Date:   Fri, 17 Mar 2023 13:52:06 +0200
From:   Mike Rapoport <rppt@kernel.org>
To:     Vlastimil Babka <vbabka@suse.cz>
Cc:     Christoph Lameter <cl@linux.com>,
        David Rientjes <rientjes@google.com>,
        Joonsoo Kim <iamjoonsoo.kim@lge.com>,
        Pekka Enberg <penberg@kernel.org>,
        Hyeonggon Yoo <42.hyeyoo@gmail.com>,
        Roman Gushchin <roman.gushchin@linux.dev>,
        Andrew Morton <akpm@linux-foundation.org>, linux-mm@kvack.org,
        rcu@vger.kernel.org, linux-fsdevel@vger.kernel.org,
        linux-kernel@vger.kernel.org, patches@lists.linux.dev,
        linux-doc@vger.kernel.org, Lorenzo Stoakes <lstoakes@gmail.com>
Subject: Re: [PATCH v2 5/6] mm/slob: remove slob.c
Message-ID: <ZBRUZvlAUQiGDE+E@kernel.org>
References: <20230317104307.29328-1-vbabka@suse.cz>
 <20230317104307.29328-6-vbabka@suse.cz>
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In-Reply-To: <20230317104307.29328-6-vbabka@suse.cz>
Precedence: bulk

On Fri, Mar 17, 2023 at 11:43:06AM +0100, Vlastimil Babka wrote:
> Remove the SLOB implementation.
> 
> RIP SLOB allocator (2006 - 2023)
> 
> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
> Acked-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
> Acked-by: Lorenzo Stoakes <lstoakes@gmail.com>
> Acked-by: Roman Gushchin <roman.gushchin@linux.dev>

Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>

> ---
>  mm/slob.c | 757 ------------------------------------------------------
>  1 file changed, 757 deletions(-)
>  delete mode 100644 mm/slob.c
> 
> diff --git a/mm/slob.c b/mm/slob.c
> deleted file mode 100644
> index fe567fcfa3a3..000000000000
> --- a/mm/slob.c
> +++ /dev/null
> @@ -1,757 +0,0 @@
> -// SPDX-License-Identifier: GPL-2.0
> -/*
> - * SLOB Allocator: Simple List Of Blocks
> - *
> - * Matt Mackall <mpm@selenic.com> 12/30/03
> - *
> - * NUMA support by Paul Mundt, 2007.
> - *
> - * How SLOB works:
> - *
> - * The core of SLOB is a traditional K&R style heap allocator, with
> - * support for returning aligned objects. The granularity of this
> - * allocator is as little as 2 bytes, however typically most architectures
> - * will require 4 bytes on 32-bit and 8 bytes on 64-bit.
> - *
> - * The slob heap is a set of linked list of pages from alloc_pages(),
> - * and within each page, there is a singly-linked list of free blocks
> - * (slob_t). The heap is grown on demand. To reduce fragmentation,
> - * heap pages are segregated into three lists, with objects less than
> - * 256 bytes, objects less than 1024 bytes, and all other objects.
> - *
> - * Allocation from heap involves first searching for a page with
> - * sufficient free blocks (using a next-fit-like approach) followed by
> - * a first-fit scan of the page. Deallocation inserts objects back
> - * into the free list in address order, so this is effectively an
> - * address-ordered first fit.
> - *
> - * Above this is an implementation of kmalloc/kfree. Blocks returned
> - * from kmalloc are prepended with a 4-byte header with the kmalloc size.
> - * If kmalloc is asked for objects of PAGE_SIZE or larger, it calls
> - * alloc_pages() directly, allocating compound pages so the page order
> - * does not have to be separately tracked.
> - * These objects are detected in kfree() because folio_test_slab()
> - * is false for them.
> - *
> - * SLAB is emulated on top of SLOB by simply calling constructors and
> - * destructors for every SLAB allocation. Objects are returned with the
> - * 4-byte alignment unless the SLAB_HWCACHE_ALIGN flag is set, in which
> - * case the low-level allocator will fragment blocks to create the proper
> - * alignment. Again, objects of page-size or greater are allocated by
> - * calling alloc_pages(). As SLAB objects know their size, no separate
> - * size bookkeeping is necessary and there is essentially no allocation
> - * space overhead, and compound pages aren't needed for multi-page
> - * allocations.
