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b=UTxr3VNy09n94NLv23qtAzTfJAA1tzEh2FT706IWQisOEW7UfErgqD9/+hBykrauR 8LBOQvvAl+S6cBuiTJXI4cSv0RFmgG345khRwwn5u4ZpChG1RhnYj3GltUYUqF1LJH 3HnK+A3hKFgBngyN92rXLeZUgJdJdzpvOCuWD6rrfsaK22so0qb8+TP+yDTgY1wg8i KbI0HgyOU+osu7cywnY7Kke5ZYiNYxB6YK7n0ULro4YSy3CtRVPB+QZLnbJsOrSYF4 0iff+EZlgIBpjWai1w9efamVUYuLX+hMcBQrr9VHaY4dI/kEqOgJoihdcrBVHl48a6 Fh9JjZw36hSsg== Date: Tue, 28 Jul 2026 22:41:05 +0900 From: Harry Yoo To: "Vlastimil Babka (SUSE)" Cc: Suren Baghdasaryan , Hao Li , 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 v3 06/13] mm/slab: abstract slabobj_ext.ref access Message-ID: References: <20260727-b4-objext_split-v3-0-c29ef0f1f257@kernel.org> <20260727-b4-objext_split-v3-6-c29ef0f1f257@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260727-b4-objext_split-v3-6-c29ef0f1f257@kernel.org> X-Rspam-User: X-Rspamd-Queue-Id: 58682140007 X-Rspamd-Server: rspam01 X-Stat-Signature: psnxyz7rq3ppw59jbrfp8y9ng58djtj5 X-HE-Tag: 1785246069-617971 X-HE-Meta: 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 +pczTjF+ 9tZ1ClgXV3H+YsL0nBFeG1HomvvJdZ/Id0wyBGqM4ktOKoC89KIDIpG5ez751np8V5MN8LqGp3cgRfofMahEhqGFJC1oUvP7+k6m6b9i7kVQx7YmPHQqeHkczF+efQHIzAZCXaef7U2/dtPcS9/iuhsIMGlLAKGcudwdin0qIx0nYRBSkwCCPLZcZ+lctWOwfGG0nHHLF0C2PtzQOdhceqIzOGW3FsmHNfigd67174A3zSTxaP7FGbMfzD3LXf+8Nk1fwUIskoGuePXzBuP9mT2ItvSgCoME250Svn8CR1y486U+vpklTrdDh6dK4m2JEtjg79ZI4/hiGHFjhlbQnlL3RWg== 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 02:54:00PM +0200, Vlastimil Babka (SUSE) wrote: > In preparation for changes to the structure, abstract access to the ref > field with a slab_obj_ext_codetag_ref() function. Rename the field to > _ctref to make an unexpected direct access a compile error. > > No functional change intended. > > Reviewed-by: Suren Baghdasaryan > Reviewed-by: Hao Li > Signed-off-by: Vlastimil Babka (SUSE) > --- Looks good to me, Reviewed-by: Harry Yoo (Oracle) With a suggestion: it would be nice to have debug warnings that trigger when slab_obj_ext_codetag_ref() is compiled but not supposed to be called. e.g.) for kfence objects, or later in the series when we reduce slabobj_ext memory (!slab_obj_ext_has_codetag()) Similarly, it would be nice (later in the series) to have a warning in slab_obj_ext_objcg() when slab_needs_objcg() returns false. > mm/slab.h | 10 +++++++++- > mm/slub.c | 42 ++++++++++++++++++++++++++++-------------- > 2 files changed, 37 insertions(+), 15 deletions(-)