Merge tag 'slab-for-6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab

Pull slab updates from Vlastimil Babka:

 - Freelist loading optimization (Chengming Zhou)

   When the per-cpu slab is depleted and a new one loaded from the cpu
   partial list, optimize the loading to avoid an irq enable/disable
   cycle. This results in a 3.5% performance improvement on the "perf
   bench sched messaging" test.

 - Kernel boot parameters cleanup after SLAB removal (Xiongwei Song)

   Due to two different main slab implementations we've had boot
   parameters prefixed either slab_ and slub_ with some later becoming
   an alias as both implementations gained the same functionality (i.e.
   slab_nomerge vs slub_nomerge). In order to eventually get rid of the
   implementation-specific names, the canonical and documented
   parameters are now all prefixed slab_ and the slub_ variants become
   deprecated but still working aliases.

 - SLAB_ kmem_cache creation flags cleanup (Vlastimil Babka)

   The flags had hardcoded #define values which became tedious and
   error-prone when adding new ones. Assign the values via an enum that
   takes care of providing unique bit numbers. Also deprecate
   SLAB_MEM_SPREAD which was only used by SLAB, so it's a no-op since
   SLAB removal. Assign it an explicit zero value. The removals of the
   flag usage are handled independently in the respective subsystems,
   with a final removal of any leftover usage planned for the next
   release.

 - Misc cleanups and fixes (Chengming Zhou, Xiaolei Wang, Zheng Yejian)

   Includes removal of unused code or function parameters and a fix of a
   memleak.

* tag 'slab-for-6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab:
  slab: remove PARTIAL_NODE slab_state
  mm, slab: remove memcg_from_slab_obj()
  mm, slab: remove the corner case of inc_slabs_node()
  mm/slab: Fix a kmemleak in kmem_cache_destroy()
  mm, slab, kasan: replace kasan_never_merge() with SLAB_NO_MERGE
  mm, slab: use an enum to define SLAB_ cache creation flags
  mm, slab: deprecate SLAB_MEM_SPREAD flag
  mm, slab: fix the comment of cpu partial list
  mm, slab: remove unused object_size parameter in kmem_cache_flags()
  mm/slub: remove parameter 'flags' in create_kmalloc_caches()
  mm/slub: remove unused parameter in next_freelist_entry()
  mm/slub: remove full list manipulation for non-debug slab
  mm/slub: directly load freelist from cpu partial slab in the likely case
  mm/slub: make the description of slab_min_objects helpful in doc
  mm/slub: replace slub_$params with slab_$params in slub.rst
  mm/slub: unify all sl[au]b parameters with "slab_$param"
  Documentation: kernel-parameters: remove noaliencache

Author: torvalds

Documentation/admin-guide/kernel-parameters.txt

@@ -3771,10 +3771,6 @@
 	no5lvl		[X86-64,RISCV,EARLY] Disable 5-level paging mode. Forces
 			kernel to use 4-level paging instead.
 
-	noaliencache	[MM, NUMA, SLAB] Disables the allocation of alien
-			caches in the slab allocator.  Saves per-node memory,
-			but will impact performance.
-
 	noalign		[KNL,ARM]
 
 	noaltinstr	[S390,EARLY] Disables alternative instructions
@@ -5930,65 +5926,58 @@
 	simeth=		[IA-64]
 	simscsi=
 
