From patchwork Wed Oct 2 23:34:03 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Rong Xu X-Patchwork-Id: 13820537 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 C22B31A0B1F for ; Wed, 2 Oct 2024 23:34:25 +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=1727912068; cv=none; b=WYXDm4DqhnAOgzYaWYLLUjL+m1DfJV2SoEZLW2RwqMvOGgRaobgPnrO50jFXD1jMFvXWFtjq1kA3fWlNGAE2sMiIuT18fK5ejPV5D9gtl3mTz2GOkJC4scV94octPkyHZyhpnckaXwx39SyURmf7EFKzoAou/pPiW7JPfNts+6c= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727912068; c=relaxed/simple; bh=HEWLg94lHcfcX7O0hjC6KFou33+KNhu6rRzJHa0B/cU=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Content-Type; b=e4lsIZrQnquq5Sqa709qM7jjwtL5DTZ0BDHLfukGMBQ0Za2/Q+gc1fKG/KnCIr7fH/z5KeEEF0onaxst7iNHZA0XrumF0IITLe6Ey0cE7fDdFlgWVA65511kY0zOzovDeJDb3vqRpjwOpStL+kjTPTjc4Hwt8d720L3LrQLcEvY= 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=TbLpxUKk; 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="TbLpxUKk" Received: by mail-yw1-f201.google.com with SMTP id 00721157ae682-6e1fea193a4so9439617b3.0 for ; Wed, 02 Oct 2024 16:34:25 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1727912065; x=1728516865; darn=vger.kernel.org; h=to:from:subject:message-id:references:mime-version:in-reply-to:date :from:to:cc:subject:date:message-id:reply-to; bh=KR/7S/qOw5pwSaOTb7JyOKPjhhpLATlydtN1CkOVSds=; b=TbLpxUKkHozVi66rLLJVm8eYkoX2hvCZPYW0HPiqSyOhu9WRHd2Vr6f4zf4hjZ7ZDU OzkpY0Rzzqo83i6yTWgTytHb9okormvaBedxN/m1gHTcjx4umsoizKmcJgakkHrAmkuu SU90N5w64fIubhixgm3VTi92gntGmB5DROu6RhZr4CvuPwZaMTj2BntBV8587dYGm1XP iKbJPeAp1jKIQH1nRibNQsJjbDgmqMYNTPt5MiCqn6WGSzX3vmWR1OlFv0X3DQVW1FCk dvh8sFQQG0CYm3rSSkR/CHYY8tMXutyCQgUhqbl4kUNxc98CRXzzSelSvs67YZpHdl7t SxHQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1727912065; x=1728516865; h=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=KR/7S/qOw5pwSaOTb7JyOKPjhhpLATlydtN1CkOVSds=; b=J9TB3h/zsnEuEyYYhwZfOw4lkZCB7xFK9CeDimx/s1ASv23Yb80/+VKGYT0REVJ+eI +n9/XCajKYptV2vHEt6qE6LOw+8rARZwQP1od+hATvcS7kRrYnHgs8NvIIxCdhCkhath hfEmgBbKKehALjndjJOQh2FEdVu3DVfs+7nEV4uijo8OIZWZnb6WozlCXUlRj0l/acYX NXqqag5dChTzBlVCq2oxXWym16ZGPoHLU9z9qev3fvB3U8n1G26mhfh3qQWwP18g0sXv 9tatDpgJbBAAXflWlT5szHpr7d0GVSq7kHKqeZF0p3bQhDqQx8cMmhNtjQ5g8df2ws/6 iFcA== X-Forwarded-Encrypted: i=1; AJvYcCUxnoHIQ+rJa5Wq9LUztMUbifgJNcFikvtlkx6adkyKrsawFCUmv913tSQHaRdnpWfvxVbeI28Kq98LJfI=@vger.kernel.org X-Gm-Message-State: AOJu0YwSSX+kYXlnaNiHMZtK34ZNaptER+SeCY2kDh35UhJtTByNwbVg 51ljiQkKohNKhrfMBi8Dl7GOlgdn3IB/E7BOpy09uHiSHt6Q4UXVNlgfl/Yz1V1a3w== X-Google-Smtp-Source: AGHT+IGtSRk7MTIglmEkTfvd6+ZSJGdRNh+Fp2nkpaXXYORf+k6X+OIhPZQKfZ6wOw9GZPzt+lVcc/w= X-Received: from xur.c.googlers.com ([fda3:e722:ac3:cc00:20:ed76:c0a8:2330]) (user=xur job=sendgmr) by 2002:a25:b303:0:b0:e25:cea9:b0e with SMTP id 3f1490d57ef6-e2638432ffamr2877276.9.1727912064775; Wed, 02 Oct 2024 16:34:24 -0700 (PDT) Date: Wed, 2 Oct 2024 16:34:03 -0700 In-Reply-To: <20241002233409.2857999-1-xur@google.com> Precedence: bulk X-Mailing-List: linux-kbuild@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20241002233409.2857999-1-xur@google.com> X-Mailer: git-send-email 2.46.1.824.gd892dcdcdd-goog Message-ID: <20241002233409.2857999-5-xur@google.com> Subject: [PATCH v2 4/6] AutoFDO: Enable -ffunction-sections for the AutoFDO build From: Rong Xu To: Rong Xu , Han Shen , Sriraman Tallam , David Li , Krzysztof Pszeniczny , Alice Ryhl , Andrew Morton , Arnd