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 3B423D3ABD3 for ; Mon, 11 Nov 2024 17:41:14 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id C5FF06B0099; Mon, 11 Nov 2024 12:41:13 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id C10AD6B009A; Mon, 11 Nov 2024 12:41:13 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id AB0866B009B; Mon, 11 Nov 2024 12:41:13 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id 8AC8D6B0099 for ; Mon, 11 Nov 2024 12:41:13 -0500 (EST) Received: from smtpin29.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay05.hostedemail.com (Postfix) with ESMTP id 3D9404093F for ; Mon, 11 Nov 2024 17:41:13 +0000 (UTC) X-FDA: 82774530048.29.3C04CE8 Received: from mail-pl1-f182.google.com (mail-pl1-f182.google.com [209.85.214.182]) by imf30.hostedemail.com (Postfix) with ESMTP id 85C6580010 for ; Mon, 11 Nov 2024 17:39:54 +0000 (UTC) Authentication-Results: imf30.hostedemail.com; dkim=pass header.d=google.com header.s=20230601 header.b=rkiMnmaJ; spf=pass (imf30.hostedemail.com: domain of rientjes@google.com designates 209.85.214.182 as permitted sender) smtp.mailfrom=rientjes@google.com; dmarc=pass (policy=reject) header.from=google.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1731346729; 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=spB5wl1urQkI+7B+IPtWDDKj9S/WJUklG9CxIStging=; b=xn312140l4QCmjC5ynbITtnsKKe2m4SFdy3k/mgSw+Vc04v7OXiCgsk9G2Jbn8K4W2wWBU mTwYkMc9p2xkfgpc8/dmYhV0RngST6r/ADxi2vOCyDa+QNCnVoAGRDdknajiFVg5G0X7NC 01t1ifAmRnJbEpfnnTlpULRwfQkGRiQ= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1731346729; a=rsa-sha256; cv=none; b=m2AHhOujMQlYngi7U0u6R41DmNLX2/fKQfSrjdUrot06+RP4I7KZ9FAKR5bzSJJuMYlXOr ltw0jGVd+FuDj/ypZSSaG/d5EalhUrkO6Ol6mPCCdjclQfCCUesXfHvrfwBVwhnlwUPXIK 550w4qoTW6Ib9GV33ugFUYgcTHBNaXo= ARC-Authentication-Results: i=1; imf30.hostedemail.com; dkim=pass header.d=google.com header.s=20230601 header.b=rkiMnmaJ; spf=pass (imf30.hostedemail.com: domain of rientjes@google.com designates 209.85.214.182 as permitted sender) smtp.mailfrom=rientjes@google.com; dmarc=pass (policy=reject) header.from=google.com Received: by mail-pl1-f182.google.com with SMTP id d9443c01a7336-20ca4877690so291755ad.1 for ; Mon, 11 Nov 2024 09:41:10 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1731346870; x=1731951670; darn=kvack.org; h=mime-version:references:message-id:in-reply-to:subject:cc:to:from :date:from:to:cc:subject:date:message-id:reply-to; bh=spB5wl1urQkI+7B+IPtWDDKj9S/WJUklG9CxIStging=; b=rkiMnmaJdXckJapaYcMR+jETd1JQcFrbXwrWIsp1v3vBo2bOjJx4BSFf8oaSd96WtR 2PFFq/uFe5rNpAHf/ZaBekYEfKsuEMjr5nDOwHbfxbS+mm/fKgQaYDjchn9Nhm8f5f1i jDzD32DR4SC4iCLNoUti/XgCpsdeoLTPyy/FiYuDZnsi3FwemH6/uAXyW+vH4GjIRy3a KI+DLO1/a4nVfoY3/M9EMLAa8lsXXBnNurpPl//noQe9THLfVjjHvZ6NyG2/Pq0gj6Ij tSVfOM1r/j4moRymUYxs37wYTyO4K6cI0wwJxkLkgPHSrGu8HmZsKI7CdayFmeNHgWZk Eylw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1731346870; x=1731951670; h=mime-version:references:message-id:in-reply-to:subject:cc:to:from :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=spB5wl1urQkI+7B+IPtWDDKj9S/WJUklG9CxIStging=; b=GFMPOe1WSs89B2I/0ETdldQ0kyQFX4dsEQMzjx1UJfcnb+dsVPUXTlvWB5uYJPxu2y zlcFOZaSY01mpcdA2S//GJ+TQ43292A5J1zYSvE0UBywBSlb1jCBXBfXY0u5ixy+smzW rm5mnE57alGzFglb9KTcC/c0kVxdLIt6L9hX0GUe+QjHSoW0YQW+FSajIAvDPM2y6Xk9 JLnYv5LjScc830nqUeKgy7Qzbhfp717gH4KyXvcW9vgXJEwEPH93kKMMY039PrCri8kF celojJ9siiDDhjModcjWy2qiVcDGf69hWbWhRbCv5R0U6WJpHvuta525ir05oa590V+c B9MQ== X-Forwarded-Encrypted: i=1; AJvYcCUGb+wjv5c2LazJSSU3B304A7CuTcD4OnhmLQtn2EUk5PorH6bHnzkyAv4cx3Od8pwUn1/9xOHaig==@kvack.org X-Gm-Message-State: AOJu0YxDbGwbLanyFQWvJHjoQLfhOpfT3pKxoih7pdl2WWDd7w8cAAaP eTYHHgAiI7yroH9kJhvOGBILWjl2sIxnkvcmjKgWlJh7Sh5hiw4cKV8x4bPlvw== X-Gm-Gg: ASbGncuiHMs6ZIVzN3PO6T2QEKLVkeBo4ofDxDI1JCthzEvEfuULdKZp2K3hKcCdo7f 3K5sJbn4LWOu9b7s3Nz65SYAtZhZayyltwyaMKWfhuKLqIxBChiD1orWyc49apdw/ywjiISq9ft JHBsNRVYvcDScnk9gSHKN+Tcx3IPaveAR7Y8A31470dI7wK3rpEwekd5CfxSNUO58JTOOPQk5EL tHoW4wyBLUEKielrdkeOBRU6S5Vl7kEDQUPTLgDm4vTOALXqLsCqOIfolNc2nJfMgv6mDZGLJXL x10l X-Google-Smtp-Source: AGHT+IHi97GLH/TqT3OzZu+s1FpiP4ABTo0w4bQUtXQTxsCqbBljDo6Rmx3Z4cy0o9PUG5WKfE9Bkg== X-Received: by 2002:a17:902:db0a:b0:20b:13a8:9f86 with SMTP id d9443c01a7336-2118df842dfmr4318285ad.28.1731346869501; Mon, 11 Nov 2024 09:41:09 -0800 (PST) Received: from [2620:0:1008:15:ae3b:d774:6c29:d63c] ([2620:0:1008:15:ae3b:d774:6c29:d63c]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-21177e4196asm78754925ad.162.2024.11.11.09.41.08 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 11 Nov 2024 09:41:09 -0800 (PST) Date: Mon, 11 Nov 2024 09:41:08 -0800 (PST) From: David Rientjes To: Joshua Hahn cc: akpm@linux-foundation.org, hannes@cmpxchg.org, nphamcs@gmail.com, shakeel.butt@linux.dev, roman.gushchin@linux.dev, muchun.song@linux.dev, chris@chrisdown.name, tj@kernel.org, lizefan.x@bytedance.com, mkoutny@suse.com, corbet@lwn.net, lnyng@meta.com, cgroups@vger.kernel.org, linux-mm@kvack.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-team@meta.com Subject: Re: [PATCH v4 1/1] memcg/hugetlb: Add hugeTLB counters to memcg In-Reply-To: Message-ID: References: <20241101204402.1885383-1-joshua.hahnjy@gmail.com> <72688d81-24db-70ba-e260-bd5c74066d27@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII X-Rspam-User: X-Rspamd-Server: rspam12 X-Rspamd-Queue-Id: 85C6580010 X-Stat-Signature: xguz5gcbriibjsra7r87k33d5aaw3rrn X-HE-Tag: 1731346794-342491 X-HE-Meta: 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 52QATuQo zAFYukx/4M3e53QJ/A3HHgAgRwhR7Q9WU++MKvrjpaPJssu5Ae172kc/YmkMARfoNJXDZP5g7QbVSpmgh8hPWVQ4oywbzBTvzv3hEFdO9imB2TxlMnojhe9QHfR6LRi5QD4cKD69sm3TcLiKTjJaaaZyj7T1hWUh6ibQmF9DeDi98YqsGCiuzz8GcRcbH50+3B5p38hYjk6mQM4RPwpzzGsoOSsiam56tDGuTKlJmJwEfI/EczJ13DiurmtC8yxOd8sI1mvxOIfuuPWIRM30ZDiPsEncITjWkRiqmS6p28Etd7D1eBJacaBQSyDz7/MlR1TqJIau3YiwzlhrVAnJ8x9U2jefxKPVjqPTBaxWBO1/me+1ZIdLxjWJ30hZKxjYCj4oa1HDKBIesprYCJrwCl8ljvHlhnFyNUbHIQ/ANK7Sf2WVSjOICKqV+WBVa9PtMjd9O