-	slram=		[HW,MTD]
-
-	slab_merge	[MM]
-			Enable merging of slabs with similar size when the
-			kernel is built without CONFIG_SLAB_MERGE_DEFAULT.
-
-	slab_nomerge	[MM]
-			Disable merging of slabs with similar size. May be
-			necessary if there is some reason to distinguish
-			allocs to different slabs, especially in hardened
-			environments where the risk of heap overflows and
-			layout control by attackers can usually be
-			frustrated by disabling merging. This will reduce
-			most of the exposure of a heap attack to a single
-			cache (risks via metadata attacks are mostly
-			unchanged). Debug options disable merging on their
-			own.
-			For more information see Documentation/mm/slub.rst.
-
-	slab_max_order=	[MM, SLAB]
-			Determines the maximum allowed order for slabs.
-			A high setting may cause OOMs due to memory
-			fragmentation.  Defaults to 1 for systems with
-			more than 32MB of RAM, 0 otherwise.
-
-	slub_debug[=options[,slabs][;[options[,slabs]]...]	[MM, SLUB]
-			Enabling slub_debug allows one to determine the
+	slab_debug[=options[,slabs][;[options[,slabs]]...]	[MM]
+			Enabling slab_debug allows one to determine the
 			culprit if slab objects become corrupted. Enabling
-			slub_debug can create guard zones around objects and
+			slab_debug can create guard zones around objects and
 			may poison objects when not in use. Also tracks the
 			last alloc / free. For more information see
 			Documentation/mm/slub.rst.
+			(slub_debug legacy name also accepted for now)
 
-	slub_max_order= [MM, SLUB]
+	slab_max_order= [MM]
 			Determines the maximum allowed order for slabs.
 			A high setting may cause OOMs due to memory
 			fragmentation. For more information see
 			Documentation/mm/slub.rst.
+			(slub_max_order legacy name also accepted for now)
+
+	slab_merge	[MM]
+			Enable merging of slabs with similar size when the
+			kernel is built without CONFIG_SLAB_MERGE_DEFAULT.
+			(slub_merge legacy name also accepted for now)
 
-	slub_min_objects=	[MM, SLUB]
+	slab_min_objects=	[MM]
 			The minimum number of objects per slab. SLUB will
-			increase the slab order up to slub_max_order to
+			increase the slab order up to slab_max_order to
 			generate a sufficiently large slab able to contain
 			the number of objects indicated. The higher the number
 			of objects the smaller the overhead of tracking slabs
 			and the less frequently locks need to be acquired.
 			For more information see Documentation/mm/slub.rst.
+			(slub_min_objects legacy name also accepted for now)
 
-	slub_min_order=	[MM, SLUB]
+	slab_min_order=	[MM]
 			Determines the minimum page order for slabs. Must be
-			lower than slub_max_order.
-			For more information see Documentation/mm/slub.rst.
+			lower or equal to slab_max_order. For more information see
+			Documentation/mm/slub.rst.
+			(slub_min_order legacy name also accepted for now)
 
-	slub_merge	[MM, SLUB]
-			Same with slab_merge.
+	slab_nomerge	[MM]
+			Disable merging of slabs with similar size. May be
+			necessary if there is some reason to distinguish
+			allocs to different slabs, especially in hardened
+			environments where the risk of heap overflows and
+			layout control by attackers can usually be
+			frustrated by disabling merging. This will reduce
+			most of the exposure of a heap attack to a single
+			cache (risks via metadata attacks are mostly
+			unchanged). Debug options disable merging on their
+			own.
+			For more information see Documentation/mm/slub.rst.
+			(slub_nomerge legacy name also accepted for now)
 
-	slub_nomerge	[MM, SLUB]
-			Same with slab_nomerge. This is supported for legacy.
-			See slab_nomerge for more information.
+	slram=		[HW,MTD]
 
 	smart2=		[HW]
 			Format: <io1>[,<io2>[,...,<io8>]]

Documentation/mm/slub.rst

@@ -9,7 +9,7 @@ SLUB can enable debugging only for selected slabs in order to avoid
 an impact on overall system performance which may make a bug more
 difficult to find.
 
-In order to switch debugging on one can add an option ``slub_debug``
+In order to switch debugging on one can add an option ``slab_debug``
 to the kernel command line. That will enable full debugging for
 all slabs.
 
@@ -26,16 +26,16 @@ be enabled on the command line. F.e. no tracking information will be
 available without debugging on and validation can only partially
 be performed if debugging was not switched on.
 
