linux/tools/perf
Milian Wolff dfc9eec771 perf stat: Wait for the correct child
When packaging the perf userland application into an AppImage, the
wait() call in perf stat returned too early. It turned out that some
other child process exited, but not the one perf stat launched:

  $ sudo strace -e fork,execve,clone,wait4 -f ./perf-x86_64.AppImage stat sleep 1
  execve("./perf-git.3a73b7f9-x86_64.AppImage", ["./perf-git.3a73b7f9-x86_64.AppIm"..., "stat", "sleep", "1"], 0x7ffec1bbf050 /* 18 vars */) = 0
  clone(child_stack=NULL, flags=CLONE_CHILD_CLEARTID|CLONE_CHILD_SETTID|SIGCHLD, child_tidptr=0x7f6a6e7efe50) = 3912
  strace: Process 3912 attached
  [pid  3912] clone(child_stack=NULL, flags=CLONE_CHILD_CLEARTID|CLONE_CHILD_SETTID|SIGCHLD, child_tidptr=0x7f6a6e7efe50) = 3914
  strace: Process 3914 attached
  [pid  3912] +++ exited with 0 +++
  [pid  3911] --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=3912, si_uid=0, si_status=0, si_utime=0, si_stime=0} ---
  [pid  3914] clone(strace: Process 3915 attached
  child_stack=0x7f6a6d9fefb0, flags=CLONE_VM|CLONE_FS|CLONE_FILES|CLONE_SIGHAND|CLONE_THREAD|CLONE_SYSVSEM|CLONE_SETTLS|CLONE_PARENT_SETTID|CLONE_CHILD_CLEARTID, parent_tidptr=0x7f6a6d9ff9d0, tls=0x7f6a6d9ff700, child_tidptr=0x7f6a6d9ff9d0) = 3915
  [pid  3911] execve("/tmp/.mount_perf-g6VYMpl/AppRun", ["./perf-git.3a73b7f9-x86_64.AppIm"..., "stat", "sleep", "1"], 0x14aab70 /* 21 vars */) = 0
  [pid  3911] clone(child_stack=NULL, flags=CLONE_CHILD_CLEARTID|CLONE_CHILD_SETTID|SIGCHLD, child_tidptr=0x7f4ae113c4d0) = 3916
  strace: Process 3916 attached
  [pid  3911] wait4(-1, [{WIFEXITED(s) && WEXITSTATUS(s) == 0}], 0, NULL) = 3912
  [pid  3916] execve("/usr/libexec/perf-core/sleep", ["sleep", "1"], 0x27d3650 /* 22 vars */) = -1 ENOENT (No such file or directory)
  [pid  3916] execve("/tmp/./sleep", ["sleep", "1"], 0x27d3650 /* 22 vars */) = -1 ENOENT (No such file or directory)
  [pid  3916] execve("/home/milian/.bin/sleep", ["sleep", "1"], 0x27d3650 /* 22 vars */) = -1 ENOENT (No such file or directory)
  [pid  3916] execve("/usr/lib/icecream/libexec/icecc/bin/sleep", ["sleep", "1"], 0x27d3650 /* 22 vars */) = -1 ENOENT (No such file or directory)
  [pid  3916] execve("/ssd2/milian/projects/compiled/other/bin/sleep", ["sleep", "1"], 0x27d3650 /* 22 vars */) = -1 ENOENT (No such file or directory)
  [pid  3916] execve("/home/milian/.bin/kf5/sleep", ["sleep", "1"], 0x27d3650 /* 22 vars */) = -1 ENOENT (No such file or directory)
  [pid  3916] execve("/ssd2/milian/projects/compiled/kf5/bin/sleep", ["sleep", "1"], 0x27d3650 /* 22 vars */) = -1 ENOENT (No such file or directory)
  [pid  3916] execve("/home/milian/projects/compiled/other/bin/sleep", ["sleep", "1"], 0x27d3650 /* 22 vars */) = -1 ENOENT (No such file or directory)
  [pid  3916] execve("/home/milian/projects/compiled/kf5/bin/sleep", ["sleep", "1"], 0x27d3650 /* 22 vars */) = -1 ENOENT (No such file or directory)
  [pid  3916] execve("/usr/local/sbin/sleep", ["sleep", "1"], 0x27d3650 /* 22 vars */) = -1 ENOENT (No such file or directory)
  [pid  3916] execve("/usr/local/bin/sleep", ["sleep", "1"], 0x27d3650 /* 22 vars */) = -1 ENOENT (No such file or directory)
  [pid  3916] execve("/usr/bin/sleep", ["sleep", "1"], 0x27d3650 /* 22 vars */
   Performance counter stats for 'sleep 1':

