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=-2.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 8468EC4361B for ; Tue, 8 Dec 2020 22:55:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5260623AC9 for ; Tue, 8 Dec 2020 22:55:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731550AbgLHWzB (ORCPT ); Tue, 8 Dec 2020 17:55:01 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33724 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730812AbgLHWy7 (ORCPT ); Tue, 8 Dec 2020 17:54:59 -0500 Received: from mail-wm1-x344.google.com (mail-wm1-x344.google.com [IPv6:2a00:1450:4864:20::344]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 47AA2C061794; Tue, 8 Dec 2020 14:54:19 -0800 (PST) Received: by mail-wm1-x344.google.com with SMTP id c198so14823wmd.0; Tue, 08 Dec 2020 14:54:19 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc:content-transfer-encoding; bh=l6v5eGqOum7wUjmDQNJGAFz828yznKEqu47GFykos8E=; b=LhH39ZJllmZgRfTf/stoFJUkdm/dcAq3xnEuGAp8Va6ittVOc4iIH8MTdfV7F3DXgY j3v5mJq/mSgfFDthJdNwlTUTwaCdcDGtJ9nyTJRCiBh7Bcz28jPFFincwK7yvmYqww+u DAKUE12Za6tSxJ7Rbe0zSQt5qrwj+HIt2wgsec2kNK5HLwOFFyLjlQsWs7zXeSE4c+qB CnxDu+nEbuB6rOAyoyuc9jUtZDFbOJxyqkE3eylvSJUrWtUSSw6hC2tAP4Uz/ne32UcK bbFq2NUfAMF+5bmOEe43HzoPU6V9+bYd7SP94MCjgLKDEkRjS+HLojKmjx+3QNpVvf7V GcdQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc:content-transfer-encoding; bh=l6v5eGqOum7wUjmDQNJGAFz828yznKEqu47GFykos8E=; b=MY63rgHCCnisO9qVA1gf5tmemcitzdYr41OGqSFl6tN4reyZx7Zwwtbg8BJbqduaFf CP8rb8CYruDB2RUgfFKvnV+FVVnsnGgRSOxXkffhWQqzlIZfqKd49gfRBuP9AtW+K69B EoX5lHTl0NSMTZxO11RnPjgHVai45g+y3RPll8lr9edVJF8yE9puia4DdnGxWautqLQu 22pnJECqT9wOMzmHaOpk0/6E9fOTZMoW9FOoNtt6t5dIj4zIyvksTwlEG6EFX7M6tXAY d1lFQNLVITAgJRKtkDVxkz7TWPKghugTTYy67Eoua5rBRxqTFds/q+ZQiDP4+1Bvwxqx t0Lw== X-Gm-Message-State: AOAM530UdjG8ydEoaDtsBcYSrGAfo00kpvKML0Vz6kEq3TX+/klBe+zq 3rvHBl8CIoHZiij7v0XYXEyP8ULgahwTqYCjoc0= X-Google-Smtp-Source: ABdhPJw400Ws44xNLBD4ZTOJFxkw8sVbXemco2YVdG5lmPlUv7qXS9ndgp56DxsGieEi2wCieOAMSG4duQr34HnEoD0= X-Received: by 2002:a1c:b742:: with SMTP id h63mr64902wmf.122.1607468057844; Tue, 08 Dec 2020 14:54:17 -0800 (PST) MIME-Version: 1.0 References: <20201206064624.GA5871@ubuntu> <4e339fb4-adae-4c28-a40b-986b5e73fd0d@suse.com> In-Reply-To: <4e339fb4-adae-4c28-a40b-986b5e73fd0d@suse.com> From: Yun Levi Date: Wed, 9 Dec 2020 07:54:06 +0900 Message-ID: Subject: Re: [PATCH v2 1/8] lib/find_bit.c: Add find_last_zero_bit To: Nikolay Borisov Cc: Greg KH , Andrew Morton , Yury Norov , Andy Shevchenko , richard.weiyang@linux.alibaba.com, christian.brauner@ubuntu.com, Arnd Bergmann , Josh Poimboeuf , rdunlap@infradead.org, masahiroy@kernel.org, peterz@infradead.org, peter.enderborg@sony.com, krzk@kernel.org, Brendan Higgins , Kees Cook , broonie@kernel.org, matti.vaittinen@fi.rohmeurope.com, mhiramat@kernel.org, jpa@git.mail.kapsi.fi, nivedita@alum.mit.edu, Alexander Potapenko , orson.zhai@unisoc.com, Takahiro Akashi , clm@fb.com, Josef Bacik , dsterba@suse.com, dushistov@mail.ru, Linux Kernel Mailing List , linux-arch@vger.kernel.org, linux-btrfs@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > btrfs' free space cache v1 is going to be removed some time in the > future so introducing kernel-wide change just for its own sake is a bit > premature But, I think it's not quite a kernel-wide change just add the correspondent function to find_last_bit. So, if we add this feature, maybe some users will use it in near future. As my fault, I sent this patch without cover in patch [0/8] to explain why So, I will send this patch again to take some review... Sorry to make a noise again and Thanks to advice. On Sun, Dec 6, 2020 at 6:01 PM Nikolay Borisov wrote: > > > > On 6.12.20 =D0=B3. 10:56 =D1=87., Yun Levi wrote: > >> This, and the change above this, are not related to this patch so you > >> might not want to include them. > > > >> Also, why is this patch series even needed? I don't see a justificati= on > >> for it anywhere, only "what" this patch is, not "why". > > > > I think the find_last_zero_bit will help to improve in > > 7th patch's change and It can be used in the future. > > But if my thinking is bad.. Please let me know.. > > > > Thanks. > > Levi. > > > > btrfs' free space cache v1 is going to be removed some time in the > future so introducing kernel-wide change just for its own sake is a bit > premature. Also do you have measurements showing it indeed improves > performances?