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3rd Party Application encountering overflow error and incorrect operation due to change in values of Solaris kernel variables kernelheap and ekernelheap (Doc ID 2431101.1)

Last updated on SEPTEMBER 18, 2019

Applies to:

Solaris Operating System - Version 11.3 and later
Information in this document applies to any platform.


A 3rd party kernel module uses the difference between two kernel variables ‘kernelheap’ and ‘ekernelheap’ doing something similar to:

size = ekernelheap-kernelheap

Which appears to work until it runs into problems on an T8 or M8 server running later Solaris 11.3 SRUs This may manifest itself as an overflow error, or a smaller or possibly negative value.

Customer or Vendor’s research may attempt to relate this to amount of system memory or a specific SRU update. If studious they may note that the issue is not seen with older systems such as the M6/M7/T7  even if they have similar amounts of physical memory.


If there is any change, it will be either a change in the 3rd party kernel module or the physical hardware.

This is due to the how these two variables are set.

The kernelheap which is the start of a virtual address space, rounded up from the end of the previous section of address space. Please compare:


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