From nobody Tue Nov 26 01:28:18 2024 Received: from mail-yw1-f201.google.com (mail-yw1-f201.google.com [209.85.128.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4E43E200106 for ; Wed, 23 Oct 2024 22:44:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729723480; cv=none; b=tmfU/gD1VRxErKAMGQc6oRAU03shU4BXm55Kj1T822gVnX30qcNla/IDAOwDmL5Z9g9qajzdnI3NXGjwWKMI/c4LtvV4hOYAj0iEJJ+haylOuXXVu1Ulbt5TBtVtQQilIxhA8Tkv3aVZSZQ3Itsx5m0Uo57CVsxVe1swnj/JXfQ= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729723480; c=relaxed/simple; bh=GQ83ywusdX8FSxm29bbJdclqT2d6vsgU+PEBocsitO0=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=fvHZLg7wHSb1N1bTQJ7yd9OonH24LSFoiMFW6tXFX3ZNlKOtU35PIpz1qYI5lsb25RAVpugXbXNZVcIbwMdAxfGFS1NMJJhO/Hto9c7wjcuDShQajSxDCHY2k9NpWHQ0bT378KYuwA4qAEC6zi8xwlC8QIJvLF49Icu/LcAHZGk= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--xur.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=UKmsct+r; arc=none smtp.client-ip=209.85.128.201 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--xur.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="UKmsct+r" Received: by mail-yw1-f201.google.com with SMTP id 00721157ae682-6e5bdb9244eso4675637b3.2 for ; Wed, 23 Oct 2024 15:44:37 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1729723476; x=1730328276; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=kTuJsSOv0TXKkgOZ/uTNzVesPzJyNiyzzwDXk3hx600=; b=UKmsct+rTGoM1udseT8z3t7+d+oD63A0kMftZu/iEioutiY5fFLSXgbhN/0nfMT3BP +/Xj+rIw/HbGKeu57IYHfSmhA6sYgWWmrK4VzhVU7IJGVwzohsLm1bS+CvufHqfhABSG FPKF/ToYLT18AqYW4Fu8QKWRNSWcKdV6Jsm0O73Bq4CvOaiM4w6iObuW4o2nT4c4BB8k 6yyyaRoiWc+Wr4APmYirmZ0Jo3Vouq4jc+3h1BQsuuZ3pdVjwkl9eEND7ZQCbtKC8rkO UMMiYp889+QGXxnQL12c63gLZmlyVE3ZpVg7FYbAnYpP6qvNBNw6LxiSZVPIlXl1QccC Y19g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1729723476; x=1730328276; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=kTuJsSOv0TXKkgOZ/uTNzVesPzJyNiyzzwDXk3hx600=; b=SCWMGcEGzfiBe/CUtVa9keDVeHwc+k7Jyg+sER2EkUIoWyHpY8TB8EwUoBfNew6cFj 4tqONT5eO+0QMTKjH94cUS+LoAJNYvp8668YcJJpcT9MymEyCM7bOrdF6fTtVPBpDOSs e87qKDyf6GUlgcaNHn/X3s8c7AuQ9tFj+BZnjTX8Oa7r+G3jeq5q2Oiakx3Ne72TGpR3 QLOKDn7LE/cqyWvoETfDqEwP6rbeoKwlklk7EZpBqFcplxqRxvOEYK17/A17SQsohw1N SSRvkO+TcnUK9TlVGNNOq2WeCgfNFQeSrmXN6pKjGXPZFA0jry6UItAoFms9ORrRqezF JKDA== X-Forwarded-Encrypted: i=1; AJvYcCX9SfssseX789cpBKJo9fMsCz6iz7hrHsXh3TYzSK7OdFZ1ABl/0A2FSjPAJgXrau/BAI7vPnzO1SsnEJo=@vger.kernel.org X-Gm-Message-State: AOJu0Yz/Ura2ApnLu76/pTUFuzxL1NrmeBsrpr95VBC+jqi467s6WWM9 8Sh1NgkBsImpLnjwlAAFpG73T64ylHQkFREoajHVvodKwQmsZ1ZsLRQVUzTPJIuIJQ== X-Google-Smtp-Source: AGHT+IFpQ/G7EWyoYT60RN1you6Dj+hT6prCnRF/AChpGyawG8i/BJxIIfyzyg2vkyXeHhpEwaCtalg= X-Received: from xur.c.googlers.com ([fda3:e722:ac3:cc00:20:ed76:c0a8:2330]) (user=xur job=sendgmr) by 2002:a25:2604:0:b0:e28:fb8b:9155 with SMTP id 3f1490d57ef6-e2e3a6d71fcmr3638276.9.1729723476306; Wed, 23 Oct 2024 15:44:36 -0700 (PDT) Date: Wed, 23 Oct 2024 15:44:04 -0700 In-Reply-To: <20241023224409.201771-1-xur@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20241023224409.201771-1-xur@google.com> X-Mailer: git-send-email 2.47.0.105.g07ac214952-goog Message-ID: <20241023224409.201771-6-xur@google.com> Subject: [PATCH v5 5/7] AutoFDO: Enable -ffunction-sections for the AutoFDO build From: Rong Xu To: Alice Ryhl , Andrew Morton , Arnd