- 06 Nov, 2015 4 commits
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Wang Nan authored
bpf_object__get_kversion() can be used to fetch value of object's 'version' section. Following patch will use it for error reporting. Signed-off-by:
Wang Nan <wangnan0@huawei.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Zefan Li <lizefan@huawei.com> Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/1446817783-86722-3-git-send-email-wangnan0@huawei.comSigned-off-by:
Arnaldo Carvalho de Melo <acme@redhat.com>
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Wang Nan authored
In this patch, a series of libbpf specific error numbers and libbpf_strerror() are introduced to help reporting errors. Functions are updated to pass correct the error number through the CHECK_ERR() macro. All users of bpf_object__open{_buffer}() and bpf_program__title() in perf are modified accordingly. In addition, due to the error codes changing, bpf__strerror_load() is also modified to use them. bpf__strerror_head() is also changed accordingly so it can parse libbpf errors. bpf_loader_strerror() is introduced for that purpose, and will be improved by the following patch. load_program() is improved not to dump log buffer if it is empty. log buffer is also used to deduce whether the error was caused by an invalid program or other problem. v1 -> v2: - Using macro for error code. - Fetch error message based on array index, eliminate for-loop. - Use log buffer to detect the reason of failure. 3 new error code are introduced to replace LIBBPF_ERRNO__LOAD. In v1: # perf record -e ./test_ill_program.o ls event syntax error: './test_ill_program.o' \___ Failed to load program: Validate your program and check 'license'/'version' sections in your object SKIP # perf record -e ./test_kversion_nomatch_program.o ls event syntax error: './test_kversion_nomatch_program.o' \___ Failed to load program: Validate your program and check 'license'/'version' sections in your object SKIP # perf record -e ./test_big_program.o ls event syntax error: './test_big_program.o' \___ Failed to load program: Validate your program and check 'license'/'version' sections in your object SKIP In v2: # perf record -e ./test_ill_program.o ls event syntax error: './test_ill_program.o' \___ Kernel verifier blocks program loading SKIP # perf record -e ./test_kversion_nomatch_program.o event syntax error: './test_kversion_nomatch_program.o' \___ Incorrect kernel version SKIP (Will be further improved by following patches) # perf record -e ./test_big_program.o event syntax error: './test_big_program.o' \___ Program too big SKIP Signed-off-by: -
Masami Hiramatsu authored
In find_perf_probe_point_from_map(), the 'ret' variable is initialized with -ENOENT but overwritten by the return code of kernel_get_symbol_address_by_name(), and after that it is re-initialized with -ENOENT again. Setting ret=-ENOENT twice looks a bit redundant. This avoids the overwriting and just returns -ENOENT if some error happens to simplify the code. Signed-off-by:
Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Wang Nan <wangnan0@huawei.com> Cc: Zefan Li <lizefan@huawei.com> Link: http://lkml.kernel.org/n/tip-ufp1zgbktzmttcputozneomd@git.kernel.orgSigned-off-by:
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Andi Kleen authored
When the browser fails to annotate it is difficult for users to find out what went wrong. Add some errors for objdump failures that are displayed in the UI. Note it would be even better to handle these errors smarter, like falling back to the binary when the debug info is somehow corrupted. But for now just giving a better error is an improvement. Committer note: This works for --stdio, where errors just scroll by the screen: # perf annotate --stdio intel_idle Failure running objdump --start-address=0xffffffff81418290 --stop-address=0xffffffff814183ae -l -d --no-show-raw -S -C /root/.debug/.build-id/28/2777c262e6b3c0451375163c9a81c893218ab1 2>/dev/null|grep -v /root/.debug/.build-id/28/2777c262e6b3c0451375163c9a81c893218ab1|expand Percent | Source code & Disassembly of vmlinux for cycles:pp ------------------------------------------------------------------ And with that one can use that command line to try to find out more about what happened instead of getting a blank screen, an improvement. We need tho to improve this further to get it to work with other UIs, like --tui and --gtk, where it continues showing a blank screen, no messages, as the pr_err() used is enough just for --stdio. Signed-off-by:
Andi Kleen <ak@linux.intel.com> Tested-by:
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- 05 Nov, 2015 9 commits
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Jiri Olsa authored
So they can be used in perf stat record command in following patch. Signed-off-by:
Jiri Olsa <jolsa@kernel.org> Tested-by:
Kan Liang <kan.liang@intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1446734469-11352-2-git-send-email-jolsa@kernel.orgSigned-off-by:
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Jiri Olsa authored
The latency subcommand holds a tree of working atoms sorted by thread's pid/tid. If there's new thread with same pid and tid, the old working atom is found and assert bug condition is hit in search function: thread_atoms_search: Assertion `!(thread != atoms->thread)' failed Changing the sort function to use thread object pointers together with pid and tid check. This way new thread will never find old one with same pid/tid. Link: http://lkml.kernel.org/n/tip-o4doazhhv0zax5zshkg8hnys@git.kernel.orgReported-by:
Mohit Agrawal <moagrawa@redhat.com> Signed-off-by:
Namhyung Kim <namhyung@kernel.org> Cc: David Ahern <dsahern@gmail.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1446462625-15807-1-git-send-email-jolsa@kernel.orgSigned-off-by:
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Wang Nan authored
