didi2@linux:~> strace -f qemu testclonenonptl
execve("/usr/local/bin/qemu", ["qemu", "testclonenonptl"], [/* 67 vars */]) = 0
uname({sys="Linux", node="linux", ...}) = 0
brk(0)                                  = 0x80463540
old_mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x40019000
open("/etc/ld.so.preload", O_RDONLY)    = -1 ENOENT (No such file or directory)
open("/etc/ld.so.cache", O_RDONLY)      = 3
fstat64(3, {st_mode=S_IFREG|0644, st_size=102185, ...}) = 0
old_mmap(NULL, 102185, PROT_READ, MAP_PRIVATE, 3, 0) = 0x4001a000
close(3)                                = 0
open("/lib/i686/libm.so.6", O_RDONLY)   = 3
read(3, "\177ELF\1\1\1\0\0\0\0\0\0\0\0\0\3\0\3\0\1\0\0\0 5\0\000"..., 512) = 512
fstat64(3, {st_mode=S_IFREG|0755, st_size=183008, ...}) = 0
old_mmap(NULL, 142672, PROT_READ|PROT_EXEC, MAP_PRIVATE, 3, 0) = 0x40033000
old_mmap(0x40055000, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED, 3, 0x21000) = 0x40055000
close(3)                                = 0
open("/lib/i686/libc.so.6", O_RDONLY)   = 3
read(3, "\177ELF\1\1\1\0\0\0\0\0\0\0\0\0\3\0\3\0\1\0\0\0\320]\1"..., 512) = 512
fstat64(3, {st_mode=S_IFREG|0755, st_size=1461208, ...}) = 0
old_mmap(NULL, 1256644, PROT_READ|PROT_EXEC, MAP_PRIVATE, 3, 0) = 0x40056000
old_mmap(0x40182000, 20480, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED, 3, 0x12c000) = 0x40182000
old_mmap(0x40187000, 7364, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x40187000
close(3)                                = 0
mprotect(0x80000000, 327680, PROT_READ|PROT_WRITE) = 0
mprotect(0x80000000, 327680, PROT_READ|PROT_EXEC) = 0
munmap(0x4001a000, 102185)              = 0
brk(0)                                  = 0x80463540
brk(0x80484540)                         = 0x80484540
brk(0)                                  = 0x80484540
brk(0x80485000)                         = 0x80485000
open("/usr/local/qemu-i386", O_RDONLY|O_NONBLOCK|O_LARGEFILE|O_DIRECTORY) = -1 ENOENT (No such file or directory)
open("testclonenonptl", O_RDONLY)       = 3
fstat64(3, {st_mode=S_IFREG|0755, st_size=9503, ...}) = 0
geteuid32()                             = 500
getegid32()                             = 100
lseek(3, 0, SEEK_SET)                   = 0
read(3, "\177ELF\1\1\1\0\0\0\0\0\0\0\0\0\2\0\3\0\1\0\0\0\360\203"..., 128) = 128
mmap2(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x4001a000
lseek(3, 52, SEEK_SET)                  = 52
read(3, "\6\0\0\0004\0\0\0004\200\4\0104\200\4\10\300\0\0\0\300"..., 192) = 192
lseek(3, 244, SEEK_SET)                 = 244
read(3, "/lib/ld-linux.so.2\0", 19)     = 19
open("/lib/ld-linux.so.2", O_RDONLY)    = 4
lseek(4, 0, SEEK_SET)                   = 0
read(4, "\177ELF\1\1\1\0\0\0\0\0\0\0\0\0\3\0\3\0\1\0\0\0\20\f\0"..., 128) = 128
mmap2(NULL, 528384, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x40189000
mprotect(0x40209000, 4096, PROT_NONE)   = 0
munmap(0x4001a000, 4096)                = 0
