[PATCH 2/2] arm: add optimized inlining

From: Stephen Boyd
Date: Wed Nov 24 2010 - 18:57:26 EST


This patch is inspired by 60a3cdd (x86: add optimized inlining,
2008-03-03). GCC is currently being forced to inline whatever
functions are marked as inline (due to the #define of inline to
the gcc attribute always_inline). The 4.x series of GCC has a
rewritten inlining algorithm which should be good enough for the
kernel's purposes. Enabling this option will allow GCC to decide
when to inline a function marked as inline. Since it's opt-in and
doesn't affect functions marked as always_inline there shouldn't
be much harm in allowing people to enable this. If there is, we
should find the affected functions and mark them as always_inline.

text data bss dec hex filename
5987182 246104 926696 7159982 6d40ae vmlinux.orig
5794190 246104 926744 6967038 6a4efe vmlinux.new

It reduces the text section of my kernel by 3.3%, which is pretty
nice.

Signed-off-by: Stephen Boyd <sboyd@xxxxxxxxxxxxxx>
---
arch/arm/Kconfig | 1 +
1 files changed, 1 insertions(+), 0 deletions(-)

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index db524e7..1ed7968 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -23,6 +23,7 @@ config ARM
select PERF_USE_VMALLOC
select HAVE_REGS_AND_STACK_ACCESS_API
select HAVE_HW_BREAKPOINT if (PERF_EVENTS && (CPU_V6 || CPU_V7))
+ select ARCH_SUPPORTS_OPTIMIZED_INLINING
help
The ARM series is a line of low-power-consumption RISC chip designs
licensed by ARM Ltd and targeted at embedded applications and
--
Sent by an employee of the Qualcomm Innovation Center, Inc.
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum.

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