From patchwork Tue Oct 12 18:17:36 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jens Axboe X-Patchwork-Id: 12553467 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 54245C433FE for ; Tue, 12 Oct 2021 18:17:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 37F4460C4B for ; Tue, 12 Oct 2021 18:17:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232865AbhJLSTz (ORCPT ); Tue, 12 Oct 2021 14:19:55 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56354 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231672AbhJLSTw (ORCPT ); Tue, 12 Oct 2021 14:19:52 -0400 Received: from mail-il1-x12f.google.com (mail-il1-x12f.google.com [IPv6:2607:f8b0:4864:20::12f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 53321C061570 for ; Tue, 12 Oct 2021 11:17:50 -0700 (PDT) Received: by mail-il1-x12f.google.com with SMTP id y17so11947ilb.9 for ; Tue, 12 Oct 2021 11:17:50 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20210112.gappssmtp.com; s=20210112; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=UWWbxxl1nqVuRPyRl4TrQ64PvIRN1ySCGLzomh2MwOY=; b=1toiFYGSPZD5+BDx2LJqqAoDP/et5H3GL7u3PweHmxR9NWV75Cjnbmt+o2mlNbL3z+ LOxLbnaFcNQolgt+c2tBw6Bbv2mSgVI/36lUGwUWIW+G/md3R6awGbv53d3XGxApP0O0 ASHPPp674rSEk5nmD/WfJw6seHbKHj5e4Y1o2o/AHccUtKQpMEhw7XX7fXu4s4IUaQTe 4uHNr43L0qAxUZLn18wf03B+PHXMLfYvYS9YIaVdpzfEn56jkaZnieWWVWpMmDIHqUmM HYo/fA71gkHF8Gp1JmFDy9Ir11ds7Q2eTo4BnDCk/MHx+tiAD0eec/MK/y23LO1I3baE ebVg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=UWWbxxl1nqVuRPyRl4TrQ64PvIRN1ySCGLzomh2MwOY=; b=bOfZZ60F0mqNVT5396ZPW0m+ozI8h/2MxGlkgp7Wydiu+zphOVEVPPcZ2ox3YyfqTX wuQW7Q6/o+SPjvkAYWZn5pmeiqR7FkJTzbSr5vkUicuIFHfvjoNujkWO0rv/MT6ssBWR EgKhR3ffVed98LLqljiZRLPP6mu0Jmabf1x9J9BX/3xwlUHbD8F1gaEyyeNWQ015Qpxo bCQa7rFwjYFQtse70w0v4YeXGtM8QcDKdM4OX+MR73YkVW2VsP5JxW5uWHcoTZH36HMz tCcxcK59UE50fB3z/afaWcJY2UvpPUvy7h47KFUmEdiMOgckkTxyckHqJBuaI7szacm1 KaaA== X-Gm-Message-State: AOAM531WB5q4q3430bGqrMuZTvWPoYNeyga7+QVlLtI+b9+yp+9ua3EI +ENp4Pas7nS8NWrx1B2e5wWcQyiayPfZrQ== X-Google-Smtp-Source: ABdhPJwRdb84J3XEqgxDMhSMFfN/MTKY/wPDxsOOOi0DpS+oyqOqxvcz/ZbTvy2MsI63zB+UkV0Rng== X-Received: by 2002:a05:6e02:1486:: with SMTP id n6mr25703510ilk.195.1634062667111; Tue, 12 Oct 2021 11:17:47 -0700 (PDT) Received: from p1.localdomain ([207.135.234.126]) by smtp.gmail.com with ESMTPSA id x5sm2242476ioh.23.2021.10.12.11.17.46 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 12 Oct 2021 11:17:46 -0700 (PDT) From: Jens Axboe To: linux-block@vger.kernel.org Cc: Jens Axboe Subject: [PATCH 3/9] sbitmap: test bit before calling test_and_set_bit() Date: Tue, 12 Oct 2021 12:17:36 -0600 Message-Id: <20211012181742.672391-4-axboe@kernel.dk> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20211012181742.672391-1-axboe@kernel.dk> References: <20211012181742.672391-1-axboe@kernel.dk> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org If we come across bits that are already set, then it's quicker to test that first and gate the test_and_set_bit() operation on the result of the bit test. Signed-off-by: Jens Axboe --- lib/sbitmap.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/lib/sbitmap.c b/lib/sbitmap.c index c6e2f1f2c4d2..11b244a8d00f 100644 --- a/lib/sbitmap.c +++ b/lib/sbitmap.c @@ -166,7 +166,7 @@ static int __sbitmap_get_word(unsigned long *word, unsigned long depth, return -1; } - if (!test_and_set_bit_lock(nr, word)) + if (!test_bit(nr, word) && !test_and_set_bit_lock(nr, word)) break; hint = nr + 1;