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[209.85.128.170]) by smtp.gmail.com with ESMTPSA id 3f1490d57ef6-e38f6089523sm82574276.32.2024.11.21.10.50.45 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 21 Nov 2024 10:50:45 -0800 (PST) Received: by mail-yw1-f170.google.com with SMTP id 00721157ae682-6eea47d51aeso12371667b3.2; Thu, 21 Nov 2024 10:50:45 -0800 (PST) X-Forwarded-Encrypted: i=1; AJvYcCUOwogVxjrOmozWFw8OvkFfPjTyZ0MusjgFFp7UejGFbbeeVkWFG8YxdQ49K+CylkkiuDmRWj4v3Eko9A==@vger.kernel.org, AJvYcCVbMzIPMGYxQ9vv3WxVFCyICEb1gg5hbXjrz0GHlIqk0NVTyNT0C3H9gZZ+u25372n8QsPiMZJ5xg==@vger.kernel.org, AJvYcCWKxL5zmNo8aMFt4bLf9PKqJ1FAWPwfmIENPOYqY0+ygdP1sGb1KQXc31f9jhjg8yvBR8Pjz9/rRXxh5ltt@vger.kernel.org X-Received: by 2002:a05:690c:6a01:b0:6ee:86da:3a49 with SMTP id 00721157ae682-6eee08aba14mr4213967b3.8.1732215045390; Thu, 21 Nov 2024 10:50:45 -0800 (PST) Precedence: bulk X-Mailing-List: io-uring@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 References: <80c767a5d5927c099aea5178fbf2c897b459fa90.1732106544.git.geert@linux-m68k.org> <4f70f8d3-4ba5-43dc-af1c-f8e207d27e9f@suse.cz> <2e704ffc-2e79-27f7-159e-8fe167d5a450@gentwo.org> <693a6243-b2bd-7f2b-2b69-c7e2308d0f58@gentwo.org> In-Reply-To: From: Geert Uytterhoeven Date: Thu, 21 Nov 2024 19:50:33 +0100 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH] slab: Fix too strict alignment check in create_cache() To: Guenter Roeck Cc: "Christoph Lameter (Ampere)" , 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 , Kees Cook , Jann Horn , linux-mm@kvack.org, io-uring@vger.kernel.org, linux-m68k@vger.kernel.org, linux-kernel@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Thu, Nov 21, 2024 at 7:30=E2=80=AFPM Guenter Roeck = wrote: > On Thu, Nov 21, 2024 at 09:23:28AM -0800, Christoph Lameter (Ampere) wrot= e: > > 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 rea= ch > > for me to have. The dream system that I never could get my hands on. Th= e > > 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. s/rate/rare/ > > 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? > > Since this keeps coming up, I think there is a much more important > question to ask: > > Do we really need to continue supporting nommu machines ? Is anyone > but me even boot testing those ? Not all m68k platform are nommu. 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