From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from gentwo.org (gentwo.org [62.72.0.81]) (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 D3F94188907; Thu, 21 Nov 2024 17:32:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=62.72.0.81 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1732210366; cv=none; b=Sjx4EV0AO6wogk6W3r/SoMXA5lf2fMQRGouQngRLkaCxmQmAN23ALYIzdk8Q4cXSAql0EFGRUYFP3X7XbX02SGPtfRzjCKC+t5SwBlrRyovyjVqh28xFuc7LnOAFPxUu2KKnsUGD2BwESPhyL1hdkzLUD38Q+0cPWuL+TCX3780= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1732210366; c=relaxed/simple; bh=dGIvAVVhr1XQ+IBWwKJiytD8adIRDF3znbGFVaI1CE8=; h=Date:From:To:cc:Subject:In-Reply-To:Message-ID:References: MIME-Version:Content-Type; b=apVXiSAF1WJu/gUMm3EeG/y1LLbn+RchCNEV1Bu+XWLGgX192h3xaQKUjZmpcIfD3h+/5zYnmIuAAOHefH/Ym0h68/K8pnjM7u1gGCsrT++gp1eWC5iuu6u5GwrEDMAkpZMu548Nw9/SkzePDORA4wjV/CLylG5QbvDsTh2BH+g= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=gentwo.org; spf=pass smtp.mailfrom=gentwo.org; dkim=pass (1024-bit key) header.d=gentwo.org header.i=@gentwo.org header.b=AUZeXvlh; arc=none smtp.client-ip=62.72.0.81 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=gentwo.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gentwo.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=gentwo.org header.i=@gentwo.org header.b="AUZeXvlh" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gentwo.org; s=default; t=1732209808; bh=dGIvAVVhr1XQ+IBWwKJiytD8adIRDF3znbGFVaI1CE8=; h=Date:From:To:cc:Subject:In-Reply-To:References:From; b=AUZeXvlhRTQXOreYKQ5tM6otggSm6Vmlfpnt6jWROdE8oB9IViP6vwvSzWiBSxH3B m+s13vkh7TkgT+a+wMGPI53H4oy4UB4eV3H+LH5QLoKAJvLaR/fxnklp+9E6qBAh5i SHbp4BMgosdGgvJTZj/UC6b9OP4roggPYEssKGzs= Received: by gentwo.org (Postfix, from userid 1003) id 8CC9B401F4; Thu, 21 Nov 2024 09:23:28 -0800 (PST) Received: from localhost (localhost [127.0.0.1]) by gentwo.org (Postfix) with ESMTP id 89830401EE; Thu, 21 Nov 2024 09:23:28 -0800 (PST) Date: Thu, 21 Nov 2024 09:23:28 -0800 (PST) From: "Christoph Lameter (Ampere)" To: Geert Uytterhoeven cc: Vlastimil Babka , Pekka Enberg , David Rientjes , Joonsoo Kim , Andrew Morton , Roman Gushchin , Hyeonggon Yoo <42.hyeyoo@gmail.com>, Jens Axboe , Pavel Begunkov , Mike Rapoport , Christian Brauner , Guenter Roeck , Kees Cook , Jann Horn , linux-mm@kvack.org, io-uring@vger.kernel.org, linux-m68k@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] slab: Fix too strict alignment check in create_cache() In-Reply-To: Message-ID: <693a6243-b2bd-7f2b-2b69-c7e2308d0f58@gentwo.org> References: <80c767a5d5927c099aea5178fbf2c897b459fa90.1732106544.git.geert@linux-m68k.org> <4f70f8d3-4ba5-43dc-af1c-f8e207d27e9f@suse.cz> <2e704ffc-2e79-27f7-159e-8fe167d5a450@gentwo.org> Precedence: bulk X-Mailing-List: io-uring@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII On Thu, 21 Nov 2024, Geert Uytterhoeven wrote: > Linux has supported m68k since last century. Yeah I fondly remember the 80s where 68K systems were always out of reach for me to have. The dream system that I never could get my hands on. The creme de la creme du jour. I just had to be content with the 6800 and 6502 processors. Then IBM started the sick road down the 8088, 8086 that led from crap to more crap. Sigh. > Any new such assumptions are fixed quickly (at least in the kernel). > If you need a specific alignment, make sure to use __aligned and/or > appropriate padding in structures. > And yes, the compiler knows, and provides __alignof__. > > > How do you deal with torn reads/writes in such a scenario? Is this UP > > only? > > Linux does not support (rate) SMP m68k machines. Ah. Ok that explains it. Do we really need to maintain support for a platform that has been obsolete for decade and does not even support SMP?