It is possible that find_perf_probe_point_from_map() fails to find a symbol but still returns 0 because of an small error when coding: find_perf_probe_point_from_map() set 'ret' to error code at first, but also use it to hold return value of kernel_get_symbol_address_by_name(). This patch resets 'ret' to error even kernel_get_symbol_address_by_name() success, so if !sym, the whole function returns error correctly. Signed-off-by:
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Peter Feiner authored
The -i flag was incorrectly listed as a short flag for --no-inherit. It should have only been listed as a short flag for --input. This documentation error has existed since the --input flag was introduced in 6810fc91 (perf trace: Add option to analyze events in a file versus live). Signed-off-by:
Peter Feiner <pfeiner@google.com> Cc: David Ahern <dsahern@gmail.com> Link: http://lkml.kernel.org/r/1446657706-14518-1-git-send-email-pfeiner@google.com Fixes: 6810fc91 ("perf trace: Add option to analyze events in a file versus live") Signed-off-by:
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Yunlong Song authored
Commit ed63f34c ("perf tools: Make perf depend on libbpf") triggers the build of libbpf when building the perf tools, dynamically creating FEATURE-DUMP.libbpf. It failed to update the tools/lib/bpf/.gitignore file to have that prefix, fix it. Signed-off-by:
Yunlong Song <yunlong.song@huawei.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Kan Liang <kan.liang@intel.com> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Wang Nan <wangnan0@huawei.com> Fixes: 65f041be ("tools lib bpf: Use FEATURE_USER to allow building in the same dir as perf") Link: http://lkml.kernel.org/r/1446706594-4142-1-git-send-email-yunlong.song@huawei.comSigned-off-by:
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Wang Nan authored
Arnaldo suggests to make LINUX_VERSION_CODE works like __func__ and __FILE__ so user don't need to care setting right linux version too much. In this patch, perf llvm transfers LINUX_VERSION_CODE macro through clang cmdline. [1] http://lkml.kernel.org/r/20151029223744.GK2923@kernel.org Committer notes: Before, forgetting to update the version: # uname -r 4.3.0-rc1+ # cat bpf.c __attribute__((section("fork=_do_fork"), used)) int fork(void *ctx) { return 1; } char _license[] __attribute__((section("license"), used)) = "GPL"; int _version __attribute__((section("version"), used)) = 0x40200; # # perf record -e bpf.c sleep 1 event syntax error: 'bpf.c' \___ Invalid argument: Are you root and runing a CONFIG_BPF_SYSCALL kernel? (add -v to see detail) Run 'perf list' for a list of valid events Usage: perf record [<options>] [<command>] or: perf record [<options>] -- <command> [<options>] -e, --event <event> event selector. use 'perf list' to list available events # After: # grep version bpf.c int _version __attribute__((section("version"), used)) = LINUX_VERSION_CODE; # perf record -e bpf.c sleep 1 [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.017 MB perf.data ] # perf evlist -v perf_bpf_probe:fork: type: 2, size: 112, config: 0x5ee, { sample_period, sample_freq }: 1, sample_type: IP|TID|TIME|CPU|PERIOD|RAW, disabled: 1, inherit: 1, mmap: 1, comm: 1, enable_on_exec: 1, task: 1, sample_id_all: 1, exclude_guest: 1, mmap2: 1, comm_exec: 1 # Suggested-and-Tested-by:
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Wang Nan authored
This patch introduces a new macro "__NR_CPUS__" to perf's embedded clang compiler, which represent the number of configured CPUs in this system. BPF programs can use this macro to create a map with the same number of system CPUs. For example: struct bpf_map_def SEC("maps") pmu_map = { .type = BPF_MAP_TYPE_PERF_EVENT_ARRAY, .key_size = sizeof(int), .value_size = sizeof(u32), .max_entries = __NR_CPUS__, }; Signed-off-by: -
Arnaldo Carvalho de Melo authored
Those tests take a long time and sometimes we stop it, so allow randomly shuffling the tests so that we have a better chance of running more of them in partial 'make build-test' runs. Using it just on the 'build-test' target, i.e.: make -C tools/perf build-test Is equivalent to: make SHUF=1 -C tools/perf -f tests/make Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Wang Nan <wangnan0@huawei.com> Link: http://lkml.kernel.org/n/tip-ey7461i9q4k8u0987j8guun6@git.kernel.orgSigned-off-by:
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Jiri Olsa authored
When new maps are cloned out of split map they are added into origin map's group, but their groups pointer is not updated. This could lead to a segfault, because map->groups is expected to be always set as reported by Markus: __map__is_kernel (map=map@entry=0x1abb7a0) at util/map.c:238 238 return __machine__kernel_map(map->groups->machine, map->type) = (gdb) bt #0 __map__is_kernel (map=map@entry=0x1abb7a0) at util/map.c:238 #1 0x00000000004393e4 in symbol_filter (map=map@entry=0x1abb7a0, sym=sym@entry #2 0x00000000004fcd4d in dso__load_sym (dso=dso@entry=0x166dae0, map=map@entry #3 0x00000000004a64e0 in dso__load (dso=0x166dae0, map=map@entry=0x1abb7a0, fi #4 0x00000000004b941f in map__load (filter=0x4393c0 <symbol_filter>, map=<opti #5 map__find_symbol (map=0x1abb7a0, addr=40188, filter=0x4393c0 <symbol_filter ... Adding __map_groups__insert function to add map into groups together with map->groups pointer update. It takes no lock as opposed to existing map_groups__insert, as maps__fixup_overlappings(), where it is being called, already has the necessary lock held. Using __map_groups__insert to add new maps after map split. Reported-by:
Markus Trippelsdorf <markus@trippelsdorf.de> Signed-off-by:
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- 04 Nov, 2015 2 commits
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Andi Kleen authored
Instead of every caller deciding whether to call abs or nsec printout do it all in a single central function. No functional changes. Signed-off-by:
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Andi Kleen authored