mmap2(0x8048000, 4096, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0) = 0x8048000
mmap2(0x8049000, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0) = 0x8049000
lseek(4, 52, SEEK_SET)                  = 52
read(4, "\1\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\354s\1\0\354s\1\0\5\0"..., 128) = 128
mmap2(NULL, 33554432, PROT_NONE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x4020a000
mmap2(0x4020a000, 98304, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 4, 0) = 0x4020a000
mmap2(0x40222000, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 4, 0x17) = 0x40222000
close(4)                                = 0
close(4)                                = -1 EBADF (Bad file descriptor)
close(3)                                = 0
getuid32()                              = 500
geteuid32()                             = 500
getgid32()                              = 100
getegid32()                             = 100
rt_sigaction(SIGHUP, {0x800276a0, ~[], SA_RESTORER|SA_SIGINFO, 0x4007faa0}, NULL, 8) = 0
rt_sigaction(SIGINT, {0x800276a0, ~[], SA_RESTORER|SA_SIGINFO, 0x4007faa0}, NULL, 8) = 0
rt_sigaction(SIGQUIT, {0x800276a0, ~[], SA_RESTORER|SA_SIGINFO, 0x4007faa0}, NULL, 8) = 0
rt_sigaction(SIGILL, {0x800276a0, ~[], SA_RESTORER|SA_SIGINFO, 0x4007faa0}, NULL, 8) = 0
rt_sigaction(SIGTRAP, {0x800276a0, ~[], SA_RESTORER|SA_SIGINFO, 0x4007faa0}, NULL, 8) = 0
rt_sigaction(SIGABRT, {0x800276a0, ~[], SA_RESTORER|SA_SIGINFO, 0x4007faa0}, NULL, 8) = 0
rt_sigaction(SIGBUS, {0x800276a0, ~[], SA_RESTORER|SA_SIGINFO, 0x4007faa0}, NULL, 8) = 0
rt_sigaction(SIGFPE, {0x800276a0, ~[], SA_RESTORER|SA_SIGINFO, 0x4007faa0}, NULL, 8) = 0
rt_sigaction(SIGKILL, {0x800276a0, ~[], SA_RESTORER|SA_SIGINFO, 0x4007faa0}, NULL, 8) = -1 EINVAL (Invalid argument)
rt_sigaction(SIGUSR1, {0x800276a0, ~[], SA_RESTORER|SA_SIGINFO, 0x4007faa0}, NULL, 8) = 0
rt_sigaction(SIGSEGV, {0x800276a0, ~[], SA_RESTORER|SA_SIGINFO, 0x4007faa0}, NULL, 8) = 0
rt_sigaction(SIGUSR2, {0x800276a0, ~[], SA_RESTORER|SA_SIGINFO, 0x4007faa0}, NULL, 8) = 0
rt_sigaction(SIGPIPE, {0x800276a0, ~[], SA_RESTORER|SA_SIGINFO, 0x4007faa0}, NULL, 8) = 0
rt_sigaction(SIGALRM, {0x800276a0, ~[], SA_RESTORER|SA_SIGINFO, 0x4007faa0}, NULL, 8) = 0
rt_sigaction(SIGTERM, {0x800276a0, ~[], SA_RESTORER|SA_SIGINFO, 0x4007faa0}, NULL, 8) = 0
rt_sigaction(SIGSTKFLT, {0x800276a0, ~[], SA_RESTORER|SA_SIGINFO, 0x4007faa0}, NULL, 8) = 0
rt_sigaction(SIGCHLD, {0x800276a0, ~[], SA_RESTORER|SA_SIGINFO, 0x4007faa0}, NULL, 8) = 0
rt_sigaction(SIGCONT, {0x800276a0, ~[], SA_RESTORER|SA_SIGINFO, 0x4007faa0}, NULL, 8) = 0
rt_sigaction(SIGSTOP, {0x800276a0, ~[], SA_RESTORER|SA_SIGINFO, 0x4007faa0}, NULL, 8) = -1 EINVAL (Invalid argument)
rt_sigaction(SIGTSTP, {0x800276a0, ~[], SA_RESTORER|SA_SIGINFO, 0x4007faa0}, NULL, 8) = 0
rt_sigaction(SIGTTIN, {0x800276a0, ~[], SA_RESTORER|SA_SIGINFO, 0x4007faa0}, NULL, 8) = 0
