From mboxrd@z Thu Jan 1 00:00:00 1970 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 60E8734A788; Mon, 6 Apr 2026 04:28:16 +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=1775449696; cv=none; b=RFl/vLDyrgq4UnO7Ca93grurU8ytex6RvKjuymU7JY0yFUpE4VvrTEepdh5jud7uP+E/lCbopOELLAb1XX8TfjgRUVOUPSjAzlYtrrgSY5+iu+Q4tTcmE1sTPZD035nqsXY+4hUIpzf4brMdTzg1AL5n9tA4eSCgYUMlTicGloI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775449696; c=relaxed/simple; bh=uYGceNTzNuZmnfMgHyxFjYMImRSA6EY2IdzY776syzU=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=Mlani9lGQlXObkyqMvelX+SiQMXAS15vVKmKuhnwcOQCDpnk42cDQHxyAJJWdd5SrgbWI+gZIArsP6aDwbKp+G+4Pl0+SDV17q7B67F9BhcW/jIHSQo5VZJDbAbn4XYoQ5VCJOeTafgJtadGu3vBgWC39GXos9la9gD9DqqVeus= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=LrIhyVRw; 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="LrIhyVRw" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8AD13C4CEF7; Mon, 6 Apr 2026 04:28:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1775449695; bh=uYGceNTzNuZmnfMgHyxFjYMImRSA6EY2IdzY776syzU=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=LrIhyVRwlhPr2buj/spqkEinh0TSUCphFFxWRJXa2SZtyWFV6c4MxfuD5ms92G8Gl vF2Xwudli8dgQTWDDFEh2TVvmX9GKFpLuavPEKdvydy+HtFjT5cJUef0ABrMCT60Bh 7jGHLax2sgOPSsQvn0dFRvioqMBwroi6D1bIVOv3zMa8uJc1tQU4nXJY0ouygzxw4d BSuRScIDayM5+b1FbWHSly4IL1lsYndWt71ihRoSN3F/8njW79cQ5nAfOC8QuJgyYW JRi2kSAo5UKGNlmcsgsdFWu0K7wAXftMgPVNCSFAi5N4Xegxsa1y1AlDGKWok42OFq MW/UF3hsWgP/w== Date: Mon, 6 Apr 2026 13:28:13 +0900 From: "Harry Yoo (Oracle)" To: "Vlastimil Babka (SUSE)" Cc: Marco Elver , Andrew Morton , Nathan Chancellor , Nicolas Schier , Dennis Zhou , Tejun Heo , Christoph Lameter , Hao Li , David Rientjes , Roman Gushchin , Kees Cook , "Gustavo A. R. Silva" , David Hildenbrand , Lorenzo Stoakes , "Liam R. Howlett" , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Alexander Potapenko , Dmitry Vyukov , Nick Desaulniers , Bill Wendling , Justin Stitt , linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-hardening@vger.kernel.org, kasan-dev@googlegroups.com, llvm@lists.linux.dev, Andrey Konovalov , Florent Revest , GONG Ruiqi , Jann Horn , KP Singh , Matteo Rizzo Subject: Re: [PATCH v1] slab: support for compiler-assisted type-based slab cache partitioning Message-ID: References: <20260331111240.153913-1-elver@google.com> Precedence: bulk X-Mailing-List: llvm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Fri, Apr 03, 2026 at 08:29:22PM +0200, Vlastimil Babka (SUSE) wrote: > On 4/3/26 08:27, Harry Yoo (Oracle) wrote: > >> diff --git a/include/linux/slab.h b/include/linux/slab.h > >> index 15a60b501b95..c0bf00ee6025 100644 > >> --- a/include/linux/slab.h > >> +++ b/include/linux/slab.h > >> @@ -864,10 +877,10 @@ unsigned int kmem_cache_sheaf_size(struct slab_sheaf *sheaf); > >> * with the exception of kunit tests > >> */ > >> > >> -void *__kmalloc_noprof(size_t size, gfp_t flags) > >> +void *__kmalloc_noprof(size_t size, gfp_t flags, kmalloc_token_t token) > >> __assume_kmalloc_alignment __alloc_size(1); > >> > >> -void *__kmalloc_node_noprof(DECL_BUCKET_PARAMS(size, b), gfp_t flags, int node) > >> +void *__kmalloc_node_noprof(DECL_BUCKET_PARAMS(size, b), gfp_t flags, int node, kmalloc_token_t token) > >> __assume_kmalloc_alignment __alloc_size(1); > > > > So the @token parameter is unused when CONFIG_PARTITION_KMALLOC_CACHES