From: Rong Xu Date: Thu, 4 Jun 2026 19:56:08 +0000 (-0700) Subject: kconfig: Remove the architecture specific config for Propeller X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=2566fa7b2f2402a77dae6a5e9b28a1bae1c20793;p=thirdparty%2Flinux.git kconfig: Remove the architecture specific config for Propeller The CONFIG_PROPELLER_CLANG option currently depends on ARCH_SUPPORTS_PROPELLER_CLANG, but this dependency seems unnecessary. Remove ARCH_SUPPORTS_PROPELLER_CLANG and allow users to control Propeller builds solely through CONFIG_PROPELLER_CLANG. This simplifies the kconfig and avoids potential confusion. Move the .llvm_bb_addr_map sections grouping to include/asm-generic/vmlinux.lds.h. The Propeller documentation has been updated to reflect the most recent tool location and now includes instructions for arm64. Contributor Acknowledgments: * SPE instructions: Daniel Hoekwater Signed-off-by: Rong Xu Suggested-by: Will Deacon Suggested-by: Nathan Chancellor Tested-by: Yabin Cui Reviewed-by: Kees Cook Link: https://patch.msgid.link/20260604195612.3757860-3-xur@google.com Signed-off-by: Nathan Chancellor --- diff --git a/Documentation/dev-tools/propeller.rst b/Documentation/dev-tools/propeller.rst index 92195958e3dbc..e927319941c95 100644 --- a/Documentation/dev-tools/propeller.rst +++ b/Documentation/dev-tools/propeller.rst @@ -28,8 +28,10 @@ A few important notes about adopting Propeller optimization: and the linker(ld.lld). #. In addition to LLVM toolchain, Propeller requires a profiling - conversion tool: https://github.com/google/autofdo with a release - after v0.30.1: https://github.com/google/autofdo/releases/tag/v0.30.1. + conversion tool: https://github.com/google/llvm-propeller. + +Current supported architectures include x86/X86_64 (via LBR), +and arm64 (via SPE). The Propeller optimization process involves the following steps: @@ -124,17 +126,30 @@ Here is an example workflow for building an AutoFDO+Propeller kernel: $ perf record --pfm-event RETIRED_TAKEN_BRANCH_INSTRUCTIONS:k -a -N -b -c -o -- - Note you can repeat the above steps to collect multiple s. + - For arm64 with SPE:: + There are a few kernel features that must be enabled to collect SPE profiles on Arm. + Below is a list of the required features: + + - CONFIG_ARM_SPE_PMU=y + - CONFIG_PID_IN_CONTEXTIDR=y + - kpti=off + + Use the following command to generate SPE perf data file:: + + $ perf record -e 'arm_spe_0/branch_filter=1,load_filter=0,store_filter=0/' -a -N -c --no-switch-events -o -- + + Note you can repeat the above steps to collect multiple s. 4) (Optional) Download the raw perf file(s) to the host machine. -5) Use the create_llvm_prof tool (https://github.com/google/autofdo) to +5) Use the generate_propeller_profiles tool (https://github.com/google/llvm-propeller) to generate Propeller profile. :: - $ create_llvm_prof --binary= --profile= - --format=propeller --propeller_output_module_name - --out=_cc_profile.txt - --propeller_symorder=_ld_profile.txt + $ generate_propeller_profiles \ + --binary= --profile= \ + --format=propeller --propeller_output_module_name \ + --out=_cc_profile.txt \ + --propeller_symorder=_ld_profile.txt "" can be something like "/home/user/dir/any_string". @@ -146,10 +161,20 @@ Here is an example workflow for building an AutoFDO+Propeller kernel: you can create a temp list file "" with each line containing one perf file name and run:: - $ create_llvm_prof --binary= --profile=@ - --format=propeller --propeller_output_module_name - --out=_cc_profile.txt - --propeller_symorder=_ld_profile.txt + $ generate_propeller_profiles \ + --binary= --profile=@ \ + --format=propeller --propeller_output_module_name \ + --out=_cc_profile.txt \ + --propeller_symorder=_ld_profile.txt + + For arm64 SPE, add the option '--profiler=perf_spe', like:: + + $ generate_propeller_profiles \ + --binary= --profile= \ + --profiler=perf_spe \ + --format=propeller --propeller_output_module_name \ + --out=_cc_profile.txt \ + --propeller_symorder=_ld_profile.txt 6) Rebuild the kernel using the AutoFDO and Propeller profiles. :: diff --git a/arch/Kconfig b/arch/Kconfig index 5e878924939a9..99c2017eb5157 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -895,13 +895,10 @@ config AUTOFDO_CLANG If unsure, say N. -config ARCH_SUPPORTS_PROPELLER_CLANG - bool - config PROPELLER_CLANG bool "Enable Clang's Propeller build" - depends on ARCH_SUPPORTS_PROPELLER_CLANG depends on CC_IS_CLANG && CLANG_VERSION >= 190000 + depends on $(cc-option,-fbasic-block-sections=list=/dev/null) help This option enables Clang’s Propeller build. When the Propeller profiles is specified in variable CLANG_PROPELLER_PROFILE_PREFIX diff --git a/arch/arm64/kernel/vmlinux.lds.S b/arch/arm64/kernel/vmlinux.lds.S index e1ac876200a3d..8aaf404980a72 100644 --- a/arch/arm64/kernel/vmlinux.lds.S +++ b/arch/arm64/kernel/vmlinux.lds.S @@ -368,6 +368,7 @@ SECTIONS STABS_DEBUG DWARF_DEBUG + PROPELLER_DATA MODINFO ELF_DETAILS diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 10bf3984102e3..b875d2f27e48c 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -130,7 +130,6 @@ config X86 select ARCH_SUPPORTS_LTO_CLANG select ARCH_SUPPORTS_LTO_CLANG_THIN select ARCH_SUPPORTS_RT - select ARCH_SUPPORTS_PROPELLER_CLANG if X86_64 select ARCH_USE_BUILTIN_BSWAP select ARCH_USE_CMPXCHG_LOCKREF if X86_CX8 select ARCH_USE_MEMTEST diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S index 4711a35e706cd..74e336d7f9dd2 100644 --- a/arch/x86/kernel/vmlinux.lds.S +++ b/arch/x86/kernel/vmlinux.lds.S @@ -423,10 +423,7 @@ SECTIONS STABS_DEBUG DWARF_DEBUG -#ifdef CONFIG_PROPELLER_CLANG - .llvm_bb_addr_map : { *(.llvm_bb_addr_map) } -#endif - + PROPELLER_DATA MODINFO ELF_DETAILS diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h index 60c8c22fd3e44..5659f4b5a1252 100644 --- a/include/asm-generic/vmlinux.lds.h +++ b/include/asm-generic/vmlinux.lds.h @@ -1011,6 +1011,12 @@ #define PERCPU_DECRYPTED_SECTION #endif +#ifdef CONFIG_PROPELLER_CLANG +#define PROPELLER_DATA \ + .llvm_bb_addr_map : { *(.llvm_bb_addr_map) } +#else +#define PROPELLER_DATA +#endif /* * Default discarded sections.