The sw clock metrics printing was missed in the earlier move to stat-shadow of all the other metric printouts. Move it too. v2: Fix metrics printing in this version to make bisect safe. Signed-off-by:
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- 03 Nov, 2015 3 commits
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Namhyung Kim authored
CC libbpf.o cc1: warnings being treated as errors libbpf.c: In function 'bpf_program__title': libbpf.c:1037: error: declaration of 'dup' shadows a global declaration /usr/include/unistd.h:528: error: shadowed declaration is here mv: cannot stat `./.libbpf.o.tmp': No such file or directory make[3]: *** [libbpf.o] Error 1 make[2]: *** [libbpf-in.o] Error 2 make[1]: *** [/linux/tools/lib/bpf/libbpf.a] Error 2 make[1]: *** Waiting for unfinished jobs.... Signed-off-by: -
Wang Nan authored
According to [1], libbpf should be muted. This patch reset info and warning message level to ensure libbpf doesn't output anything even if error happened. [1] http://lkml.kernel.org/r/20151020151255.GF5119@kernel.org Committer note: Before: Testing it with an incompatible kernel version in the .c file that generated foo.o: [root@zoo ~]# perf record -e /tmp/foo.o sleep 1 libbpf: load bpf program failed: Invalid argument libbpf: -- BEGIN DUMP LOG --- libbpf: libbpf: -- END LOG -- libbpf: failed to load program 'fork=_do_fork' libbpf: failed to load object '/tmp/foo.o' event syntax error: '/tmp/foo.o' \___ Invalid argument: Are you root and runing a CONFIG_BPF_SYSCALL kernel? (add -v to see detail) Run 'perf list' for a list of valid events Usage: perf record [<options>] [<command>] or: perf record [<options>] -- <command> [<options>] -e, --event <event> event selector. use 'perf list' to list available events [root@zoo ~]# After: [root@zoo ~]# perf record -e /tmp/foo.o sleep 1 event syntax error: '/tmp/foo.o' \___ Invalid argument: Are you root and runing a CONFIG_BPF_SYSCALL kernel? (add -v to see detail) Run 'perf list' for a list of valid events Usage: perf record [<options>] [<command>] or: perf record [<options>] -- <command> [<options>] -e, --event <event> event selector. use 'perf list' to list available events [root@zoo ~]# This, BTW, need fixing to emit a proper message by validating the version in the foo.o "version" ELF section against the running kernel, warning the user instead of asking the kernel to load a binary that it will refuse due to unmatching kernel version. Signed-off-by:
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Wang Nan authored
According to [1], 'perf test' should avoid output too much information if '-v' is not set, only 'Ok', 'FAIL' or 'Skip' need to be printed. This patch removes several messages sent directly to stderr to make the output clean. Before this patch: # perf test dummy 23: Test using a dummy software event to keep tracking : (not supported) Ok After this patch: # perf test dummy 23: Test using a dummy software event to keep tracking : Skip [1] http://lkml.kernel.org/r/20151020134155.GE4400@redhat.comSigned-off-by:
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- 30 Oct, 2015 1 commit
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Ingo Molnar authored
Merge tag 'perf-core-for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/core Pull perf/core improvements and fixes from Arnaldo Carvalho de Melo: New features: - Allow passing C language eBPF scriptlets via --event in all tools, so that it gets built using clang and then pass it to the kernel via sys_bpf(). (Wang Nan) - Wire up the loaded ebpf object file with associated kprobes, so that it can determine if the kprobes will be filtered or not. (Wang Nan) User visible changes: - Add cmd string table to decode sys_bpf first arg in 'trace'. (Arnaldo Carvalho de Melo) - Enable printing of branch stack in 'perf script'. (Stephane Eranian) - Pass the right file with debug info to libunwind. (Rabin Vincent) Build Fixes: - Make sure fixdep is built before libbpf, fixing a race. (Jiri Olsa) - Fix libiberty feature detection. (Rabin Vincent) Signed-off-by:
Ingo Molnar <mingo@kernel.org>
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- 29 Oct, 2015 10 commits
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Rabin Vincent authored
Even if --symfs is used to point to the debug binaries, we send in the non-debug filenames to libunwind, which leads to libunwind not finding the debug frame. Fix this by preferring the file in --symfs, if it is available. Signed-off-by:
Rabin Vincent <rabin.vincent@axis.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Rabin Vincent <rabinv@axis.com> Link: http://lkml.kernel.org/r/1446104978-26429-1-git-send-email-rabin.vincent@axis.comSigned-off-by:
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Rabin Vincent authored
Any CFLAGS or LDFLAGS set by the user need to be passed to the feature build command. This many include for example -I or -L to point to libraries and include files in custom paths. In most of the test-*.bin rules in build/feature/Makefile, we use the BUILD macro which always sends in CFLAGS and LDFLAGS. The libiberty build line however doesn't use the BUILD macro and thus needs to send in CFLAGS and LDFLAGS explicitly. Without this, when using custom CFLAGS/LDFLAGS, libiberty fails to be detected and the perf link fails with something like: LINK perf libbfd.a(bfd.o): In function `bfd_errmsg': bfd.c:(.text+0x168): undefined reference to `xstrerror' bbfd.a(opncls.o): In function `_bfd_new_bfd': opncls.c:(.text+0xe8): undefined reference to `objalloc_create' ... Signed-off-by:
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Wang Nan authored
