Using small pages for allocating large memory areas can lead to bad performance (Doc ID 1633730.1)

Last updated on JULY 29, 2016

Applies to:

Solaris Operating System - Version 11 to 11.3 [Release 11.0]
Solaris Operating System - Version 10 10/09 U8 to 10 1/13 U11 [Release 10.0]
Information in this document applies to any platform.

Symptoms

This issue can result in various symptoms:

  1. The commands "prstat -a", ps and pmap need a longer time to complete; they do not provide an output within a second.
  2. The daemons rcapd and zstatd are running for a longer time and produce a  higher CPU usage as seen in prstat or CPU sys as seen in "prstat -m".
  3. The CPU sys percentage shown by vmstat, mpstat and "prstat -m" is increased.
  4. ps prints the output for several processes, then stops for a while (freezes) before it continues printing the rest of the processes.

Changes

Small pages (as 8 KB on SPARC or 4 KB on x86/x64) can be used for memory allocations by the processes. This can be configured system-wide via the following /etc/system parameters:

Note that the mapping of text (executable code) will not change.

Cause

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