From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from canpmsgout09.his.huawei.com (canpmsgout09.his.huawei.com [113.46.200.224]) (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 0BC21317173; Wed, 9 Sep 2026 03:12:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=113.46.200.224 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788923554; cv=none; b=miQmJfmgJpkCQQBhoJXzVja2ziiGPev0cTDO7JE8BfFk6/hrAuxSvGLDeeLyQeVwliqjjzR+l6ZNfx8p+qKUi9yetbBrNGyar+pvPdMX/KeMfi57H3fq7ixnbn24T7DyFAhyZFxAWuyTyA7+ofhbqnzNYU3jNMxP9tDEljugo6c= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788923554; c=relaxed/simple; bh=RLeYLogumFQ6XJsvIWq9nwJXeI7KIoroKGT7W1Vl3UE=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=FZOta/09D7WTqFMCUVL5Hr//79vYeCG0mbT1NQURNp5FBFAPVis6bwFIxR2PVLNDteVoszpFLUogddY1APIjxAC4dnWQlajZsIV46XzrmQ64m81nKAOD91q5GBzhB8IoMit3XnrIwW9fuzYZOKNZ++e4X5Rez6vsy7e5qX/t2Wc= 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; dkim=pass (1024-bit key) header.d=huawei.com header.i=@huawei.com header.b=Z0ANVXml; arc=none smtp.client-ip=113.46.200.224 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 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=huawei.com header.i=@huawei.com header.b="Z0ANVXml" dkim-signature: v=1; a=rsa-sha256; d=huawei.com; s=dkim; c=relaxed/relaxed; q=dns/txt; h=From; bh=f1TwHlr/HpBR52LSyzPtzCCusLmy4u97Fnscmci/Mx0=; b=Z0ANVXml8rYLQpFJoMTkGjk938y8I+J7bAD2bD5HQhwJZ5KBFfTFaguGmXGD4JN2K0uXTWQbT Uc7+XmXoDBHkpGeCuRQBXC+BGvw7ji5DIeyXaIiHCn4PzY/s096wknobqo+JkeOf77ROQpz3mPm OTQ5/7R6Xfq+FB9j+0RnYbM= Received: from mail.maildlp.com (unknown [172.19.163.15]) by canpmsgout09.his.huawei.com (SkyGuard) with ESMTPS id 4hflvJ66ygz1cyQh; Wed, 9 Sep 2026 11:01:32 +0800 (CST) Received: from dggpemr200001.china.huawei.com (unknown [7.185.36.96]) by mail.maildlp.com (Postfix) with ESMTPS id 5FADF40578; Wed, 9 Sep 2026 11:12:26 +0800 (CST) Received: from huawei.com (10.50.85.155) by dggpemr200001.china.huawei.com (7.185.36.96) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.2562.46; Wed, 9 Sep 2026 11:12:25 +0800 From: Ran Hongyun To: CC: , , , , , , , , , , , , , , , , , , , , , , , , , Subject: Re: [QUESTION] Are these issues PREEMPT_RT-specific? Date: Wed, 9 Sep 2026 11:05:05 +0800 Message-ID: <20260909030506.344667-1-ranhongyun1@huawei.com> X-Mailer: git-send-email 2.52.0 In-Reply-To: <63d5cd58e9b85acccdaaac9aed4a8c550cc7b868.camel@siemens.com> References: <63d5cd58e9b85acccdaaac9aed4a8c550cc7b868.camel@siemens.com> Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8bit X-ClientProxiedBy: kwepems100002.china.huawei.com (7.221.188.206) To dggpemr200001.china.huawei.com (7.185.36.96) Florian, Thank you for your reply. Now I understand that the issues are particularly critical on PREEMPT_RT. However, I’m still not entirely clear about the "performance or throughput drop" you mentioned for !RT systems. Since !RT kernels are non-preemptible, unbounded priority inversion and stalls should not occur. Are there any other factors that could still cause such a performance or throughput drop? In other words, if I am running a !RT system, what benefit can I actually expect from switching from rwlock to spinlock? I`d appreciate any further insights. Thanks, Ran Hongyun