> - *
> - * NUMA support in SLOB is fairly simplistic, pushing most of the real
> - * logic down to the page allocator, and simply doing the node accounting
> - * on the upper levels. In the event that a node id is explicitly
> - * provided, __alloc_pages_node() with the specified node id is used
> - * instead. The common case (or when the node id isn't explicitly provided)
> - * will default to the current node, as per numa_node_id().
> - *
> - * Node aware pages are still inserted in to the global freelist, and
> - * these are scanned for by matching against the node id encoded in the
> - * page flags. As a result, block allocations that can be satisfied from
> - * the freelist will only be done so on pages residing on the same node,
> - * in order to prevent random node placement.
> - */
> -
> -#include <linux/kernel.h>
> -#include <linux/slab.h>
> -
> -#include <linux/mm.h>
> -#include <linux/swap.h> /* struct reclaim_state */
> -#include <linux/cache.h>
> -#include <linux/init.h>
> -#include <linux/export.h>
> -#include <linux/rcupdate.h>
> -#include <linux/list.h>
> -#include <linux/kmemleak.h>
> -
> -#include <trace/events/kmem.h>
> -
> -#include <linux/atomic.h>
> -
> -#include "slab.h"
> -/*
> - * slob_block has a field 'units', which indicates size of block if +ve,
> - * or offset of next block if -ve (in SLOB_UNITs).
> - *
> - * Free blocks of size 1 unit simply contain the offset of the next block.
> - * Those with larger size contain their size in the first SLOB_UNIT of
> - * memory, and the offset of the next free block in the second SLOB_UNIT.
> - */
> -#if PAGE_SIZE <= (32767 * 2)
> -typedef s16 slobidx_t;
> -#else
> -typedef s32 slobidx_t;
> -#endif
> -
> -struct slob_block {
> -	slobidx_t units;
> -};
> -typedef struct slob_block slob_t;
> -
> -/*
> - * All partially free slob pages go on these lists.
> - */
> -#define SLOB_BREAK1 256
> -#define SLOB_BREAK2 1024
> -static LIST_HEAD(free_slob_small);
> -static LIST_HEAD(free_slob_medium);
> -static LIST_HEAD(free_slob_large);
> -
> -/*
> - * slob_page_free: true for pages on free_slob_pages list.
> - */
> -static inline int slob_page_free(struct slab *slab)
> -{
> -	return PageSlobFree(slab_page(slab));
> -}
> -
> -static void set_slob_page_free(struct slab *slab, struct list_head *list)
> -{
> -	list_add(&slab->slab_list, list);
> -	__SetPageSlobFree(slab_page(slab));
> -}
> -
> -static inline void clear_slob_page_free(struct slab *slab)
> -{
> -	list_del(&slab->slab_list);
> -	__ClearPageSlobFree(slab_page(slab));
> -}
> -
> -#define SLOB_UNIT sizeof(slob_t)
> -#define SLOB_UNITS(size) DIV_ROUND_UP(size, SLOB_UNIT)
> -
> -/*
> - * struct slob_rcu is inserted at the tail of allocated slob blocks, which
> - * were created with a SLAB_TYPESAFE_BY_RCU slab. slob_rcu is used to free
> - * the block using call_rcu.
> - */
> -struct slob_rcu {
> -	struct rcu_head head;
> -	int size;
> -};
> -
> -/*
> - * slob_lock protects all slob allocator structures.
> - */
> -static DEFINE_SPINLOCK(slob_lock);
> -
> -/*
> - * Encode the given size and next info into a free slob block s.
> - */
> -static void set_slob(slob_t *s, slobidx_t size, slob_t *next)
> -{
> -	slob_t *base = (slob_t *)((unsigned long)s & PAGE_MASK);
> -	slobidx_t offset = next - base;
> -
> -	if (size > 1) {
> -		s[0].units = size;
> -		s[1].units = offset;
> -	} else
> -		s[0].units = -offset;
> -}
> -
> -/*
> - * Return the size of a slob block.
> - */
> -static slobidx_t slob_units(slob_t *s)
> -{
> -	if (s->units > 0)
> -		return s->units;
> -	return 1;
> -}
> -
> -/*
> - * Return the next free slob block pointer after this one.
