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HP-UX Reference > NNSTREVENT(5)Tunable Kernel ParametersHP-UX 11i Version 2: December 2007 Update |
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NAMENSTREVENT — maximum number of outstanding STREAMS bufcalls DESCRIPTIONThis tunable limits the maximum number of outstanding bufcalls that are allowed to exist in the system at any given time. This tunable is intended to protect the system against resource overload caused by the combination of modules running in all streams issuing an excessive number of bufcalls. The value selected should be equal to or greater than the combined maximum number of bufcalls that can be reasonably expected during normal operation from all streams on the system. bufcalls are used by STREAMS modules in low memory situations. What Are the Side Effects of Raising the Value of This Tunable?If too big a number is chosen, the STREAMS subsystem preallocates more memory for internal data structures than may be needed. This reduces the amount of memory available to applications and the system. When Should the Value of This Tunable Be Lowered?If the tunable is increased for a particular STREAMS module/driver, this tunable can be lowered when that STREAMS module/driver is removed. It should be returned to its previous value. However, HP does not recommend a value lower than the default value. 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. |
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