From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E52D6C433B4 for ; Mon, 10 May 2021 23:34:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A30B461154 for ; Mon, 10 May 2021 23:34:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229925AbhEJXff (ORCPT ); Mon, 10 May 2021 19:35:35 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45542 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229561AbhEJXfd (ORCPT ); Mon, 10 May 2021 19:35:33 -0400 Received: from mail-qt1-x82b.google.com (mail-qt1-x82b.google.com [IPv6:2607:f8b0:4864:20::82b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CC71BC061574; Mon, 10 May 2021 16:34:26 -0700 (PDT) Received: by mail-qt1-x82b.google.com with SMTP id f8so9180189qth.6; Mon, 10 May 2021 16:34:26 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=VBkKGU/ki1TRk8sMHAAIgbib+6nzNUIdtQYyvnJ5USQ=; b=CxW+dEAVXDk0b2mz4xXAAOo7sYkrFcE5NyMGbLT9v+fVGYHFySZSszVTHx4H/liqji Xeq5aF0hmaVzNedK+/d1+rTH5aIzQVpZxviWs9tQSVhAQHdsHYpsiGrXFh9u5DhT9Zdg UOLuhNpNuPl6307+StHDNUrYjsb6XR8CheLiAeP54NkA0/tKve4OYAUOIvtsTBmfYqfX HaUySPfTrhoIhD7m1OE4acogxJl33PpXBFRPV5BXoAowrb44D61fGrkf9BsTxNXaH0w4 Q3sirpM2o1JXsSpmWHU/B7y+310h8D691jnYP+y8aTs+tcl8mr76M1RU+hghStXgptK/ m1RQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=VBkKGU/ki1TRk8sMHAAIgbib+6nzNUIdtQYyvnJ5USQ=; b=QLT8TjWGD9WqHlkyHuC2lzMYLc1Cd0gzazxwpTVwQbo/CU9q51N9HXY3gUvjkeKqv/ WjWMDXeepjubPeXq+m00+xFoGUtVlf46hrVkOMDUsi/wBVWNjuRW3ImDKp3mgMNkeDFX tE1uHh8uQPriAI2FebSJf2IncdwZ3xKTIMKmjkJAqxW7MXkaKUyIDhCXgMzImP1y75BA z81pQB4YG00NkH9Azf14dUJYOS3DwMovzZzivf2Mix3BfRoTbo/0gPA6VFcJz/pkdIkK 0FGqk4KKMJ4ZpwbemEQd5Wk+L7gGZvXGzlbxZjcjT8Lee84kMciPoQ3ZkUH6a4uXzJSk E/+Q== X-Gm-Message-State: AOAM5339LvzZLcI3Mm+43JJQCIKNgLeLyVNs2dny/9gay5c/6Ujc2mUE ektDForauqgi7zWj12NY7SEXxrGpkhdVDA== X-Google-Smtp-Source: ABdhPJx3h/hkHoHuys3vF3Pv9tha50NlDAjZ7yH2vb6gQ0kPvY6LQcUL8DPQUTXcb5C3DWHyADBvBg== X-Received: by 2002:a05:622a:2c9:: with SMTP id a9mr10456062qtx.38.1620689665622; Mon, 10 May 2021 16:34:25 -0700 (PDT) Received: from localhost ([207.98.216.60]) by smtp.gmail.com with ESMTPSA id z4sm12639919qtv.7.2021.05.10.16.34.24 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 10 May 2021 16:34:25 -0700 (PDT) From: Yury Norov To: linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org Cc: Yury Norov , Alexander Lobakin , Alexey Klimov , Andy Shevchenko , Anton Ivanov , Arnd Bergmann , Borislav Petkov , Catalin Marinas , Christian Borntraeger , Dan Williams , "H. Peter Anvin" , Heiko Carstens , Ingo Molnar , Jacob Keller , Jarkko Sakkinen , Jeff Dike , Kees Cook , Mark Brown , Matti Vaittinen , Nick Terrell , Palmer Dabbelt , Rasmus Villemoes , Richard Weinberger , Thomas Bogendoerfer , Thomas Gleixner , Vasily Gorbik , Vijayanand Jitta , Vineet Gupta , Will Deacon , Yogesh Lal Subject: [PATCH] all: remove GENERIC_FIND_FIRST_BIT Date: Mon, 10 May 2021 16:34:21 -0700 Message-Id: <20210510233421.18684-1-yury.norov@gmail.com> X-Mailer: git-send-email 2.30.2 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-arch@vger.kernel.org In the 5.12 cycle we enabled the GENERIC_FIND_FIRST_BIT config option for ARM64 and MIPS. It increased performance and shrunk .text size; and so far I didn't receive any negative feedback on the change. https://lore.kernel.org/linux-arch/20210225135700.1381396-1-yury.norov@gmail.com/ I think it's time to make all architectures use find_{first,last}_bit() unconditionally and remove the corresponding config option. This patch doesn't introduce functional changes for arc, arm64, mips, s390 and x86 because they already enable GENERIC_FIND_FIRST_BIT. There will be no changes for arm because it implements find_{first,last}_bit in arch code. For other architectures I expect improvement both in performance and .text size. It would be great if people with an access to real hardware would