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| author | Anton Blanchard <anton@samba.org> | 2009-10-26 18:50:29 +0000 |
|---|---|---|
| committer | Paul Mackerras <paulus@samba.org> | 2009-10-28 16:13:04 +1100 |
| commit | c8cd093a6e9f96ea6b871576fd4e46d7c818bb89 (patch) | |
| tree | 2bad2c3a2cc68a35fb93d986a49bf543efcd0156 /arch/powerpc/Kconfig.debug | |
| parent | 6795b85c6a4f690e61e7be31aa150d945c723fb5 (diff) | |
| download | linux-c8cd093a6e9f96ea6b871576fd4e46d7c818bb89.tar.gz linux-c8cd093a6e9f96ea6b871576fd4e46d7c818bb89.tar.bz2 linux-c8cd093a6e9f96ea6b871576fd4e46d7c818bb89.zip | |
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.debug | 2 |
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 |