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 67B58D16260 for ; Mon, 14 Oct 2024 13:00:43 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id F33386B0085; Mon, 14 Oct 2024 09:00:42 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id EE3176B0088; Mon, 14 Oct 2024 09:00:42 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id DAAB96B008C; Mon, 14 Oct 2024 09:00:42 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0013.hostedemail.com [216.40.44.13]) by kanga.kvack.org (Postfix) with ESMTP id BEDBF6B0085 for ; Mon, 14 Oct 2024 09:00:42 -0400 (EDT) Received: from smtpin10.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay03.hostedemail.com (Postfix) with ESMTP id EE1B1A0EEA for ; Mon, 14 Oct 2024 13:00:27 +0000 (UTC) X-FDA: 82672216956.10.96D052A Received: from mail-oo1-f50.google.com (mail-oo1-f50.google.com [209.85.161.50]) by imf22.hostedemail.com (Postfix) with ESMTP id A1A1BC0019 for ; Mon, 14 Oct 2024 13:00:32 +0000 (UTC) Authentication-Results: imf22.hostedemail.com; dkim=pass header.d=cmpxchg-org.20230601.gappssmtp.com header.s=20230601 header.b=sCNM6TiQ; spf=pass (imf22.hostedemail.com: domain of hannes@cmpxchg.org designates 209.85.161.50 as permitted sender) smtp.mailfrom=hannes@cmpxchg.org; dmarc=pass (policy=none) header.from=cmpxchg.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1728910699; 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=HcEOyQjDS7a6A9bsQE6vr5VWzjSUJouS2AgRnzgA9wE=; b=d9I558Rij6gm63iZoN0i5rp+7YpglZjIcMQVM1Bc4+adc7mQus4XkO9gbskw/tFFzm62Se R8GjRwnMPEpT+7zaAN/WW0JWgKMHWjiEX7A4t4bBPeXhnPeknifvz1klvLcEWYIr6SUm4D c63IPCqUTQlg+ean3goqihQo3GNkSCI= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1728910699; a=rsa-sha256; cv=none; b=5DjCUiadE2fapyOKBNkYlHcNWtSqXaBFeHR6/bf25r9MM+djZkUG+FRKahCPWDS8OMD3/n JPRZ7gxV6u9keQB7rjgLZa+XucBJ2chcIRKLq7xKC9T/jfPsKauyhOObZfRmM/KGS91N3X k2v7jlr1PKJy7v4z85/sz0LODG1OnHc= ARC-Authentication-Results: i=1; imf22.hostedemail.com; dkim=pass header.d=cmpxchg-org.20230601.gappssmtp.com header.s=20230601 header.b=sCNM6TiQ; spf=pass (imf22.hostedemail.com: domain of hannes@cmpxchg.org designates 209.85.161.50 as permitted sender) smtp.mailfrom=hannes@cmpxchg.org; dmarc=pass (policy=none) header.from=cmpxchg.org Received: by mail-oo1-f50.google.com with SMTP id 006d021491bc7-5e8d819df48so2060513eaf.0 for ; Mon, 14 Oct 2024 06:00:39 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cmpxchg-org.20230601.gappssmtp.com; s=20230601; t=1728910839; x=1729515639; 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=HcEOyQjDS7a6A9bsQE6vr5VWzjSUJouS2AgRnzgA9wE=; b=sCNM6TiQ0JzBGolg/CKKH3neWR7VQrmcANUUL+qAJCoylbaoght6TU97Okoj7/DnII xcEESz5izwvuCk/CvQNRIBCJ6xnKHvdzx6JmVPRjzbuQAOqthwiiUjK2s/7i0NBjFYEa IavVkALuyVodew36DlnUvTJQfey6rJcCe5Asm3vjEIZP7Medcb2ToXznWHEZxlZBaz4A RtC0+NEY4Z6EMgfMhYjwfRbOYRuSV4H/7Go0u1yoiCu9NvhmYqgZpSzpLp1UEfVY3v/6 v0njgMx6RSwVIno1Ro/eZutOX/oOqoFOV8F+YCLsc2qIBpCxhTIlf1h/cQTf0482K69H lTWQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1728910839; x=1729515639; 