From c8cd093a6e9f96ea6b871576fd4e46d7c818bb89 Mon Sep 17 00:00:00 2001 From: Anton Blanchard Date: Mon, 26 Oct 2009 18:50:29 +0000 Subject: powerpc: tracing: Add hypervisor call tracepoints Add hcall_entry and hcall_exit tracepoints. This replaces the inline assembly HCALL_STATS code and converts it to use the new tracepoints. To keep the disabled case as quick as possible, we embed a status word in the TOC so we can get at it with a single load. By doing so we keep the overhead at a minimum. Time taken for a null hcall: No tracepoint code: 135.79 cycles Disabled tracepoints: 137.95 cycles For reference, before this patch enabling HCALL_STATS resulted in a null hcall of 201.44 cycles! Signed-off-by: Anton Blanchard Signed-off-by: Paul Mackerras --- arch/powerpc/Kconfig.debug | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/powerpc/Kconfig.debug') diff --git a/arch/powerpc/Kconfig.debug b/arch/powerpc/Kconfig.debug index 3b1005185390..bf3382f1904d 100644 --- a/arch/powerpc/Kconfig.debug +++ b/arch/powerpc/Kconfig.debug @@ -46,7 +46,7 @@ config DEBUG_STACK_USAGE config HCALL_STATS bool "Hypervisor call instrumentation" - depends on PPC_PSERIES && DEBUG_FS + depends on PPC_PSERIES && DEBUG_FS && TRACEPOINTS help Adds code to keep track of the number of hypervisor calls made and the amount of time spent in hypervisor calls. Wall time spent in -- cgit v1.2.1