<div dir="ltr">Hi Dmitry, thanks for replying:<div><br></div><div>I'm not using the -l1 option. I see this behavior on both Ubuntu 12.10/x86-64 and CentOS 6.3/x86-64.</div><div><br></div><div>If I kill the target process, it always works correctly. The problem is if I use CTRL-C to detach from the target process. Eventually I managed to get it to produce the statistical output, as shown below. I used it for a few hours, then left the terminal open over night, and the next day it was not printing the output again. So it looks like this:</div>
<div><br></div><div>$ sudo strace -p 31457 -c<br></div><div><div>Process 31457 attached - interrupt to quit</div><div>^CProcess 31457 detached</div></div><div>$ sudo strace -p 31457 -c</div><div><div><div>Process 31457 attached - interrupt to quit</div>
<div>^CProcess 31457 detached</div></div></div><div>$ sudo strace -c -p 31457 <-- NOTE CHANGING COMMAND LINE ARGS ORDER<br></div><div>Process 31457 attached - interrupt to quit<br></div><div><div>^CProcess 31457 detached</div>
<div>% time seconds usecs/call calls errors syscall</div><div>------ ----------- ----------- --------- --------- ----------------</div><div> 75.38 0.047831 66 730 poll</div><div> 24.62 0.015622 20 793 sendto</div>
<div> 0.00 0.000000 0 39 ioctl</div><div> 0.00 0.000000 0 39 select</div><div> 0.00 0.000000 0 769 recvfrom</div><div> 0.00 0.000000 0 107 29 futex</div>
<div>------ ----------- ----------- --------- --------- ----------------</div><div>100.00 0.063453 2477 29 total</div></div><div><br></div><div>After this it worked for a while *regardless* of the order of the command line arguments. And then after 24 hours, it doesn't work again at all, *regardless* of command line argument order. So I just can't reproduce it reliably.</div>
<div><br></div><div>- I thought it might be because there were no system calls in the target process - that the target was blocked in one call, such as "select", but that's not the case.</div><div>- I tried sending SIGINT and SIGTERM to the strace process from another terminal, both signals cause the process to simply exit the same as if I pressed CTRL-C, i.e. no data printed.</div>
<div><br></div><div>- Bud</div><div><div><br></div></div><div><br></div><div><br></div></div><div class="gmail_extra"><br><br><div class="gmail_quote">On Thu, May 8, 2014 at 11:11 PM, Dmitry V. Levin <span dir="ltr"><<a href="mailto:ldv@altlinux.org" target="_blank">ldv@altlinux.org</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Hi,<br>
<div class=""><br>
On Wed, May 07, 2014 at 04:54:40PM +0200, Bud Millwood wrote:<br>
> Hi all, I'm not on this list but I'll keep an eye out for a response<br>
> to this message.<br>
><br>
> In the past I noticed that if I ran "strace -c" against a process, I<br>
> could press CTRL-C and strace would print out the statistics it had<br>
> collected so far, then exit. It now seems to just exit without<br>
> printing any of the statistics.<br>
<br>
</div>Strange, it works for me, both in simple and in -p mode.<br>
For example:<br>
<br>
$ strace -c cat & sleep 1 && kill -INT $!<br>
[1] 19981<br>
Process 19985 detached<br>
% time seconds usecs/call calls errors syscall<br>
------ ----------- ----------- --------- --------- ----------------<br>
$ 27.65 0.000060 8 8 mmap<br>
14.29 0.000031 8 4 mprotect<br>
10.14 0.000022 6 4 fstat<br>
7.83 0.000017 9 2 open<br>
7.83 0.000017 4 4 brk<br>
6.45 0.000014 7 2 1 read<br>
5.53 0.000012 12 1 1 access<br>
5.07 0.000011 6 2 fadvise64<br>
4.61 0.000010 5 2 close<br>
4.61 0.000010 10 1 munmap<br>
3.69 0.000008 8 1 execve<br>
2.30 0.000005 5 1 arch_prctl<br>
------ ----------- ----------- --------- --------- ----------------<br>
100.00 0.000217 32 2 total<br>
[1]+ Done strace -c cat<br>
<br>
$ sleep 2 && sleep 2 & sleep 1; strace -cp $! & sleep 2 && kill -INT $!<br>
[1] 19986<br>
[2] 19989<br>
Process 19986 attached<br>
Process 19986 detached<br>
% time seconds usecs/call calls errors syscall<br>
------ ----------- ----------- --------- --------- ----------------<br>
$ 80.77 0.000710 355 2 1 wait4<br>
15.81 0.000139 139 1 clone<br>
2.62 0.000023 4 6 rt_sigprocmask<br>
0.46 0.000004 2 2 rt_sigaction<br>
0.34 0.000003 3 1 rt_sigreturn<br>
------ ----------- ----------- --------- --------- ----------------<br>
100.00 0.000879 12 1 total<br>
[2]+ Done strace -cp $!<br>
[1]- Done sleep 2 && sleep 2<br>
<br>
You aren't using -I1 option, are you?<br>
<span class="HOEnZb"><font color="#888888"><br>
<br>
--<br>
ldv<br>
</font></span></blockquote></div><br></div>