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=-2.8 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 3C4FCC4338F for ; Sun, 15 Aug 2021 11:10:24 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id C91286054E for ; Sun, 15 Aug 2021 11:10:23 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org C91286054E Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvack.org Received: by kanga.kvack.org (Postfix) id 65FA56B006C; Sun, 15 Aug 2021 07:10:23 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 610846B0071; Sun, 15 Aug 2021 07:10:23 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 4D8676B0072; Sun, 15 Aug 2021 07:10:23 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0009.hostedemail.com [216.40.44.9]) by kanga.kvack.org (Postfix) with ESMTP id 30C546B006C for ; Sun, 15 Aug 2021 07:10:23 -0400 (EDT) Received: from smtpin10.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id C33DD1E4F0 for ; Sun, 15 Aug 2021 11:10:22 +0000 (UTC) X-FDA: 78477046284.10.74D99A0 Received: from mail-pj1-f48.google.com (mail-pj1-f48.google.com [209.85.216.48]) by imf20.hostedemail.com (Postfix) with ESMTP id 918B0D00065B for ; Sun, 15 Aug 2021 11:10:22 +0000 (UTC) Received: by mail-pj1-f48.google.com with SMTP id hv22-20020a17090ae416b0290178c579e424so22872986pjb.3 for ; Sun, 15 Aug 2021 04:10:22 -0700 (PDT) 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; bh=1hTo1UwRlyqp+pMdlXGYPhfq0rOnoJLrck7pYizHgPU=; b=ki4MbLSO6ktJBBmJWeAW9iXHb99ZK/NlJzMuyhU1WHgiB1izAuZcFaDxzfK8e5I4GN GNd6Ga0s6XH90h8kPCmLzUU1hnM+OEcwApME4miRVOxbrBhnYa4Phm5kgSW8z+yDtdBJ hYos1WTb8FiECvf6YO6Ie9c3VDtniCE7hS0VR6AbuIsXJx/aeU8NOKMNkVoR9Qz38BCg L42/kNp8yGfmgJwLWJ1n6XsD9Ccr6bDMoD/Qwua2omJgB+pJkyiJsC2qO2bAyKxPgh3S N9ykDctPuAiy0lQ/wzrmJIxRPmkVOtIU0B54EJ0s3R2ShftkFCbK/TEbvxqaM99en7C/ Tvmw== 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; bh=1hTo1UwRlyqp+pMdlXGYPhfq0rOnoJLrck7pYizHgPU=; b=mpVV5Gzh8k82zzQUN3vxRQU/vcvikonV12oIcbgdG13IZDXWlU/vFP5k3dAxUkADwd 4OLKEaUERuxRcd+KtJHnSOLu1iiLIfEeLNMiYwUZhex+hd5wbq0oZTYFEWY50FQaB68m CugAQvuEBK5r/ZpEXPwq4kEKF95bx+x2jGeqRFtK2+Lo/ecmRs1YKQGrU5O85y/6vWoX 8O447DBpqVoAfW1iwazhRNZf/+tpueJGg27MR+BLZtn7R9E73zjfBUEpYKP3c92BAZfj Kc0OnUoQ0ceGYQidBOMyZAmoBvbsT54gkfpqMahAU+rc4a83bHkg2sI5VLr81/8wEAns gFiw== X-Gm-Message-State: AOAM531OIhWsOxqMF/6+em4pHC4aErUCuEnjlQwqI4GmZoFznqsXBx+B ZvAfHa8wQGDa83HJl2zANcSaNfryja06ug5Pt2g= X-Google-Smtp-Source: ABdhPJyX0puTwgDSKe17THJRks86nytntC1/Vm9fFgYZajAdikFyaOpXXy9Bg8UpfdHkE4M8OR1qUHu1CsaKoe3XyEw= X-Received: by 2002:a17:902:ced0:b029:12d:4ce1:ce3a with SMTP id d16-20020a170902ced0b029012d4ce1ce3amr9073769plg.0.1629025821388; Sun, 15 Aug 2021 04:10:21 -0700 (PDT) MIME-Version: 1.0 References: <20210814211713.180533-1-yury.norov@gmail.com> <20210814211713.180533-18-yury.norov@gmail.com> In-Reply-To: <20210814211713.180533-18-yury.norov@gmail.com> From: Andy Shevchenko Date: Sun, 15 Aug 2021 14:09:45 +0300 Message-ID: Subject: Re: [PATCH 17/17] vsprintf: rework bitmap_list_string To: Yury Norov Cc: Andrew Morton , Linux Kernel Mailing List , linux-mm , Linux-Arch , "open list:KERNEL SELFTEST FRAMEWORK" , linux-mmc , linux-perf-users@vger.kernel.org, "open list:VFIO DRIVER" , "James E.J. Bottomley" , Alexander Lobakin , Alexander Shishkin , Alexey Klimov , Andrea Merello , Andy Shevchenko , Arnaldo Carvalho de Melo , Arnd Bergmann , Ben Gardon , Benjamin Herrenschmidt , Brian Cain , Catalin Marinas , Christoph Lameter , Daniel Bristot de Oliveira , David Hildenbrand , Dennis Zhou , Geert Uytterhoeven , Heiko Carstens , Ian Rogers , Ingo Molnar , Jaegeuk Kim , Jakub Kicinski , Jiri Olsa , Joe Perches , Jonas Bonn , Leo Yan , Mark Rutland , Namhyung Kim , Palmer Dabbelt , Paolo Bonzini , Peter Xu , Peter Zijlstra , Petr Mladek , Rasmus Villemoes , Rich Felker , Samuel Mendoza-Jonas , Sean Christopherson , Sergey Senozhatsky , Shuah Khan , Stefan Kristiansson , Steven Rostedt , Tejun Heo , Thomas Bogendoerfer , Ulf Hansson , Will Deacon , Wolfram Sang , Yoshinori Sato Content-Type: text/plain; charset="UTF-8" X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: 918B0D00065B X-Stat-Signature: uzyzznhm4s8udkonauqtowbbwzp3ct8s Authentication-Results: imf20.hostedemail.com; dkim=pass header.d=gmail.com header.s=20161025 header.b=ki4MbLSO; dmarc=pass (policy=none) header.from=gmail.com; spf=pass (imf20.hostedemail.com: domain of andyshevchenko@gmail.com designates 209.85.216.48 as permitted sender) smtp.mailfrom=andyshevchenko@gmail.com X-HE-Tag: 1629025822-946112 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Sun, Aug 15, 2021 at 12:21 AM Yury Norov wrote: > > bitmap_list_string() is very ineffective when printing bitmaps with long > ranges of set bits because it calls find_next_bit for each bit in the > bitmap. We can do better by detecting ranges of set bits. > > In my environment, before/after is 943008/31008 ns. I would add a couple of words, maybe in parentheses, to describe what your environment is. ... > + buf = number(++buf, end, rtop - 1, default_dec_spec); ++buf is a bit confusing here. Since you will rewrite the buf value anyway, I would write the parameter as buf + 1. -- With Best Regards, Andy Shevchenko