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 E41E8CD5BBD for ; Tue, 19 Sep 2023 13:34:24 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 6DA6A6B051A; Tue, 19 Sep 2023 09:34:24 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 68D866B051C; Tue, 19 Sep 2023 09:34:24 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 553486B051D; Tue, 19 Sep 2023 09:34:24 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id 45A4A6B051A for ; Tue, 19 Sep 2023 09:34:24 -0400 (EDT) Received: from smtpin03.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay01.hostedemail.com (Postfix) with ESMTP id 1A9411CA882 for ; Tue, 19 Sep 2023 13:34:24 +0000 (UTC) X-FDA: 81253441248.03.435F375 Received: from mail-yb1-f173.google.com (mail-yb1-f173.google.com [209.85.219.173]) by imf06.hostedemail.com (Postfix) with ESMTP id 1DC2518001F for ; Tue, 19 Sep 2023 13:34:21 +0000 (UTC) Authentication-Results: imf06.hostedemail.com; dkim=none; spf=pass (imf06.hostedemail.com: domain of geert.uytterhoeven@gmail.com designates 209.85.219.173 as permitted sender) smtp.mailfrom=geert.uytterhoeven@gmail.com; dmarc=none ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1695130462; 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:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=ZgBzNeouwMIIeGDTMgFICEbkSUZU58KfvTsi1HmIQSU=; b=KGYybIhJvuTxQhEleHGo2umYDmnhNUO+MlwTNUYmvC7c/8kHzW8Hz4Et7CgBbs8lDPi6jJ PgDqZnPro8/WuaIqfv7EHGa2CDg+wRkdpHTSldmdZGxuYPttJ3nCKnyE+M/nTRtX5vvvCE qLTmvmyDjqWFO9399Fb30+OAVbWHQA0= ARC-Authentication-Results: i=1; imf06.hostedemail.com; dkim=none; spf=pass (imf06.hostedemail.com: domain of geert.uytterhoeven@gmail.com designates 209.85.219.173 as permitted sender) smtp.mailfrom=geert.uytterhoeven@gmail.com; dmarc=none ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1695130462; a=rsa-sha256; cv=none; b=Utf1N634OOpS3sZxGhz8ZJyPPO3QIh84BxzS5M3bnUtVMJSuV9uYo7i437o9VGedUWvFBx YrNdsQvbk0dlOFUMqOb3Rf7edAU7UaprhjBHJh6xbEGuTvVqg4a1hyorrH7A8bcQV5++QA ZwV/SBFd2oppseWhKTuqMwznA15i6KM= Received: by mail-yb1-f173.google.com with SMTP id 3f1490d57ef6-d7b79a4899bso5180252276.2 for ; Tue, 19 Sep 2023 06:34:21 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1695130461; x=1695735261; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=ZgBzNeouwMIIeGDTMgFICEbkSUZU58KfvTsi1HmIQSU=; b=mrTqiuAXa5PRus4tGOFqp+86DoTOFsdGfGbSWJujd6Kut2VjFXijfKqJgNXNnyvgIx ApWJ7+axw3aXvENZq5HyfLLoRZ6zbcTRMwWDLk8PzDYmcJ4EzKFbXdoto48KeCM0bnQa FQj/hei360GGDJJ7uAFKRYXeKVv2Fr8cajT02ZI6bOwo6+cw2RjsP/SvcgEc7cTZmzkV CKl6oNxnn024B6nEPg7gtaE+TFjcAQ+wvDtLJxjoYhEzLJhW8KWCXzPsdeJRTTczvbKl wPK5QSYQsv7nGRUg0d0zyeL7jkL3QActLPNjObXNaqKJQBKgadkIfE0R42ZprpEw8vfu v7XQ== X-Gm-Message-State: AOJu0YyG8ThXUI6LvXUE5jOA8c05EBwu7pkReLBZ7LOPNkSySIVdo3Ed 5+zyl2umhSD9gacPVx2ptc7TaxA0LwMzfA== X-Google-Smtp-Source: AGHT+IFcUsMgY24kC10ZPB3wDd6f0neQEes+q3Hwei0nO2/NHk0t7GUD2ebB9vF25ia3dyLb4vJryg== X-Received: by 2002:a25:abe5:0:b0:d78:441d:4d62 with SMTP id v92-20020a25abe5000000b00d78441d4d62mr11896381ybi.22.1695130460768; Tue, 19 Sep 2023 06:34:20 -0700 (PDT) Received: from mail-yw1-f169.google.com (mail-yw1-f169.google.com. [209.85.128.169]) by smtp.gmail.com with