is > > disabled but still increases the kernel size by a few kilobytes... > > but yeah I'm not sure if we can get avoid it without hurting readability. > > > > Just saying. (does anybody care?) > > Well we did care enough with CONFIG_SLAB_BUCKETS to hide the unused param > using DECL_BUCKET_PARAMS(), Hmm yeah. I wasn't sure if we could do this without hurting readability, but perhaps we could... > so maybe extend that idea? > I think it's not just kernel size, but increased register pressure etc. Something like this should work? (diff on top of this patch) -- Cheers, Harry / Hyeonggon diff --git a/include/linux/slab.h b/include/linux/slab.h index c0bf00ee6025..0496d2e63f5e 100644 --- a/include/linux/slab.h +++ b/include/linux/slab.h @@ -871,16 +871,32 @@ unsigned int kmem_cache_sheaf_size(struct slab_sheaf *sheaf); #define PASS_BUCKET_PARAM(_b) NULL #endif +#ifdef CONFIG_PARTITION_KMALLOC_CACHES +#define DECL_TOKEN_PARAM(_token) , kmalloc_token_t (_token) +#define _PASS_TOKEN_PARAM(_token) , (_token) +#define PASS_TOKEN_PARAM(_token) (_token) +#else +#define DECL_TOKEN_PARAM(_token) +#define _PASS_TOKEN_PARAM(_token) +#define PASS_TOKEN_PARAM(_token) ((kmalloc_token_t){}) +#endif + +#define DECL_KMALLOC_PARAMS(_size, _b, _token) DECL_BUCKET_PARAMS(_size, _b) \ + DECL_TOKEN_PARAM(_token) + +#define PASS_KMALLOC_PARAMS(_size, _b, _token) PASS_BUCKET_PARAMS(_size, _b) \ + _PASS_TOKEN_PARAM(_token) + /* * The following functions are not to be used directly and are intended only * for internal use from kmalloc() and kmalloc_node() * with the exception of kunit tests */ -void *__kmalloc_noprof(size_t size, gfp_t flags, kmalloc_token_t token) +void *__kmalloc_noprof(DECL_KMALLOC_PARAMS(size, b, token), gfp_t flags) __assume_kmalloc_alignment __alloc_size(1); -void *__kmalloc_node_noprof(DECL_BUCKET_PARAMS(size, b), gfp_t flags, int node, kmalloc_token_t token) +void *__kmalloc_node_noprof(DECL_KMALLOC_PARAMS(size, b, token), gfp_t flags, int node) __assume_kmalloc_alignment __alloc_size(1); void *__kmalloc_cache_noprof(struct kmem_cache *s, gfp_t flags, size_t size) @@ -964,7 +980,7 @@ static __always_inline __alloc_size(1) void *_kmalloc_noprof(size_t size, gfp_t kmalloc_caches[kmalloc_type(flags, token)][index], flags, size); } - return __kmalloc_noprof(size, flags, token); + return __kmalloc_noprof(PASS_KMALLOC_PARAMS(size, NULL, token), flags); } #define kmalloc_noprof(...) _kmalloc_noprof(__VA_ARGS__, __kmalloc_token(__VA_ARGS__)) #define kmalloc(...) alloc_hooks(kmalloc_noprof(__VA_ARGS__)) @@ -1075,10 +1091,10 @@ void *_kmalloc_nolock_noprof(size_t size, gfp_t gfp_flags, int node, kmalloc_tok __alloc_flex(kvzalloc, default_gfp(__VA_ARGS__), typeof(P), FAM, COUNT) #define kmem_buckets_alloc(_b, _size, _flags) \ - alloc_hooks(__kmalloc_node_noprof(PASS_BUCKET_PARAMS(_size, _b), _flags, NUMA_NO_NODE, __kmalloc_token(_size))) + alloc_hooks(__kmalloc_node_noprof(PASS_KMALLOC_PARAMS(_size, _b, __kmalloc_token(_size)), _flags, NUMA_NO_NODE)) #define kmem_buckets_alloc_track_caller(_b, _size, _flags) \ - alloc_hooks(__kmalloc_node_track_caller_noprof(PASS_BUCKET_PARAMS(_size, _b), _flags, NUMA_NO_NODE, _RET_IP_, __kmalloc_token(_size))) + alloc_hooks(__kmalloc_node_track_caller_noprof(PASS_KMALLOC_PARAMS(_size, _b, __kmalloc_token(_size)), _flags, NUMA_NO_NODE, _RET_IP_)) static __always_inline __alloc_size(1) void *_kmalloc_node_noprof(size_t size, gfp_t flags, int node, kmalloc_token_t token) { @@ -1093,7 +1109,7 @@ static __always_inline __alloc_size(1) void *_kmalloc_node_noprof(size_t size, g kmalloc_caches[kmalloc_type(flags, token)][index], flags, node, size); } - return __kmalloc_node_noprof(PASS_BUCKET_PARAMS(size, NULL), flags, node, token); + return __kmalloc_node_noprof(PASS_KMALLOC_PARAMS(size, NULL, token), flags, node); } #define kmalloc_node_noprof(...) _kmalloc_node_noprof(__VA_ARGS__, __kmalloc_token(__VA_ARGS__)) #define kmalloc_node(...) alloc_hooks(kmalloc_node_noprof(__VA_ARGS__)) @@ -1154,10 +1170,10 @@ static inline __realloc_size(2, 3) void * __must_check krealloc_array_noprof(voi */ #define kcalloc(n, size, flags) kmalloc_array(n, size, (flags) | __GFP_ZERO) -void *__kmalloc_node_track_caller_noprof(DECL_BUCKET_PARAMS(size, b), gfp_t flags, int node, - unsigned long caller, kmalloc_token_t token) __alloc_size(1); +void *__kmalloc_node_track_caller_noprof(DECL_KMALLOC_PARAMS(size, b, token), gfp_t flags, int node, + unsigned long caller) __alloc_size(1); #define kmalloc_node_track_caller_noprof(size, flags, node, caller) \ - __kmalloc_node_track_caller_noprof(PASS_BUCKET_PARAMS(size, NULL), flags, node, caller, __kmalloc_token(size)) + __kmalloc_node_track_caller_noprof(PASS_KMALLOC_PARAMS(size, NULL, __kmalloc_token(size)), flags, node, caller) #define kmalloc_node_track_caller(...) \ alloc_hooks(kmalloc_node_track_caller_noprof(__VA_ARGS__, _RET_IP_)) @@ -1183,7 +1199,7 @@ static inline __alloc_size(1, 2) void *_kmalloc_array_node_noprof(size_t n, size return NULL; if (__builtin_constant_p(n) && __builtin_constant_p(size)) return _kmalloc_node_noprof(bytes, flags, node, token); - return __kmalloc_node_noprof(PASS_BUCKET_PARAMS(bytes, NULL), flags, node, token); + return __kmalloc_node_noprof(PASS_KMALLOC_PARAMS(bytes, NULL, token), flags, node); } #define kmalloc_array_node_noprof(...) _kmalloc_array_node_noprof(__VA_ARGS__, __kmalloc_token(__VA_ARGS__)) #define kmalloc_array_node(...) alloc_hooks(kmalloc_array_node_noprof(__VA_ARGS__)) @@ -1209,10 +1225,10 @@ static inline __alloc_size(1) void *_kzalloc_noprof(size_t size, gfp_t flags, km #define kzalloc(...) alloc_hooks(kzalloc_noprof(__VA_ARGS__)) #define kzalloc_node(_size, _flags, _node) kmalloc_node(_size, (_flags)|__GFP_ZERO, _node) -void *__kvmalloc_node_noprof(DECL_BUCKET_PARAMS(size, b), unsigned long align, - gfp_t flags, int node, kmalloc_token_t token) __alloc_size(1); +void *__kvmalloc_node_noprof(DECL_KMALLOC_PARAMS(size, b, token), unsigned long align, + gfp_t flags, int node) __alloc_size(1); #define kvmalloc_node_align_noprof(_size, _align, _flags, _node) \ - __kvmalloc_node_noprof(PASS_BUCKET_PARAMS(_size, NULL), _align, _flags, _node, __kmalloc_token(_size)) + __kvmalloc_node_noprof(PASS_KMALLOC_PARAMS(_size, NULL, __kmalloc_token(_size)), _align, _flags, _node) #define kvmalloc_node_align(...) \ alloc_hooks(kvmalloc_node_align_noprof(__VA_ARGS__)) #define kvmalloc_node(_s, _f, _n) kvmalloc_node_align(_s, 1, _f, _n) @@ -1225,7 +1241,7 @@ void *__kvmalloc_node_noprof(DECL_BUCKET_PARAMS(size, b), unsigned long align, #define kvzalloc_node(_size, _flags, _node) kvmalloc_node(_size, (_flags)|__GFP_ZERO, _node) #define kmem_buckets_valloc(_b, _size, _flags) \ - alloc_hooks(__kvmalloc_node_noprof(PASS_BUCKET_PARAMS(_size, _b), 