This patch provides infrastructure for passing source files to --event directly using: # perf record --event bpf-file.c command This patch does following works: 1) Allow passing '.c' file to '--event'. parse_events_load_bpf() is expanded to allow caller tell it whether the passed file is source file or object. 2) llvm__compile_bpf() is called to compile the '.c' file, the result is saved into memory. Use bpf_object__open_buffer() to load the in-memory object. Introduces a bpf-script-example.c so we can manually test it: # perf record --clang-opt "-DLINUX_VERSION_CODE=0x40200" --event ./bpf-script-example.c sleep 1 Note that '--clang-opt' must put before '--event'. Futher patches will merge it into a testcase so can be tested automatically. Signed-off-by:Alexei Starovoitov <ast@plumgrid.com> Cc: Brendan Gregg <brendan.d.gregg@gmail.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: David Ahern <dsahern@gmail.com> Cc: He Kuang <hekuang@huawei.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Kaixu Xia <xiakaixu@huawei.com> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Zefan Li <lizefan@huawei.com> Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/1444826502-49291-10-git-send-email-wangnan0@huawei.comSigned-off-by:
He Kuang <hekuang@huawei.com> Signed-off-by:
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Wang Nan authored
Although previous patch allows setting BPF compiler related options in perfconfig, on some ad-hoc situation it still requires passing options through cmdline. This patch introduces 2 options to 'perf record' for this propose: --clang-path and --clang-opt. Signed-off-by:
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Wang Nan authored
This is the final patch which makes basic BPF filter work. After applying this patch, users are allowed to use BPF filter like: # perf record --event ./hello_world.o ls A bpf_fd field is appended to 'struct evsel', and setup during the callback function add_bpf_event() for each 'probe_trace_event'. PERF_EVENT_IOC_SET_BPF ioctl is used to attach eBPF program to a newly created perf event. The file descriptor of the eBPF program is passed to perf record using previous patches, and stored into evsel->bpf_fd. It is possible that different perf event are created for one kprobe events for different CPUs. In this case, when trying to call the ioctl, EEXIST will be return. This patch doesn't treat it as an error. Committer note: The bpf proggie used so far: __attribute__((section("fork=_do_fork"), used)) int fork(void *ctx) { return 0; } char _license[] __attribute__((section("license"), used)) = "GPL"; int _version __attribute__((section("version"), used)) = 0x40300; failed to produce any samples, even with forks happening and it being running in system wide mode. That is because now the filter is being associated, and the code above always returns zero, meaning that all forks will be probed but filtered away ;-/ Change it to 'return 1;' instead and after that: # trace --no-syscalls --event /tmp/foo.o 0.000 perf_bpf_probe:fork:(ffffffff8109be30)) 2.333 perf_bpf_probe:fork:(ffffffff8109be30)) 3.725 perf_bpf_probe:fork:(ffffffff8109be30)) 4.550 perf_bpf_probe:fork:(ffffffff8109be30)) ^C# And it works with all tools, including 'perf trace'. Signed-off-by: -
Jiri Olsa authored
While doing 'make -C tools/perf build-test': LD fixdep-in.o LINK fixdep /bin/sh: /home/acme/git/linux/tools/build/fixdep: Permission denied make[6]: *** [bpf.o] Error 1 make[5]: *** [libbpf-in.o] Error 2 make[4]: *** [/home/acme/git/linux/tools/lib/bpf/libbpf.a] Error 2 make[4]: *** Waiting for unfinished jobs.... The fixdep tool needs to be built as the first binary. Libraries are built in paralel, so each of them needs to depend on fixdep target. Reported-by:
Jiri Olsa <jolsa@redhat.com> Cc: Wang Nan <wangnan0@huawei.com> Link: http://lkml.kernel.org/r/20151028204450.GA25553@krava.redhat.comSigned-off-by:
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Stephane Eranian authored
This patch improves perf script by enabling printing of the branch stack via the 'brstack' and 'brstacksym' arguments to the field selection option -F. The option is off by default and operates only if the perf.data file has branch stack content. The branches are printed in to/from pairs. The most recent branch is printed first. The number of branch entries vary based on the underlying hardware and filtering used. The brstack prints FROM/TO addresses in raw hexadecimal format. The brstacksym prints FROM/TO addresses in symbolic form wherever possible. $ perf script -F ip,brstack 5d3000 0x401aa0/0x5d2000/M/-/-/-/0 ... $ perf script -F ip,brstacksym 4011e0 noploop+0x0/noploop+0x0/P/-/-/0 The notation F/T/M/X/A/C describes the attributes of the branch. F=from, T=to, M/P=misprediction/prediction, X=TSX, A=TSX abort, C=cycles (SKL) Signed-off-by:
Stephane Eranian <eranian@google.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Kan Liang <kan.liang@intel.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Yuanfang Chen <cyfmxc@gmail.com> Link: http://lkml.kernel.org/r/1441039273-16260-5-git-send-email-eranian@google.comSigned-off-by:
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Arnaldo Carvalho de Melo authored
# perf trace -e bpf perf record -e /tmp/foo.o -a 362.779 (0.130 ms): perf/3451 bpf(cmd: PROG_LOAD, uattr: 0x7ffe9a6825d0, size: 48) = 3 Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexei Starovoitov <ast@plumgrid.com> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Wang Nan <wangnan0@huawei.com> Link: http://lkml.kernel.org/n/tip-2b0nknu53baz9e0wj4thcdd8@git.kernel.orgSigned-off-by:
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Ingo Molnar authored
