 64 bytes from ::1: icmp_seq=1 ttl=64 time=0.078 ms --- ::1 ping statistics --- 1 packets transmitted, 1 received, 0% packet loss, time 0ms rtt min/avg/max/mdev = 0.078/0.078/0.078/0.000 ms 0.000 probe_libc:inet_pton:(7fa157696350)) __GI___inet_pton (/usr/lib64/libc-2.26.so) getaddrinfo (/usr/lib64/libc-2.26.so) [0xffffa9ba39c74f40] (/usr/bin/ping) # Acked-by: Namhyung Kim Cc: Adrian Hunter Cc: David Ahern Cc: Hendrick Brueckner Cc: Jiri Olsa Cc: Thomas Richter Cc: Wang Nan Link: https://lkml.kernel.org/r/20180116182650.GE16107@kernel.org Signed-off-by: Arnaldo Carvalho de Melo

Merge branch 'linus' into perf/core, to fix conflicts

2017-11-07T09:30:18Z

Conflicts: tools/perf/arch/arm/annotate/instructions.c tools/perf/arch/arm64/annotate/instructions.c tools/perf/arch/powerpc/annotate/instructions.c tools/perf/arch/s390/annotate/instructions.c tools/perf/arch/x86/tests/intel-cqm.c tools/perf/ui/tui/progress.c tools/perf/util/zlib.c Signed-off-by: Ingo Molnar

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

2017-11-02T10:10:55Z

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 Reviewed-by: Philippe Ombredanne Reviewed-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman

perf callchain: Fix double mapping al->addr for children without self period

2017-10-31T19:14:50Z

Milian Wolff found a problem he described in [1] and that for him would get fixed: "Note how most of the large offset values are now gone. Most notably, we get proper srcline resolution for the random.h and complex headers." Then Namhyung found the root cause: "I looked into it and found a bug handling cumulative (children) entries. For children entries that have no self period, the al->addr (so he->ip) ends up having an doubly-mapped address. It seems to be there from the beginning but only affects entries that have no srclines - finding srcline itself is done using a different address but it will show the invalid address if no srcline was found. I think we should fix the commit c7405d85d7a3 ("perf tools: Update cpumode for each cumulative entry")." [1] https://lkml.kernel.org/r/20171018185350.14893-7-milian.wolff@kdab.com Reported-by: Milian Wolff Signed-off-by: Namhyung Kim Tested-by: Milian Wolff Cc: Jin Yao Cc: Jiri Olsa Cc: kernel-team@lge.com Fixes: c7405d85d7a3 ("perf tools: Update cpumode for each cumulative entry") Link: https://lkml.kernel.org/r/20171020051533.GA2746@sejong Signed-off-by: Arnaldo Carvalho de Melo