1, _flags, NUMA_NO_NODE, __kmalloc_token(_size))) + alloc_hooks(__kvmalloc_node_noprof(PASS_KMALLOC_PARAMS(_size, _b, __kmalloc_token(_size)), 1, _flags, NUMA_NO_NODE)) static inline __alloc_size(1, 2) void * _kvmalloc_array_node_noprof(size_t n, size_t size, gfp_t flags, int node, kmalloc_token_t token) @@ -1235,7 +1251,7 @@ _kvmalloc_array_node_noprof(size_t n, size_t size, gfp_t flags, int node, kmallo if (unlikely(check_mul_overflow(n, size, &bytes))) return NULL; - return __kvmalloc_node_noprof(PASS_BUCKET_PARAMS(bytes, NULL), 1, flags, node, token); + return __kvmalloc_node_noprof(PASS_KMALLOC_PARAMS(bytes, NULL, token), 1, flags, node); } #define kvmalloc_array_node_noprof(...) _kvmalloc_array_node_noprof(__VA_ARGS__, __kmalloc_token(__VA_ARGS__)) #define kvmalloc_array_noprof(...) kvmalloc_array_node_noprof(__VA_ARGS__, NUMA_NO_NODE) diff --git a/mm/slub.c b/mm/slub.c index 5630dde94df0..84f129d79c99 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -5293,15 +5293,17 @@ void *__do_kmalloc_node(size_t size, kmem_buckets *b, gfp_t flags, int node, trace_kmalloc(caller, ret, size, s->size, flags, node); return ret; } -void *__kmalloc_node_noprof(DECL_BUCKET_PARAMS(size, b), gfp_t flags, int node, kmalloc_token_t token) +void *__kmalloc_node_noprof(DECL_KMALLOC_PARAMS(size, b, token), gfp_t flags, int node) { - return __do_kmalloc_node(size, PASS_BUCKET_PARAM(b), flags, node, _RET_IP_, token); + return __do_kmalloc_node(size, PASS_BUCKET_PARAM(b), flags, node, + _RET_IP_, PASS_TOKEN_PARAM(token)); } EXPORT_SYMBOL(__kmalloc_node_noprof); -void *__kmalloc_noprof(size_t size, gfp_t flags, kmalloc_token_t token) +void *__kmalloc_noprof(DECL_KMALLOC_PARAMS(size, b, token), gfp_t flags) { - return __do_kmalloc_node(size, NULL, flags, NUMA_NO_NODE, _RET_IP_, token); + return __do_kmalloc_node(size, PASS_BUCKET_PARAM(b), flags, + NUMA_NO_NODE, _RET_IP_, PASS_TOKEN_PARAM(token)); } EXPORT_SYMBOL(__kmalloc_noprof); @@ -5394,10 +5396,11 @@ void *_kmalloc_nolock_noprof(size_t size, gfp_t gfp_flags, int node, kmalloc_tok } EXPORT_SYMBOL_GPL(_kmalloc_nolock_noprof); -void *__kmalloc_node_track_caller_noprof(DECL_BUCKET_PARAMS(size, b), gfp_t flags, - int node, unsigned long caller, kmalloc_token_t token) +void *__kmalloc_node_track_caller_noprof(DECL_KMALLOC_PARAMS(size, b, token), gfp_t flags, + int node, unsigned long caller) { - return __do_kmalloc_node(size, PASS_BUCKET_PARAM(b), flags, node, caller, token); + return __do_kmalloc_node(size, PASS_BUCKET_PARAM(b), flags, node, + caller, PASS_TOKEN_PARAM(token)); } EXPORT_SYMBOL(__kmalloc_node_track_caller_noprof); @@ -6812,8 +6815,8 @@ static gfp_t kmalloc_gfp_adjust(gfp_t flags, size_t size) * * Return: pointer to the allocated memory of %NULL in case of failure */ -void *__kvmalloc_node_noprof(DECL_BUCKET_PARAMS(size, b), unsigned long align, - gfp_t flags, int node, kmalloc_token_t token) +void *__kvmalloc_node_noprof(DECL_KMALLOC_PARAMS(size, b, token), + unsigned long align, gfp_t flags, int node) { bool allow_block; void *ret; @@ -6824,7 +6827,7 @@ void *__kvmalloc_node_noprof(DECL_BUCKET_PARAMS(size, b), unsigned long align, */ ret = __do_kmalloc_node(size, PASS_BUCKET_PARAM(b), kmalloc_gfp_adjust(flags, size), - node, _RET_IP_, token); + node, _RET_IP_, PASS_TOKEN_PARAM(token)); if (ret || size <= PAGE_SIZE) return ret; -- 2.43.0