Bergmann , Bill Wendling , Borislav Petkov , Breno Leitao , Brian Gerst , Dave Hansen , David Li , Han Shen , Heiko Carstens , "H. Peter Anvin" , Ingo Molnar , Jann Horn , Jonathan Corbet , Josh Poimboeuf , Juergen Gross , Justin Stitt , Kees Cook , Masahiro Yamada , "Mike Rapoport (IBM)" , Nathan Chancellor , Nick Desaulniers , Nicolas Schier , "Paul E. McKenney" , Peter Zijlstra , Rong Xu , Sami Tolvanen , Thomas Gleixner , Wei Yang , workflows@vger.kernel.org, Miguel Ojeda , Maksim Panchenko , Yonghong Song , Yabin Cui , Krzysztof Pszeniczny , Sriraman Tallam , Stephane Eranian Cc: x86@kernel.org, linux-arch@vger.kernel.org, linux-doc@vger.kernel.org, linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org, llvm@lists.linux.dev Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Enable -ffunction-sections by default for the AutoFDO build. With -ffunction-sections, the compiler places each function in its own section named .text.function_name instead of placing all functions in the .text section. In the AutoFDO build, this allows the linker to utilize profile information to reorganize functions for improved utilization of iCache and iTLB. Co-developed-by: Han Shen Signed-off-by: Han Shen Signed-off-by: Rong Xu Suggested-by: Sriraman Tallam Tested-by: Yonghong Song --- include/asm-generic/vmlinux.lds.h | 11 +++++++++-- scripts/Makefile.autofdo | 2 +- 2 files changed, 10 insertions(+), 3 deletions(-) diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinu= x.lds.h index e02973f3b418..bd64fdedabd2 100644 --- a/include/asm-generic/vmlinux.lds.h +++ b/include/asm-generic/vmlinux.lds.h @@ -95,18 +95,25 @@ * With LTO_CLANG, the linker also splits sections by default, so we need * these macros to combine the sections during the final link. * + * With AUTOFDO_CLANG, by default, the linker splits text sections and + * regroups functions into subsections. + * * RODATA_MAIN is not used because existing code already defines .rodata.x * sections to be brought in with rodata. */ -#if defined(CONFIG_LD_DEAD_CODE_DATA_ELIMINATION) || defined(CONFIG_LTO_CL= ANG) +#if defined(CONFIG_LD_DEAD_CODE_DATA_ELIMINATION) || defined(CONFIG_LTO_CL= ANG) || \ +defined(CONFIG_AUTOFDO_CLANG) #define TEXT_MAIN .text .text.[0-9a-zA-Z_]* +#else +#define TEXT_MAIN .text +#endif +#if defined(CONFIG_LD_DEAD_CODE_DATA_ELIMINATION) || defined(CONFIG_LTO_CL= ANG) #define DATA_MAIN .data .data.[0-9a-zA-Z_]* .data..L* .data..compoundliter= al* .data.$__unnamed_* .data.$L* #define SDATA_MAIN .sdata .sdata.[0-9a-zA-Z_]* #define RODATA_MAIN .rodata .rodata.[0-9a-zA-Z_]* .rodata..L* #define BSS_MAIN .bss .bss.[0-9a-zA-Z_]* .bss..L* .bss..compoundliteral* #define SBSS_MAIN .sbss .sbss.[0-9a-zA-Z_]* #else -#define TEXT_MAIN .text #define DATA_MAIN .data #define SDATA_MAIN .sdata #define RODATA_MAIN .rodata diff --git a/scripts/Makefile.autofdo b/scripts/Makefile.autofdo index ff96a63fea7c..6155d6fc4ca7 100644 --- a/scripts/Makefile.autofdo +++ b/scripts/Makefile.autofdo @@ -9,7 +9,7 @@ ifndef CONFIG_DEBUG_INFO endif =20 ifdef CLANG_AUTOFDO_PROFILE - CFLAGS_AUTOFDO_CLANG +=3D -fprofile-sample-use=3D$(CLANG_AUTOFDO_PROFILE) + CFLAGS_AUTOFDO_CLANG +=3D -fprofile-sample-use=3D$(CLANG_AUTOFDO_PROFILE= ) -ffunction-sections endif =20 ifdef CONFIG_LTO_CLANG_THIN --=20 2.47.0.105.g07ac214952-goog