From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from lithops.sigma-star.at (mailout.nod.at [116.203.167.152]) (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 31EA11DB12E; Mon, 6 Oct 2025 20:22:34 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=116.203.167.152 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1759782155; cv=none; b=tKoZDnB0hBzGO6bffOduMaLHcxW7pythGshR+KvDPxXDHzsDOCTHUhj98N8ulhbX7Z3iXdCmZ00lYzUSIFUpWtB/hz7HfUfypwTFenCsQR+qFL30zFo1SVo/tJXpP5heQcOOjI9ZES9kHouIp4QSQlfL9FFOg+K5X1w5iaPJGh4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1759782155; c=relaxed/simple; bh=LhjB5H9mrCqOGAXj5HXNdyEVYPj6mQQyTvJX1KEHiMI=; h=Date:From:To:Cc:Message-ID:In-Reply-To:References:Subject: MIME-Version:Content-Type; b=jHYxgiin8Aj5maU50jptELm1NBlbc60+XOn3m+L03lF/7CpMu3PF7dxhyXiZZxmlHEqc9tCBTruB39RJg6/J9TzKwdz//kt6rEeh1ibAFEkuLANpHQf3ej1CzcfERrnbmz6Hf56vzf9ISnow50Z8SztWmG7zTgfIxKHwwtgKf7M= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=nod.at; spf=fail smtp.mailfrom=nod.at; arc=none smtp.client-ip=116.203.167.152 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=nod.at Authentication-Results: smtp.subspace.kernel.org; spf=fail smtp.mailfrom=nod.at Received: from localhost (localhost [127.0.0.1]) by lithops.sigma-star.at (Postfix) with ESMTP id 853FF2B4F9D; Mon, 6 Oct 2025 22:15:23 +0200 (CEST) Received: from lithops.sigma-star.at ([127.0.0.1]) by localhost (lithops.sigma-star.at [127.0.0.1]) (amavisd-new, port 10032) with ESMTP id JD4v2hnJ6q9P; Mon, 6 Oct 2025 22:15:22 +0200 (CEST) Received: from localhost (localhost [127.0.0.1]) by lithops.sigma-star.at (Postfix) with ESMTP id 0C4012B03C9; Mon, 6 Oct 2025 22:15:22 +0200 (CEST) Received: from lithops.sigma-star.at ([127.0.0.1]) by localhost (lithops.sigma-star.at [127.0.0.1]) (amavisd-new, port 10026) with ESMTP id j6VbrBHYDJpt; Mon, 6 Oct 2025 22:15:21 +0200 (CEST) Received: from lithops.sigma-star.at (lithops.sigma-star.at [195.201.40.130]) by lithops.sigma-star.at (Postfix) with ESMTP id B486A2ABFC1; Mon, 6 Oct 2025 22:15:21 +0200 (CEST) Date: Mon, 6 Oct 2025 22:15:21 +0200 (CEST) From: Richard Weinberger To: Arnd Bergmann Cc: Dave Hansen , ksummit , linux-kernel , linux-arm-kernel , linuxppc-dev , linux-mips , linux-mm , imx , Christophe Leroy , Lucas Stach , Linus Walleij , Geert Uytterhoeven , Ankur Arora , David Hildenbrand , Mike Rapoport , Lorenzo Stoakes , Matthew Wilcox , Andrew Morton , "Liam R. Howlett" , vbabka , Suren Baghdasaryan , Ira Weiny , Nishanth Menon , heiko , Alexander Sverdlin , "Chester A. Unal" , Sergio Paracuellos , Andreas Larsson Message-ID: <1190290449.3827.1759781721487.JavaMail.zimbra@nod.at> In-Reply-To: <4fcd272f-81e3-4729-922b-588ad144e39b@app.fastmail.com> References: <4ff89b72-03ff-4447-9d21-dd6a5fe1550f@app.fastmail.com> <497308537.21756.1757513073548.JavaMail.zimbra@nod.at> <640041197.22387.1757536385810.JavaMail.zimbra@nod.at> <4fcd272f-81e3-4729-922b-588ad144e39b@app.fastmail.com> Subject: Re: [TECH TOPIC] Reaching consensus on CONFIG_HIGHMEM phaseout Precedence: bulk X-Mailing-List: ksummit@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-Mailer: Zimbra 8.8.12_GA_3807 (ZimbraWebClient - FF141 (Linux)/8.8.12_GA_3809) Thread-Topic: Reaching consensus on CONFIG_HIGHMEM phaseout Thread-Index: 4qe/Jvt6A7Z6bNoIFm3Eugvg7UbUaA== ----- Urspr=C3=BCngliche Mail ----- > Von: "Arnd Bergmann" >>> Has anybody run into actual end user visible problems when using one of >>> weirdo PAGE_OFFSET configs? >> >> In the past I saw that programs such as the Java Runtime (JRE) ran into >> address space limitations due to a 2G/2G split on embedded systems. >> Reverting to a 3G/1G split fixed the problems. >=20 > Right, that makes sense, given the tricks they likely play on the > virtual address space. Are the 2GB devices you maintain using a JRE, > or was this on other embedded hardware? How common is Java still in > this type of workload? Sorry for the late reply, I was on vacation. No, the devices with the JRE issues are from a different customer. Since I work as a consultant lots of strange issues get thrown my way I wouldn't say Java is super common but I still see it from time to time. =20 Thanks, //richard