Bergmann , Bill Wendling , Borislav Petkov , Breno Leitao , Brian Gerst , Dave Hansen , Heiko Carstens , "H. Peter Anvin" , Ingo Molnar , Jann Horn , Jonathan Corbet , Josh Poimboeuf , Juergen Gross , Justin Stitt , Kees Cook , linux-arch@vger.kernel.org, linux-doc@vger.kernel.org, linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org, llvm@lists.linux.dev, Masahiro Yamada , "Mike Rapoport (IBM)" , Nathan Chancellor , Nick Desaulniers , Nicolas Schier , "Paul E. McKenney" , Peter Zijlstra , Samuel Holland , Thomas Gleixner , Wei Yang , workflows@vger.kernel.org, x86@kernel.org, "Xin Li (Intel)" 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 --- include/asm-generic/vmlinux.lds.h | 37 ++++++++++++++++++++++++------- scripts/Makefile.autofdo | 2 +- 2 files changed, 30 insertions(+), 9 deletions(-) diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h index 5df589c60401..ace617d1af9b 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 LTO_CLANG, the linker also splits sections by default, so we need + * these macros to combine the sections during the final link. + * * 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_CLANG) +#if defined(CONFIG_LD_DEAD_CODE_DATA_ELIMINATION) || defined(CONFIG_LTO_CLANG) || \ +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_CLANG) #define DATA_MAIN .data .data.[0-9a-zA-Z_]* .data..L* .data..compoundliteral* .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 @@ -549,6 +556,20 @@ __cpuidle_text_end = .; \ __noinstr_text_end = .; +#ifdef CONFIG_AUTOFDO_CLANG +#define TEXT_HOT \ + __hot_text_start = .; \ + *(.text.hot .text.hot.*) \ + __hot_text_end = .; +#define TEXT_UNLIKELY \ + __unlikely_text_start = .; \ + *(.text.unlikely .text.unlikely.*) \ + __unlikely_text_end = .; +#else +#define TEXT_HOT *(.text.hot .text.hot.*) +#define TEXT_UNLIKELY *(.text.unlikely .text.unlikely.*) +#endif + /* * .text section. Map to function alignment to avoid address changes * during second ld run in second ld pass when generating System.map @@ -557,30 +578,30 @@ * code elimination or function-section is enabled. Match these symbols * first when in these builds. */ -#if defined(CONFIG_LD_DEAD_CODE_DATA_ELIMINATION) || defined(CONFIG_LTO_CLANG) +#if defined(CONFIG_LD_DEAD_CODE_DATA_ELIMINATION) || defined(CONFIG_LTO_CLANG) || \ +defined(CONFIG_AUTOFDO_CLANG) #define TEXT_TEXT \ ALIGN_FUNCTION(); \ *(.text.asan.* .text.tsan.*) \ *(.text.unknown .text.unknown.*) \ - *(.text.unlikely .text.unlikely.*) \ + TEXT_UNLIKELY \ . = ALIGN(PAGE_SIZE); \ - *(.text.hot .text.hot.*) \ + TEXT_HOT \ *(TEXT_MAIN .text.fixup) \ NOINSTR_TEXT \ *(.ref.text) #else #define TEXT_TEXT \ ALIGN_FUNCTION(); \ - *(.text.hot .text.hot.*) \ + TEXT_HOT \ *(TEXT_MAIN .text.fixup) \ - *(.text.unlikely .text.unlikely.*) \ + TEXT_UNLIKELY \ *(.text.unknown .text.unknown.*) \ NOINSTR_TEXT \ *(.ref.text) \ *(.text.asan.* .text.tsan.*) #endif - /* 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 \ diff --git a/scripts/Makefile.autofdo b/scripts/Makefile.autofdo index 1c9f224bc221..9c9a530ef090 100644 --- a/scripts/Makefile.autofdo +++ b/scripts/Makefile.autofdo @@ -10,7 +10,7 @@ ifndef CONFIG_DEBUG_INFO endif ifdef CLANG_AUTOFDO_PROFILE - CFLAGS_AUTOFDO_CLANG += -fprofile-sample-use=$(CLANG_AUTOFDO_PROFILE) + CFLAGS_AUTOFDO_CLANG += -fprofile-sample-use=$(CLANG_AUTOFDO_PROFILE) -ffunction-sections endif ifdef CONFIG_LTO_CLANG_THIN