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=-5.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 77ACDC433EF for ; Thu, 9 Sep 2021 14:39:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5D6186120A for ; Thu, 9 Sep 2021 14:39:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1350425AbhIIOkK (ORCPT ); Thu, 9 Sep 2021 10:40:10 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46348 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237947AbhIIOkE (ORCPT ); Thu, 9 Sep 2021 10:40:04 -0400 Received: from ustc.edu.cn (email6.ustc.edu.cn [IPv6:2001:da8:d800::8]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 6535AC1A16FC for ; Thu, 9 Sep 2021 06:56:05 -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=AS4GoMNuNsExioqPJiOWEVu+3vDbz3bR3P ju384umbs=; b=Q0mP44lKzggbQhiTjNegXyJD4X+EDPSQAEquIo+Ib3iEGvj4eI NDlzUEUFl04iFojHsp7XC7RKM482eu2GIYRg/tff3iXi74q9S2ba+HzQJ6gXRSWO r5eWgt0Y+2rm5wn77BdY6ur8xEF2nuVkz08cGcd5L1JDelro1wRu7wE8k= Received: from xhacker (unknown [101.86.20.15]) by newmailweb.ustc.edu.cn (Coremail) with SMTP id LkAmygB3fgJsEjphqk0PAA--.207S2; Thu, 09 Sep 2021 21:55:56 +0800 (CST) Date: Thu, 9 Sep 2021 21:49:29 +0800 From: Jisheng Zhang To: Kefeng Wang Cc: Paul Walmsley , Palmer Dabbelt , Albert Ou , , Subject: Re: [PATCH] riscv: enable GENERIC_FIND_FIRST_BIT Message-ID: <20210909214929.7c2b9ae0@xhacker> In-Reply-To: References: <20210718001423.6b8e1d23@xhacker> <20210908230427.3a92fb87@xhacker> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable X-CM-TRANSID: LkAmygB3fgJsEjphqk0PAA--.207S2 X-Coremail-Antispam: 1UD129KBjvdXoW7GF18GF4DJw1xZrW8Kr4xCrg_yoWkuFX_Wr y0y3ykCw4UZrs7Aan8XayavFWqkF48W34ruw4jyrn8XrW3J3y8CF4kWF9aqayrCr40yF4U KF9Iv3W5Xr97JjkaLaAFLSUrUUUUUb8apTn2vfkv8UJUUUU8Yxn0WfASr-VFAUDa7-sFnT 9fnUUIcSsGvfJTRUUUbrAYjsxI4VWxJwAYFVCjjxCrM7AC8VAFwI0_Jr0_Gr1l1xkIjI8I 6I8E6xAIw20EY4v20xvaj40_Wr0E3s1l1IIY67AEw4v_Jr0_Jr4l8cAvFVAK0II2c7xJM2 8CjxkF64kEwVA0rcxSw2x7M28EF7xvwVC0I7IYx2IY67AKxVW7JVWDJwA2z4x0Y4vE2Ix0 cI8IcVCY1x0267AKxVWxJVW8Jr1l84ACjcxK6I8E87Iv67AKxVW0oVCq3wA2z4x0Y4vEx4 A2jsIEc7CjxVAFwI0_GcCE3s1le2I262IYc4CY6c8Ij28IcVAaY2xG8wAqx4xG64xvF2IE w4CE5I8CrVC2j2WlYx0E2Ix0cI8IcVAFwI0_Jr0_Jr4lYx0Ex4A2jsIE14v26r1j6r4UMc vjeVCFs4IE7xkEbVWUJVW8JwACjcxG0xvEwIxGrwCF04k20xvY0x0EwIxGrwCFx2IqxVCF s4IE7xkEbVWUJVW8JwC20s026c02F40E14v26r1j6r18MI8I3I0E7480Y4vE14v26r106r 1rMI8E67AF67kF1VAFwI0_JF0_Jw1lIxkGc2Ij64vIr41lIxAIcVC0I7IYx2IY67AKxVWU JVWUCwCI42IY6xIIjxv20xvEc7CjxVAFwI0_Jr0_Gr1lIxAIcVCF04k26cxKx2IYs7xG6r W3Jr0E3s1lIxAIcVC2z280aVAFwI0_Jr0_Gr1lIxAIcVC2z280aVCY1x0267AKxVWUJVW8 JbIYCTnIWIevJa73UjIFyTuYvjxU2_HUDUUUU X-CM-SenderInfo: xmv2xttqjtqzxdloh3xvwfhvlgxou0/ Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 9 Sep 2021 08:58:31 +0800 Kefeng Wang wrote: > On 2021/9/8 23:04, Jisheng Zhang wrote: > > Hi Palmer, > > > > On Sun, 18 Jul 2021 00:14:23 +0800 > > Jisheng Zhang wrote: > > =20 > >> From: Jisheng Zhang > >> > >> riscv doesn't implement architecture-optimized bitsearching functions > >> such as find_first_{zero}_bit() etc. > >> > >> When GENERIC_FIND_FIRST_BIT=3Dn, 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%. =20 > > It seems this patch is missed. Is it possible to pick it up for 2nd 5.1= 5-rc1 PR? > > > > Thanks =20 >=20 > It is enabled unconditionally by following commit >=20 > commit dbbccfe505ef8fae804677abf0564c1e07479102 >=20 > Author: Yury Norov > Date:=C2=A0=C2=A0 Tue Aug 24 09:59:56 2021 +1000 >=20 > =C2=A0=C2=A0=C2=A0 arch: remove GENERIC_FIND_FIRST_BIT entirely >=20 Aha, thanks for the information. After Yury's commit, this patch is useless now. thanks