|
|
HP-UX Reference > Mmaxrsessiz(5)Tunable Kernel ParametersItanium(R)-Based System Only HP-UX 11i Version 2: December 2007 Update |
|
NAMEmaxrsessiz, maxrsessiz_64bit — maximum size (in bytes) of the RSE stack for any user process on the Itanium-based platform DESCRIPTIONItanium-based systems utilize a per-process register stack in main memory (for more information see the Intel IA-64 Architecture Software Developer's Manual, Volume 2, Chapter 6). This stack moves registers between the physical registers and main memory and is maintained by the Register Stack Engine (RSE). maxrsessiz determines the size of this stack. When Should the Value of This Tunable Be Raised?maxrsessiz should be raised if user processes are being terminated with the error SIGBUS due to overflow of the RSE stack. What Are the Side Effects of Raising the Value?User processes will dedicate more virtual memory to the RSE stack. This will result in less virtual memory being available for data allocation. When Should the Value of This Tunable Be Lowered?This tunable should be lowered only if swap space is at a premium on the system, since virtual memory for the RSE stack still requires matching swap reservation or allocation. Serious consideration should be given if maxrsessiz is being lowered below the default as this may cause unexpected failures of user applications on RSE stack overflow. This tunable is best left unchanged without complete and detailed knowledge of the RSE stack usage of the machine workload. WARNINGSAll HP-UX kernel tunable parameters are release specific. This parameter may be removed or have its meaning changed in future releases of HP-UX. Installation of optional kernel software, from HP or other vendors, may cause changes to tunable parameter values. After installation, some tunable parameters may no longer be at the default or recommended values. For information about the effects of installation on tunable values, consult the documentation for the kernel software being installed. For information about optional kernel software that was factory installed on your system, see HP-UX Release Notes at http://docs.hp.com. |
|