Patch Management User Guide for HP-UX 11.x Systems (5900-3011, March 2013)

For example, the Other Dependencies section for PHKL_28766 shows that PHKL_21549
is needed only if you want a specific performance improvement. If not, you do not need to
download the listed patch.
Other Dependencies
PHKL_21549 is required when using the gang scheduler.
Without PHKL_21549, the gang scheduler exhibits unacceptable
perfomance after this patch is installed.
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