X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, 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 Mon, 11 Nov 2024, Joshua Hahn wrote: > > > diff --git a/Documentation/admin-guide/cgroup-v2.rst b/Documentation/admin-guide/cgroup-v2.rst > > > index 69af2173555f..bd7e81c2aa2b 100644 > > > --- a/Documentation/admin-guide/cgroup-v2.rst > > > +++ b/Documentation/admin-guide/cgroup-v2.rst > > > @@ -1646,6 +1646,11 @@ The following nested keys are defined. > > > pgdemote_khugepaged > > > Number of pages demoted by khugepaged. > > > > > > + hugetlb > > > + Amount of memory used by hugetlb pages. This metric only shows > > > + up if hugetlb usage is accounted for in memory.current (i.e. > > > + cgroup is mounted with the memory_hugetlb_accounting option). > > > + > > > memory.numa_stat > > > A read-only nested-keyed file which exists on non-root cgroups. > > > > > > > Definitely makes sense to include this. > > > > Any reason to not account different hugetlb page sizes separately in this > > stat, however? IOW, should there be separate hugetlb_2048kB and > > hugetlb_1048576kB stats on x86? > > Hello David, Thank you for reviewing my patch! > > The reason that I opted not to include a breakdown of each hugetlb > size in memory.stat is only because I wanted to keep the addition that > this patch makes as minimal as possible, while still addressing > the goal of bridging the gap between memory.stat and memory.current. > Users who are curious about this breakdown can see how much memory > is used by each hugetlb size by enabling the hugetlb controller as well. > While the patch may be minimal, this is solidifying a kernel API that users will start to count on. Users who may be interested in their hugetlb usage may not have control over the configuration of their kernel? Does it make sense to provide a breakdown in memory.stat so that users can differentiate between mapping one 1GB hugetlb page and 512 2MB hugetlb pages, which are different global resources? > It's true that this is the case as well for total hugeltb usage, but > I felt that not including hugetlb memory usage in memory.stat when it > is accounted by memory.current would cause confusion for the users > not being able to see that memory.current = sum of memory.stat. On the > other hand, seeing the breakdown of how much each hugetlb size felt more > like an optimization, and not a solution that bridges a confusion. > If broken down into hugetlb_2048kB and hugetlb_1048576kB on x86, for example, users could still do sum of memory.stat, no?> > I have not had a scenario where I had to look at the breakdown of the > hugetlb sizes (without the hugetlb controller), or a scenario where not > knowing this causes some sort of confusion. If others have had this > problem, I would love to hear about it, and perhaps work on a solution > that can address this point as well! > > I hope you have a great day! You too!