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=HcEOyQjDS7a6A9bsQE6vr5VWzjSUJouS2AgRnzgA9wE=; b=HYMunSK1nQ7lSCjakUtXtxZBOo2m5gk5lHZSmTLTvNRHtsAMbmnsrMhKrfpU3rWsev ak+RJqsmFcZWIblwJjQLwc6H97xq+eVZ0z2EQL5G6Dk5D+B7ZASYnwBA1tVktCa0BhJk Z7BmTUfPrLFMgzprZErotADeF1s/2hrSXTjtWe0/Rog8u4DFZEFxMUnCKYz5cBvoD5ql +QjJn5kpeiGoifKh+8qNbGbN5QYHqJjJfl3lbnddrBGxVpCuGdyMm6T+yUuZ/s/XiLG8 o3dHdBCAHNyecN8cak8D8Eslpwg31cZbcbuSsQyfQ9rjHm46SDP6+83ugM9eWDqspuQB c9+w== X-Forwarded-Encrypted: i=1; AJvYcCXSj705n6c7z4Kh0VcpqZ3opC9ZckqBTQpSVuHZTQmMLqNxfvEOgnLhcYATY8m21aNkji2nCcJbrg==@kvack.org X-Gm-Message-State: AOJu0YyDwbrBV5c4ddAh/d9qd40GnAmFzW2mql5kbH41hqK93xJsv6Cn fbbt8RmnckSL5AUwuWPedARLkaCIjvTMqvGmCI+2eLI6GSu70mv/3eIXpC4MTRBwjXbMphclM7h P X-Google-Smtp-Source: AGHT+IGls0KX1bRa/5udb60IOUG7S3+RObbDPF9EP/nc4moCuctIsvmDxZp8/MHeexJO2YJQ3fajDQ== X-Received: by 2002:a05:6214:300a:b0:6cb:55e4:54d5 with SMTP id 6a1803df08f44-6cbe5239cc6mr302364356d6.10.1728910819640; Mon, 14 Oct 2024 06:00:19 -0700 (PDT) Received: from localhost ([2603:7000:c01:2716:da5e:d3ff:fee7:26e7]) by smtp.gmail.com with ESMTPSA id 6a1803df08f44-6cbe85a5d49sm44835096d6.29.2024.10.14.06.00.18 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 14 Oct 2024 06:00:18 -0700 (PDT) Date: Mon, 14 Oct 2024 09:00:17 -0400 From: Johannes Weiner To: Ryan Roberts Cc: Andrew Morton , Anshuman Khandual , Ard Biesheuvel , Catalin Marinas , David Hildenbrand , Greg Marsden , Ivan Ivanov , Kalesh Singh , Marc Zyngier , Mark Rutland , Matthias Brugger , Michal Hocko , Miroslav Benes , Roman Gushchin , Shakeel Butt , Will Deacon , cgroups@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [RFC PATCH v1 03/57] mm/memcontrol: Fix seq_buf size to save memory when PAGE_SIZE is large Message-ID: <20241014130017.GA1021@cmpxchg.org> References: <20241014105514.3206191-1-ryan.roberts@arm.com> <20241014105912.3207374-1-ryan.roberts@arm.com> <20241014105912.3207374-3-ryan.roberts@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20241014105912.3207374-3-ryan.roberts@arm.com> X-Rspamd-Queue-Id: A1A1BC0019 X-Stat-Signature: 3181j17qfb6zd6zd9hh76tm5tt6zhmsy X-Rspamd-Server: rspam09 X-Rspam-User: X-HE-Tag: 1728910832-552452 X-HE-Meta: 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 O3/+EyGj 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 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, Oct 14, 2024 at 11:58:10AM +0100, Ryan Roberts wrote: > Previously the seq_buf used for accumulating the memory.stat output was > sized at PAGE_SIZE. But the amount of output is invariant to PAGE_SIZE; > If 4K is enough on a 4K page system, then it should also be enough on a > 64K page system, so we can save 60K om the static buffer used in > mem_cgroup_print_oom_meminfo(). Let's make it so. > > This also has the beneficial side effect of removing a place in the code > that assumed PAGE_SIZE is a compile-time constant. So this helps our > quest towards supporting boot-time page size selection. > > Signed-off-by: Ryan Roberts Acked-by: Johannes Weiner