tree 2bad2c3a2cc68a35fb93d986a49bf543efcd0156
parent 6795b85c6a4f690e61e7be31aa150d945c723fb5
author Anton Blanchard <anton@samba.org> 1256583029 +0000
committer Paul Mackerras <paulus@samba.org> 1256706784 +1100

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>