From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 151FA3AE718 for ; Fri, 10 Jul 2026 06:04:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783663447; cv=none; b=VH+lxy/VHzGeuVURJrb50tPygt71MXKiKAs8GBlkSVrXxh2sVyQkux154ZD2uOer43XcAaBRwIzLO5TyDXhum5QLVoVeK7L/61qKBgft73ciSzm8iPTSwOhuCp8jhkPhI1kuOxBa0VBqn9+ZXHb/2aExUqGMUwa349FzQ9qEKa8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783663447; c=relaxed/simple; bh=K1a3EtzTeF+HcDRELSmK01zHs39BG2hyHFPstEtuRBI=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=b8vaS5Q2WAPdpGHYFx2/WsrmMhWcfP9SWuBTRSIYebkOzxkckyIATxrnldKOxO9m0P78raWDuTJ1hrudoi2PYmnjykDhhrmYoRjWJqICxDnk3kJyPLZ6B1SV2CTr2THt8mfkJnO1h2df2425vmE0Uu/hZLkS4qPXvaSTulaHF58= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=h66H3jNc; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="h66H3jNc" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 898081F00A3D; Fri, 10 Jul 2026 06:04:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1783663446; bh=vDVLveXJA8tyZM5x+2AUKuT7u3jiA9Hoaj06+pMMJeE=; h=From:Date:Subject:References:In-Reply-To:To:Cc; b=h66H3jNcRv7BzM08w6K8XqIrUenCowDf1LZm1yDgcD8Y7uHBzWUQbPPebxQnZXIEB hYVplaHL/qYAUp1U4yOnYClnjwTqil6y2dLvUUtUoEuWQ5Zn7gc1B4fB+rpFvrEBUA /1Bcx2oeqe8nwdhy+8Vk7YMXiy6xYlbUmWyHXJQ5Z/KgMvQgqc9xiJZdp/kzxZb/XP 32zn4z9n/9h4B19VG5RZZAqiR46d5i+ZZ+S9bb1w/6I4UvrAGNEb8/aBKxe6DntkDy ti0JmapcGO9NMR1S2xmN8MCCDeoQFW9/z73yiVr2NtxRpyG8vvXcu96YnVS1i0kpN+ 5bXu+0mQKNKfw== From: "Harry Yoo (Oracle)" Date: Fri, 10 Jul 2026 15:03:33 +0900 Subject: [PATCH slab/for-next-fixes v2 2/3] mm/slab: decouple SLAB_NO_SHEAVES from SLAB_NO_OBJ_EXT Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20260710-kmalloc-no-objext-v2-2-2709afb6a030@kernel.org> References: <20260710-kmalloc-no-objext-v2-0-2709afb6a030@kernel.org> In-Reply-To: <20260710-kmalloc-no-objext-v2-0-2709afb6a030@kernel.org> To: Vlastimil Babka , Andrew Morton , Hao Li , Christoph Lameter , David Rientjes , Roman Gushchin , Suren Baghdasaryan , Hao Ge , Kees Cook , Pedro Falcato , Shakeel Butt , Danielle Constantino , "Liam R. Howlett" Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, "Harry Yoo (Oracle)" X-Mailer: b4 0.14.3 Bootstrap caches are created with SLAB_NO_OBJ_EXT to disallow sheaves and obj_exts. To allow disabling obj_exts while allowing sheaves, decouple SLAB_NO_SHEAVES from SLAB_NO_OBJ_EXT. Bootstrap caches now have both SLAB_NO_SHEAVES and SLAB_NO_OBJ_EXT. No functional change intended. Cc: stable@vger.kernel.org Fixes: e47c897a2949 ("slab: add sheaves to most caches") Reviewed-by: Vlastimil Babka (SUSE) Signed-off-by: Harry Yoo (Oracle) --- include/linux/slab.h | 13 +++++++++++-- mm/slub.c | 10 ++++++---- 2 files changed, 17 insertions(+), 6 deletions(-) diff --git a/include/linux/slab.h b/include/linux/slab.h index 51f03f18c9a7..08d7b6c9c4d6 100644 --- a/include/linux/slab.h +++ b/include/linux/slab.h @@ -58,10 +58,13 @@ enum _slab_flag_bits { #endif _SLAB_OBJECT_POISON, _SLAB_CMPXCHG_DOUBLE, +#ifdef CONFIG_SLAB_OBJ_EXT _SLAB_NO_OBJ_EXT, -#if defined(CONFIG_SLAB_OBJ_EXT) && defined(CONFIG_64BIT) +#ifdef CONFIG_64BIT _SLAB_OBJ_EXT_IN_OBJ, #endif +#endif + _SLAB_NO_SHEAVES, _SLAB_FLAGS_LAST_BIT }; @@ -239,8 +242,14 @@ enum _slab_flag_bits { #endif #define SLAB_TEMPORARY SLAB_RECLAIM_ACCOUNT /* Objects are short-lived */ -/* Slab created using create_boot_cache */ +/* Slab caches without obj_exts array */ +#ifdef CONFIG_SLAB_OBJ_EXT #define SLAB_NO_OBJ_EXT __SLAB_FLAG_BIT(_SLAB_NO_OBJ_EXT) +#else +#define SLAB_NO_OBJ_EXT __SLAB_FLAG_UNUSED +#endif + +#define SLAB_NO_SHEAVES __SLAB_FLAG_BIT(_SLAB_NO_SHEAVES) #if defined(CONFIG_SLAB_OBJ_EXT) && defined(CONFIG_64BIT) #define SLAB_OBJ_EXT_IN_OBJ __SLAB_FLAG_BIT(_SLAB_OBJ_EXT_IN_OBJ) diff --git a/mm/slub.c b/mm/slub.c index f9461a0c47d3..abe748b7dddb 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -7799,12 +7799,12 @@ static unsigned int calculate_sheaf_capacity(struct kmem_cache *s, return 0; /* - * Bootstrap caches can't have sheaves for now (SLAB_NO_OBJ_EXT). + * Bootstrap caches can't have sheaves for now (SLAB_NO_SHEAVES). * SLAB_NOLEAKTRACE caches (e.g., kmemleak's object_cache) must not * have sheaves to avoid recursion when sheaf allocation triggers * kmemleak tracking. */ - if (s->flags & (SLAB_NO_OBJ_EXT | SLAB_NOLEAKTRACE)) + if (s->flags & (SLAB_NO_SHEAVES | SLAB_NOLEAKTRACE)) return 0; /* @@ -8586,7 +8586,8 @@ void __init kmem_cache_init(void) create_boot_cache(kmem_cache_node, "kmem_cache_node", sizeof(struct kmem_cache_node), - SLAB_HWCACHE_ALIGN | SLAB_NO_OBJ_EXT, 0, 0); + SLAB_HWCACHE_ALIGN | SLAB_NO_SHEAVES | SLAB_NO_OBJ_EXT, + 0, 0); hotplug_node_notifier(slab_memory_callback, SLAB_CALLBACK_PRI); @@ -8596,7 +8597,8 @@ void __init kmem_cache_init(void) create_boot_cache(kmem_cache, "kmem_cache", offsetof(struct kmem_cache, per_node) + nr_node_ids * sizeof(struct kmem_cache_per_node_ptrs), - SLAB_HWCACHE_ALIGN | SLAB_NO_OBJ_EXT, 0, 0); + SLAB_HWCACHE_ALIGN | SLAB_NO_SHEAVES | SLAB_NO_OBJ_EXT, + 0, 0); kmem_cache = bootstrap(&boot_kmem_cache); kmem_cache_node = bootstrap(&boot_kmem_cache_node); -- 2.53.0