From mboxrd@z Thu Jan 1 00:00:00 1970 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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id C150BE6B27C for ; Fri, 1 Nov 2024 13:50:23 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 334526B009B; Fri, 1 Nov 2024 09:50:23 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 2E43B6B009C; Fri, 1 Nov 2024 09:50:23 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 1AC346B009D; Fri, 1 Nov 2024 09:50:23 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0014.hostedemail.com [216.40.44.14]) by kanga.kvack.org (Postfix) with ESMTP id EFF906B009B for ; Fri, 1 Nov 2024 09:50:22 -0400 (EDT) Received: from smtpin08.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id B780BABF32 for ; Fri, 1 Nov 2024 13:50:22 +0000 (UTC) X-FDA: 82737659424.08.17DFF1F Received: from mail-ej1-f41.google.com (mail-ej1-f41.google.com [209.85.218.41]) by imf11.hostedemail.com (Postfix) with ESMTP id F3A2040012 for ; Fri, 1 Nov 2024 13:49:45 +0000 (UTC) Authentication-Results: imf11.hostedemail.com; dkim=pass header.d=suse.com header.s=google header.b=BbpHeQwz; spf=pass (imf11.hostedemail.com: domain of mhocko@suse.com designates 209.85.218.41 as permitted sender) smtp.mailfrom=mhocko@suse.com; dmarc=pass (policy=quarantine) header.from=suse.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1730468842; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=GMQKKJ98iVpHNH3i2CXUx1LW5hgoaOShr2IlFC3AvNA=; b=c2V8keoCLHRWzdMiageCs+Us3ydw9zspIJwvik+8HRsamaumlOWsKPtX4kJMpkSQ4g/keX n7UHruL2/ElFmBkCCP78f1LXSkpKiWhx+XKj9iPGBbtsTsk2cVXj7ssC36CKM9LQv05luh 3LKOrJsQlWRRT1LAVDnbA/osfBfheKI= ARC-Authentication-Results: i=1; imf11.hostedemail.com; dkim=pass header.d=suse.com header.s=google header.b=BbpHeQwz; spf=pass (imf11.hostedemail.com: domain of mhocko@suse.com designates 209.85.218.41 as permitted sender) smtp.mailfrom=mhocko@suse.com; dmarc=pass (policy=quarantine) header.from=suse.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1730468842; a=rsa-sha256; cv=none; b=s1pfyArPeGvJG95aVDoDO9W86QOuaWhSLwW3MyeCDg8q9/Xr7WrHHIeSH/sYaCrCPQnurs qsvbBCp3uZWLJ8Xe1MtSdY9KYmXhnorTd2KDH4bmUS937CGVa4zG7cjFulmrzIbaTuwY+n OEJ2j4aBHG6/y9e1czMwP+lJZHp2dZs= Received: by mail-ej1-f41.google.com with SMTP id a640c23a62f3a-a9932aa108cso296235566b.2 for ; Fri, 01 Nov 2024 06:50:20 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=google; t=1730469019; x=1731073819; darn=kvack.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=GMQKKJ98iVpHNH3i2CXUx1LW5hgoaOShr2IlFC3AvNA=; b=BbpHeQwzkP6Nl5MgVBOZRSTaChMvb3whGdGmJFQVPpVHVtbXt1RiRKV/y9NdnjeO13 1HU1D/dvLg5C4C2APtDepeenhf3y7I2r40d8bX8lFLTBm6GT85eAh7NOm4u4NLkpk4QH 1Z8SSvqasSvc5H6h5/Ek4R6SmtJfAa97FGpj5t8PUXzl/t6xwJGRKfGzUaGU/AS+zrJx iLjVgiOwOo5+70nXo9KEEYOk4BSJskEWYC5XsgEHdpjJPvTdjrq4wvIn5dhKY3xXijWw Sl+hqyv7jECEj6svIp4icPDstPoQqYQ8QaI8a19I47NvjwdNUCJJ4gBQbeJ2D3a/nBDA xwTQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1730469019; x=1731073819; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=GMQKKJ98iVpHNH3i2CXUx1LW5hgoaOShr2IlFC3AvNA=; b=ffFbJRyDWBtKiWGezyxuwYE7pnBmpa6H9EjviZuqKPcMYHziRXzblddK7fkTM63N7G LUuxwBLhS6rEsxcQIjAbgm4jzo4zA9c0XVbGYH4mjaoYyhhFMFnNzfEWUzMHVGV0T6tA 5yn5aARThg5m07ksCNrxRR8+fqQCYCzDypnAvO+OHGFYLerU08TZB7FfWQxw6u6/Hx7J /1p84a0iwGxaIG+cJlA4NRYCWdy9kTarVKxIYa/yqN0iJSeyD6yv/XrOQMSfS1XR1XI+ OFlYVO/YQ2psqO6u9Seu/IxexLCrqfcWzprivPMGAo2BKEoNoKz/39p66vbRpNkcJ0Qv +n5g== X-Forwarded-Encrypted: i=1; AJvYcCUM1JDNNh8VSZ2ZSNd8xgeTiZpmNzP7/jrhed4Gyh2jYI7Rw8efdpWif4UTgMcOFBIEwYXCN6/scQ==@kvack.org X-Gm-Message-State: AOJu0Yz2KiRgaPvsY6snY54+h34pUqM+kGHe/Thlo/pKSW+XN2VkF6iy Cyi/aECEU9EYhh2TxsJxdjI8C7qPMD9RPtj9KYOyKaXFf1flw51CK5o9WTaRhu0= X-Google-Smtp-Source: AGHT+IE3cmDk5BoxktCJSNUuOb2jDNHY+v5dPRdUMK5bfZM+U1Uy2em//nFYolTGT6CKFGhcPhkwpA== X-Received: by 2002:a17:907:3f9f:b0:a9a:2afc:e4d7 with SMTP id a640c23a62f3a-a9e50b948d0mr670223566b.44.1730469019255; Fri, 01 Nov 2024 06:50:19 -0700 (PDT) Received: from localhost (109-81-81-105.rct.o2.cz. [109.81.81.105]) by smtp.gmail.com with ESMTPSA id a640c23a62f3a-a9e56494465sm182111266b.30.2024.11.01.06.50.18 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 01 Nov 2024 06:50:18 -0700 (PDT) Date: Fri, 1 Nov 2024 14:50:18 +0100 From: Michal Hocko To: Stepanov Anatoly Cc: Gutierrez Asier , akpm@linux-foundation.org, david@redhat.com, ryan.roberts@arm.com, baohua@kernel.org, willy@infradead.org, peterx@redhat.com, hannes@cmpxchg.org, hocko@kernel.org, roman.gushchin@linux.dev, shakeel.butt@linux.dev, muchun.song@linux.dev, cgroups@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, alexander.kozhevnikov@huawei-partners.com, guohanjun@huawei.com, weiyongjun1@huawei.com, wangkefeng.wang@huawei.com, judy.chenhui@huawei.com, yusongping@huawei.com, artem.kuzin@huawei.com, kang.sun@huawei.com, nikita.panov@huawei-partners.com Subject: Re: [RFC PATCH 0/3] Cgroup-based THP control Message-ID: References: <80d76bad-41d8-4108-ad74-f891e5180e47@huawei.com> <274e1560-9f6c-4dd9-b27c-2fd0f0c54d03@huawei.com> <5120497d-d60a-4a4b-a39d-9b1dbe89154c@huawei.com> <5baa6024-a0a4-4b0b-a7d1-641bba7e5b87@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5baa6024-a0a4-4b0b-a7d1-641bba7e5b87@huawei.com> X-Rspamd-Server: rspam07 X-Rspamd-Queue-Id: F3A2040012 X-Stat-Signature: hphjg48btjkjgd66bfphepa8uw79rubr X-Rspam-User: X-HE-Tag: 1730468985-393366 X-HE-Meta: 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 KROMyRBl nD5Dmd476gq2s+QcWmfthWbnB2yWEpu/gBtcuzsurgYSCtSgUboo7cyuXdKkDmn30W6s/DPlOcfZqMz3c0GTCjONQxiV3kBgINHoG2Zz9uJcMqnR3f3YT8YlvRB5J/QhNedMlrdYMGOozPfUTST7ZdEWHBpiQ5fAp5Pi3KlUQLNtVn9HBoPddZ/CxjhizKgDkhbHH1vcjTWv2Db8RkwhVkzw0k6wf/IfnggcY5md1RgYPU8Y6wNvoCdIco8aHwD5GKFzlwaCIhz6TG2ZxlRpnDtU/kQ8rKReacIinT8XmUy2czR7gkr+WersqXg== X-Bogosity: Ham, tests=bogofilter, spamicity=0.111668, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Fri 01-11-24 16:39:07, Stepanov Anatoly wrote: > 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. So you essentially expect user tell you that they want THP and you want to make that happen on fly, correct? It is not like there is an actual monitoring and dynamic policing. If that is the case then I am not really convinced this is a worthwhile to support TBH. I can see that a workload knows in advance that they benefit from THP but I am much more dubious about "learning during the runtime" is a real life thing. I might be wrong of course but if somebody has performance monitoring that is able to identify performance bottlenecks based on specific workload then applying THP on the whole group of proceesses seems like a very crude way to deal with that. I could see a case for madvice_process(MADV_COLLAPSE) to deal with specific memory hotspots though. -- Michal Hocko SUSE Labs