RFR [XS] : 8204598 : add more thread-related system settings info to hs_error file on Linux

[Baesken, Matthias]

Hi could you please review  this small Linux related change ?

In linux os::print_os_info ,  I  print additional  info about a number of system parameters influencing thread creation on Linux.

We noticed the influence of these parameters when looking into an application creating over 10.000 threads on Linux at the same time; there we got an OOM : unable to create new native thread
which was caused by a failing pthread_create (error EAGAIN) .

The machine had plenty of memory, so we looked into various kernel params and in the end noticed that /proc/sys/kernel/pid_max was too low.
The other added parameters "threads-max" and "max_map_count" are also known to be related to problems when running with high thread numbers, so I add them too .



Webrev :

http://cr.openjdk.java.net/~mbaesken/webrevs/8204598/

Bug :

https://bugs.openjdk.java.net/browse/JDK-8204598


Thanks, Matthias