From nobody Wed Dec 31 15:46:16 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 789FAC41535 for ; Wed, 1 Nov 2023 22:58:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1347439AbjKAW6g (ORCPT ); Wed, 1 Nov 2023 18:58:36 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40692 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1347154AbjKAW6d (ORCPT ); Wed, 1 Nov 2023 18:58:33 -0400 Received: from mail-yw1-x112a.google.com (mail-yw1-x112a.google.com [IPv6:2607:f8b0:4864:20::112a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4B2EDB9 for ; Wed, 1 Nov 2023 15:58:31 -0700 (PDT) Received: by mail-yw1-x112a.google.com with SMTP id 00721157ae682-5a82c2eb50cso4391417b3.2 for ; Wed, 01 Nov 2023 15:58:31 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1698879510; x=1699484310; 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=4k0IeS2aGdp15vS08AFa8OvRrkQNOjngbPieIhmhkWY=; b=IJ+fV339yMky4n0SaOgxnEYUAvEJUPGtWNZA4D+nacF7hMV0d4NQ8a7EgRErCQa7Y5 ui5EZbEYgWAKMDweypSJvK7IPpIwX8H/3k/Kf8/KSIxdkLx/KyPPDO9ALphduoXdoDNF 9lneFyPSBxoLNmgI2vK4Gez3Pb1wmvhmfwHQN6OOg5RzXVIqPP1w6eu+7nsOkkSSoybs ci53iRCH0dhVw756+oGE3rH2hEaSVyfcESPiawFawEXI9oAZqgrIMCsegtUL7JOVzz2J UygAU1aVBI5i7zbk3q0hnTWAavqxHpVmh5pNOeKTqhg5JZUukyuozupu4P34jlYURwyH DsEQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1698879510; x=1699484310; 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=4k0IeS2aGdp15vS08AFa8OvRrkQNOjngbPieIhmhkWY=; b=N/BOn79s6a/k7yQgh1FHsoDIcRaDw2qlVi/WImUGH55TQty3GsDuElyjIj+ULNprxR X7ryWCbOdhv3jBGOidWrN4q7VVkdJkQ80cw32XK27W7e47YGgsFcTMEn9qaVvsszw1Kp dWO6OWN4hWmeHXeL/18k0jnuOxVi/qfjZexag53R6rCiXc+6tXxPDze9C1VZllEPtBOL afhTt8p1Nl6EeVsJPHZouIO8ZW2EmQ1TkG2P6fJdgm8IKClgd3UrXx5nxA7vQnvYU3YD hIuohw+rT9G/9mnAHw1oMUmgAAN7kFcOtDDpuLqFxuWRVE2Gep6jnOQuWEazpPT/3XV5 BC9w== X-Gm-Message-State: AOJu0YzFp8DF9tT7bMYAd0Of4x4pJJ7zcJvkpB1FRKbhtYK/qWrzNwyr sLO2sTSVHfal3CMXpxPkWTQ= X-Google-Smtp-Source: AGHT+IHoBQkkXpFMyW6Pf4ikXQPtueOnCt4+iD4agZ9Ho67+ob6SzRX7ZsSo2JjSzlwCE2DyxXFaRg== X-Received: by 2002:a81:ae63:0:b0:5a7:b8e6:6441 with SMTP id g35-20020a81ae63000000b005a7b8e66441mr14841928ywk.16.1698879510385; Wed, 01 Nov 2023 15:58:30 -0700 (PDT) Received: from localhost ([50.221.102.30]) by smtp.gmail.com with ESMTPSA id i13-20020a81910d000000b005a7bfec6c34sm529504ywg.46.2023.11.01.15.58.29 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 01 Nov 2023 15:58:29 -0700 (PDT) From: Yury Norov To: Thomas Gleixner , linux-kernel@vger.kernel.org Cc: Yury Norov , Andy Shevchenko , Rasmus Villemoes Subject: [PATCH 2/4] lib/group_cpus: relax atomicity requirement in grp_spread_init_one() Date: Wed, 1 Nov 2023 15:58:18 -0700 Message-Id: <20231101225820.51342-3-yury.norov@gmail.com> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20231101225820.51342-1-yury.norov@gmail.com> References: <20231101225820.51342-1-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" Because the function is called with cpus_read_lock() held, all the masks involved are stabilized, and thus any extra atomicity is not required. Signed-off-by: Yury Norov --- lib/group_cpus.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) diff --git a/lib/group_cpus.c b/lib/group_cpus.c index aa3f6815bb12..b1e7d9cc9da9 100644 --- a/lib/group_cpus.c +++ b/lib/group_cpus.c @@ -24,8 +24,8 @@ static void grp_spread_init_one(struct cpumask *irqmsk, s= truct cpumask *nmsk, if (cpu >=3D nr_cpu_ids) return; =20 - cpumask_clear_cpu(cpu, nmsk); - cpumask_set_cpu(cpu, irqmsk); + __cpumask_clear_cpu(cpu, nmsk); + __cpumask_set_cpu(cpu, irqmsk); cpus_per_grp--; =20 /* If the cpu has siblings, use them first */ @@ -34,9 +34,8 @@ static void grp_spread_init_one(struct cpumask *irqmsk, s= truct cpumask *nmsk, sibl =3D cpumask_next(sibl, siblmsk); if (sibl >=3D nr_cpu_ids) break; - if (!cpumask_test_and_clear_cpu(sibl, nmsk)) - continue; - cpumask_set_cpu(sibl, irqmsk); + __cpumask_clear_cpu(sibl, nmsk); + __cpumask_set_cpu(sibl, irqmsk); cpus_per_grp--; } } --=20 2.39.2