ESMTPSA id e202-20020a25e7d3000000b00d7b9fab78bfsm2882972ybh.7.2023.09.19.06.34.20 for (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 19 Sep 2023 06:34:20 -0700 (PDT) Received: by mail-yw1-f169.google.com with SMTP id 00721157ae682-59bdad64411so57874117b3.3 for ; Tue, 19 Sep 2023 06:34:20 -0700 (PDT) X-Received: by 2002:a0d:cc55:0:b0:59b:cb53:ad5a with SMTP id o82-20020a0dcc55000000b0059bcb53ad5amr12005299ywd.35.1695130459846; Tue, 19 Sep 2023 06:34:19 -0700 (PDT) MIME-Version: 1.0 References: <87edj64rj1.fsf@oracle.com> <87zg1u1h5t.fsf@oracle.com> <20230911150410.GC9098@noisy.programming.kicks-ass.net> <87h6o01w1a.fsf@oracle.com> <20230912082606.GB35261@noisy.programming.kicks-ass.net> <87cyyfxd4k.ffs@tglx> <87led2wdj0.ffs@tglx> In-Reply-To: From: Geert Uytterhoeven Date: Tue, 19 Sep 2023 15:34:08 +0200 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: Arches that don't support PREEMPT To: Matthew Wilcox Cc: Thomas Gleixner , Linus Torvalds , Peter Zijlstra , Ankur Arora , linux-kernel@vger.kernel.org, linux-mm@kvack.org, x86@kernel.org, akpm@linux-foundation.org, luto@kernel.org, bp@alien8.de, dave.hansen@linux.intel.com, hpa@zytor.com, mingo@redhat.com, juri.lelli@redhat.com, vincent.guittot@linaro.org, mgorman@suse.de, rostedt@goodmis.org, jon.grimm@amd.com, bharata@amd.com, raghavendra.kt@amd.com, boris.ostrovsky@oracle.com, konrad.wilk@oracle.com, jgross@suse.com, andrew.cooper3@citrix.com, linux-m68k@lists.linux-m68k.org, Richard Weinberger , Anton Ivanov , Johannes Berg , linux-um@lists.infradead.org, Brian Cain , linux-hexagon@vger.kernel.org, Richard Henderson , Ivan Kokshaysky , Matt Turner , linux-alpha@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Rspamd-Queue-Id: 1DC2518001F X-Rspam-User: X-Stat-Signature: x81r79kfkt56dq6zqoij5decjoaufx8e X-Rspamd-Server: rspam01 X-HE-Tag: 1695130461-355980 X-HE-Meta: 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 +oAog5kP 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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: Hi Willy, On Tue, Sep 19, 2023 at 3:01=E2=80=AFPM Matthew Wilcox wrote: > On Tue, Sep 19, 2023 at 02:30:59PM +0200, Thomas Gleixner wrote: > > Though it just occured to me that there are dragons lurking: > > > > arch/alpha/Kconfig: select ARCH_NO_PREEMPT > > arch/hexagon/Kconfig: select ARCH_NO_PREEMPT > > arch/m68k/Kconfig: select ARCH_NO_PREEMPT if !COLDFIRE > > arch/um/Kconfig: select ARCH_NO_PREEMPT > > Sounds like three-and-a-half architectures which could be queued up for > removal right behind ia64 ... > > I suspect none of these architecture maintainers have any idea there's a > problem. Look at commit 87a4c375995e and the discussion in > https://lore.kernel.org/lkml/20180724175646.3621-1-hch@lst.de/ These links don't really point out there is a grave problem? > Let's cc those maintainers so they can remove this and fix whatever > breaks. Gr{oetje,eeting}s, Geert --=20 Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k= .org In personal conversations with technical people, I call myself a hacker. Bu= t when I'm talking to journalists I just say "programmer" or something like t= hat. -- Linus Torvalds