kernel/tools/perf/util/machine.c, branch linux-4.15.y

perf machine: Guard against NULL in machine__exit()

2017-11-28T17:21:01Z

A recent fix for 'perf trace' introduced a bug where machine__exit(trace->host) could be called while trace->host was still NULL, so make this more robust by guarding against NULL, just like free() does. The problem happens, for instance, when !root users try to run 'perf trace': [acme@jouet linux]$ trace Error: No permissions to read /sys/kernel/debug/tracing/events/raw_syscalls/sys_(enter|exit) Hint: Try 'sudo mount -o remount,mode=755 /sys/kernel/debug/tracing' perf: Segmentation fault Obtained 7 stack frames. [0x4f1b2e] /lib64/libc.so.6(+0x3671f) [0x7f43a1dd971f] [0x4f3fec] [0x47468b] [0x42a2db] /lib64/libc.so.6(__libc_start_main+0xe9) [0x7f43a1dc3509] [0x42a6c9] Segmentation fault (core dumped) [acme@jouet linux]$ Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Andrei Vagin Cc: David Ahern Cc: Jiri Olsa Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Vasily Averin Cc: Wang Nan Fixes: 33974a414ce2 ("perf trace: Call machine__exit() at exit") 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 report: Cache srclines for callchain nodes

2017-10-25T13:50:46Z

On one hand this ensures that the memory is properly freed when the DSO gets freed. On the other hand this significantly speeds up the processing of the callchain nodes when lots of srclines are requested. For one of my data files e.g.: Before: Performance counter stats for 'perf report -s srcline -g srcline --stdio': 52496.495043 task-clock (msec) # 0.999 CPUs utilized 634 context-switches # 0.012 K/sec 2 cpu-migrations # 0.000 K/sec 191,561 page-faults # 0.004 M/sec 165,074,498,235 cycles # 3.144 GHz 334,170,832,408 instructions # 2.02 insn per cycle 90,220,029,745 branches # 1718.591 M/sec 654,525,177 branch-misses # 0.73% of all branches 52.533273822 seconds time elapsedProcessed 236605 events and lost 40 chunks! After: Performance counter stats for 'perf report -s srcline -g srcline --stdio': 22606.323706 task-clock (msec) # 1.000 CPUs utilized 31 context-switches # 0.001 K/sec 0 cpu-migrations # 0.000 K/sec 185,471 page-faults # 0.008 M/sec 71,188,113,681 cycles # 3.149 GHz 133,204,943,083 instructions # 1.87 insn per cycle 34,886,384,979 branches # 1543.214 M/sec 278,214,495 branch-misses # 0.80% of all branches 22.609857253 seconds time elapsed Note that the difference is only this large when `--inline` is not passed. In such situations, we would use the inliner cache and thus do not run this code path that often. I think that this cache should actually be used in other places, too. When looking at the valgrind leak report for perf report, we see tons of srclines being leaked, most notably from calls to hist_entry__get_srcline. The problem is that get_srcline has many different formatting options (show_sym, show_addr, potentially even unwind_inlines when calling __get_srcline directly). As such, the srcline cannot easily be cached for all calls, or we'd have to add caches for all formatting combinations (6 so far). An alternative would be to remove the formatting options and handle that on a different level - i.e. print the sym/addr on demand wherever we actually output something. And the unwind_inlines could be moved into a separate function that does not return the srcline. 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/20171019113836.5548-4-milian.wolff@kdab.com Signed-off-by: Arnaldo Carvalho de Melo

perf report: Cache failed lookups of inlined frames

2017-10-25T13:50:45Z

When no inlined frames could be found for a given address, we did not store this information anywhere. That means we potentially do the costly inliner lookup repeatedly for cases where we know it can never succeed. This patch makes dso__parse_addr_inlines always return a valid inline_node. It will be empty when no inliners are found. This enables us to cache the empty list in the DSO, thereby improving the performance when many addresses fail to find the inliners. For my trivial example, the performance impact is already quite significant: Before: ~~~~~ Performance counter stats for 'perf report --stdio --inline -g srcline -s srcline' (5 runs): 594.804032 task-clock (msec) # 0.998 CPUs utilized ( +- 0.07% ) 53 context-switches # 0.089 K/sec ( +- 4.09% ) 0 cpu-migrations # 0.000 K/sec ( +-100.00% ) 5,687 page-faults # 0.010 M/sec ( +- 0.02% ) 2,300,918,213 cycles # 3.868 GHz ( +- 0.09% ) 4,395,839,080 instructions # 1.91 insn per cycle ( +- 0.00% ) 939,177,205 branches # 1578.969 M/sec ( +- 0.00% ) 11,824,633 branch-misses # 1.26% of all branches ( +- 0.10% ) 0.596246531 seconds time elapsed ( +- 0.07% ) ~~~~~ After: ~~~~~ Performance counter stats for 'perf report --stdio --inline -g srcline -s srcline' (5 runs): 113.111405 task-clock (msec) # 0.990 CPUs utilized ( +- 0.89% ) 29 context-switches # 0.255 K/sec ( +- 54.25% ) 0 cpu-migrations # 0.000 K/sec 5,380 page-faults # 0.048 M/sec ( +- 0.01% ) 432,378,779 cycles # 3.823 GHz ( +- 0.75% ) 670,057,633 instructions # 1.55 insn per cycle ( +- 0.01% ) 141,001,247 branches # 1246.570 M/sec ( +- 0.01% ) 2,346,845 branch-misses # 1.66% of all branches ( +- 0.19% ) 0.114222393 seconds time elapsed ( +- 1.19% ) ~~~~~ 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/20171019113836.5548-3-milian.wolff@kdab.com Signed-off-by: Arnaldo Carvalho de Melo

