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=-13.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=unavailable 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 31520C47095 for ; Mon, 7 Jun 2021 15:39:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CA27F61159 for ; Mon, 7 Jun 2021 15:39:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230231AbhFGPlq (ORCPT ); Mon, 7 Jun 2021 11:41:46 -0400 Received: from mga18.intel.com ([134.134.136.126]:38495 "EHLO mga18.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230319AbhFGPlo (ORCPT ); Mon, 7 Jun 2021 11:41:44 -0400 IronPort-SDR: 625sZc+yuCfYs0SBsG8HP5awRZEVJf9INIKxBPu24NaUALAAmw9xQ0d0I+4nRK49dnhjO/V3Hn EeuJbHCbFgXQ== X-IronPort-AV: E=McAfee;i="6200,9189,10008"; a="191973139" X-IronPort-AV: E=Sophos;i="5.83,255,1616482800"; d="scan'208";a="191973139" Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by orsmga106.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 07 Jun 2021 08:39:49 -0700 IronPort-SDR: JEulWHbYEZ0vI+ChaCM0Jf62WFEqLfTtyUICPiiKAbbMQemuErGwBHuNSraEJ79byY2DnDuCVG Uirel1mH5lCQ== X-IronPort-AV: E=Sophos;i="5.83,255,1616482800"; d="scan'208";a="449130585" Received: from smile.fi.intel.com (HELO smile) ([10.237.68.40]) by fmsmga008-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 07 Jun 2021 08:39:42 -0700 Received: from andy by smile with local (Exim 4.94) (envelope-from ) id 1lqHLm-000I2j-6H; Mon, 07 Jun 2021 18:39:38 +0300 Date: Mon, 7 Jun 2021 18:39:38 +0300 From: Andy Shevchenko To: Yury Norov Cc: linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, Alexander Lobakin , Alexey Klimov , 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: Re: [PATCH] all: remove GENERIC_FIND_FIRST_BIT Message-ID: References: <20210510233421.18684-1-yury.norov@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210510233421.18684-1-yury.norov@gmail.com> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, May 10, 2021 at 04:34:21PM -0700, Yury Norov wrote: > 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. Subject like s/all:/arch:/. > 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. This is rather comment (should be below cutter '---' line). Anyway, seems good to my by the code: Reviewed-by: Andy Shevchenko > 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 > -- With Best Regards, Andy Shevchenko