diff options
| author | Rong Xu <xur@google.com> | 2024-11-02 18:51:13 +0100 |
|---|---|---|
| committer | Masahiro Yamada <masahiroy@kernel.org> | 2024-11-27 01:38:27 +0100 |
| commit | 2fd65f7afd5a73b685a1651cb651ade120b53e15 (patch) | |
| tree | e086e6e6453d4353c330caecfc3e39f503c801df /include | |
| parent | AutoFDO: Enable -ffunction-sections for the AutoFDO build (diff) | |
| download | linux-2fd65f7afd5a73b685a1651cb651ade120b53e15.tar.xz linux-2fd65f7afd5a73b685a1651cb651ade120b53e15.zip | |
AutoFDO: Enable machine function split optimization for AutoFDO
Enable the machine function split optimization for AutoFDO in Clang.
Machine function split (MFS) is a pass in the Clang compiler that
splits a function into hot and cold parts. The linker groups all
cold blocks across functions together. This decreases hot code
fragmentation and improves iCache and iTLB utilization.
MFS requires a profile so this is enabled only for the AutoFDO builds.
Co-developed-by: Han Shen <shenhan@google.com>
Signed-off-by: Han Shen <shenhan@google.com>
Signed-off-by: Rong Xu <xur@google.com>
Suggested-by: Sriraman Tallam <tmsriram@google.com>
Suggested-by: Krzysztof Pszeniczny <kpszeniczny@google.com>
Tested-by: Yonghong Song <yonghong.song@linux.dev>
Tested-by: Yabin Cui <yabinc@google.com>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Kees Cook <kees@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/asm-generic/vmlinux.lds.h | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h index bd64fdedabd2..8a0bb3946cf0 100644 --- a/include/asm-generic/vmlinux.lds.h +++ b/include/asm-generic/vmlinux.lds.h @@ -556,6 +556,11 @@ defined(CONFIG_AUTOFDO_CLANG) __cpuidle_text_end = .; \ __noinstr_text_end = .; +#define TEXT_SPLIT \ + __split_text_start = .; \ + *(.text.split .text.split.[0-9a-zA-Z_]*) \ + __split_text_end = .; + #define TEXT_UNLIKELY \ __unlikely_text_start = .; \ *(.text.unlikely .text.unlikely.*) \ @@ -582,6 +587,7 @@ defined(CONFIG_AUTOFDO_CLANG) ALIGN_FUNCTION(); \ *(.text.asan.* .text.tsan.*) \ *(.text.unknown .text.unknown.*) \ + TEXT_SPLIT \ TEXT_UNLIKELY \ . = ALIGN(PAGE_SIZE); \ TEXT_HOT \ @@ -589,7 +595,6 @@ defined(CONFIG_AUTOFDO_CLANG) NOINSTR_TEXT \ *(.ref.text) - /* sched.text is aling to function alignment to secure we have same * address even at second ld pass when generating System.map */ #define SCHED_TEXT \ |