> - */
> -static slob_t *slob_next(slob_t *s)
> -{
> -	slob_t *base = (slob_t *)((unsigned long)s & PAGE_MASK);
> -	slobidx_t next;
> -
> -	if (s[0].units < 0)
> -		next = -s[0].units;
> -	else
> -		next = s[1].units;
> -	return base+next;
> -}
> -
> -/*
> - * Returns true if s is the last free block in its page.
> - */
> -static int slob_last(slob_t *s)
> -{
> -	return !((unsigned long)slob_next(s) & ~PAGE_MASK);
> -}
> -
> -static void *slob_new_pages(gfp_t gfp, int order, int node)
> -{
> -	struct page *page;
> -
> -#ifdef CONFIG_NUMA
> -	if (node != NUMA_NO_NODE)
> -		page = __alloc_pages_node(node, gfp, order);
> -	else
> -#endif
> -		page = alloc_pages(gfp, order);
> -
> -	if (!page)
> -		return NULL;
> -
> -	mod_node_page_state(page_pgdat(page), NR_SLAB_UNRECLAIMABLE_B,
> -			    PAGE_SIZE << order);
> -	return page_address(page);
> -}
> -
> -static void slob_free_pages(void *b, int order)
> -{
> -	struct page *sp = virt_to_page(b);
> -
> -	if (current->reclaim_state)
> -		current->reclaim_state->reclaimed_slab += 1 << order;
> -
> -	mod_node_page_state(page_pgdat(sp), NR_SLAB_UNRECLAIMABLE_B,
> -			    -(PAGE_SIZE << order));
> -	__free_pages(sp, order);
> -}
> -
> -/*
> - * slob_page_alloc() - Allocate a slob block within a given slob_page sp.
> - * @sp: Page to look in.
> - * @size: Size of the allocation.
> - * @align: Allocation alignment.
> - * @align_offset: Offset in the allocated block that will be aligned.
> - * @page_removed_from_list: Return parameter.
> - *
> - * Tries to find a chunk of memory at least @size bytes big within @page.
> - *
> - * Return: Pointer to memory if allocated, %NULL otherwise.  If the
> - *         allocation fills up @page then the page is removed from the
> - *         freelist, in this case @page_removed_from_list will be set to
> - *         true (set to false otherwise).
> - */
> -static void *slob_page_alloc(struct slab *sp, size_t size, int align,
> -			      int align_offset, bool *page_removed_from_list)
> -{
> -	slob_t *prev, *cur, *aligned = NULL;
> -	int delta = 0, units = SLOB_UNITS(size);
> -
> -	*page_removed_from_list = false;
> -	for (prev = NULL, cur = sp->freelist; ; prev = cur, cur = slob_next(cur)) {
> -		slobidx_t avail = slob_units(cur);
> -
> -		/*
> -		 * 'aligned' will hold the address of the slob block so that the
> -		 * address 'aligned'+'align_offset' is aligned according to the
> -		 * 'align' parameter. This is for kmalloc() which prepends the
> -		 * allocated block with its size, so that the block itself is
> -		 * aligned when needed.
> -		 */
> -		if (align) {
> -			aligned = (slob_t *)
> -				(ALIGN((unsigned long)cur + align_offset, align)
> -				 - align_offset);
> -			delta = aligned - cur;
> -		}
> -		if (avail >= units + delta) { /* room enough? */
> -			slob_t *next;
> -
> -			if (delta) { /* need to fragment head to align? */
> -				next = slob_next(cur);
> -				set_slob(aligned, avail - delta, next);
> -				set_slob(cur, delta, aligned);
> -				prev = cur;
> -				cur = aligned;
> -				avail = slob_units(cur);
> -			}
> -
> -			next = slob_next(cur);
> -			if (avail == units) { /* exact fit? unlink. */
> -				if (prev)
> -					set_slob(prev, slob_units(prev), next);
> -				else
> -					sp->freelist = next;
> -			} else { /* fragment */
> -				if (prev)
> -					set_slob(prev, slob_units(prev), cur + units);
> -				else
> -					sp->freelist = cur + units;
> -				set_slob(cur + units, avail - units, next);
> -			}
> -
> -			sp->units -= units;
> -			if (!sp->units) {
> -				clear_slob_page_free(sp);
> -				*page_removed_from_list = true;
> -			}
> -			return cur;
> -		}
> -		if (slob_last(cur))
> -			return NULL;
> -	}
> -}
> -
> -/*
> - * slob_alloc: entry point into the slob allocator.