perf report: Use srcline from callchain for hist entries

2017-10-25T13:50:46Z

This also removes the symbol name from the srcline column, more on this below. This ensures we use the correct srcline, which could originate from a potentially inlined function. The hist entries used to query for the srcline based purely on the IP, which leads to wrong results for inlined entries. Before: ~~~~~ perf report --inline -s srcline -g none --stdio ... # Children Self Source:Line # ........ ........ .................................................................................................................................. # 94.23% 0.00% __libc_start_main+18446603487898210537 94.23% 0.00% _start+41 44.58% 0.00% main+100 44.58% 0.00% std::_Norm_helper::_S_do_it+100 44.58% 0.00% std::__complex_abs+100 44.58% 0.00% std::abs+100 44.58% 0.00% std::norm+100 36.01% 0.00% hypot+18446603487892193300 25.81% 0.00% main+41 25.81% 0.00% std::__detail::_Adaptor, double>::operator()+41 25.81% 0.00% std::uniform_real_distribution::operator() >+41 25.75% 25.75% random.h:143 18.39% 0.00% main+57 18.39% 0.00% std::__detail::_Adaptor, double>::operator()+57 18.39% 0.00% std::uniform_real_distribution::operator() >+57 13.80% 13.80% random.tcc:3330 5.64% 0.00% ??:0 4.13% 4.13% __hypot_finite+163 4.13% 0.00% __hypot_finite+18446603487892193443 ... ~~~~~ After: ~~~~~ perf report --inline -s srcline -g none --stdio ... # Children Self Source:Line # ........ ........ ........................................... # 94.30% 1.19% main.cpp:39 94.23% 0.00% __libc_start_main+18446603487898210537 94.23% 0.00% _start+41 48.44% 1.70% random.h:1823 48.44% 0.00% random.h:1814 46.74% 2.53% random.h:185 44.68% 0.10% complex:589 44.68% 0.00% complex:597 44.68% 0.00% complex:654 44.68% 0.00% complex:664 40.61% 13.80% random.tcc:3330 36.01% 0.00% hypot+18446603487892193300 26.81% 0.00% random.h:151 26.81% 0.00% random.h:332 25.75% 25.75% random.h:143 5.64% 0.00% ??:0 4.13% 4.13% __hypot_finite+163 4.13% 0.00% __hypot_finite+18446603487892193443 ... ~~~~~ Note that this change removes the symbol from the source:line hist column. If this information is desired, users should explicitly query for it if needed. I.e. run this command instead: ~~~~~ perf report --inline -s sym,srcline -g none --stdio ... # To display the perf.data header info, please use --header/--header-only options. # # # Total Lost Samples: 0 # # Samples: 1K of event 'cycles:uppp' # Event count (approx.): 1381229476 # # Children Self Symbol Source:Line # ........ ........ ................................................................................................................................... ........................................... # 94.30% 1.19% [.] main main.cpp:39 94.23% 0.00% [.] __libc_start_main __libc_start_main+18446603487898210537 94.23% 0.00% [.] _start _start+41 48.44% 0.00% [.] std::uniform_real_distribution::operator() > (inlined) random.h:1814 48.44% 0.00% [.] std::uniform_real_distribution::operator() > (inlined) random.h:1823 46.74% 0.00% [.] std::__detail::_Adaptor, double>::operator() (inlined) random.h:185 44.68% 0.00% [.] std::_Norm_helper::_S_do_it (inlined) complex:654 44.68% 0.00% [.] std::__complex_abs (inlined) complex:589 44.68% 0.00% [.] std::abs (inlined) complex:597 44.68% 0.00% [.] std::norm (inlined) complex:664 39.80% 13.59% [.] std::generate_canonical > random.tcc:3330 36.01% 0.00% [.] hypot hypot+18446603487892193300 26.81% 0.00% [.] std::__detail::__mod (inlined) random.h:151 26.81% 0.00% [.] std::linear_congruential_engine::operator() (inlined) random.h:332 25.75% 0.00% [.] std::__detail::_Mod::__calc (inlined) random.h:143 25.19% 25.19% [.] std::generate_canonical > random.h:143 4.13% 4.13% [.] __hypot_finite __hypot_finite+163 4.13% 0.00% [.] __hypot_finite __hypot_finite+18446603487892193443 ... ~~~~~ Compared to the old behavior, this reduces duplication in the output. Before we used to print the symbol name in the srcline column even when the sym column was explicitly requested. I.e. the output was: ~~~~~ perf report --inline -s sym,srcline -g none --stdio ... # To display the perf.data header info, please use --header/--header-only options. # # # Total Lost Samples: 0 # # Samples: 1K of event 'cycles:uppp' # Event count (approx.): 1381229476 # # Children Self Symbol Source:Line # ........ ........ ................................................................................................................................... .................................................................................................................................. # 94.23% 0.00% [.] __libc_start_main __libc_start_main+18446603487898210537 94.23% 0.00% [.] _start _start+41 44.58% 0.00% [.] main main+100 44.58% 0.00% [.] std::_Norm_helper::_S_do_it (inlined) std::_Norm_helper::_S_do_it+100 44.58% 0.00% [.] std::__complex_abs (inlined) std::__complex_abs+100 44.58% 0.00% [.] std::abs (inlined) std::abs+100 44.58% 0.00% [.] std::norm (inlined) std::norm+100 36.01% 0.00% [.] hypot hypot+18446603487892193300 25.81% 0.00% [.] main main+41 25.81% 0.00% [.] std::__detail::_Adaptor, double>::operator() (inlined) std::__detail::_Adaptor, double>::operator()+41 25.81% 0.00% [.] std::uniform_real_distribution::operator() > (inlined) std::uniform_real_distribution::operator() >+41 25.69% 25.69% [.] std::generate_canonical > random.h:143 18.39% 0.00% [.] main main+57 18.39% 0.00% [.] std::__detail::_Adaptor, double>::operator() (inlined) std::__detail::_Adaptor, double>::operator()+57 18.39% 0.00% [.] std::uniform_real_distribution::operator() > (inlined) std::uniform_real_distribution::operator() >+57 13.80% 13.80% [.] std::generate_canonical > random.tcc:3330 4.13% 4.13% [.] __hypot_finite __hypot_finite+163 4.13% 0.00% [.] __hypot_finite __hypot_finite+18446603487892193443 ... ~~~~~ Signed-off-by: Milian Wolff Reviewed-by: Andi Kleen Cc: David Ahern Cc: Jin Yao Cc: Jiri Olsa Cc: Namhyung Kim Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/20171019113836.5548-5-milian.wolff@kdab.com Signed-off-by: Arnaldo Carvalho de Melo