Merge tag 'perf-ebpf-for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/core Pull basic perf/ebpf integration: "Please see the changeset comments, but this is the very basic integration of perf with libbpf that, given a .o file built for the 'bpf' target with clang, will get it validated and loaded into the kernel via the sys_bpf syscall, which can be seen using 'perf trace' to trace the whole thing looking just for the bpf and perf_event_open syscalls: # perf trace -e bpf,perf_event_open perf record -g --event /tmp/foo.o -a 362.779 ( 0.129 ms): perf/22408 bpf(cmd: 5, uattr: 0x7ffd4edb6db0, size: 48 ) = 3 384.192 ( 0.016 ms): perf/22408 perf_event_open(attr_uptr: 0x7ffd4edbace0, pid: -1, cpu: 3, group_fd: -1, flags: FD_CLOEXEC) = 5 384.247 ( 0.038 ms): perf/22408 perf_event_open(attr_uptr: 0x37aedd8, pid: -1, group_fd: -1, flags: FD_CLOEXEC) = 5 384.261 ( 0.007 ms): perf/22408 perf_event_open(attr_uptr: 0x37aedd8, pid: -1, group_fd: -1, flags: FD_CLOEXEC) = 5 387.680 ( 3.413 ms): perf/22408 perf_event_open(attr_uptr: 0x3222f08, pid: -1, group_fd: -1, flags: FD_CLOEXEC) = 5 387.688 ( 0.005 ms): perf/22408 perf_event_open(attr_uptr: 0x3222f08, pid: -1, cpu: 1, group_fd: -1, flags: FD_CLOEXEC) = 6 387.693 ( 0.004 ms): perf/22408 perf_event_open(attr_uptr: 0x3222f08, pid: -1, cpu: 2, group_fd: -1, flags: FD_CLOEXEC) = 7 387.698 ( 0.003 ms): perf/22408 perf_event_open(attr_uptr: 0x3222f08, pid: -1, cpu: 3, group_fd: -1, flags: FD_CLOEXEC) = 8 ^C[ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.221 MB perf.data (2 samples) ] # perf script bash 18389 [002] 83446.412607: perf_bpf_probe:fork: (ffffffff8109be30) 29be31 _do_fork (/lib/modules/4.3.0-rc6+/build/vmlinux) 96d662 tracesys_phase2 (/lib/modules/4.3.0-rc6+/build/vmlinux) bd56c __libc_fork (/usr/lib64/libc-2.17.so) 413b2 make_child (/usr/bin/bash) bash 18389 [002] 83447.227255: perf_bpf_probe:fork: (ffffffff8109be30) 29be31 _do_fork (/lib/modules/4.3.0-rc6+/build/vmlinux) 96d662 tracesys_phase2 (/lib/modules/4.3.0-rc6+/build/vmlinux) bd56c __libc_fork (/usr/lib64/libc-2.17.so) 413b2 make_child (/usr/bin/bash) # perf evlist -v perf_bpf_probe:fork: type: 2, size: 112, config: 0x6cf, { sample_period, sample_freq }: 1, sample_type: IP|TID|TIME|CALLCHAIN|CPU|PERIOD|RAW, disabled: 1, inherit: 1, mmap: 1, comm: 1, task: 1, sample_id_all: 1, exclude_guest: 1, mmap2: 1, comm_exec: 1 # More work is about to be reviewed, tested and merged that will allow the whole process of going from a .c file to an .o file via clang, etc to be done automagically. (Wang Nan)" Signed-off-by:
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Ingo Molnar authored
Merge tag 'perf-core-for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/core Pull perf/core improvements and fixes from Arnaldo Carvalho de Melo: User visible changes: - Enable per-event perf_event_attr.inherit setting by config terms, i.e. this becomes possible: $ perf record -e cycles/inherit/ -e instructions/no-inherit/ This affects the default, that can be changed globally using the --no-inherit option. This fine grained control appeared in the eBPF patchkit, but this added flexibility may end up being useful in other scenarios. (Wang Nan) - Setup pager when printing usage and help, we have long lists of options, better use the pager like we do with normal tooling output, i.e. when needed, and including any error messages in the paged output. (Namhyung Kim) - Search for more options when passing args to -h, e.g.: (Arnaldo Carvalho de Melo) $ perf report -h interface Usage: perf report [<options>] --gtk Use the GTK2 interface --stdio Use the stdio interface --tui Use the TUI interface - Fix reading separate debuginfo files based on a build-id, problem found on a Debian system. (Dima Kogan) - Fix endless loop when splitting kallsyms symbols per section for handling kcore files, problem found on a s390x system. (Jiri Olsa) Infrastructure changes: - Prep work for the 'perf stat record' work that will allow generating perf.data files with counting data in addition to the sampling mode we have now (Jiri Olsa) Signed-off-by:
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- 28 Oct, 2015 10 commits
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Wang Nan authored
This patch creates a 'struct perf_evsel' for every probe in a BPF object file(s) and fills 'struct evlist' with them. The previously introduced dummy event is now removed. After this patch, the following command: # perf record --event filter.o ls Can trace on each of the probes defined in filter.o. The core of this patch is bpf__foreach_tev(), which calls a callback function for each 'struct probe_trace_event' event for a bpf program with each associated file descriptors. The add_bpf_event() callback creates evsels by calling parse_events_add_tracepoint(). Since bpf-loader.c will not be built if libbpf is turned off, an empty bpf__foreach_tev() is defined in bpf-loader.h to avoid build errors. Committer notes: Before: # /tmp/oldperf record --event /tmp/foo.o -a usleep 1 [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.198 MB perf.data ] # perf evlist /tmp/foo.o # perf evlist -v /tmp/foo.o: type: 1, size: 112, config: 0x9, { sample_period, sample_freq }: 4000, sample_type: IP|TID|TIME|CPU|PERIOD, disabled: 1, inherit: 1, mmap: 1, comm: 1, freq: 1, task: 1, sample_id_all: 1, exclude_guest: 1, mmap2: 1, comm_exec: 1 I.e. we create just the PERF_TYPE_SOFTWARE (type: 1), PERF_COUNT_SW_DUMMY(config 0x9) event, now, with this patch: # perf record --event /tmp/foo.o -a usleep 1 [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.210 MB perf.data ] # perf evlist -v perf_bpf_probe:fork: type: 2, size: 112, config: 0x6bd, { sample_period, sample_freq }: 1, sample_type: IP|TID|TIME|CPU|PERIOD|RAW, disabled: 1, inherit: 1, mmap: 1, comm: 1, task: 1, sample_id_all: 1, exclude_guest: 1, mmap2: 1, comm_exec: 1 # We now have a PERF_TYPE_SOFTWARE (type: 1), but the config states 0x6bd, which is how, after setting up the event via the kprobes interface, the 'perf_bpf_probe:fork' event is accessible via the perf_event_open syscall. This is all transient, as soon as the 'perf record' session ends, these probes will go away. To see how it looks like, lets try doing a neverending session, one that expects a control+C to end: # perf record --event /tmp/foo.o -a So, with that in place, we can use 'perf probe' to see what is in place: # perf probe -l perf_bpf_probe:fork (on _do_fork@acme/git/linux/kernel/fork.c) We also can use debugfs: [root@felicio ~]# cat /sys/kernel/debug/tracing/kprobe_events p:perf_bpf_probe/fork _text+638512 Ok, now lets stop and see if we got some forks: [root@felicio linux]# perf record --event /tmp/foo.o -a ^C[ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.325 MB perf.data (111 samples) ] [root@felicio linux]# perf script sshd 1271 [003] 81797.507678: perf_bpf_probe:fork: (ffffffff8109be30) sshd 18309 [000] 81797.524917: perf_bpf_probe:fork: (ffffffff8109be30) sshd 18309 [001] 81799.381603: perf_bpf_probe:fork: (ffffffff8109be30) sshd 18309 [001] 81799.408635: perf_bpf_probe:fork: (ffffffff8109be30) <SNIP> Sure enough, we have 111 forks :-) Callchains seems to work as well: # perf report --stdio --no-child # To display the perf.data header info, please use --header/--header-only options. # # Total Lost Samples: 0 # # Samples: 562 of event 'perf_bpf_probe:fork' # Event count (approx.): 562 # # Overhead Command Shared Object Symbol # ........ ........ ................ ............ # 44.66% sh [kernel.vmlinux] [k] _do_fork | ---_do_fork entry_SYSCALL_64_fastpath __libc_fork make_child 26.16% make [kernel.vmlinux] [k] _do_fork <SNIP> # Signed-off-by: -
Wang Nan authored
This patch utilizes bpf_object__load() provided by libbpf to load all objects into kernel. Committer notes: Testing it: When using an incorrect kernel version number, i.e., having this in your eBPF proggie: int _version __attribute__((section("version"), used)) = 0x40100; For a 4.3.0-rc6+ kernel, say, this happens and needs checking at event parsing time, to provide a better error report to the user: # perf record --event /tmp/foo.o sleep 1 libbpf: load bpf program failed: Invalid argument libbpf: -- BEGIN DUMP LOG --- libbpf: libbpf: -- END LOG -- libbpf: failed to load program 'fork=_do_fork' libbpf: failed to load object '/tmp/foo.o' event syntax error: '/tmp/foo.o' \___ Invalid argument: Are you root and runing a CONFIG_BPF_SYSCALL kernel? (add -v to see detail) Run 'perf list' for a list of valid events Usage: perf record [<options>] [<command>] or: perf record [<options>] -- <command> [<options>] -e, --event <event> event selector. use 'perf list' to list available events If we instead make it match, i.e. use 0x40300 on this v4.3.0-rc6+ kernel, the whole process goes thru: # perf record --event /tmp/foo.o -a usleep 1 [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.202 MB perf.data ] # perf evlist -v /tmp/foo.o: type: 1, size: 112, config: 0x9, { sample_period, sample_freq }: 4000, sample_type: IP|TID|TIME|CPU|PERIOD, disabled: 1, inherit: 1, mmap: 1, comm: 1, freq: 1, task: 1, sample_id_all: 1, exclude_guest: 1, mmap2: 1, comm_exec: 1 # Signed-off-by: -
Wang Nan authored
This patch introduces bpf__{un,}probe() functions to enable callers to create kprobe points based on section names a BPF program. It parses the section names in the program and creates corresponding 'struct perf_probe_event' structures. The parse_perf_probe_command() function is used to do the main parsing work. The resuling 'struct perf_probe_event' is stored into program private data for further using. By utilizing the new probing API, this patch creates probe points during event parsing. To ensure probe points be removed correctly, register an atexit hook so even perf quit through exit() bpf__clear() is still called, so probing points are cleared. Note that bpf_clear() should be registered before bpf__probe() is called, so failure of bpf__probe() can still trigger bpf__clear() to remove probe points which are already probed. strerror style error reporting scaffold is created by this patch. bpf__strerror_probe() is the first error reporting function in bpf-loader.c. Committer note: Trying it: To build a test eBPF object file: I am testing using a script I built from the 'perf test -v LLVM' output: $ cat ~/bin/hello-ebpf export KERNEL_INC_OPTIONS="-nostdinc -isystem /usr/lib/gcc/x86_64-redhat-linux/4.8.3/include -I/home/acme/git/linux/arch/x86/include -Iarch/x86/include/generated/uapi -Iarch/x86/include/generated -I/home/acme/git/linux/include -Iinclude -I/home/acme/git/linux/arch/x86/include/uapi -Iarch/x86/include/generated/uapi -I/home/acme/git/linux/include/uapi -Iinclude/generated/uapi -include /home/acme/git/linux/include/linux/kconfig.h" export WORKING_DIR=/lib/modules/4.2.0/build export CLANG_SOURCE=- export CLANG_OPTIONS=-xc OBJ=/tmp/foo.o rm -f $OBJ echo '__attribute__((section("fork=do_fork"), used)) int fork(void *ctx) {return 0;} char _license[] __attribute__((section("license"), used)) = "GPL";int _version __attribute__((section("version"), used)) = 0x40100;' | \ clang -D__KERNEL__ $CLANG_OPTIONS $KERNEL_INC_OPTIONS -Wno-unused-value -Wno-pointer-sign -working-directory $WORKING_DIR -c "$CLANG_SOURCE" -target bpf -O2 -o /tmp/foo.o && file $OBJ --- First asking to put a probe in a function not present in the kernel (misses the initial _): $ perf record --event /tmp/foo.o sleep 1 Probe point 'do_fork' not found. event syntax error: '/tmp/foo.o' \___ You need to check probing points in BPF file (add -v to see detail) Run 'perf list' for a list of valid events Usage: perf record [<options>] [<command>] or: perf record [<options>] -- <command> [<options>] -e, --event <event> event selector. use 'perf list' to list available events $ --- Now, with "__attribute__((section("fork=_do_fork"), used)): $ grep _do_fork /proc/kallsyms ffffffff81099ab0 T _do_fork $ perf record --event /tmp/foo.o sleep 1 Failed to open kprobe_events: Permission denied event syntax error: '/tmp/foo.o' \___ Permission denied --- Cool, we need to provide some better hints, "kprobe_events" is too low level, one doesn't strictly need to know the precise details of how these things are put in place, so something that shows the command needed to fix the permissions would be more helpful. Lets try as root instead: # perf record --event /tmp/foo.o sleep 1 Lowering default frequency rate to 1000. Please consider tweaking /proc/sys/kernel/perf_event_max_sample_rate. [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.013 MB perf.data ] # perf evlist /tmp/foo.o [root@felicio ~]# perf evlist -v /tmp/foo.o: type: 1, size: 112, config: 0x9, { sample_period, sample_freq }: 1000, sample_type: IP|TID|TIME|PERIOD, disabled: 1, inherit: 1, mmap: 1, comm: 1, freq: 1, enable_on_exec: 1, task: 1, sample_id_all: 1, exclude_guest: 1, mmap2: 1, comm_exec: 1 --- Signed-off-by: -