> - */
> -static void *slob_alloc(size_t size, gfp_t gfp, int align, int node,
> -							int align_offset)
> -{
> -	struct folio *folio;
> -	struct slab *sp;
> -	struct list_head *slob_list;
> -	slob_t *b = NULL;
> -	unsigned long flags;
> -	bool _unused;
> -
> -	if (size < SLOB_BREAK1)
> -		slob_list = &free_slob_small;
> -	else if (size < SLOB_BREAK2)
> -		slob_list = &free_slob_medium;
> -	else
> -		slob_list = &free_slob_large;
> -
> -	spin_lock_irqsave(&slob_lock, flags);
> -	/* Iterate through each partially free page, try to find room */
> -	list_for_each_entry(sp, slob_list, slab_list) {
> -		bool page_removed_from_list = false;
> -#ifdef CONFIG_NUMA
> -		/*
> -		 * If there's a node specification, search for a partial
> -		 * page with a matching node id in the freelist.
> -		 */
> -		if (node != NUMA_NO_NODE && slab_nid(sp) != node)
> -			continue;
> -#endif
> -		/* Enough room on this page? */
> -		if (sp->units < SLOB_UNITS(size))
> -			continue;
> -
> -		b = slob_page_alloc(sp, size, align, align_offset, &page_removed_from_list);
> -		if (!b)
> -			continue;
> -
> -		/*
> -		 * If slob_page_alloc() removed sp from the list then we
> -		 * cannot call list functions on sp.  If so allocation
> -		 * did not fragment the page anyway so optimisation is
> -		 * unnecessary.
> -		 */
> -		if (!page_removed_from_list) {
> -			/*
> -			 * Improve fragment distribution and reduce our average
> -			 * search time by starting our next search here. (see
> -			 * Knuth vol 1, sec 2.5, pg 449)
> -			 */
> -			if (!list_is_first(&sp->slab_list, slob_list))
> -				list_rotate_to_front(&sp->slab_list, slob_list);
> -		}
> -		break;
> -	}
> -	spin_unlock_irqrestore(&slob_lock, flags);
> -
> -	/* Not enough space: must allocate a new page */
> -	if (!b) {
> -		b = slob_new_pages(gfp & ~__GFP_ZERO, 0, node);
> -		if (!b)
> -			return NULL;
> -		folio = virt_to_folio(b);
> -		__folio_set_slab(folio);
> -		sp = folio_slab(folio);
> -
> -		spin_lock_irqsave(&slob_lock, flags);
> -		sp->units = SLOB_UNITS(PAGE_SIZE);
> -		sp->freelist = b;
> -		INIT_LIST_HEAD(&sp->slab_list);
> -		set_slob(b, SLOB_UNITS(PAGE_SIZE), b + SLOB_UNITS(PAGE_SIZE));
> -		set_slob_page_free(sp, slob_list);
> -		b = slob_page_alloc(sp, size, align, align_offset, &_unused);
> -		BUG_ON(!b);
> -		spin_unlock_irqrestore(&slob_lock, flags);
> -	}
> -	if (unlikely(gfp & __GFP_ZERO))
> -		memset(b, 0, size);
> -	return b;
> -}
> -
> -/*
> - * slob_free: entry point into the slob allocator.
> - */
> -static void slob_free(void *block, int size)
> -{
> -	struct slab *sp;
> -	slob_t *prev, *next, *b = (slob_t *)block;
> -	slobidx_t units;
> -	unsigned long flags;
> -	struct list_head *slob_list;
> -
> -	if (unlikely(ZERO_OR_NULL_PTR(block)))
> -		return;
> -	BUG_ON(!size);
> -
> -	sp = virt_to_slab(block);
> -	units = SLOB_UNITS(size);
> -
> -	spin_lock_irqsave(&slob_lock, flags);
> -
> -	if (sp->units + units == SLOB_UNITS(PAGE_SIZE)) {
> -		/* Go directly to page allocator. Do not pass slob allocator */
> -		if (slob_page_free(sp))
> -			clear_slob_page_free(sp);
> -		spin_unlock_irqrestore(&slob_lock, flags);
> -		__folio_clear_slab(slab_folio(sp));
> -		slob_free_pages(b, 0);
> -		return;
> -	}
> -
> -	if (!slob_page_free(sp)) {
> -		/* This slob page is about to become partially free. Easy! */
> -		sp->units = units;
> -		sp->freelist = b;
> -		set_slob(b, units,
> -			(void *)((unsigned long)(b +
> -					SLOB_UNITS(PAGE_SIZE)) & PAGE_MASK));
> -		if (size < SLOB_BREAK1)
> -			slob_list = &free_slob_small;
> -		else if (size < SLOB_BREAK2)
> -			slob_list = &free_slob_medium;
> -		else
> -			slob_list = &free_slob_large;
> -		set_slob_page_free(sp, slob_list);
> -		goto out;
> -	}
> -
> -	/*
> -	 * Otherwise the page is already partially free, so find reinsertion
> -	 * point.
