From nobody Wed Dec 17 13:45:26 2025 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C789A3D62 for ; Wed, 10 Jul 2024 01:51:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720576269; cv=none; b=moOKco18U1Sq655TCeQRC8KYaS2YMjZzo7/KbtLUrpffdZyEY9EXrdeixWzeN22j9Kl9AEx7AWkemA4gApuGpsY8OjWZ/XRbIE4OAb9M5OenoPYMWBi+zKeOd5gTZLOBsku5vOOPLG/ZrDyW/OoZhmyIUYQy27MJYSbsdq9U36Y= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720576269; c=relaxed/simple; bh=ZvLp7r5qYpXgQ8FeJYMYjuwJ6F6KhsV/1xQSB21NOzY=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=oYb0T0bbXo3iTcyTzwxVVHckVVM1MNYjSP8khoeQQIWwNjoxKGPsqUDTuPCLHpy09h5sk4yEpAcKNPz3CFtS+aclPx7Db+ZdgLaeAyqvv80D2vc239vru54Y3thuxbQrT69UZu6TBphEPeei97ejv276UD/IHJEMrTuAKvL+voo= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=EpAHh+3s; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="EpAHh+3s" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0D9E6C3277B; Wed, 10 Jul 2024 01:51:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1720576269; bh=ZvLp7r5qYpXgQ8FeJYMYjuwJ6F6KhsV/1xQSB21NOzY=; h=From:To:Cc:Subject:Date:From; b=EpAHh+3sKtz1m+bYgcFLVMI5KjLyu0QMXujNasDcqXOK+IGr7IQBtM+eHAk5nzRz+ tMk6XRyqPl7l5A1BVK5AqaccCektN/8Dhy752zi3rsCDh6EqrASj9AfqE06oNPkb+u RlqtaGS7nBYx58z+sPhHOPJIIsH2Q17uZDG7LEp8cyWQVUNJ++Pv1ZrgEndq4VYyKr 3nk94moYyIg8C5KVOH5nS5Y1KwoL2gN3Sp1BNDwqP0SduRUZAjhSYGlDgpfHDV4kC+ uHBbVV2EPUclEOEMkuqShJFgIeiEdgIXV25oVk93Q+IEPLqZSzJDaMOVZtzkCOODSe 6qDR8/rj6yEkQ== From: alexs@kernel.org To: Christoph Lameter , Pekka Enberg , David Rientjes , Joonsoo Kim , Vlastimil Babka , Roman Gushchin , Hyeonggon Yoo <42.hyeyoo@gmail.com>, "Gustavo A . R . Silva" , Vincent Guittot , linux-mm@kvack.org, linux-kernel@vger.kernel.org Cc: Petr Mladek , Masahiro Yamada , Randy Dunlap , Yoann Congal , "Alex Shi (Tencent)" , Suren Baghdasaryan Subject: [PATCH v2] mm/memcg: alignment memcg_data define condition Date: Wed, 10 Jul 2024 09:56:08 +0800 Message-ID: <20240710015608.100801-1-alexs@kernel.org> X-Mailer: git-send-email 2.43.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: "Alex Shi (Tencent)" commit 21c690a349ba ("mm: introduce slabobj_ext to support slab object extensions") changed the folio/page->memcg_data define condition from MEMCG to SLAB_OBJ_EXT. And selected SLAB_OBJ_EXT for MEMCG, just for SLAB_MATCH(memcg_data, obj_exts), even no other relationship between them. Above action make memcg_data exposed and include SLAB_OBJ_EXT for !MEMCG. That's incorrect in logcial and pay on code size. So let's remove SLAB_OBJ_EXT from MEMCG and as Vlastimil Babka suggested, add _unused_slab_obj_ext for SLAB_MATCH for slab.obj_exts while !MEMCG. That could resolve the match issue, clean up the feature logical and save the unnessary code adding. Signed-off-by: Alex Shi (Tencent) Cc: Randy Dunlap Cc: Yoann Congal Cc: Masahiro Yamada Cc: Petr Mladek Cc: Suren Baghdasaryan Cc: Vlastimil Babka --- include/linux/mm_types.h | 8 ++++++-- init/Kconfig | 1 - mm/slab.h | 4 ++++ 3 files changed, 10 insertions(+), 3 deletions(-) diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h index ef09c4eef6d3..4ac3abc673d3 100644 --- a/include/linux/mm_types.h +++ b/include/linux/mm_types.h @@ -180,8 +180,10 @@ struct page { /* Usage count. *DO NOT USE DIRECTLY*. See page_ref.h */ atomic_t _refcount; =20 -#ifdef CONFIG_SLAB_OBJ_EXT +#ifdef CONFIG_MEMCG unsigned long memcg_data; +#elif defined(CONFIG_SLAB_OBJ_EXT) + unsigned long _unused_slab_obj_ext; #endif =20 /* @@ -343,8 +345,10 @@ struct folio { }; atomic_t _mapcount; atomic_t _refcount; -#ifdef CONFIG_SLAB_OBJ_EXT +#ifdef CONFIG_MEMCG unsigned long memcg_data; +#elif defined(CONFIG_SLAB_OBJ_EXT) + unsigned long _unused_slab_obj_ext; #endif #if defined(WANT_PAGE_VIRTUAL) void *virtual; diff --git a/init/Kconfig b/init/Kconfig index 26bf8bb0a7ce..61e43ac9fe75 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -965,7 +965,6 @@ config MEMCG bool "Memory controller" select PAGE_COUNTER select EVENTFD - select SLAB_OBJ_EXT help Provides control over the memory footprint of tasks in a cgroup. =20 diff --git a/mm/slab.h b/mm/slab.h index 3586e6183224..8ffdd4f315f8 100644 --- a/mm/slab.h +++ b/mm/slab.h @@ -98,7 +98,11 @@ SLAB_MATCH(flags, __page_flags); SLAB_MATCH(compound_head, slab_cache); /* Ensure bit 0 is clear */ SLAB_MATCH(_refcount, __page_refcount); #ifdef CONFIG_SLAB_OBJ_EXT +#ifdef CONFIG_MEMCG SLAB_MATCH(memcg_data, obj_exts); +#else +SLAB_MATCH(_unused_slab_obj_ext, obj_exts); +#endif #endif #undef SLAB_MATCH static_assert(sizeof(struct slab) <=3D sizeof(struct page)); --=20 2.43.0