-Some more sophisticated uses of slub_debug:
+Some more sophisticated uses of slab_debug:
 -------------------------------------------
 
-Parameters may be given to ``slub_debug``. If none is specified then full
+Parameters may be given to ``slab_debug``. If none is specified then full
 debugging is enabled. Format:
 
-slub_debug=<Debug-Options>
+slab_debug=<Debug-Options>
 	Enable options for all slabs
 
-slub_debug=<Debug-Options>,<slab name1>,<slab name2>,...
+slab_debug=<Debug-Options>,<slab name1>,<slab name2>,...
 	Enable options only for select slabs (no spaces
 	after a comma)
 
@@ -60,52 +60,52 @@ Possible debug options are::
 
 F.e. in order to boot just with sanity checks and red zoning one would specify::
 
-	slub_debug=FZ
+	slab_debug=FZ
 
 Trying to find an issue in the dentry cache? Try::
 
-	slub_debug=,dentry
+	slab_debug=,dentry
 
 to only enable debugging on the dentry cache.  You may use an asterisk at the
 end of the slab name, in order to cover all slabs with the same prefix.  For
 example, here's how you can poison the dentry cache as well as all kmalloc
 slabs::
 
-	slub_debug=P,kmalloc-*,dentry
+	slab_debug=P,kmalloc-*,dentry
 
 Red zoning and tracking may realign the slab.  We can just apply sanity checks
 to the dentry cache with::
 
-	slub_debug=F,dentry
+	slab_debug=F,dentry
 
 Debugging options may require the minimum possible slab order to increase as
 a result of storing the metadata (for example, caches with PAGE_SIZE object
 sizes).  This has a higher liklihood of resulting in slab allocation errors
 in low memory situations or if there's high fragmentation of memory.  To
 switch off debugging for such caches by default, use::
 
-	slub_debug=O
+	slab_debug=O
 
 You can apply different options to different list of slab names, using blocks
 of options. This will enable red zoning for dentry and user tracking for
 kmalloc. All other slabs will not get any debugging enabled::
 
-	slub_debug=Z,dentry;U,kmalloc-*
+	slab_debug=Z,dentry;U,kmalloc-*
 
 You can also enable options (e.g. sanity checks and poisoning) for all caches
 except some that are deemed too performance critical and don't need to be
 debugged by specifying global debug options followed by a list of slab names
 with "-" as options::
 
-	slub_debug=FZ;-,zs_handle,zspage
+	slab_debug=FZ;-,zs_handle,zspage
 
 The state of each debug option for a slab can be found in the respective files
 under::
 
 	/sys/kernel/slab/<slab name>/
 
 If the file contains 1, the option is enabled, 0 means disabled. The debug
-options from the ``slub_debug`` parameter translate to the following files::
+options from the ``slab_debug`` parameter translate to the following files::
 
 	F	sanity_checks
 	Z	red_zone
@@ -129,7 +129,7 @@ in order to reduce overhead and increase cache hotness of objects.
 Slab validation
 ===============
 
-SLUB can validate all object if the kernel was booted with slub_debug. In
+SLUB can validate all object if the kernel was booted with slab_debug. In
 order to do so you must have the ``slabinfo`` tool. Then you can do
 ::
 
@@ -150,29 +150,29 @@ list_lock once in a while to deal with partial slabs. That overhead is
 governed by the order of the allocation for each slab. The allocations
 can be influenced by kernel parameters:
 
-.. slub_min_objects=x		(default 4)
-.. slub_min_order=x		(default 0)
-.. slub_max_order=x		(default 3 (PAGE_ALLOC_COSTLY_ORDER))
+.. slab_min_objects=x		(default: automatically scaled by number of cpus)
+.. slab_min_order=x		(default 0)
+.. slab_max_order=x		(default 3 (PAGE_ALLOC_COSTLY_ORDER))
 
-``slub_min_objects``
+``slab_min_objects``
 	allows to specify how many objects must at least fit into one
 	slab in order for the allocation order to be acceptable.  In
 	general slub will be able to perform this number of
 	allocations on a slab without consulting centralized resources
 	(list_lock) where contention may occur.
 