Wang Nan authored
By introducing new rules in tools/perf/util/parse-events.[ly], this patch enables 'perf record --event bpf_file.o' to select events by an eBPF object file. It calls parse_events_load_bpf() to load that file, which uses bpf__prepare_load() and finally calls bpf_object__open() for the object files. After applying this patch, commands like: # perf record --event foo.o sleep become possible. However, at this point it is unable to link any useful things onto the evsel list because the creating of probe points and BPF program attaching have not been implemented. Before real events are possible to be extracted, to avoid perf report error because of empty evsel list, this patch link a dummy evsel. The dummy event related code will be removed when probing and extracting code is ready. Commiter notes: Using it: $ ls -la foo.o ls: cannot access foo.o: No such file or directory $ perf record --event foo.o sleep libbpf: failed to open foo.o: No such file or directory event syntax error: 'foo.o' \___ BPF object file 'foo.o' is invalid (add -v to see detail) Run 'perf list' for a list of valid events Usage: perf record [<options>] [<command>] or: perf record [<options>] -- <command> [<options>] -e, --event <event> event selector. use 'perf list' to list available events $ $ file /tmp/build/perf/perf.o /tmp/build/perf/perf.o: ELF 64-bit LSB relocatable, x86-64, version 1 (SYSV), not stripped $ perf record --event /tmp/build/perf/perf.o sleep libbpf: /tmp/build/perf/perf.o is not an eBPF object file event syntax error: '/tmp/build/perf/perf.o' \___ BPF object file '/tmp/build/perf/perf.o' is invalid (add -v to see detail) Run 'perf list' for a list of valid events Usage: perf record [<options>] [<command>] or: perf record [<options>] -- <command> [<options>] -e, --event <event> event selector. use 'perf list' to list available events $ $ file /tmp/foo.o /tmp/foo.o: ELF 64-bit LSB relocatable, no machine, version 1 (SYSV), not stripped $ perf record --event /tmp/foo.o sleep 1 [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.013 MB perf.data ] $ perf evlist /tmp/foo.o $ perf evlist -v /tmp/foo.o: type: 1, size: 112, config: 0x9, { sample_period, sample_freq }: 4000, sample_type: IP|TID|TIME|PERIOD, disabled: 1, inherit: 1, mmap: 1, comm: 1, freq: 1, enable_on_exec: 1, task: 1, sample_id_all: 1, exclude_guest: 1, mmap2: 1, comm_exec: 1 $ So, type 1 is PERF_TYPE_SOFTWARE, config 0x9 is PERF_COUNT_SW_DUMMY, ok. $ perf report --stdio Error: The perf.data file has no samples! # To display the perf.data header info, please use --header/--header-only options. # $ Signed-off-by: -
Wang Nan authored
The 'bpf-loader.[ch]' files are introduced in this patch. Which will be the interface between perf and libbpf. bpf__prepare_load() resides in bpf-loader.c. Following patches will enrich these two files. Signed-off-by:
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Wang Nan authored
By adding libbpf into perf's Makefile, this patch enables perf to build libbpf if libelf is found and neither NO_LIBELF nor NO_LIBBPF is set. The newly introduced code is similar to how libapi and libtraceevent are wired into Makefile.perf. MANIFEST is also updated for 'make perf-*-src-pkg'. Append make_no_libbpf to tools/perf/tests/make. The 'bpf' feature check is appended into default FEATURE_TESTS and FEATURE_DISPLAY, so perf will check the API version of bpf in /path/to/kernel/include/uapi/linux/bpf.h. Which should not fail except when we are trying to port this code to an old kernel. Error messages are also updated to notify users about the lack of BPF support in 'perf record' if libelf is missing or the BPF API check failed. tools/lib/bpf is added to TAG_FOLDERS to allow us to navigate libbpf files when working on perf using tools/perf/tags. Signed-off-by:
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Jiri Olsa authored
Currently we split symbols based on the map comparison, but symbols are stored within dso objects and maps could point into same dso objects (kernel maps). Hence we could end up changing rbtree we are currently iterating and mess it up. It's easily reproduced on s390x by running: $ perf record -a -- sleep 3 $ perf buildid-list -i perf.data --with-hits The fix is to compare dso objects instead. Reported-by:
Michael Petlan <mpetlan@redhat.com> Signed-off-by:
Adrian Hunter <adrian.hunter@intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Kan Liang <kan.liang@intel.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20151026135130.GA26003@krava.brq.redhat.comSigned-off-by:
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Wang Nan authored
This patch allows perf record setting event's attr.inherit bit by config terms like: # perf record -e cycles/no-inherit/ ... # perf record -e cycles/inherit/ ... So user can control inherit bit for each event separately. In following example, a.out fork()s in main then do some complex CPU intensive computations in both of its children. Basic result with and without inherit: # perf record -e cycles -e instructions ./a.out [ perf record: Woken up 9 times to write data ] [ perf record: Captured and wrote 2.205 MB perf.data (47920 samples) ] # perf report --stdio # ... # Samples: 23K of event 'cycles' # Event count (approx.): 23641752891 ... # Samples: 24K of event 'instructions' # Event count (approx.): 30428312415 # perf record -i -e cycles -e instructions ./a.out [ perf record: Woken up 5 times to write data ] [ perf record: Captured and wrote 1.111 MB perf.data (24019 samples) ] ... # Samples: 12K of event 'cycles' # Event count (approx.): 11699501775 ... # Samples: 12K of event 'instructions' # Event count (approx.): 15058023559 Cancel inherit for one event when globally enable: # perf record -e cycles/no-inherit/ -e instructions ./a.out [ perf record: Woken up 7 times to write data ] [ perf record: Captured and wrote 