From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from frasgout.his.huawei.com (frasgout.his.huawei.com [185.176.79.56]) (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 0AA3A15B984; Fri, 1 Nov 2024 13:39:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.176.79.56 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730468354; cv=none; b=c24GNzurkKTfvuYIIPkm739eutUBKU2ULb4KkuG8M9BhtFp9mBapPB21ISLtMBRVpGyUvYal9Op2pparLtAXGDprPtY2v+KM490/byxVU/IDZo6oJK/Ct+oUjdool4cK7kmdxYRgAPssXQKqD/bEKZ16hyyjBLKhKixPFlQqVEk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730468354; c=relaxed/simple; bh=6w9ddJfdC+wbWkJ9nmnUl3R3iz0LbUYDbRnBNm1Sjdo=; h=Message-ID:Date:MIME-Version:Subject:To:CC:References:From: In-Reply-To:Content-Type; b=QfyU7OdguEw+MNGh8S8xew/jFrLYbp4Vpv0R5JKaf+1v6m/NJn4MAy+4kAR98CHDKSkdyTwar8/DwvU/iULAf2Es4Rnxc8vACbngpJ1efh70uwOPUosCsXyliiuL+kdP3hvm6kk+zgFYgXZNEDIlYKZKW05IuOSPFy2+1EA97mc= 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=185.176.79.56 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 [172.18.186.31]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4Xg1zp0lQYz6LD3y; Fri, 1 Nov 2024 21:34:14 +0800 (CST) Received: from mscpeml500003.china.huawei.com (unknown [7.188.49.51]) by mail.maildlp.com (Postfix) with ESMTPS id 2A46B140445; Fri, 1 Nov 2024 21:39:08 +0800 (CST) Received: from [10.123.123.226] (10.123.123.226) by mscpeml500003.china.huawei.com (7.188.49.51) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1258.34; Fri, 1 Nov 2024 16:39:07 +0300 Message-ID: <5baa6024-a0a4-4b0b-a7d1-641bba7e5b87@huawei.com> Date: Fri, 1 Nov 2024 16:39:07 +0300 Precedence: bulk X-Mailing-List: cgroups@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [RFC PATCH 0/3] Cgroup-based THP control To: Michal Hocko CC: Gutierrez Asier , , , , , , , , , , , , , , , , , , , , , , , References: <80d76bad-41d8-4108-ad74-f891e5180e47@huawei.com> <274e1560-9f6c-4dd9-b27c-2fd0f0c54d03@huawei.com> <5120497d-d60a-4a4b-a39d-9b1dbe89154c@huawei.com> Content-Language: en-US From: Stepanov Anatoly In-Reply-To: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit X-ClientProxiedBy: mscpeml500004.china.huawei.com (7.188.26.250) To mscpeml500003.china.huawei.com (7.188.49.51) On 11/1/2024 4:28 PM, Michal Hocko wrote: > On Fri 01-11-24 16:24:55, Stepanov Anatoly wrote: >> On 11/1/2024 4:15 PM, Michal Hocko wrote: >>> On Fri 01-11-24 14:54:27, Stepanov Anatoly wrote: >>>> On 11/1/2024 10:35 AM, Michal Hocko wrote: >>>>> On Thu 31-10-24 17:37:12, Stepanov Anatoly wrote: >>>>>> If we consider the inheritance approach (prctl + launcher), it's fine until we need to change >>>>>> THP mode property for several tasks at once, in this case some batch-change approach needed. >>>>> >>>>> I do not follow. How is this any different from a single process? Or do >>>>> you mean to change the mode for an already running process? >>>>> >>>> yes, for already running set of processes >>> >> >>> Why is that preferred over setting the policy upfront? >> Setting the policy in advance is fine, as the first step to do. >> But we might not know in advance >> which exact policy is the most beneficial for one set of apps or another. > > How do you plan to find that out when the application is running > already? For example, if someone willing to compare some DB server performance with THP-off vs THP-on, and DB server restart isn't an option. Of course, if the restart is ok then we don't need such feature, "launcher" approach would be enough. if i got your question right. -- Anatoly Stepanov, Huawei