perf report: Properly handle branch count in match_chain()

2017-10-25T13:50:37Z

Some of the code paths I introduced before returned too early without running the code to handle a node's branch count. By refactoring match_chain to only have one exit point, this can be remedied. Signed-off-by: Milian Wolff Acked-by: Namhyung Kim Cc: David Ahern Cc: Jin Yao Cc: Peter Zijlstra Cc: Ravi Bangoria Link: http://lkml.kernel.org/r/1707691.qaJ269GSZW@agathebauer Link: http://lkml.kernel.org/r/20171018185350.14893-2-milian.wolff@kdab.com Signed-off-by: Arnaldo Carvalho de Melo

perf callchain: Compare symbol name for inlined frames when matching

2017-10-24T12:59:56Z

The fake symbols we create for inlined frames will represent different functions but can use the symbol start address. This leads to issues when different inline branches all lead to the same function. Before: ~~~~~ $ perf report -s sym -i perf.inlining.data --inline --stdio -g function ... --38.86%--_start __libc_start_main main | --37.57%--std::norm (inlined) std::_Norm_helper::_S_do_it (inlined) | --36.36%--std::abs (inlined) std::__complex_abs (inlined) | --12.24%--std::linear_congruential_engine::operator() (inlined) std::__detail::__mod (inlined) std::__detail::_Mod::__calc (inlined) ~~~~~ Note that this backtrace representation is completely bogus. Complex abs does not call the linear congruential engine! It is just a side-effect of a longer inlined stack being appended to a shorter, different inlined stack, both of which originate in the same function (main). This patch fixes the issue: ~~~~~ $ perf report -s sym -i perf.inlining.data --inline --stdio -g function ... --38.86%--_start __libc_start_main main | |--35.59%--std::uniform_real_distribution::operator() > (inlined) | std::uniform_real_distribution::operator() > (inlined) | | | --34.37%--std::__detail::_Adaptor, double>::operator() (inlined) | std::generate_canonical > (inlined) | | | --12.24%--std::linear_congruential_engine::operator() (inlined) | std::__detail::__mod (inlined) | std::__detail::_Mod::__calc (inlined) | --1.99%--std::norm (inlined) std::_Norm_helper::_S_do_it (inlined) std::abs (inlined) std::__complex_abs (inlined) ~~~~~ Signed-off-by: Milian Wolff Reviewed-by: Jiri Olsa Reviewed-by: Namhyung Kim Cc: David Ahern Cc: Peter Zijlstra Cc: Ravi Bangoria Cc: Yao Jin Link: http://lkml.kernel.org/r/20171009203310.17362-10-milian.wolff@kdab.com Cc: Arnaldo Carvalho de Melo [ Fix up conflict with c1fbc0cf81f1 ("perf callchain: Compare dsos (as well) for CCKEY_FUNCTION"), remove unneeded hunk ] Signed-off-by: Arnaldo Carvalho de Melo

