Re: [PATCH v1 06/22] powerpc/ftrace: Inline ftrace_modify_code()

From: Naveen N. Rao
Date: Mon Apr 18 2022 - 02:08:34 EST


Christophe Leroy wrote:
Inlining ftrace_modify_code(), it increases a bit the
size of ftrace code but brings 5% improvment on ftrace
activation.

Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
---
arch/powerpc/kernel/trace/ftrace.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/powerpc/kernel/trace/ftrace.c b/arch/powerpc/kernel/trace/ftrace.c
index 41c45b9c7f39..98e82fa4980f 100644
--- a/arch/powerpc/kernel/trace/ftrace.c
+++ b/arch/powerpc/kernel/trace/ftrace.c
@@ -53,7 +53,7 @@ ftrace_call_replace(unsigned long ip, unsigned long addr, int link)
return op;
}

-static int
+static inline int
ftrace_modify_code(unsigned long ip, ppc_inst_t old, ppc_inst_t new)
{
ppc_inst_t replaced;

I thought gcc was free to inline functions without the need for 'inline'. Don't you see this being inlined otherwise?

On the flip side, don't we need __always_inline if we want to force inlining?


- Naveen