tracing/function-graph: x86_64 stack allocation cleanup

Only 24 bytes needs to be reserved on the stack for the function graph
tracer on x86_64.

Signed-off-by: Jiri Olsa <jolsa@redhat.com>
LKML-Reference: <20090729085837.GB4998@jolsa.lab.eng.brq.redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
index c251be7451079ac9150033b5987f6259902328b0..d59fe323807ed5ebf521909574fe022302653456 100644 (file)
--- a/arch/x86/kernel/entry_64.S
+++ b/arch/x86/kernel/entry_64.S
@@ -146,7 +146,7 @@ ENTRY(ftrace_graph_caller)
 END(ftrace_graph_caller)
 
 GLOBAL(return_to_handler)
-       subq  $80, %rsp
+       subq  $24, %rsp
 
        /* Save the return values */
        movq %rax, (%rsp)
@@ -155,10 +155,10 @@ GLOBAL(return_to_handler)
 
        call ftrace_return_to_handler
 
-       movq %rax, 72(%rsp)
+       movq %rax, 16(%rsp)
        movq 8(%rsp), %rdx
        movq (%rsp), %rax
-       addq $72, %rsp
+       addq $16, %rsp
        retq
 #endif