From: xur@google•com
To: Yabin Cui <yabinc@google•com>, Will Deacon <will@kernel•org>,
Han Shen <shenhan@google•com>,
Thomas Gleixner <tglx@linutronix•de>,
Ingo Molnar <mingo@redhat•com>, Borislav Petkov <bp@alien8•de>,
Dave Hansen <dave.hansen@linux•intel.com>,
"H. Peter Anvin" <hpa@zytor•com>, Kees Cook <kees@kernel•org>,
Nathan Chancellor <nathan@kernel•org>,
Nicolas Schier <nicolas.schier@linux•dev>,
Linus Walleij <linusw@kernel•org>, Arnd Bergmann <arnd@arndb•de>,
Mathieu Desnoyers <mathieu.desnoyers@efficios•com>,
Rong Xu <xur@google•com>, Miguel Ojeda <ojeda@kernel•org>,
Peter Zijlstra <peterz@infradead•org>,
Jinjie Ruan <ruanjinjie@huawei•com>,
Lukas Bulwahn <lukas.bulwahn@redhat•com>,
linux-kernel@vger•kernel.org, Juergen Gross <jgross@suse•com>,
Helge Deller <deller@gmx•de>,
Ryan Roberts <ryan.roberts@arm•com>,
Marc Zyngier <maz@kernel•org>, Ard Biesheuvel <ardb@kernel•org>,
Vincent Donnefort <vdonnefort@google•com>,
Alice Ryhl <aliceryhl@google•com>
Cc: x86@kernel•org, linux-arm-kernel@lists•infradead.org
Subject: [PATCH v4 2/2] kconfig: Remove the architecture specific config for Propeller
Date: Thu, 4 Jun 2026 12:56:08 -0700 [thread overview]
Message-ID: <20260604195612.3757860-3-xur@google.com> (raw)
In-Reply-To: <20260604195612.3757860-1-xur@google.com>
From: Rong Xu <xur@google•com>
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 <hoekwater@google•com>
Signed-off-by: Rong Xu <xur@google•com>
Suggested-by: Will Deacon <will@kernel•org>
Suggested-by: Nathan Chancellor <nathan@kernel•org>
Tested-by: Yabin Cui <yabinc@google•com>
Reviewed-by: Kees Cook <kees@kernel•org>
---
Documentation/dev-tools/propeller.rst | 49 ++++++++++++++++++++-------
arch/Kconfig | 5 +--
arch/arm64/kernel/vmlinux.lds.S | 1 +
arch/x86/Kconfig | 1 -
arch/x86/kernel/vmlinux.lds.S | 5 +--
include/asm-generic/vmlinux.lds.h | 6 ++++
6 files changed, 46 insertions(+), 21 deletions(-)
diff --git a/Documentation/dev-tools/propeller.rst b/Documentation/dev-tools/propeller.rst
index 92195958e3db..e927319941c9 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 <count> -o <perf_file> -- <loadtest>
- Note you can repeat the above steps to collect multiple <perf_file>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 <count> --no-switch-events -o <perf_file> -- <loadtest>
+
+ Note you can repeat the above steps to collect multiple <perf_file>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=<vmlinux> --profile=<perf_file>
- --format=propeller --propeller_output_module_name
- --out=<propeller_profile_prefix>_cc_profile.txt
- --propeller_symorder=<propeller_profile_prefix>_ld_profile.txt
+ $ generate_propeller_profiles \
+ --binary=<vmlinux> --profile=<perf_file> \
+ --format=propeller --propeller_output_module_name \
+ --out=<propeller_profile_prefix>_cc_profile.txt \
+ --propeller_symorder=<propeller_profile_prefix>_ld_profile.txt
"<propeller_profile_prefix>" 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 "<perf_file_list>" with each line
containing one perf file name and run::
- $ create_llvm_prof --binary=<vmlinux> --profile=@<perf_file_list>
- --format=propeller --propeller_output_module_name
- --out=<propeller_profile_prefix>_cc_profile.txt
- --propeller_symorder=<propeller_profile_prefix>_ld_profile.txt
+ $ generate_propeller_profiles \
+ --binary=<vmlinux> --profile=@<perf_file_list> \
+ --format=propeller --propeller_output_module_name \
+ --out=<propeller_profile_prefix>_cc_profile.txt \
+ --propeller_symorder=<propeller_profile_prefix>_ld_profile.txt
+
+ For arm64 SPE, add the option '--profiler=perf_spe', like::
+
+ $ generate_propeller_profiles \
+ --binary=<vmlinux> --profile=<perf_file> \
+ --profiler=perf_spe \
+ --format=propeller --propeller_output_module_name \
+ --out=<propeller_profile_prefix>_cc_profile.txt \
+ --propeller_symorder=<propeller_profile_prefix>_ld_profile.txt
6) Rebuild the kernel using the AutoFDO and Propeller
profiles. ::
diff --git a/arch/Kconfig b/arch/Kconfig
index 5e878924939a..99c2017eb515 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 e1ac876200a3..8aaf404980a7 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 10bf3984102e..b875d2f27e48 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 4711a35e706c..74e336d7f9dd 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 60c8c22fd3e4..5659f4b5a125 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.
--
2.54.0.1032.g2f8565e1d1-goog
prev parent reply other threads:[~2026-06-04 19:56 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-06-04 19:56 [PATCH v4 0/2] kconfig: Remove the architecture specific config for AutoFDO and Propeller xur
2026-06-04 19:56 ` [PATCH v4 1/2] kconfig: Remove the architecture specific config for AutoFDO xur
2026-06-04 19:56 ` xur [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20260604195612.3757860-3-xur@google.com \
--to=xur@google$(echo .)com \
--cc=aliceryhl@google$(echo .)com \
--cc=ardb@kernel$(echo .)org \
--cc=arnd@arndb$(echo .)de \
--cc=bp@alien8$(echo .)de \
--cc=dave.hansen@linux$(echo .)intel.com \
--cc=deller@gmx$(echo .)de \
--cc=hpa@zytor$(echo .)com \
--cc=jgross@suse$(echo .)com \
--cc=kees@kernel$(echo .)org \
--cc=linusw@kernel$(echo .)org \
--cc=linux-arm-kernel@lists$(echo .)infradead.org \
--cc=linux-kernel@vger$(echo .)kernel.org \
--cc=lukas.bulwahn@redhat$(echo .)com \
--cc=mathieu.desnoyers@efficios$(echo .)com \
--cc=maz@kernel$(echo .)org \
--cc=mingo@redhat$(echo .)com \
--cc=nathan@kernel$(echo .)org \
--cc=nicolas.schier@linux$(echo .)dev \
--cc=ojeda@kernel$(echo .)org \
--cc=peterz@infradead$(echo .)org \
--cc=ruanjinjie@huawei$(echo .)com \
--cc=ryan.roberts@arm$(echo .)com \
--cc=shenhan@google$(echo .)com \
--cc=tglx@linutronix$(echo .)de \
--cc=vdonnefort@google$(echo .)com \
--cc=will@kernel$(echo .)org \
--cc=x86@kernel$(echo .)org \
--cc=yabinc@google$(echo .)com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox