linux/tools
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
..
accounting
arch tools headers: Sync cpu features kernel ABI headers with tooling headers 2017-08-28 16:44:46 -03:00
build tools build tests: Don't hardcode gcc name 2017-08-28 16:44:44 -03:00
cgroup
firewire
gpio gpio-hammer: fix make consumer_label suitable to work on gpio-nails 2017-01-26 16:29:09 +01:00
hv Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2017-07-05 12:31:59 -07:00
iio iio: tools: generic_buffer: increase trigger length 2017-05-07 16:08:04 +01:00
include tools include linux: Guard against redefinition of some macros 2017-09-12 12:33:39 -03:00
kvm/kvm_stat tools/kvm_stat: add '-f help' to get the available event list 2017-07-26 19:04:53 +02:00
laptop
leds tools/leds: Add led_hw_brightness_mon program 2017-02-14 22:20:23 +01:00
lib tools lib api: Fix make DEBUG=1 build 2017-09-12 12:34:14 -03:00
net tools: bpf_jit_disasm: Handle large images. 2017-06-14 15:03:22 -04:00
nfsd
objtool objtool: Handle GCC stack pointer adjustment bug 2017-08-30 10:48:41 +02:00
pci tools: PCI: Add sample test script to invoke pcitest 2017-04-28 10:23:20 -05:00
pcmcia
perf perf stat: Wait for the correct child 2017-09-12 12:49:13 -03:00
power ACPI updates for v4.13-rc1 2017-07-04 14:16:49 -07:00
scripts perf tools: Robustify detection of clang binary 2017-08-28 16:44:46 -03:00
spi spi: spidev_test: add option to continuously transfer data 2017-03-21 18:44:40 +00:00
testing Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-09-04 13:06:34 -07:00
thermal/tmon
time
usb usb: changes for v4.13 merge window 2017-06-20 11:39:34 +08:00
virtio tools/virtio: fix spelling mistake: "wakeus" -> "wakeups" 2017-05-09 16:43:24 +03:00
vm tools/vm: add missing Makefile rules 2017-02-22 16:41:26 -08:00
Makefile x86/lguest: Remove lguest support 2017-08-24 09:57:28 +02:00