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=-16.0 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 D07DAC07E99 for ; Fri, 9 Jul 2021 03:45:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B944761445 for ; Fri, 9 Jul 2021 03:45:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231294AbhGIDsU (ORCPT ); Thu, 8 Jul 2021 23:48:20 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56328 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231231AbhGIDsJ (ORCPT ); Thu, 8 Jul 2021 23:48:09 -0400 Received: from mail-qv1-xf2b.google.com (mail-qv1-xf2b.google.com [IPv6:2607:f8b0:4864:20::f2b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 90015C061574 for ; Thu, 8 Jul 2021 20:45:25 -0700 (PDT) Received: by mail-qv1-xf2b.google.com with SMTP id ck17so3438880qvb.9 for ; Thu, 08 Jul 2021 20:45:25 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=LZc6PQvxJE3vuowyf5qW3WCAvlsyelNP3ykNDlBCd4A=; b=peRb848JP0XojBcDzRRia1v4sfZsZkCPLhNPiqDk47nE/YHcnau8FUbgkQsOXltIrp eEV0brbekkLX5ip2oaMIyIp0wvX4z0w6MS9jy7f4rtLHG34ca4FugsmWXLbdctRbE/5U XlBxhUs8ygwh5Nas7siRlT1ShQjL3y9GPZSqJuOtGbP8kAicPYSIjCusa+Y6MJDnYK3H r5Urbmp7WesBlUm1K+KC9ZgVNZUgT3FKvi5kIWpRajpsoD5IVHuyoK3b9PCXkwA+VqUQ dQ/8yV/4v3tEfjAGZsmFIIrV9dSSnPiH1w4DFUVLV7NgKsuTbVBY0TRWJUygGTsTbsZh Gqdw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=LZc6PQvxJE3vuowyf5qW3WCAvlsyelNP3ykNDlBCd4A=; b=rA/cHWO4suxXp/yHy78vQPV2za6+Wn1y4nEnA2jRlJw9avKbgopF1EONQbx6L6HgYu 7l8+y5/z0iNk8zbjOIQtK89suhq6oWpcsORfbWrMlq+c5Bw2fidzz9Fgbqu/YHVK/jTi FruoEosnQTMVn3cpIynNQmhsT56bSG2W+oTKwKKb9ELL1xCM0qR32NpmcM0HyFeNIIHk hU4UYbFudSj50ChKUCvtwAbIcGtL2fYh5d/N2IBoOs6F/SuKi4fZKZE1W5Zo1zYjGJVi kaKzopLY4b31ROK77yKBeMSLQpciA4V4KKBWlHU7fF+gj4t3fajOXsneDRAxsjFFBwQE lNLw== X-Gm-Message-State: AOAM531TK0rm86EjYLCQRhKjvLKk18CYUKVLykvbatlBpCTkLEk0Zdjk dr8J4ET+y8OHCCL7hMx6hCzbH+1xxLo= X-Google-Smtp-Source: ABdhPJziLEsfdBh7HPtU/ANQ0WrGdPj0Hqhl/zbC8MJOKqCIXaIKhf/qRfKhC0Vy9fk4XTSPDS6Hqw== X-Received: by 2002:a05:6214:90e:: with SMTP id dj14mr33498193qvb.10.1625802324438; Thu, 08 Jul 2021 20:45:24 -0700 (PDT) Received: from localhost ([207.98.216.60]) by smtp.gmail.com with ESMTPSA id p187sm1977782qkd.101.2021.07.08.20.45.24 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 08 Jul 2021 20:45:24 -0700 (PDT) From: Yury Norov To: linux-kernel@vger.kernel.org Cc: Yury Norov , Andy Shevchenko , Rasmus Villemoes , Petr Mladek , Steven Rostedt , Sergey Senozhatsky , Tejun Heo Subject: [PATCH 2/2] bitmap: introduce for_each_set_bitrange Date: Thu, 8 Jul 2021 20:45:19 -0700 Message-Id: <20210709034519.2859777-3-yury.norov@gmail.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210709034519.2859777-1-yury.norov@gmail.com> References: <20210709034519.2859777-1-yury.norov@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org bitmap_list_string() is very ineffective when printing bitmaps with long ranges of set bits because it calls find_next_bit for each bit. We can do better by detecting ranges of set bits. This patch introduces a macro for_each_set_bitrange and uses it in bitmap_list_string(). In my environment, before/after is 943008/31008 ns. Signed-off-by: Yury Norov --- include/linux/find.h | 7 +++++++ lib/vsprintf.c | 40 ++++++++++++++++------------------------ 2 files changed, 23 insertions(+), 24 deletions(-) diff --git a/include/linux/find.h b/include/linux/find.h index ae9ed52b52b8..1a5ed45dc81b 100644 --- a/include/linux/find.h +++ b/include/linux/find.h @@ -301,6 +301,13 @@ unsigned long find_next_bit_le(const void *addr, unsigned (bit) < (size); \ (bit) = find_next_zero_bit((addr), (size), (bit) + 1)) +#define for_each_set_bitrange(b, e, addr, size) \ + for ((b) = find_next_bit((addr), (size), 0), \ + (e) = find_next_zero_bit((addr), (size), (b) + 1); \ + (b) < (size); \ + (b) = find_next_bit((addr), (size), (e) + 1), \ + (e) = find_next_zero_bit((addr), (size), (b) + 1)) + /** * for_each_set_clump8 - iterate over bitmap for each 8-bit clump with set bits * @start: bit offset to start search and to store the current iteration offset diff --git a/lib/vsprintf.c b/lib/vsprintf.c index 87acf66f0e4c..1ee54dace71e 100644 --- a/lib/vsprintf.c +++ b/lib/vsprintf.c @@ -1240,38 +1240,30 @@ char *bitmap_list_string(char *buf, char *end, unsigned long *bitmap, struct printf_spec spec, const char *fmt) { int nr_bits = max_t(int, spec.field_width, 0); - /* current bit is 'cur', most recently seen range is [rbot, rtop] */ - int cur, rbot, rtop; - bool first = true; + char *start = buf; + int b, e; if (check_pointer(&buf, end, bitmap, spec)) return buf; - rbot = cur = find_first_bit(bitmap, nr_bits); - while (cur < nr_bits) { - rtop = cur; - cur = find_next_bit(bitmap, nr_bits, cur + 1); - if (cur < nr_bits && cur <= rtop + 1) - continue; + for_each_set_bitrange(b, e, bitmap, nr_bits) { + buf = number(buf, end, b, default_dec_spec); + if (e == b + 1) + goto put_comma; - if (!first) { - if (buf < end) - *buf = ','; - buf++; - } - first = false; + if (buf < end) + *buf = '-'; - buf = number(buf, end, rbot, default_dec_spec); - if (rbot < rtop) { - if (buf < end) - *buf = '-'; - buf++; + buf = number(++buf, end, e - 1, default_dec_spec); +put_comma: + if (buf < end) + *buf = ','; + buf++; + } - buf = number(buf, end, rtop, default_dec_spec); - } + if (buf > start) + buf--; - rbot = cur; - } return buf; } -- 2.30.2