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authorAnton Blanchard <anton@samba.org>2009-10-26 18:50:29 +0000
committerPaul Mackerras <paulus@samba.org>2009-10-28 16:13:04 +1100
commitc8cd093a6e9f96ea6b871576fd4e46d7c818bb89 (patch)
tree2bad2c3a2cc68a35fb93d986a49bf543efcd0156 /arch/powerpc/Kconfig.debug
parent6795b85c6a4f690e61e7be31aa150d945c723fb5 (diff)
downloadlinux-c8cd093a6e9f96ea6b871576fd4e46d7c818bb89.tar.bz2
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 <anton@samba.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
Diffstat (limited to 'arch/powerpc/Kconfig.debug')
-rw-r--r--arch/powerpc/Kconfig.debug2
1 files changed, 1 insertions, 1 deletions
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