# $Id: Kconfig,v 1.7.2.2 2004/11/13 16:32:05 mikpe Exp $ # Performance-monitoring counters driver configuration # menu "Performance-monitoring counters support" config PERFCTR tristate "Performance monitoring counters support" help This driver provides access to the performance-monitoring counter registers available in some (but not all) modern processors. These special-purpose registers can be programmed to count low-level performance-related events which occur during program execution, such as cache misses, pipeline stalls, etc. You can safely say Y here, even if you intend to run the kernel on a processor without performance-monitoring counters. You can also say M here to compile the driver as a module; the module will be called `perfctr'. config KPERFCTR bool depends on PERFCTR default y config PERFCTR_DEBUG bool "Additional internal consistency checks" depends on PERFCTR help This option enables additional internal consistency checking in the perfctr driver. The scope of these checks is unspecified and may vary between different versions of the driver. Enabling this option will reduce performance, so say N unless you are debugging the driver. config PERFCTR_INIT_TESTS bool "Init-time hardware tests" depends on PERFCTR help This option makes the driver perform additional hardware tests during initialisation, and log their results in the kernel's message buffer. For most supported processors, these tests simply measure the runtime overheads of performance counter operations. If you have a less well-known processor (one not listed in the etc/costs/ directory in the user-space package), you should enable this option and email the results to the perfctr developers. If unsure, say N. config PERFCTR_VIRTUAL bool "Virtual performance counters support" depends on PERFCTR help The processor's performance-monitoring counters are special-purpose global registers. This option adds support for virtual per-process performance-monitoring counters which only run when the process to which they belong is executing. This improves the accuracy of performance measurements by reducing "noise" from other processes. Say Y. config PERFCTR_GLOBAL bool "Global performance counters support" depends on PERFCTR help This option adds driver support for global-mode (system-wide) performance-monitoring counters. In this mode, the driver allows each performance-monitoring counter on each processor to be controlled and read. The driver provides a sampling timer to maintain 64-bit accumulated event counts. Global-mode performance counters cannot be used if some process is currently using virtual-mode performance counters, and vice versa. Say Y. config PERFCTR_INTERRUPT_SUPPORT prompt "Performance counter overflow interrupt support" if PPC bool depends on PERFCTR default y if X86_LOCAL_APIC config PERFCTR_CPUS_FORBIDDEN_MASK bool depends on PERFCTR default y if X86 && SMP endmenu