rt_sigaction(SIGTTOU, {0x800276a0, ~[], SA_RESTORER|SA_SIGINFO, 0x4007faa0}, NULL, 8) = 0
rt_sigaction(SIGURG, {0x800276a0, ~[], SA_RESTORER|SA_SIGINFO, 0x4007faa0}, NULL, 8) = 0
rt_sigaction(SIGXCPU, {0x800276a0, ~[], SA_RESTORER|SA_SIGINFO, 0x4007faa0}, NULL, 8) = 0
rt_sigaction(SIGXFSZ, {0x800276a0, ~[], SA_RESTORER|SA_SIGINFO, 0x4007faa0}, NULL, 8) = 0
rt_sigaction(SIGVTALRM, {0x800276a0, ~[], SA_RESTORER|SA_SIGINFO, 0x4007faa0}, NULL, 8) = 0
rt_sigaction(SIGPROF, {0x800276a0, ~[], SA_RESTORER|SA_SIGINFO, 0x4007faa0}, NULL, 8) = 0
rt_sigaction(SIGWINCH, {0x800276a0, ~[], SA_RESTORER|SA_SIGINFO, 0x4007faa0}, NULL, 8) = 0
rt_sigaction(SIGIO, {0x800276a0, ~[], SA_RESTORER|SA_SIGINFO, 0x4007faa0}, NULL, 8) = 0
rt_sigaction(SIGPWR, {0x800276a0, ~[], SA_RESTORER|SA_SIGINFO, 0x4007faa0}, NULL, 8) = 0
rt_sigaction(SIGSYS, {0x800276a0, ~[], SA_RESTORER|SA_SIGINFO, 0x4007faa0}, NULL, 8) = 0
rt_sigaction(SIGRTMIN, {0x800276a0, ~[], SA_RESTORER|SA_SIGINFO, 0x4007faa0}, NULL, 8) = 0
rt_sigaction(SIGRT_1, {0x800276a0, ~[], SA_RESTORER|SA_SIGINFO, 0x4007faa0}, NULL, 8) = 0
rt_sigaction(SIGRT_2, {0x800276a0, ~[], SA_RESTORER|SA_SIGINFO, 0x4007faa0}, NULL, 8) = 0
rt_sigaction(SIGRT_3, {0x800276a0, ~[], SA_RESTORER|SA_SIGINFO, 0x4007faa0}, NULL, 8) = 0
rt_sigaction(SIGRT_4, {0x800276a0, ~[], SA_RESTORER|SA_SIGINFO, 0x4007faa0}, NULL, 8) = 0
rt_sigaction(SIGRT_5, {0x800276a0, ~[], SA_RESTORER|SA_SIGINFO, 0x4007faa0}, NULL, 8) = 0
rt_sigaction(SIGRT_6, {0x800276a0, ~[], SA_RESTORER|SA_SIGINFO, 0x4007faa0}, NULL, 8) = 0
rt_sigaction(SIGRT_7, {0x800276a0, ~[], SA_RESTORER|SA_SIGINFO, 0x4007faa0}, NULL, 8) = 0
rt_sigaction(SIGRT_8, {0x800276a0, ~[], SA_RESTORER|SA_SIGINFO, 0x4007faa0}, NULL, 8) = 0
rt_sigaction(SIGRT_9, {0x800276a0, ~[], SA_RESTORER|SA_SIGINFO, 0x4007faa0}, NULL, 8) = 0
rt_sigaction(SIGRT_10, {0x800276a0, ~[], SA_RESTORER|SA_SIGINFO, 0x4007faa0}, NULL, 8) = 0
rt_sigaction(SIGRT_11, {0x800276a0, ~[], SA_RESTORER|SA_SIGINFO, 0x4007faa0}, NULL, 8) = 0
rt_sigaction(SIGRT_12, {0x800276a0, ~[], SA_RESTORER|SA_SIGINFO, 0x4007faa0}, NULL, 8) = 0
rt_sigaction(SIGRT_13, {0x800276a0, ~[], SA_RESTORER|SA_SIGINFO, 0x4007faa0}, NULL, 8) = 0
rt_sigaction(SIGRT_14, {0x800276a0, ~[], SA_RESTORER|SA_SIGINFO, 0x4007faa0}, NULL, 8) = 0
rt_sigaction(SIGRT_15, {0x800276a0, ~[], SA_RESTORER|SA_SIGINFO, 0x4007faa0}, NULL, 8) = 0
rt_sigaction(SIGRT_16, {0x800276a0, ~[], SA_RESTORER|SA_SIGINFO, 0x4007faa0}, NULL, 8) = 0
rt_sigaction(SIGRT_17, {0x800276a0, ~[], SA_RESTORER|SA_SIGINFO, 0x4007faa0}, NULL, 8) = 0
rt_sigaction(SIGRT_18, {0x800276a0, ~[], SA_RESTORER|SA_SIGINFO, 0x4007faa0}, NULL, 8) = 0
rt_sigaction(SIGRT_19, {0x800276a0, ~[], SA_RESTORER|SA_SIGINFO, 0x4007faa0}, NULL, 8) = 0
rt_sigaction(SIGRT_20, {0x800276a0, ~[], SA_RESTORER|SA_SIGINFO, 0x4007faa0}, NULL, 8) = 0
rt_sigaction(SIGRT_21, {0x800276a0, ~[], SA_RESTORER|SA_SIGINFO, 0x4007faa0}, NULL, 8) = 0
rt_sigaction(SIGRT_22, {0x800276a0, ~[], SA_RESTORER|SA_SIGINFO, 0x4007faa0}, NULL, 8) = 0
