From patchwork Wed Oct 13 16:54:11 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jens Axboe X-Patchwork-Id: 12556369 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 3E173C4332F for ; Wed, 13 Oct 2021 16:54:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 29AAE6112D for ; Wed, 13 Oct 2021 16:54:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237563AbhJMQ40 (ORCPT ); Wed, 13 Oct 2021 12:56:26 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55884 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237193AbhJMQ40 (ORCPT ); Wed, 13 Oct 2021 12:56:26 -0400 Received: from mail-il1-x12b.google.com (mail-il1-x12b.google.com [IPv6:2607:f8b0:4864:20::12b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D79E1C061749 for ; Wed, 13 Oct 2021 09:54:22 -0700 (PDT) Received: by mail-il1-x12b.google.com with SMTP id h10so426257ilq.3 for ; Wed, 13 Oct 2021 09:54:22 -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=CflgU2lNxFISUs7Wvc/XFgDqwIo5d6uA52jlkovsmf2d3JZ4uAkoCdFnq8suCN0ic/ Oh0lXdUwWq0YKA/gQES0XUq3P81BmEdIDQpxFiRGjkKitiUtafjm8ksVrehZby7DWjY0 GW1hrVL+KIuyhCiKIcso7Drlp/6KtYHYEKCbvVaI+EEFs74aO3ihzw9fXzXMhosEJ8wH rLu3xh9661EdHfkcy+hcH0GoPhIzUUSWT2+kjwxCmSFqk7DRjX3s4WBXSkNJoy0h8ZIW iEsKCx/9EGVZ7rSWjS/IjGPIMp8L0ih1aMF6iR1gN87fVQbd6ts7AZWTn06ZWodaj/5c 8Tmg== 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=pi7fbkf2Sm/BJXrCuiIlggDwl1KuTImIlYoSdshnw0AxXljIsstjV9jXIZzaPZ2IqP hemOX5j8PphXfzbCtB85c2fDLpRf5dKxsjp6VzMsvZzYs0gH0fnuEEjC/mGXn2awsXVU vsLRnPR/dJVov9fRiNM02B4uamucrE/AJTnARiTtqTKF2fudPKCxh5dR9ffT9dOCCSUM FHrCcozs84dMX4wXuRrZyFaA4nepJebKMJUoG6hRZXgFw96zUxQeVAuAzh3rhg1DyXkA 1v/rqt6MOeVimlXm5qKN+Tdd1Yoqc3X99LfSIbc/GelzXDcTohZ+M1gKJR1YzLemZNoI zilw== X-Gm-Message-State: AOAM533RMka8m5eg1hQuYo+hYjFxEHr2my/cVuTcqfFX+BCENIYcY8Ou LFYKpuk8JKzHZIEYWOU6cJN2rY+xsltaKg== X-Google-Smtp-Source: ABdhPJz0XpqF3ukDwj/1tNTioMwvr6SBUJaon891lNXBWnGTFI6QRM5p1x/cay79NvB7a/TEdCoywA== X-Received: by 2002:a05:6e02:1569:: with SMTP id k9mr89672ilu.317.1634144062169; Wed, 13 Oct 2021 09:54:22 -0700 (PDT) Received: from p1.localdomain ([207.135.234.126]) by smtp.gmail.com with ESMTPSA id r7sm65023ior.25.2021.10.13.09.54.21 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 13 Oct 2021 09:54:21 -0700 (PDT) From: Jens Axboe To: linux-block@vger.kernel.org Cc: Jens Axboe Subject: [PATCH 4/9] sbitmap: test bit before calling test_and_set_bit() Date: Wed, 13 Oct 2021 10:54:11 -0600 Message-Id: <20211013165416.985696-5-axboe@kernel.dk> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20211013165416.985696-1-axboe@kernel.dk> References: <20211013165416.985696-1-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;