-``slub_min_order``
+``slab_min_order``
 	specifies a minimum order of slabs. A similar effect like
-	``slub_min_objects``.
+	``slab_min_objects``.
 
-``slub_max_order``
-	specified the order at which ``slub_min_objects`` should no
+``slab_max_order``
+	specified the order at which ``slab_min_objects`` should no
 	longer be checked. This is useful to avoid SLUB trying to
-	generate super large order pages to fit ``slub_min_objects``
+	generate super large order pages to fit ``slab_min_objects``
 	of a slab cache with large object sizes into one high order
 	page. Setting command line parameter
 	``debug_guardpage_minorder=N`` (N > 0), forces setting
-	``slub_max_order`` to 0, what cause minimum possible order of
+	``slab_max_order`` to 0, what cause minimum possible order of
 	slabs allocation.
 
 SLUB Debug output
@@ -219,7 +219,7 @@ Here is a sample of slub debug output::
  FIX kmalloc-8: Restoring Redzone 0xc90f6d28-0xc90f6d2b=0xcc
 
 If SLUB encounters a corrupted object (full detection requires the kernel
-to be booted with slub_debug) then the following output will be dumped
+to be booted with slab_debug) then the following output will be dumped
 into the syslog:
 
 1. Description of the problem encountered
@@ -239,7 +239,7 @@ into the syslog:
 	pid=<pid of the process>
 
    (Object allocation / free information is only available if SLAB_STORE_USER is
-   set for the slab. slub_debug sets that option)
+   set for the slab. slab_debug sets that option)
 
 2. The object contents if an object was involved.
 
@@ -262,7 +262,7 @@ into the syslog:
 	the object boundary.
 
 	(Redzone information is only available if SLAB_RED_ZONE is set.
-	slub_debug sets that option)
+	slab_debug sets that option)
 
    Padding <address> : <bytes>
 	Unused data to fill up the space in order to get the next object
@@ -296,7 +296,7 @@ Emergency operations
 
 Minimal debugging (sanity checks alone) can be enabled by booting with::
 
-	slub_debug=F
+	slab_debug=F
 
 This will be generally be enough to enable the resiliency features of slub
 which will keep the system running even if a bad kernel component will
@@ -311,13 +311,13 @@ and enabling debugging only for that cache
 
 I.e.::
 
-	slub_debug=F,dentry
+	slab_debug=F,dentry
 
 If the corruption occurs by writing after the end of the object then it
 may be advisable to enable a Redzone to avoid corrupting the beginning
 of other objects::
 
-	slub_debug=FZ,dentry
+	slab_debug=FZ,dentry
 
 Extended slabinfo mode and plotting
 ===================================

drivers/misc/lkdtm/heap.c

@@ -48,7 +48,7 @@ static void lkdtm_VMALLOC_LINEAR_OVERFLOW(void)
  * correctly.
  *
  * This should get caught by either memory tagging, KASan, or by using
- * CONFIG_SLUB_DEBUG=y and slub_debug=ZF (or CONFIG_SLUB_DEBUG_ON=y).
+ * CONFIG_SLUB_DEBUG=y and slab_debug=ZF (or CONFIG_SLUB_DEBUG_ON=y).
  */
 static void lkdtm_SLAB_LINEAR_OVERFLOW(void)
 {

include/linux/kasan.h

@@ -429,7 +429,6 @@ struct kasan_cache {
 };
 
 size_t kasan_metadata_size(struct kmem_cache *cache, bool in_object);
-slab_flags_t kasan_never_merge(void);
 void kasan_cache_create(struct kmem_cache *cache, unsigned int *size,
 			slab_flags_t *flags);
 
@@ -446,11 +445,6 @@ static inline size_t kasan_metadata_size(struct kmem_cache *cache,
 {
 	return 0;
 }
-/* And thus nothing prevents cache merging. */
-static inline slab_flags_t kasan_never_merge(void)
-{
-	return 0;
-}
 /* And no cache-related metadata initialization is required. */
 static inline void kasan_cache_create(struct kmem_cache *cache,
 				      unsigned int *size,