> -	 */
> -	sp->units += units;
> -
> -	if (b < (slob_t *)sp->freelist) {
> -		if (b + units == sp->freelist) {
> -			units += slob_units(sp->freelist);
> -			sp->freelist = slob_next(sp->freelist);
> -		}
> -		set_slob(b, units, sp->freelist);
> -		sp->freelist = b;
> -	} else {
> -		prev = sp->freelist;
> -		next = slob_next(prev);
> -		while (b > next) {
> -			prev = next;
> -			next = slob_next(prev);
> -		}
> -
> -		if (!slob_last(prev) && b + units == next) {
> -			units += slob_units(next);
> -			set_slob(b, units, slob_next(next));
> -		} else
> -			set_slob(b, units, next);
> -
> -		if (prev + slob_units(prev) == b) {
> -			units = slob_units(b) + slob_units(prev);
> -			set_slob(prev, units, slob_next(b));
> -		} else
> -			set_slob(prev, slob_units(prev), b);
> -	}
> -out:
> -	spin_unlock_irqrestore(&slob_lock, flags);
> -}
> -
> -#ifdef CONFIG_PRINTK
> -void __kmem_obj_info(struct kmem_obj_info *kpp, void *object, struct slab *slab)
> -{
> -	kpp->kp_ptr = object;
> -	kpp->kp_slab = slab;
> -}
> -#endif
> -
> -/*
> - * End of slob allocator proper. Begin kmem_cache_alloc and kmalloc frontend.
> - */
> -
> -static __always_inline void *
> -__do_kmalloc_node(size_t size, gfp_t gfp, int node, unsigned long caller)
> -{
> -	unsigned int *m;
> -	unsigned int minalign;
> -	void *ret;
> -
> -	minalign = max_t(unsigned int, ARCH_KMALLOC_MINALIGN,
> -			 arch_slab_minalign());
> -	gfp &= gfp_allowed_mask;
> -
> -	might_alloc(gfp);
> -
> -	if (size < PAGE_SIZE - minalign) {
> -		int align = minalign;
> -
> -		/*
> -		 * For power of two sizes, guarantee natural alignment for
> -		 * kmalloc()'d objects.
> -		 */
> -		if (is_power_of_2(size))
> -			align = max_t(unsigned int, minalign, size);
> -
> -		if (!size)
> -			return ZERO_SIZE_PTR;
> -
> -		m = slob_alloc(size + minalign, gfp, align, node, minalign);
> -
> -		if (!m)
> -			return NULL;
> -		*m = size;
> -		ret = (void *)m + minalign;
> -
> -		trace_kmalloc(caller, ret, size, size + minalign, gfp, node);
> -	} else {
> -		unsigned int order = get_order(size);
> -
> -		if (likely(order))
> -			gfp |= __GFP_COMP;
> -		ret = slob_new_pages(gfp, order, node);
> -
> -		trace_kmalloc(caller, ret, size, PAGE_SIZE << order, gfp, node);
> -	}
> -
> -	kmemleak_alloc(ret, size, 1, gfp);
> -	return ret;
> -}
> -
> -void *__kmalloc(size_t size, gfp_t gfp)
> -{
> -	return __do_kmalloc_node(size, gfp, NUMA_NO_NODE, _RET_IP_);
> -}
> -EXPORT_SYMBOL(__kmalloc);
> -
> -void *__kmalloc_node_track_caller(size_t size, gfp_t gfp,
> -					int node, unsigned long caller)
> -{
> -	return __do_kmalloc_node(size, gfp, node, caller);
> -}
> -EXPORT_SYMBOL(__kmalloc_node_track_caller);
> -
> -void kfree(const void *block)
> -{
> -	struct folio *sp;
> -
> -	trace_kfree(_RET_IP_, block);
> -
> -	if (unlikely(ZERO_OR_NULL_PTR(block)))
> -		return;
> -	kmemleak_free(block);
> -
> -	sp = virt_to_folio(block);
