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My department is considering moving to RHEL5 from RHEL4 but we've hit a problem. We have some software that executes a bunch of system calls in succession and we've noticed that it takes much, much longer on RHEL5. The scripts are written in bash shell but we're also seeing the problem in C shell, Perl, and Groovy. An example:

foreach run (`seq 1 1000`)
  echo `expr 1 - 1` >& /dev/null

This script takes .99s to run on a RHEL4 machine but 13.35s to run on an identical RHEL5 machine.

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Have you profiled it to see where the bottleneck is? – symcbean Aug 20 '13 at 16:16
You really should consider just skipping RHEL5 and going straight to RHEL6. EL6 is not exactly brand new. Who knows, your issue may be solved in EL6. – Dan Pritts Aug 20 '13 at 16:27
RH6 fixes some serious performance problems we have been having in NFS. – mdpc Aug 20 '13 at 17:51
@symcbean No haven't profiled it yet and not familiar with how to do that. Link to more info? – balor123 Aug 20 '13 at 19:56

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