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,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 C9FFDC433EF for ; Wed, 8 Sep 2021 15:11:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A4F2E61051 for ; Wed, 8 Sep 2021 15:11:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1350727AbhIHPMQ (ORCPT ); Wed, 8 Sep 2021 11:12:16 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41280 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229945AbhIHPMO (ORCPT ); Wed, 8 Sep 2021 11:12:14 -0400 Received: from ustc.edu.cn (email6.ustc.edu.cn [IPv6:2001:da8:d800::8]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 81A6BC061575 for ; Wed, 8 Sep 2021 08:11:05 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mail.ustc.edu.cn; s=dkim; h=Received:Date:From:To:Cc:Subject: Message-ID:In-Reply-To:References:MIME-Version:Content-Type: Content-Transfer-Encoding; bh=0C3YBGnfpbG9UOTagLlfTYYKY8tokMJAvI Ql9p4G3lI=; b=gT8DVp8CbcFATMUBS9fwOB0WS36+q/qdnpW8Hy5wjuZJZ/lTuM TPNZ/tUrqqulOn9moSy17+wIG+I5hJKVxIoeEqI9KMf9UWu6OMtZ/p/dGH7b91lr 9DFaPbVSbmqGqCNXsGByk514vPeG7aHtAJEMBdsBixqxj7rRL5H8Q5jLs= Received: from xhacker (unknown [101.86.20.15]) by newmailweb.ustc.edu.cn (Coremail) with SMTP id LkAmygAnL0t+0jhh3cACAA--.2155S2; Wed, 08 Sep 2021 23:10:54 +0800 (CST) Date: Wed, 8 Sep 2021 23:04:27 +0800 From: Jisheng Zhang To: Paul Walmsley , Palmer Dabbelt , Albert Ou Cc: linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] riscv: enable GENERIC_FIND_FIRST_BIT Message-ID: <20210908230427.3a92fb87@xhacker> In-Reply-To: <20210718001423.6b8e1d23@xhacker> References: <20210718001423.6b8e1d23@xhacker> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-CM-TRANSID: LkAmygAnL0t+0jhh3cACAA--.2155S2 X-Coremail-Antispam: 1UD129KBjvJXoWrKrW8Zr1UXF15ur17XrWxCrg_yoW8JrWfpr 45CF1Fgr45JFyrWF1fKFy7u34xWa1fG393Kr95t3W5Xry3urZ5urn3Kr13W34UCrs5Wryf JFyfC34UAayYyrDanT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUyFb7Iv0xC_tr1lb4IE77IF4wAFF20E14v26r1j6r4UM7CY07I2 0VC2zVCF04k26cxKx2IYs7xG6rWj6s0DM7CIcVAFz4kK6r1j6r18M28lY4IEw2IIxxk0rw A2F7IY1VAKz4vEj48ve4kI8wA2z4x0Y4vE2Ix0cI8IcVAFwI0_Ar0_tr1l84ACjcxK6xII jxv20xvEc7CjxVAFwI0_Cr0_Gr1UM28EF7xvwVC2z280aVAFwI0_GcCE3s1l84ACjcxK6I 8E87Iv6xkF7I0E14v26rxl6s0DM2AIxVAIcxkEcVAq07x20xvEncxIr21l5I8CrVACY4xI 64kE6c02F40Ex7xfMcIj6xIIjxv20xvE14v26r1j6r18McIj6I8E87Iv67AKxVWUJVW8Jw Am72CE4IkC6x0Yz7v_Jr0_Gr1lF7xvr2IY64vIr41l42xK82IYc2Ij64vIr41l4I8I3I0E 4IkC6x0Yz7v_Jr0_Gr1lx2IqxVAqx4xG67AKxVWUJVWUGwC20s026x8GjcxK67AKxVWUGV WUWwC2zVAF1VAY17CE14v26r126r1DMIIYrxkI7VAKI48JMIIF0xvE2Ix0cI8IcVAFwI0_ Jr0_JF4lIxAIcVC0I7IYx2IY6xkF7I0E14v26r1j6r4UMIIF0xvE42xK8VAvwI8IcIk0rV WrZr1j6s0DMIIF0xvEx4A2jsIE14v26r1j6r4UMIIF0xvEx4A2jsIEc7CjxVAFwI0_Jr0_ GrUvcSsGvfC2KfnxnUUI43ZEXa7IU8v_M3UUUUU== X-CM-SenderInfo: xmv2xttqjtqzxdloh3xvwfhvlgxou0/ Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Palmer, On Sun, 18 Jul 2021 00:14:23 +0800 Jisheng Zhang wrote: > From: Jisheng Zhang > > riscv doesn't implement architecture-optimized bitsearching functions > such as find_first_{zero}_bit() etc. > > When GENERIC_FIND_FIRST_BIT=n, find_first_bit() is implemented with > find_next_bit() which is less efficient. Enable GENERIC_FIND_FIRST_BIT > for riscv to get more optimized find_first_bit() implementation, an > initial test(lib/find_bit_benchmark) shows find_first_bit() performance > is improved by nearly 32%. It seems this patch is missed. Is it possible to pick it up for 2nd 5.15-rc1 PR? Thanks > > Signed-off-by: Jisheng Zhang > --- > arch/riscv/Kconfig | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig > index 8fcceb8eda07..7ebc54c5c245 100644 > --- a/arch/riscv/Kconfig > +++ b/arch/riscv/Kconfig > @@ -47,6 +47,7 @@ config RISCV > select GENERIC_ATOMIC64 if !64BIT > select GENERIC_CLOCKEVENTS_BROADCAST if SMP > select GENERIC_EARLY_IOREMAP > + select GENERIC_FIND_FIRST_BIT > select GENERIC_GETTIMEOFDAY if HAVE_GENERIC_VDSO > select GENERIC_IOREMAP > select GENERIC_IRQ_MULTI_HANDLER