       <not counted>	task-clock
       <not counted>	context-switches
       <not counted>	cpu-migrations
       <not counted>	page-faults
       <not counted>	cycles
       <not counted>	instructions
       <not counted>      branches
       <not counted>      branch-misses

         0.000047194 seconds time elapsed

  [pid  3916] --- SIGTERM {si_signo=SIGTERM, si_code=SI_USER, si_pid=3911, si_uid=0} ---
  [pid  3916] +++ killed by SIGTERM +++
  [pid  3911] --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_KILLED, si_pid=3916, si_uid=0, si_status=SIGTERM, si_utime=0, si_stime=0} ---
  [pid  3915] --- SIGPIPE {si_signo=SIGPIPE, si_code=SI_USER, si_pid=3914, si_uid=0} ---
  [pid  3911] +++ exited with 0 +++
  [pid  3915] --- SIGHUP {si_signo=SIGHUP, si_code=SI_USER, si_pid=3914, si_uid=0} ---
  [pid  3915] +++ exited with 0 +++
  +++ exited with 0 +++

This patch uses waitpid instead to ensure the call waits for the
debuggee application launched by 'perf stat'. This fixes 'perf stat'
when launched from an AppImage:

  $ ./perf-x86_64.AppImage stat sleep 1

   Performance counter stats for 'sleep 1':

          0.357235      task-clock (msec)         #    0.000 CPUs utilized
                 1      context-switches          #    0.003 M/sec
                 0      cpu-migrations            #    0.000 K/sec
                50      page-faults               #    0.140 M/sec
           1269602      cycles                    #    3.554 GHz
            654278      instructions              #    0.52  insn per cycle
            129963      branches                  #  363.803 M/sec
              7082      branch-misses             #    5.45% of all branches