rt_sigaction(SIGRT_23, {0x800276a0, ~[], SA_RESTORER|SA_SIGINFO, 0x4007faa0}, NULL, 8) = 0
rt_sigaction(SIGRT_24, {0x800276a0, ~[], SA_RESTORER|SA_SIGINFO, 0x4007faa0}, NULL, 8) = 0
rt_sigaction(SIGRT_25, {0x800276a0, ~[], SA_RESTORER|SA_SIGINFO, 0x4007faa0}, NULL, 8) = 0
rt_sigaction(SIGRT_26, {0x800276a0, ~[], SA_RESTORER|SA_SIGINFO, 0x4007faa0}, NULL, 8) = 0
rt_sigaction(SIGRT_27, {0x800276a0, ~[], SA_RESTORER|SA_SIGINFO, 0x4007faa0}, NULL, 8) = 0
rt_sigaction(SIGRT_28, {0x800276a0, ~[], SA_RESTORER|SA_SIGINFO, 0x4007faa0}, NULL, 8) = 0
rt_sigaction(SIGRT_29, {0x800276a0, ~[], SA_RESTORER|SA_SIGINFO, 0x4007faa0}, NULL, 8) = 0
rt_sigaction(SIGRT_30, {0x800276a0, ~[], SA_RESTORER|SA_SIGINFO, 0x4007faa0}, NULL, 8) = 0
rt_sigaction(SIGRT_31, {0x800276a0, ~[], SA_RESTORER|SA_SIGINFO, 0x4007faa0}, NULL, 8) = 0
rt_sigaction(SIGRT_32, {0x800276a0, ~[], SA_RESTORER|SA_SIGINFO, 0x4007faa0}, NULL, 8) = 0
uname({sys="Linux", node="linux", ...}) = 0
mmap2(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x4001a000
open("/etc/ld.so.preload", O_RDONLY)    = -1 ENOENT (No such file or directory)
open("/etc/ld.so.cache", O_RDONLY)      = 3
fstat64(3, {st_mode=S_IFREG|0644, st_size=102185, ...}) = 0
mmap2(NULL, 102400, PROT_READ, MAP_PRIVATE, 3, 0) = 0x4220a000
close(3)                                = 0
open("/lib/i686/libc.so.6", O_RDONLY)   = 3
mprotect(0x40207000, 4096, PROT_READ|PROT_WRITE) = 0
read(3, "\177ELF\1\1\1\0\0\0\0\0\0\0\0\0\3\0\3\0\1\0\0\0\320]\1"..., 512) = 512
fstat64(3, {st_mode=S_IFREG|0755, st_size=1461208, ...}) = 0
mmap2(NULL, 1257472, PROT_READ|PROT_EXEC, MAP_PRIVATE, 3, 0) = 0x42223000
mmap2(0x4234f000, 20480, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED, 3, 0x12c) = 0x4234f000
mmap2(0x42354000, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x42354000
close(3)                                = 0
munmap(0x4220a000, 102400)              = 0
mmap2(0x804a000, 135168, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, 0, 0) = 0x804a000
mmap2(0x806b000, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, 0, 0) = 0x806b000
clone(Process 2751 attached
child_stack=0x80479dd4, flags=CLONE_VM|CLONE_FS|CLONE_FILES|SIGCHLD) = 2751
[pid  2750] clone(Process 2752 attached
child_stack=0x8047c144, flags=CLONE_VM|CLONE_FS|CLONE_FILES|SIGCHLD) = 2752
[pid  2750] waitpid(2751, Process 2750 suspended
 <unfinished ...>
[pid  2752] --- SIGSTOP (Stopped (signal)) @ 0 (0) ---
[pid  2752] write(1, "thread2: 0 hello2\n", 18thread2: 0 hello2
) = 18
[pid  2752] nanosleep({0, 120000000},  <unfinished ...>
[pid  2751] --- SIGSTOP (Stopped (signal)) @ 0 (0) ---
[pid  2751] write(1, "thread1: 0 hello1\n", 18thread1: 0 hello1
) = 18
[pid  2751] nanosleep({0, 100000000}, {0, 0}) = 0
[pid  2751] write(1, "thread1: 1 hello1\n", 18thread1: 1 hello1
) = 18
[pid  2751] nanosleep({0, 100000000},  <unfinished ...>
[pid  2752] <... nanosleep resumed> {0, 0}) = 0
