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b=SVEHUOBA7CyCoOVLY/ESfqlRLqBpy+D4VC2WG7oRWQawBvKmGC6GXqF0e/l2CLrh7 Re42J+XY+5+BtaEx1DNNnTecrDLK6VhrY4YQn+OTxKzsFcT9DJmaWb4ajk3Ok/Q8S+ ndtBJlUw7rPBkHi+ita3ubgG3I0pT9dVXl9kAXvV8QdmsCyn5LhfKHVlsBNl0xSUZr +nsaWW02S0oMAAPOr12qfJhAq7Q9JqV7eJ+ca2k8PQvm55YSirsY7iKVJtQKa1RKcE qNgbG9zMXjzQKAFOXs9d0nv2z5fNF0CAXu517NsTlSLDWrvYA27zotLoavtsHt0oxy fKXpv466jMQlQ== Message-ID: Date: Fri, 24 Jul 2026 17:42:32 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2 09/13] mm/slab: change struct slabobj_ext to a union Content-Language: en-US To: Hao Li , Harry Yoo Cc: Suren Baghdasaryan , Shakeel Butt , Alexander Potapenko , Marco Elver , Andrew Morton , Christoph Lameter , David Rientjes , Roman Gushchin , linux-mm@kvack.org, linux-kernel@vger.kernel.org, cgroups@vger.kernel.org References: <20260720-b4-objext_split-v2-0-2fa7c6f60dbe@kernel.org> <20260720-b4-objext_split-v2-9-2fa7c6f60dbe@kernel.org> <9b2dadb7-8e3d-4b9b-a870-969be9a7a432@kernel.org> From: "Vlastimil Babka (SUSE)" Autocrypt: addr=vbabka@kernel.org; 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charset=UTF-8 Content-Transfer-Encoding: 7bit X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: AF4831C000E X-Rspam-User: X-Stat-Signature: 73rrbsj5rsiz1qujwnqyeq5p6hswb39s X-HE-Tag: 1784907757-538493 X-HE-Meta: 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 I1lxbwOY QCaPBivZsPD6K4WnFttoBMS7VnAyh3JaX60Ny43npxOiDgqeo6r1qa1FxYu75N1+wDXupfuGZjMgmEmdONN8DKY/1qk9wQJXzJI+bPFqpnjgPM2Dx7qlVneqts2Fck+tug7ZvkzO1cwLBp6QBJh2my2EVbfzTrgozSQPWc6jc9f0KYy084FK+hZ6IBT90jIZb0ui82LhpBenr2OFp4r3h7EDGmKeHtLz+GY1+u+nJaSTgcizjYNIIByFT3F3KSdRBX2BEyeL/JYekPjxkEK0b2E0C6WWkH4rJsq8C95BvFRGqddl8U4gnjQNwyg== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 7/23/26 11:56, Hao Li wrote: > On Thu, Jul 23, 2026 at 03:27:51PM +0900, Harry Yoo wrote: >> >> and drop OBJEXT_FLAG_UNUSED. > > Yes, this idea is insightful and I think it may need a standalone patch without > blocking current patchset. > >> >> ...not sure how much we care about this on 32bit though. > > Yeah, 32bit is a rare arch today :) Agreed with you both. Let's deal with it later. Also AFAICS the memory was already wasted on 32bit prior this series when e.g. CONFIG_MEM_ALLOC_PROFILING was disabled, so there was just 4-byte objcg pointer in 8-byte aligned slabobj_ext, right?