From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from szxga04-in.huawei.com (szxga04-in.huawei.com [45.249.212.190]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id F2F802034BA; Wed, 21 Aug 2024 09:44:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.190 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724233452; cv=none; b=fRo01+A+Fu2jAdBDYHSgmme8f0X7m/giDeGfc8Y1JNjONxOZzTu5ZUbxXgHHn2nT4luOuTW/qPqWJ4TXPMrEticFhGZEQzu9+gakwgc9Tv0AxPnlTp/WC0a/BsH6OdIK7tA7dnd7jHZCt7CxQKZ7GedSQxAlStF2+u2LlUJRWlI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724233452; c=relaxed/simple; bh=Zka2nUbhX8rAlsL9boNe6OWXAy8Hqq9Riz4Gon1WzIQ=; h=Message-ID:Date:MIME-Version:Subject:To:CC:References:From: In-Reply-To:Content-Type; b=EsGSdk0HnyQSxYJMg2u9y0YyHF7aylX0GxtUTiuQZKiO46j1y0h5wlxRPxJ+OhaMpjZ8fNhzXb755xV3rffVLzIWdNfDsGDlVRMd/zVO2wwlT6FcuI1LBpM78rYijXb6/kBqnHRrEAqOcpW7NsBGrv95aL6QanHVt5TmhlRGZ9Y= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com; spf=pass smtp.mailfrom=huawei.com; arc=none smtp.client-ip=45.249.212.190 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huawei.com Received: from mail.maildlp.com (unknown [172.19.88.234]) by szxga04-in.huawei.com (SkyGuard) with ESMTP id 4WphHS5Srwz2Cn70; Wed, 21 Aug 2024 17:44:04 +0800 (CST) Received: from kwepemm600004.china.huawei.com (unknown [7.193.23.242]) by mail.maildlp.com (Postfix) with ESMTPS id 067781400CA; Wed, 21 Aug 2024 17:44:07 +0800 (CST) Received: from [10.67.121.59] (10.67.121.59) by kwepemm600004.china.huawei.com (7.193.23.242) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.1.2507.39; Wed, 21 Aug 2024 17:44:06 +0800 Message-ID: <8744a789-0424-0cc6-7cb1-b7c9b17f56cc@huawei.com> Date: Wed, 21 Aug 2024 17:44:05 +0800 Precedence: bulk X-Mailing-List: linux-pm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Thunderbird/91.2.0 Subject: Re: [PATCH v3 02/14] thermal: core: Rearrange checks in thermal_bind_cdev_to_trip() To: Daniel Lezcano , "Rafael J. Wysocki" CC: LKML , Lukasz Luba , Zhang Rui , Linux PM References: <2205737.irdbgypaU6@rjwysocki.net> <3324214.44csPzL39Z@rjwysocki.net> <68ed6185-a602-c0fc-721e-b5d68fea83f8@huawei.com> <66bb19a0-00ba-40a5-91ef-73368659b30a@linaro.org> From: "lihuisong (C)" In-Reply-To: <66bb19a0-00ba-40a5-91ef-73368659b30a@linaro.org> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 8bit X-ClientProxiedBy: dggems702-chm.china.huawei.com (10.3.19.179) To kwepemm600004.china.huawei.com (7.193.23.242) 在 2024/8/21 17:28, Daniel Lezcano 写道: > On 21/08/2024 10:49, lihuisong (C) wrote: > > [ ... ] > >>> -    list_for_each_entry(pos2, &thermal_cdev_list, node) { >>> -        if (pos2 == cdev) >>> -            break; >>> -    } >>> +    lockdep_assert_held(&thermal_list_lock); >>> -    if (tz != pos1 || cdev != pos2) >>> +    if (list_empty(&tz->node) || list_empty(&cdev->node)) >> The old verification is ensure that tz and cdev already add to >> thermal_tz_list and thermal_cdev_list，respectively. >> Namely, tz and cdev are definitely registered and intialized. >> The check is ok for all untizalized thermal_zone_device and cooling >> device. >> But the new verification doesn't seem to do that. > > If the tz or the cdev are registered then their "->node" is not empty > because they are linked with the thermal_list and cdev_list > > So either way is browsing the lists to find the tz/cdev or just check > "->node" is not empty. The latter the faster. Assume that tz/cdev isn't intiazlized and registered to thermal_tz_list or thermal_cdev_list. And then directly call this interface. > > Did I misunderstood your comment ? > > [ ... ] >