From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matthew Wilcox Subject: Arches that don't support PREEMPT Date: Tue, 19 Sep 2023 14:00:54 +0100 Message-ID: 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> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=0mZ8ACdsK+VaAg7kKPasqutxqQcWQOsH9cuSizg07kA=; b=sq/syEJ+wc6LZ6 aZoF9JDbkMqNWC5RT/Vcm9ESyO9/ReHxT2aTS/HGr6l5VKInsIno6aWquCS8M2tiET2T5nTatwoLn 6MF3HwOv+lt2xjMLqEf523vXchaObHMkDzADE4ickyu2AfbluHAI0CoIFZe1k1EJfb5W6pJhyHLD6 dvXTLOvDeYGbGZwteD+IJLXj/mqzw4XA7GXX1xokvclW1esPK64wQj9utE2FMeVFSnFgjvWLl12oz WVWIAGiOged+KbdQWZ50G3In0pnRhq4sIC1zhlJs8qKwXXNJ2o+qHV8TSD9M+QdzBbJdN7SuSy0if ucD7y0xyWSiM34bMG7jg==; DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=UQqbtC4LU7CWz7n0Qti5YLvSVy7RAt2aZ0CW6vnfgZE=; b=Re/9h8bA2l5R9rS+t5jWP44yYf BD+D17QDievItTZT8XCUjAygltixoCakyWJVYollwPJN+8J4YpztmZA/sMcUv90RlabAnSY9WQ4Q5 kljuiW6Cp/gHdVwZuPoajR8jGbsUenSGzi9mEG6tIRVZj0rpmnWEoTdwR4IlnbCmrhYh71f/ffZwD zA71QJEsU16dBg8UTSfZAHBIFPXxlH+0HL85WXEeFNsoDqUzKX5tjdXYgp/4e6wfzSGAKQCk05a4i Klv/roly2FY9BRa21dQGgYeEcWYYb7A4C+ID92Ny/pq8ytpWrLKuBOGrdB94Fc5u0I/Yvk/fJrDb0 xGCYQG0g==; Content-Disposition: inline In-Reply-To: <87led2wdj0.ffs@tglx> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-um" Errors-To: linux-um-bounces+glud-user-mode-linux-devel=m.gmane-mx.org@lists.infradead.org To: Thomas Gleixner Cc: 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, Geert Uytterhoeven , 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 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/ Let's cc those maintainers so they can remove this and fix whatever breaks.