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AJvYcCVpQSEHn75C+2hu620pBvL5tQ+/wVhZmwB1exgbQXJ9/i4AtLAlisiRvYYTd/78klC+djsXYK5UhUU8@vger.kernel.org X-Gm-Message-State: AOJu0YwhCU2ZEHPYPrrY6ck9/iN6SEMqHh85JRVl8FiaOH9Av4TRcUO1 Z0so5dqnMWtVMCjyiBzQIK9aYdwI8tc2R0q5JBPPn+C0thfi9zPnnbgkF/O7g2g= X-Gm-Gg: ASbGncs8bVuomh1snx6FXPdjSJr1eQtnOhp12wy8qgE0shOEwdr/YlEzn+LNG4POVQA J2mRdSMFUG+vlmozB83PIEjMWM10+Z9qbvNrzE0//gf8hsnj3rCz1FQ0Rhr8dEVJduvIWZZCNFS UCY8F6Ta5TFla3yXh6Be5Xp7ZKQYgA6GXxViRk+7M3NpNzbIJZvi6QliLVWEVmsBfkRgZLnG+7s qzZtlPgxl6OtvETbvAsHl5z3vrwhH9GftTO22QaPkxPtQ== X-Google-Smtp-Source: AGHT+IGQ9k8wS2TS60qT8IVjc3fnuFCoLgHqv0GNMp58Q1HLV2LNWsVqKRLFgpF9Cw9p6ZAQqUdenA== X-Received: by 2002:a05:6870:9619:b0:296:b0d8:9025 with SMTP id 586e51a60fabf-296d9bcedd8mr8467428fac.20.1732214113009; Thu, 21 Nov 2024 10:35:13 -0800 (PST) Received: from [192.168.1.116] ([96.43.243.2]) by smtp.gmail.com with ESMTPSA id 586e51a60fabf-2971d87e96dsm52987fac.45.2024.11.21.10.35.11 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 21 Nov 2024 10:35:12 -0800 (PST) Message-ID: <3fe55eba-1a8c-464f-8598-6068ce03f296@kernel.dk> Date: Thu, 21 Nov 2024 11:35:10 -0700 Precedence: bulk X-Mailing-List: linux-m68k@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] slab: Fix too strict alignment check in create_cache() To: Guenter Roeck , "Christoph Lameter (Ampere)" Cc: Geert Uytterhoeven , Vlastimil Babka , Pekka Enberg , David Rientjes , Joonsoo Kim , Andrew Morton , Roman Gushchin , Hyeonggon Yoo <42.hyeyoo@gmail.com>, 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 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> Content-Language: en-US From: Jens Axboe In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 11/21/24 11:30 AM, Guenter Roeck wrote: > On Thu, Nov 21, 2024 at 09:23:28AM -0800, Christoph Lameter (Ampere) wrote: >> 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? I asked that earlier in this thread too... > 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 ? Getting rid of nommu would be nice for sure in terms of maintenance, it's one of those things that pop up as a build breaking thing because nobody is using/testing them. I'm all for axing relics from the codebase. Doesn't mean they can't be maintained out-of-tree, but that is where they belong imho. -- Jens Axboe