perf callchain: Mark inlined frames in output by " (inlined)" suffix

2017-10-24T12:59:56Z

The original patch that introduced inline frame output in the various browsers used this suffix already. The new centralized approach that uses fake symbols for inlined frames was missing this approach so far. Instead of changing the symbol name itself, we only print the suffix where needed. This allows us to efficiently lookup the symbol for a given name without first having to append the suffix before the lookup. Signed-off-by: Milian Wolff Reviewed-by: Jiri Olsa Reviewed-by: Namhyung Kim Cc: David Ahern Cc: Peter Zijlstra Cc: Yao Jin Link: http://lkml.kernel.org/r/20171009203310.17362-8-milian.wolff@kdab.com Signed-off-by: Arnaldo Carvalho de Melo

perf report: Fall-back to function name comparison for -g srcline

2017-10-24T12:59:55Z

When a callchain entry has no srcline available, we ended up comparing the instruction pointer. I consider this to be not too useful. Rather, I think we should group the entries by function name, which this patch adds. For people who want to split the data on the IP boundary, using `-g address` is the correct choice. Before: ~~~~~ 100.00% 38.86% [.] main | |--61.14%--main inlining.cpp:14 | std::norm complex:664 | std::_Norm_helper::_S_do_it complex:654 | std::abs complex:597 | std::__complex_abs complex:589 | | | |--56.03%--hypot | | | | | |--8.45%--__hypot_finite | | | | | |--7.62%--__hypot_finite | | | | | |--2.29%--__hypot_finite | | | | | |--2.24%--__hypot_finite | | | | | |--2.06%--__hypot_finite | | | | | |--1.81%--__hypot_finite ... ~~~~~ After: ~~~~~ 100.00% 38.86% [.] main | |--61.14%--main inlining.cpp:14 | std::norm complex:664 | std::_Norm_helper::_S_do_it complex:654 | std::abs complex:597 | std::__complex_abs complex:589 | | | |--60.29%--hypot | | | | | --56.03%--__hypot_finite | | | --0.85%--cabs ~~~~~ Signed-off-by: Milian Wolff Reviewed-by: Jiri Olsa Reviewed-by: Namhyung Kim Cc: David Ahern Cc: Peter Zijlstra Cc: Yao Jin Link: http://lkml.kernel.org/r/20171009203310.17362-7-milian.wolff@kdab.com Signed-off-by: Arnaldo Carvalho de Melo

perf callchain: Store srcline in callchain_cursor_node

2017-10-24T12:59:55Z

This is mostly a preparation to enable the creation of full callchain nodes for inline frames. Such frames will reference the IP of the non-inlined frame, but hold the symbol and srcline for an inlined location. As such, we won't be able to query the srcline on-demand based on the IP alone. Instead, we will leverage the functionality provided by this patch here, and store the srcline for the inlined nodes in the new srcline member of callchain_cursor_node. Note that this patch on its own leaks the srcline, as there is no free_callchain_cursor_node or similar. A future patch will add caching of the srcline and handle deletion properly. Signed-off-by: Milian Wolff Reviewed-by: Jiri Olsa Reviewed-by: Namhyung Kim Cc: David Ahern Cc: Peter Zijlstra Cc: Yao Jin Link: http://lkml.kernel.org/r/20171009203310.17362-3-milian.wolff@kdab.com Signed-off-by: Arnaldo Carvalho de Melo