From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Zijlstra Subject: Re: Arches that don't support PREEMPT Date: Tue, 19 Sep 2023 15:42:18 +0200 Message-ID: <20230919134218.GA39281@noisy.programming.kicks-ass.net> References: <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> <0e69f7df80dc5878071deb0d80938138d19de1d1.camel@physik.fu-berlin.de> 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=THwnAJC5YQbioj0041PCz+s4SQRfAFp/x517xPEog3U=; b=0O2AxMdUkGeOI0 ka4f0Dl270VXkz4re3qObxOYe2TGXRA78pkzimrCK9uVgYPHqRJHoNz8rx6m+fovaaR73N3WBtBax mRV+Ce64Dbub/TCWekm6FUnR8Ci550k05G5zUXfaVDkI7VIdaPLrgP6m23pM8yZEZ8qrieur47UFn 7Cq1jFCnv1eTFbWxZ0FwNYoRCtDFuYuW0WOeUu3eABwzy0F0uoOYLKJCoSTK8FjrOKGHPX8UYrbpH ICdjEYQlmPzcVUguRPrZ2QOdHYuvTAo7vv0IIv1TYXQvSE9aywCcvQhMHn1QdpnQUCPwbBoIVUzG1 ObahQwr3d+92H/BgRKOA==; DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; 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=xF9/8QKvWWkbeOJr21JLbJCynp3yqjzThzTACYbxHTg=; b=haZzJuTZBCZsOTNcMz6ga4dc9s gPbmwmK5daZnt7lwf0QPIOwrHm1HLUNltZ5eyE7kwaAHo437epvLvvbzCxKSKbClSjly0J6iO9U3b 2kE1iDoDjDVteIas0Hrdvw+mKegt5l3ahQOD8ROwy0dNBYdx5nyfI2MgkQbm1ywCSrKpMQQOJ03ry fMO9W8zUlfaxtXOtSOifpGhKXDQC78ttaD5wvdJrMOlfoZ6h4lc4Ci+ktx1zVTf3yZSfsmPXvx846 2ADzJq0jb+18JXgy/PoeRUfMkREC/wv/U6mZE4obztCo1xpba1RDNlGOmFJ0zI1uUNmc+WjwUgXaS YwmBv/0Q==; Content-Disposition: inline In-Reply-To: <0e69f7df80dc5878071deb0d80938138d19de1d1.camel@physik.fu-berlin.de> 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: John Paul Adrian Glaubitz Cc: Matthew Wilcox , Thomas Gleixner , Linus Torvalds , 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 On Tue, Sep 19, 2023 at 03:37:24PM +0200, John Paul Adrian Glaubitz wrote: > On Tue, 2023-09-19 at 14:00 +0100, 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 ... > > The agreement to kill off ia64 wasn't an invitation to kill off other stuff > that people are still working on! Can we please not do this? If you're working on one of them, then surely it's a simple matter of working on adding CONFIG_PREEMPT support :-)