perf callchain: Create real callchain entries for inlined frames

2017-10-24T12:59:55Z

The inline_node structs are maintained by the new dso->inlines tree. This in turn keeps ownership of the fake symbols and srcline string representing an inline frame. This tree is sorted by address to allow quick lookups. All other entries of the symbol beside the function name are unused for inline frames. The advantage of this approach is that all existing users of the callchain API can now transparently display inlined frames without having to patch their code. 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/20171009203310.17362-6-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

perf top: Implement multithreading for perf_event__synthesize_threads

2017-10-03T12:27:46Z

The proc files which is sorted with alphabetical order are evenly assigned to several synthesize threads to be processed in parallel. For 'perf top', the threads number hard code to online CPU number. The following patch will introduce an option to set it. For other perf tools, the thread number is 1. Because the process function is not ready for multithreading, e.g. process_synthesized_event. This patch series only support event synthesize multithreading for 'perf top'. For other tools, it can be done separately later. With multithread applied, the total processing time can get up to 1.56x speedup on Knights Mill for 'perf top'. For specific single event processing, the processing time could increase because of the lock contention. So proc_map_timeout may need to be increased. Otherwise some proc maps will be truncated. Based on my test, increasing the proc_map_timeout has small impact on the total processing time. The total processing time still get 1.49x speedup on Knights Mill after increasing the proc_map_timeout. The patch itself doesn't increase the proc_map_timeout. Doesn't need to implement multithreading for per task monitoring, perf_event__synthesize_thread_map. It doesn't have performance issue. Committer testing: # getconf _NPROCESSORS_ONLN 4 # perf trace --no-inherit -e clone -o /tmp/output perf top # tail -4 /tmp/bla 0.124 ( 0.041 ms): clone(flags: VM|FS|FILES|SIGHAND|THREAD|SYSVSEM|SETTLS|PARENT_SETTID|CHILD_CLEARTID, child_stack: 0x7fc3eb3a8f30, parent_tidptr: 0x7fc3eb3a99d0, child_tidptr: 0x7fc3eb3a99d0, tls: 0x7fc3eb3a9700) = 9548 (perf) 0.246 ( 0.023 ms): clone(flags: VM|FS|FILES|SIGHAND|THREAD|SYSVSEM|SETTLS|PARENT_SETTID|CHILD_CLEARTID, child_stack: 0x7fc3eaba7f30, parent_tidptr: 0x7fc3eaba89d0, child_tidptr: 0x7fc3eaba89d0, tls: 0x7fc3eaba8700) = 9549 (perf) 0.286 ( 0.019 ms): clone(flags: VM|FS|FILES|SIGHAND|THREAD|SYSVSEM|SETTLS|PARENT_SETTID|CHILD_CLEARTID, child_stack: 0x7fc3ea3a6f30, parent_tidptr: 0x7fc3ea3a79d0, child_tidptr: 0x7fc3ea3a79d0, tls: 0x7fc3ea3a7700) = 9550 (perf) 246.540 ( 0.047 ms): clone(flags: VM|FS|FILES|SIGHAND|THREAD|SYSVSEM|SETTLS|PARENT_SETTID|CHILD_CLEARTID, child_stack: 0x7fc3ea3a6f30, parent_tidptr: 0x7fc3ea3a79d0, child_tidptr: 0x7fc3ea3a79d0, tls: 0x7fc3ea3a7700) = 9551 (perf) # Signed-off-by: Kan Liang Tested-by: Arnaldo Carvalho de Melo Acked-by: Jiri Olsa Cc: Adrian Hunter Cc: Alexei Starovoitov Cc: Andi Kleen Cc: He Kuang Cc: Lukasz Odzioba Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Wang Nan Link: http://lkml.kernel.org/r/1506696477-146932-4-git-send-email-kan.liang@intel.com Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Provide mutex wrappers for pthreads rwlocks

2017-09-21T16:28:06Z

Andi reported a performance drop in single threaded perf tools such as 'perf script' due to the growing number of locks being put in place to allow for multithreaded tools, so wrap the POSIX threads rwlock routines with the names used for such kinds of locks in the Linux kernel and then allow for tools to ask for those locks to be used or not. I.e. a tool may have a multithreaded phase and then switch to single threaded, like the upcoming patches for the synthesizing of PERF_RECORD_{FORK,MMAP,etc} for pre-existing processes to then switch to single threaded mode in 'perf top'. The init routines will not be conditional, this way starting as single threaded to then move to multi threaded mode should be possible. Reported-by: Andi Kleen Cc: Adrian Hunter Cc: David Ahern Cc: Jiri Olsa Cc: Kan Liang Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Wang Nan Link: http://lkml.kernel.org/r/20170404161739.GH12903@kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf machine: Optimize a bit the machine__findnew_thread() methods

2017-09-18T12:40:19Z

In some cases we already have calculated the hash bucket, so reuse it. Cc: Adrian Hunter Cc: Andi Kleen Cc: David Ahern Cc: Jiri Olsa Cc: Kan Liang Cc: Lukasz Odzioba Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Wang Nan Link: http://lkml.kernel.org/n/tip-800zehjsyy03er4s4jf0e99v@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo