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
hv	Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next	2017-07-05 12:31:59 -07:00
iio
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
lib	tools lib api: Fix make DEBUG=1 build	2017-09-12 12:34:14 -03:00
net
nfsd
objtool	objtool: Handle GCC stack pointer adjustment bug	2017-08-30 10:48:41 +02:00
pci
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
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
vm
Makefile	x86/lguest: Remove lguest support	2017-08-24 09:57:28 +02:00