share the output of bloat-o-meter and lib/find_bit_benchmark. Signed-off-by: Yury Norov --- arch/arc/Kconfig | 1 - arch/arm64/Kconfig | 1 - arch/mips/Kconfig | 1 - arch/s390/Kconfig | 1 - arch/x86/Kconfig | 1 - arch/x86/um/Kconfig | 1 - include/asm-generic/bitops/find.h | 12 ------------ lib/Kconfig | 3 --- 8 files changed, 21 deletions(-) diff --git a/arch/arc/Kconfig b/arch/arc/Kconfig index bc8d6aecfbbd..9c991ba50db3 100644 --- a/arch/arc/Kconfig +++ b/arch/arc/Kconfig @@ -19,7 +19,6 @@ config ARC select COMMON_CLK select DMA_DIRECT_REMAP select GENERIC_ATOMIC64 if !ISA_ARCV2 || !(ARC_HAS_LL64 && ARC_HAS_LLSC) - select GENERIC_FIND_FIRST_BIT # for now, we don't need GENERIC_IRQ_PROBE, CONFIG_GENERIC_IRQ_CHIP select GENERIC_IRQ_SHOW select GENERIC_PCI_IOMAP diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index e09a9591af45..9d5b36f7d981 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -108,7 +108,6 @@ config ARM64 select GENERIC_CPU_AUTOPROBE select GENERIC_CPU_VULNERABILITIES select GENERIC_EARLY_IOREMAP - select GENERIC_FIND_FIRST_BIT select GENERIC_IDLE_POLL_SETUP select GENERIC_IRQ_IPI select GENERIC_IRQ_PROBE diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig index b72458215d20..3ddae7918386 100644 --- a/arch/mips/Kconfig +++ b/arch/mips/Kconfig @@ -27,7 +27,6 @@ config MIPS select GENERIC_ATOMIC64 if !64BIT select GENERIC_CMOS_UPDATE select GENERIC_CPU_AUTOPROBE - select GENERIC_FIND_FIRST_BIT select GENERIC_GETTIMEOFDAY select GENERIC_IOMAP select GENERIC_IRQ_PROBE diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig index c1ff874e6c2e..3a10ceb8a097 100644 --- a/arch/s390/Kconfig +++ b/arch/s390/Kconfig @@ -125,7 +125,6 @@ config S390 select GENERIC_CPU_AUTOPROBE select GENERIC_CPU_VULNERABILITIES select GENERIC_ENTRY - select GENERIC_FIND_FIRST_BIT select GENERIC_GETTIMEOFDAY select GENERIC_PTDUMP select GENERIC_SMP_IDLE_THREAD diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index b83364a15d34..6a7d8305365e 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -123,7 +123,6 @@ config X86 select GENERIC_CPU_VULNERABILITIES select GENERIC_EARLY_IOREMAP select GENERIC_ENTRY - select GENERIC_FIND_FIRST_BIT select GENERIC_IOMAP select GENERIC_IRQ_EFFECTIVE_AFF_MASK if SMP select GENERIC_IRQ_MATRIX_ALLOCATOR if X86_LOCAL_APIC diff --git a/arch/x86/um/Kconfig b/arch/x86/um/Kconfig index 95d26a69088b..40d6a06e41c8 100644 --- a/arch/x86/um/Kconfig +++ b/arch/x86/um/Kconfig @@ -8,7 +8,6 @@ endmenu config UML_X86 def_bool y - select GENERIC_FIND_FIRST_BIT config 64BIT bool "64-bit kernel" if "$(SUBARCH)" = "x86" diff --git a/include/asm-generic/bitops/find.h b/include/asm-generic/bitops/find.h index 0d132ee2a291..8a7b70c79e15 100644 --- a/include/asm-generic/bitops/find.h +++ b/include/asm-generic/bitops/find.h @@ -95,8 +95,6 @@ unsigned long find_next_zero_bit(const unsigned long *addr, unsigned long size, } #endif -#ifdef CONFIG_GENERIC_FIND_FIRST_BIT - /** * find_first_bit - find the first set bit in a memory region * @addr: The address to start the search at @@ -136,16 +134,6 @@ unsigned long find_first_zero_bit(const unsigned long *addr, unsigned long size) return _find_first_zero_bit(addr, size); } -#else /* CONFIG_GENERIC_FIND_FIRST_BIT */ - -#ifndef find_first_bit -#define find_first_bit(addr, size) find_next_bit((addr), (size), 0) -#endif -#ifndef find_first_zero_bit -#define find_first_zero_bit(addr, size) find_next_zero_bit((addr), (size), 0) -#endif - -#endif /* CONFIG_GENERIC_FIND_FIRST_BIT */ #ifndef find_last_bit /** diff --git a/lib/Kconfig b/lib/Kconfig index a38cc61256f1..8346b3181214 100644 --- a/lib/Kconfig +++ b/lib/Kconfig @@ -59,9 +59,6 @@ config GENERIC_STRNLEN_USER config GENERIC_NET_UTILS bool -config GENERIC_FIND_FIRST_BIT - bool - source "lib/math/Kconfig" config NO_GENERIC_PCI_IOPORT_MAP -- 2.25.1