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From: Hao Li To: Harry Yoo Cc: "Vlastimil Babka (SUSE)" , 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 Subject: Re: [PATCH v2 09/13] mm/slab: change struct slabobj_ext to a union Message-ID: 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> <89662cae-b3d9-4aa4-a7fa-cf5931781dbc@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <89662cae-b3d9-4aa4-a7fa-cf5931781dbc@kernel.org> X-Migadu-Flow: FLOW_OUT X-Rspam-User: X-Rspamd-Queue-Id: E25B6160004 X-Rspamd-Server: rspam01 X-Stat-Signature: o56ibwcjypcpzxsxor6994948os6gtq3 X-HE-Tag: 1785133373-186025 X-HE-Meta: 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 jzJ++R3e NG5jacCgWzJTowoAmABVHxraPSqwxeIsSgQtMmm8ovCN0gbzcUPLht9UO8HjNQeYbHRhY8fodTx0b03vjQ9goNtga013G5DdK8p/2by747LEt+3/1kXno5RoBR1bUmwdydqhNwLAjPCWBuxgtMoYUzeNvRRQsRNaTTjQD2sen5bS2BTI123Nd1GWNrL8BRpu6FyyAqjK+7SkQNfCjJqTKIXaXv4KyhdTYEApZhXXI01v2j61fqz/09qSrpj7X3NaeFSxt Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Mon, Jul 27, 2026 at 02:41:20PM +0900, Harry Yoo wrote: > > > On 7/25/26 12:42 AM, Vlastimil Babka (SUSE) wrote: > > 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. > > Sounds reasonable. Yes, agree. > > > 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? > > Right. Exactly. -- Thanks, Hao