       1.000633420 seconds time elapsed

Signed-off-by: Milian Wolff <milian.wolff@kdab.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/20170912152523.4497-1-milian.wolff@kdab.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2017-09-12 12:49:13 -03:00
..
arch perf report: Fix module symbol adjustment for s390x 2017-08-11 16:06:32 -03:00
bench perf tools: Use __maybe_unused consistently 2017-06-19 15:27:06 -03:00
Documentation perf script: Support physical address 2017-09-01 14:46:29 -03:00
jvmti perf jit: fix typo: "incalid" -> "invalid" 2017-06-27 11:55:06 -03:00
pmu-events perf vendor events powerpc: Remove duplicate events 2017-09-01 14:46:00 -03:00
python perf python: Add tracepoint example 2016-07-12 16:23:35 -03:00
scripts perf script python: Add support for sqlite3 to call-graph-from-sql.py 2017-08-15 17:03:38 -03:00
tests perf tests: Fix compile when libunwind's unwind.h is available 2017-09-12 12:34:02 -03:00
trace perf trace beauty: Beautify pkey_{alloc,free,mprotect} arguments 2017-08-28 16:44:47 -03:00
ui perf ui progress: Fix progress update 2017-09-12 12:34:54 -03:00
util perf tools: Open perf.data with O_CLOEXEC flag 2017-09-12 12:34:23 -03:00
.gitignore perf tools: Ignore generated files pmu-events/{jevents,pmu-events.c} for git 2017-03-13 10:59:36 -03:00
Build perf trace: Only build tools/perf/trace/beauty/ when building 'perf trace' 2017-07-18 23:13:52 -03:00
builtin-annotate.c perf annotate browser: Support --show-nr-samples option 2017-08-18 11:15:09 -03:00
builtin-bench.c perf tools: Remove unused 'prefix' from builtin functions 2017-03-27 11:58:09 -03:00
builtin-buildid-cache.c perf buildid-cache: Cache debuginfo 2017-07-18 23:14:11 -03:00
builtin-buildid-list.c perf tools: Include errno.h where needed 2017-04-19 13:01:51 -03:00
builtin-c2c.c perf tools: Replace error() with pr_err() 2017-06-27 11:22:31 -03:00
builtin-config.c perf config: Check not only section->from_system_config but also item's 2017-09-12 12:35:11 -03:00
builtin-data.c perf data: Add doc when no conversion support compiled 2017-07-28 16:30:45 -03:00
builtin-diff.c perf config: Do not die when parsing u64 or int config values 2017-06-27 11:44:58 -03:00
builtin-evlist.c perf tools: Remove unused 'prefix' from builtin functions 2017-03-27 11:58:09 -03:00
builtin-ftrace.c tools include: Adopt strstarts() from the kernel 2017-07-20 15:46:10 -03:00
builtin-help.c tools include: Adopt strstarts() from the kernel 2017-07-20 15:46:10 -03:00
builtin-inject.c perf tools: Add feature header record to pipe-mode 2017-07-18 23:14:36 -03:00
builtin-kallsyms.c perf tools: Including missing inttypes.h header 2017-04-19 13:01:46 -03:00
builtin-kmem.c mm, tree wide: replace __GFP_REPEAT by __GFP_RETRY_MAYFAIL with more useful semantic 2017-07-12 16:26:03 -07:00
builtin-kvm.c perf tools: Remove poll.h and wait.h from util.h 2017-04-24 13:43:34 -03:00
builtin-list.c perf tools: Remove unused 'prefix' from builtin functions 2017-03-27 11:58:09 -03:00
builtin-lock.c perf tools: Include errno.h where needed 2017-04-19 13:01:51 -03:00
builtin-mem.c perf mem: Support physical address 2017-09-01 14:46:23 -03:00
builtin-probe.c perf buildid-cache: Support binary objects from other namespaces 2017-07-18 23:14:11 -03:00
builtin-record.c perf tools: Support new sample type for physical address 2017-09-01 14:46:00 -03:00
builtin-report.c perf report: Group stat values on global event id 2017-08-28 16:44:44 -03:00
builtin-sched.c perf tools: Replace error() with pr_err() 2017-06-27 11:22:31 -03:00
builtin-script.c perf script: Support physical address 2017-09-01 14:46:29 -03:00
builtin-stat.c perf stat: Wait for the correct child 2017-09-12 12:49:13 -03:00
builtin-timechart.c perf tools: Use just forward declarations for struct thread where possible 2017-04-24 13:43:35 -03:00
builtin-top.c perf top: Support lookup of symbols in other mount namespaces. 2017-07-25 22:43:16 -03:00
builtin-trace.c perf trace: Support syscall name globbing 2017-09-01 14:45:58 -03:00
builtin-version.c perf tools: Remove string.h, unistd.h and sys/stat.h from util.h 2017-04-24 13:43:33 -03:00
builtin.h perf tools: Remove stale prototypes from builtin.h 2017-04-24 13:43:33 -03:00
check-headers.sh tools include uapi: Grab a copy of linux/vhost.h 2017-08-01 13:04:56 -03:00
command-list.txt perf tools: Missing c2c command in command-list 2017-03-13 10:59:31 -03:00
CREDITS
design.txt
Makefile perf build tests: Do parallell builds with 'build-test' 2016-02-04 15:57:00 -03:00
Makefile.config perf tools: Robustify detection of clang binary 2017-08-28 16:44:46 -03:00
Makefile.perf perf trace beauty: Beautify pkey_{alloc,free,mprotect} arguments 2017-08-28 16:44:47 -03:00
MANIFEST tools include uapi: Grab a copy of linux/vhost.h 2017-08-01 13:04:56 -03:00
perf-archive.sh
perf-completion.sh
perf-read-vdso.c
perf-sys.h perf tools: Use default CPUINFO_PROC where it fits 2017-08-17 16:58:21 -03:00
perf-with-kcore.sh
perf.c perf tools: Support running perf binaries with a dash in their name 2017-09-12 12:48:54 -03:00
perf.h perf tools: Support new sample type for physical address 2017-09-01 14:46:00 -03:00