[pid  2752] write(1, "thread2: 1 hello2\n", 18thread2: 1 hello2
) = 18
[pid  2752] nanosleep({0, 120000000},  <unfinished ...>
[pid  2751] <... nanosleep resumed> {0, 0}) = 0
[pid  2751] write(1, "thread1: 2 hello1\n", 18thread1: 2 hello1
) = 18
[pid  2751] nanosleep({0, 100000000},  <unfinished ...>
[pid  2752] <... nanosleep resumed> {0, 0}) = 0
[pid  2752] write(1, "thread2: 2 hello2\n", 18thread2: 2 hello2
) = 18
[pid  2752] nanosleep({0, 120000000},  <unfinished ...>
[pid  2751] <... nanosleep resumed> {0, 0}) = 0
[pid  2751] write(1, "thread1: 3 hello1\n", 18thread1: 3 hello1
) = 18
[pid  2751] nanosleep({0, 100000000},  <unfinished ...>
[pid  2752] <... nanosleep resumed> {0, 0}) = 0
[pid  2752] write(1, "thread2: 3 hello2\n", 18thread2: 3 hello2
) = 18
[pid  2752] nanosleep({0, 120000000},  <unfinished ...>
[pid  2751] <... nanosleep resumed> {0, 0}) = 0
[pid  2751] write(1, "thread1: 4 hello1\n", 18thread1: 4 hello1
) = 18
[pid  2751] nanosleep({0, 100000000},  <unfinished ...>
[pid  2752] <... nanosleep resumed> {0, 0}) = 0
[pid  2752] write(1, "thread2: 4 hello2\n", 18thread2: 4 hello2
) = 18
[pid  2752] nanosleep({0, 120000000},  <unfinished ...>
[pid  2751] <... nanosleep resumed> {0, 0}) = 0
[pid  2751] write(1, "thread1: 5 hello1\n", 18thread1: 5 hello1
) = 18
[pid  2751] nanosleep({0, 100000000},  <unfinished ...>
[pid  2752] <... nanosleep resumed> {0, 0}) = 0
[pid  2751] <... nanosleep resumed> {0, 0}) = 0
[pid  2752] write(1, "thread2: 5 hello2\n", 18 <unfinished ...>
[pid  2751] write(1, "thread1: 6 hello1\n", 18thread2: 5 hello2
 <unfinished ...>
[pid  2752] <... write resumed> )       = 18
thread1: 6 hello1
[pid  2751] <... write resumed> )       = 18
[pid  2752] nanosleep({0, 120000000},  <unfinished ...>
[pid  2751] nanosleep({0, 100000000}, {0, 0}) = 0
[pid  2751] write(1, "thread1: 7 hello1\n", 18thread1: 7 hello1
) = 18
[pid  2751] nanosleep({0, 100000000},  <unfinished ...>
[pid  2752] <... nanosleep resumed> {0, 0}) = 0
[pid  2752] write(1, "thread2: 6 hello2\n", 18thread2: 6 hello2
) = 18
[pid  2752] nanosleep({0, 120000000},  <unfinished ...>
[pid  2751] <... nanosleep resumed> {0, 0}) = 0
[pid  2751] write(1, "thread1: 8 hello1\n", 18thread1: 8 hello1
) = 18
[pid  2751] nanosleep({0, 100000000},  <unfinished ...>
[pid  2752] <... nanosleep resumed> {0, 0}) = 0
[pid  2752] write(1, "thread2: 7 hello2\n", 18thread2: 7 hello2
) = 18
[pid  2752] nanosleep({0, 120000000},  <unfinished ...>
[pid  2751] <... nanosleep resumed> {0, 0}) = 0
[pid  2751] write(1, "thread1: 9 hello1\n", 18thread1: 9 hello1
) = 18
[pid  2751] nanosleep({0, 100000000},  <unfinished ...>
[pid  2752] <... nanosleep resumed> {0, 0}) = 0
[pid  2752] write(1, "thread2: 8 hello2\n", 18thread2: 8 hello2
) = 18
[pid  2752] nanosleep({0, 120000000},  <unfinished ...>
[pid  2751] <... nanosleep resumed> {0, 0}) = 0
[pid  2751] exit_group(0)               = ?
