rt_sigaction have many unfinished ...

[Alexandre Guillaume]

Hello,

OS: Ubuntu 12.04 64Bits

After an private exchange on Apache Mailing, I post my problem on the Ubuntu list.

Apache crash randomly and returning Error 500 (Premature end of script headers).

I was ubuntu 10.04 and I never problems (Apache and PHP are compiled, I do not use APT).
I upgraded to Ubuntu 12.04 and Apache randomly returns errors 500 when I load a PHP page.

Here is a STRACE when it does not work:
http://pastebin.com/mNw9v4SR

Before migrating from 10.04 to 12.04 I've compiled PHP 5.2.16.
After the migration I've have compiled 5.2.17.

If I use PHP 5.2.17 Apache have random errors.
If I use PHP 5.2.16 Apache have never error.

In summary, all new compilations give random errors (PHP 5.2.X, 5.3.X PHP, PHP 5.4.x).

In de STRACE when Apache return a 500 I see many "unfinished":

21885 <... clone resumed> child_stack=0, flags=CLONE_CHILD_CLEARTID|CLONE_CHILD_SETTID|SIGCHLD, child_tidptr=0x7f53c53c39d0) = 25293
25293 set_robust_list(0x7f53c53c39e0, 0x18 <unfinished ...>
25293 <... set_robust_list resumed> )   = 0
25293 rt_sigaction(SIGHUP, {0x48a470, [], SA_RESTORER|SA_INTERRUPT, 0x7f53c4315cb0},  <unfinished ...>
25293 <... rt_sigaction resumed> {0x489cd0, [HUP USR1], SA_RESTORER, 0x7f53c4315cb0}, 8) = 0
25293 rt_sigaction(SIGTERM, {0x48a470, [], SA_RESTORER|SA_INTERRUPT, 0x7f53c4315cb0},  <unfinished ...>
25293 <... rt_sigaction resumed> {0x489ca0, [], SA_RESTORER, 0x7f53c4315cb0}, 8) = 0
25293 rt_sigaction(SIGUSR1, {0x489ec0, [], SA_RESTORER|SA_INTERRUPT, 0x7f53c4315cb0},  <unfinished ...>
25293 <... rt_sigaction resumed> {0x489cd0, [HUP USR1], SA_RESTORER, 0x7f53c4315cb0}, 8) = 0

I tried to start with a 2.6 kernel and recompile PHP 5.2.17 but I always random errors.
Errors appear even on basic scripts as PHPMyAdmin.

syslog/kernel log does not return error.
Compil again PHP & Apache & MySQL does not fix the problem.


Do you have any idea, what I can check to understand where these errors "unfinished ...".

Bests Regards,
Alexandre