1.660 MB perf.data (36004 samples) ] ... # Samples: 12K of event 'cycles/no-inherit/' # Event count (approx.): 11895759282 ... # Samples: 24K of event 'instructions' # Event count (approx.): 30668000441 Enable inherit for one event when globally disable: # perf record -i -e cycles/inherit/ -e instructions ./a.out [ perf record: Woken up 7 times to write data ] [ perf record: Captured and wrote 1.654 MB perf.data (35868 samples) ] ... # Samples: 23K of event 'cycles/inherit/' # Event count (approx.): 23285400229 ... # Samples: 11K of event 'instructions' # Event count (approx.): 14969050259 Committer note: One can check if the bit was set, in addition to seeing the result in the perf.data file size as above by doing one of: # perf record -e cycles -e instructions -a usleep 1 [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.911 MB perf.data (63 samples) ] # perf evlist -v cycles: size: 112, { sample_period, sample_freq }: 4000, sample_type: IP|TID|TIME|ID|CPU|PERIOD, read_format: ID, disabled: 1, inherit: 1, mmap: 1, comm: 1, freq: 1, task: 1, sample_id_all: 1, exclude_guest: 1, mmap2: 1, comm_exec: 1 instructions: size: 112, config: 0x1, { sample_period, sample_freq }: 4000, sample_type: IP|TID|TIME|ID|CPU|PERIOD, read_format: ID, disabled: 1, inherit: 1, freq: 1, sample_id_all: 1, exclude_guest: 1 # So, the inherit bit was set in both, now, if we disable it globally using --no-inherit: # perf record --no-inherit -e cycles -e instructions -a usleep 1 [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.910 MB perf.data (56 samples) ] # perf evlist -v cycles: size: 112, { sample_period, sample_freq }: 4000, sample_type: IP|TID|TIME|ID|CPU|PERIOD, read_format: ID, disabled: 1, mmap: 1, comm: 1, freq: 1, task: 1, sample_id_all: 1, exclude_guest: 1, mmap2: 1, comm_exec: 1 instructions: size: 112, config: 0x1, { sample_period, sample_freq }: 4000, sample_type: IP|TID|TIME|ID|CPU|PERIOD, read_format: ID, disabled: 1, freq: 1, sample_id_all: 1, exclude_guest: 1 No inherit bit set, then disabling it and setting just on the cycles event: # perf record --no-inherit -e cycles/inherit/ -e instructions -a usleep 1 [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.909 MB perf.data (48 samples) ] # perf evlist -v cycles/inherit/: size: 112, { sample_period, sample_freq }: 4000, sample_type: IP|TID|TIME|ID|CPU|PERIOD, read_format: ID, disabled: 1, inherit: 1, mmap: 1, comm: 1, freq: 1, task: 1, sample_id_all: 1, exclude_guest: 1, mmap2: 1, comm_exec: 1 instructions: size: 112, config: 0x1, { sample_period, sample_freq }: 4000, sample_type: IP|TID|TIME|ID|CPU|PERIOD, read_format: ID, disabled: 1, freq: 1, sample_id_all: 1, exclude_guest: 1 # We can see it as well in by using a more verbose level of debug messages in the tool that sets up the perf_event_attr, 'perf record' in this case: [root@zoo ~]# perf record -vv --no-inherit -e cycles/inherit/ -e instructions -a usleep 1 ------------------------------------------------------------ perf_event_attr: size 112 { sample_period, sample_freq } 4000 sample_type IP|TID|TIME|ID|CPU|PERIOD read_format ID disabled 1 inherit 1 mmap 1 comm 1 freq 1 task 1 sample_id_all 1 exclude_guest 1 mmap2 1 comm_exec 1 ------------------------------------------------------------ sys_perf_event_open: pid -1 cpu 0 group_fd -1 flags 0x8 sys_perf_event_open: pid -1 cpu 1 group_fd -1 flags 0x8 sys_perf_event_open: pid -1 cpu 2 group_fd -1 flags 0x8 sys_perf_event_open: pid -1 cpu 3 group_fd -1 flags 0x8 ------------------------------------------------------------ perf_event_attr: size 112 config 0x1 { sample_period, sample_freq } 4000 sample_type IP|TID|TIME|ID|CPU|PERIOD read_format ID disabled 1 freq 1 sample_id_all 1 exclude_guest 1 ------------------------------------------------------------ sys_perf_event_open: pid -1 cpu 0 group_fd -1 flags 0x8 <SNIP> Signed-off-by: -
Dima Kogan authored
Recent GDB (at least on a vanilla Debian box) looks for debug information in /usr/lib/debug/.build-id/nn/nnnnnnn where nn/nnnnnn is the build-id of the stripped ELF binary. This is documented here: https://sourceware.org/gdb/onlinedocs/gdb/Separate-Debug-Files.html This was not working in perf because we didn't read the build id until AFTER we searched for the separate debug information file. This patch reads the build ID and THEN does the search. Signed-off-by:
Dima Kogan <dima@secretsauce.net> Link: http://lkml.kernel.org/r/87si6pfwz4.fsf@secretsauce.netSigned-off-by:
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Dima Kogan authored
This was benign, but wrong. The build-id should live in a char[], not a char*[] Signed-off-by:
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- 27 Oct, 2015 1 commit
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Arnaldo Carvalho de Melo authored
Recently 'perf <tool> -h' was made aware of arguments and would show just the help for the arguments specified, but that required a strict form, i.e.: $ perf -h --tui worked, but: $ perf -h tui didn't. Make it support both cases and also look at the option help when neither matches, so that he following examples works: $ perf report -h interface Usage: perf report [<options>] --gtk Use the GTK2 interface --stdio Use the stdio interface --tui Use the TUI interface $ perf report -h stack Usage: perf report [<options>] -g, --call-graph <print_type,threshold[,print_limit],order, sort_key[,branch]> Display call graph (stack chain/backtrace): print_type: call graph printing style (graph|flat|fractal|none) threshold: minimum call graph inclusion threshold (<percent>) print_limit: maximum number of call graph entry (<number>) order: call graph order (caller|callee) sort_key: call graph sort key (function|address) branch: include last branch info to call graph (branch) Default: graph,0.5,caller,function --max-stack <n> Set the maximum stack depth when parsing the callchain, anything beyond the specified depth will be ignored. Default: 127 $ Suggested-by:
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