From nobody Wed Dec 17 08:19:07 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5D091C10F13 for ; Tue, 12 Dec 2023 02:28:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1345719AbjLLC2F (ORCPT ); Mon, 11 Dec 2023 21:28:05 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43558 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231235AbjLLC1x (ORCPT ); Mon, 11 Dec 2023 21:27:53 -0500 Received: from mail-ot1-x32c.google.com (mail-ot1-x32c.google.com [IPv6:2607:f8b0:4864:20::32c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DCB46D5; Mon, 11 Dec 2023 18:27:59 -0800 (PST) Received: by mail-ot1-x32c.google.com with SMTP id 46e09a7af769-6d9e993d94dso2881092a34.0; Mon, 11 Dec 2023 18:27:59 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1702348078; x=1702952878; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=LuotiINhbKGxGGef8K7G7yCOze6MU0SeJK9/E0VqPZk=; b=mOu2oZ9PdmyEQBvwYpbB4CxFhLPixosCG/9dqh1Cc/zIR24Fy9cxxE1bnhoq1S4HSH 2vlmhvyBtQA6tn2USXss6mEQeM9wt3l7Id3Tbu6029uRdoR/RA2glANWTWs/YjBv1Hrf RO/Bq3AuywwoN+LCLd+t/kP5HmkKKJGtbX3R58KaCqjuMoNFp/yw9rDdjSIIHkKMPiFJ ejqmZaLjmHXR4jE3vqghgoNj8WYXML9w9KOYHNlI/6E8PzshNsPZ6oKg7RLlSFj0GSaE 4DFw8w8uzqma1JnB04lU5hqrxYCQFneSE1bTt7mVJi7m4RNINMm7qpk/IDGJxwD7hexQ o9wA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1702348078; x=1702952878; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=LuotiINhbKGxGGef8K7G7yCOze6MU0SeJK9/E0VqPZk=; b=hNOl2H/obmBkuHof2JdmjYHXOu7+BQ9EvpAl/06W62xhN8MKny6AmKD7YGffI7etC1 lpnA5K9w6xOx5pFZQ4V2x8SXsVHz4AnUc1PqpGqXBAMHqsNjZeWdAakpsccUVFS6qetv QGZx0/w6+ZecW/OIU6oI9D8/rcx0DcqVsHuAfpg9LvHKbMxH2YhPTy6IolGN9wvyl2IN zmwvaySq4eUxSEl6Qlo9AYisCF5BLRvQeAr9QbqK+QbmMmgJb67/gpBgIF/Z/5/Pr31q lvR80DxVqOpy3nmrfOHDNZfxyIRpBrl6ovmdsXd/5sw8S7C1ssA5dyI9Vn4BfrNo3Viy ZdIg== X-Gm-Message-State: AOJu0YyMGJIhoR/j94c6UT2TGKIBe06djo4hGnT1j80nujKkkwCefYEV RRJemezSlojt0l0VbYAGfpuu5zgrB038Dw== X-Google-Smtp-Source: AGHT+IEHnCevx/zjXgMWzqImSiSNPCTlhUeZk/gNmGSenVJT/HCL0VqZAYmviFs6i1xsO2WZY35Fqw== X-Received: by 2002:a05:6830:16d9:b0:6d8:74e2:6f48 with SMTP id l25-20020a05683016d900b006d874e26f48mr4356891otr.68.1702348078162; Mon, 11 Dec 2023 18:27:58 -0800 (PST) Received: from localhost ([2601:344:8301:57f0:38aa:1c88:df05:9b73]) by smtp.gmail.com with ESMTPSA id q1-20020a0de701000000b005cb1bf4d466sm3464287ywe.82.2023.12.11.18.27.56 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 11 Dec 2023 18:27:57 -0800 (PST) From: Yury Norov To: linux-kernel@vger.kernel.org, Jens Axboe , linux-block@vger.kernel.org Cc: Yury Norov , Jan Kara , Mirsad Todorovac , Matthew Wilcox , Rasmus Villemoes , Andy Shevchenko , Maxim Kuvyrkov , Alexey Klimov , Bart Van Assche , Sergey Shtylyov Subject: [PATCH v3 03/35] lib/sbitmap; optimize __sbitmap_get_word() by using find_and_set_bit() Date: Mon, 11 Dec 2023 18:27:17 -0800 Message-Id: <20231212022749.625238-4-yury.norov@gmail.com> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20231212022749.625238-1-yury.norov@gmail.com> References: <20231212022749.625238-1-yury.norov@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" __sbitmap_get_word() opencodes either find_and_set_bit_wrap(), or find_and_set_next_bit() depending on wrap parameter. Simplify it by using atomic find_bit() API. While here, simplify sbitmap_find_bit_in_word(), which calls it. CC: Jens Axboe Signed-off-by: Yury Norov Reviewed-by: Jan Kara --- lib/sbitmap.c | 46 +++++++++------------------------------------- 1 file changed, 9 insertions(+), 37 deletions(-) diff --git a/lib/sbitmap.c b/lib/sbitmap.c index d0a5081dfd12..8ecd830ba9e8 100644 --- a/lib/sbitmap.c +++ b/lib/sbitmap.c @@ -133,38 +133,13 @@ void sbitmap_resize(struct sbitmap *sb, unsigned int = depth) } EXPORT_SYMBOL_GPL(sbitmap_resize); =20 -static int __sbitmap_get_word(unsigned long *word, unsigned long depth, +static inline int __sbitmap_get_word(unsigned long *word, unsigned long de= pth, unsigned int hint, bool wrap) { - int nr; - - /* don't wrap if starting from 0 */ - wrap =3D wrap && hint; - - while (1) { - nr =3D find_next_zero_bit(word, depth, hint); - if (unlikely(nr >=3D depth)) { - /* - * We started with an offset, and we didn't reset the - * offset to 0 in a failure case, so start from 0 to - * exhaust the map. - */ - if (hint && wrap) { - hint =3D 0; - continue; - } - return -1; - } + if (wrap) + return find_and_set_bit_wrap_lock(word, depth, hint); =20 - if (!test_and_set_bit_lock(nr, word)) - break; - - hint =3D nr + 1; - if (hint >=3D depth - 1) - hint =3D 0; - } - - return nr; + return find_and_set_next_bit_lock(word, depth, hint); } =20 static int sbitmap_find_bit_in_word(struct sbitmap_word *map, @@ -175,15 +150,12 @@ static int sbitmap_find_bit_in_word(struct sbitmap_wo= rd *map, int nr; =20 do { - nr =3D __sbitmap_get_word(&map->word, depth, - alloc_hint, wrap); - if (nr !=3D -1) - break; - if (!sbitmap_deferred_clear(map)) - break; - } while (1); + nr =3D __sbitmap_get_word(&map->word, depth, alloc_hint, wrap); + if (nr < depth) + return nr; + } while (sbitmap_deferred_clear(map)); =20 - return nr; + return -1; } =20 static int sbitmap_find_bit(struct sbitmap *sb, --=20 2.40.1