Process 2750 resumed
Process 2751 detached
[pid  2750] <... waitpid resumed> [WIFEXITED(s) && WEXITSTATUS(s) == 0], 0) = 2751
[pid  2750] --- SIGCHLD (Child exited) @ 0 (0) ---
[pid  2750] rt_sigreturn(0xabf)         = 2751
[pid  2750] waitpid(2752, Process 2750 suspended
 <unfinished ...>
[pid  2752] <... nanosleep resumed> {0, 0}) = 0
[pid  2752] write(1, "thread2: 9 hello2\n", 18thread2: 9 hello2
) = 18
[pid  2752] nanosleep({0, 120000000}, {0, 0}) = 0
[pid  2752] write(1, "thread2: 10 hello2\n", 19thread2: 10 hello2
) = 19
[pid  2752] nanosleep({0, 120000000}, {0, 0}) = 0
[pid  2752] write(1, "thread2: 11 hello2\n", 19thread2: 11 hello2
) = 19
[pid  2752] nanosleep({0, 120000000}, {0, 0}) = 0
[pid  2752] write(1, "thread2: 12 hello2\n", 19thread2: 12 hello2
) = 19
[pid  2752] nanosleep({0, 120000000}, {0, 0}) = 0
[pid  2752] write(1, "thread2: 13 hello2\n", 19thread2: 13 hello2
) = 19
[pid  2752] nanosleep({0, 120000000}, {0, 0}) = 0
[pid  2752] write(1, "thread2: 14 hello2\n", 19thread2: 14 hello2
) = 19
[pid  2752] nanosleep({0, 120000000}, {0, 0}) = 0
[pid  2752] write(1, "thread2: 15 hello2\n", 19thread2: 15 hello2
) = 19
[pid  2752] nanosleep({0, 120000000}, {0, 0}) = 0
[pid  2752] write(1, "thread2: 16 hello2\n", 19thread2: 16 hello2
) = 19
[pid  2752] nanosleep({0, 120000000}, {0, 0}) = 0
[pid  2752] write(1, "thread2: 17 hello2\n", 19thread2: 17 hello2
) = 19
[pid  2752] nanosleep({0, 120000000}, {0, 0}) = 0
[pid  2752] write(1, "thread2: 18 hello2\n", 19thread2: 18 hello2
) = 19
[pid  2752] nanosleep({0, 120000000}, {0, 0}) = 0
[pid  2752] write(1, "thread2: 19 hello2\n", 19thread2: 19 hello2
) = 19
[pid  2752] nanosleep({0, 120000000}, {0, 0}) = 0
[pid  2752] exit_group(0)               = ?
Process 2750 resumed
Process 2752 detached
<... waitpid resumed> [WIFEXITED(s) && WEXITSTATUS(s) == 0], 0) = 2752
--- SIGCHLD (Child exited) @ 0 (0) ---
rt_sigreturn(0xac0)                     = 2752
fstat64(1, {st_mode=S_IFCHR|0600, st_rdev=makedev(136, 1), ...}) = 0
mmap2(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x4001b000
write(1, "status1=0x0\n", 12status1=0x0
)           = 12
write(1, "status2=0x0\n", 12status2=0x0
)           = 12
write(1, "End of clone test.\n", 19End of clone test.
)    = 19
munmap(0x4001b000, 4096)                = 0
exit_group(0)                           = ?
didi2@linux:~>