> -	if (folio_test_slab(sp)) {
> -		unsigned int align = max_t(unsigned int,
> -					   ARCH_KMALLOC_MINALIGN,
> -					   arch_slab_minalign());
> -		unsigned int *m = (unsigned int *)(block - align);
> -
> -		slob_free(m, *m + align);
> -	} else {
> -		unsigned int order = folio_order(sp);
> -
> -		mod_node_page_state(folio_pgdat(sp), NR_SLAB_UNRECLAIMABLE_B,
> -				    -(PAGE_SIZE << order));
> -		__free_pages(folio_page(sp, 0), order);
> -
> -	}
> -}
> -EXPORT_SYMBOL(kfree);
> -
> -size_t kmalloc_size_roundup(size_t size)
> -{
> -	/* Short-circuit the 0 size case. */
> -	if (unlikely(size == 0))
> -		return 0;
> -	/* Short-circuit saturated "too-large" case. */
> -	if (unlikely(size == SIZE_MAX))
> -		return SIZE_MAX;
> -
> -	return ALIGN(size, ARCH_KMALLOC_MINALIGN);
> -}
> -
> -EXPORT_SYMBOL(kmalloc_size_roundup);
> -
> -/* can't use ksize for kmem_cache_alloc memory, only kmalloc */
> -size_t __ksize(const void *block)
> -{
> -	struct folio *folio;
> -	unsigned int align;
> -	unsigned int *m;
> -
> -	BUG_ON(!block);
> -	if (unlikely(block == ZERO_SIZE_PTR))
> -		return 0;
> -
> -	folio = virt_to_folio(block);
> -	if (unlikely(!folio_test_slab(folio)))
> -		return folio_size(folio);
> -
> -	align = max_t(unsigned int, ARCH_KMALLOC_MINALIGN,
> -		      arch_slab_minalign());
> -	m = (unsigned int *)(block - align);
> -	return SLOB_UNITS(*m) * SLOB_UNIT;
> -}
> -
> -int __kmem_cache_create(struct kmem_cache *c, slab_flags_t flags)
> -{
> -	if (flags & SLAB_TYPESAFE_BY_RCU) {
> -		/* leave room for rcu footer at the end of object */
> -		c->size += sizeof(struct slob_rcu);
> -	}
> -
> -	/* Actual size allocated */
> -	c->size = SLOB_UNITS(c->size) * SLOB_UNIT;
> -	c->flags = flags;
> -	return 0;
> -}
> -
> -static void *slob_alloc_node(struct kmem_cache *c, gfp_t flags, int node)
> -{
> -	void *b;
> -
> -	flags &= gfp_allowed_mask;
> -
> -	might_alloc(flags);
> -
> -	if (c->size < PAGE_SIZE) {
> -		b = slob_alloc(c->size, flags, c->align, node, 0);
> -		trace_kmem_cache_alloc(_RET_IP_, b, c, flags, node);
> -	} else {
> -		b = slob_new_pages(flags, get_order(c->size), node);
> -		trace_kmem_cache_alloc(_RET_IP_, b, c, flags, node);
> -	}
> -
> -	if (b && c->ctor) {
> -		WARN_ON_ONCE(flags & __GFP_ZERO);
> -		c->ctor(b);
> -	}
> -
> -	kmemleak_alloc_recursive(b, c->size, 1, c->flags, flags);
> -	return b;
> -}
> -
> -void *kmem_cache_alloc(struct kmem_cache *cachep, gfp_t flags)
> -{
> -	return slob_alloc_node(cachep, flags, NUMA_NO_NODE);
> -}
> -EXPORT_SYMBOL(kmem_cache_alloc);
> -
> -
> -void *kmem_cache_alloc_lru(struct kmem_cache *cachep, struct list_lru *lru, gfp_t flags)
> -{
> -	return slob_alloc_node(cachep, flags, NUMA_NO_NODE);
> -}
> -EXPORT_SYMBOL(kmem_cache_alloc_lru);
> -
> -void *__kmalloc_node(size_t size, gfp_t gfp, int node)
> -{
> -	return __do_kmalloc_node(size, gfp, node, _RET_IP_);
> -}
> -EXPORT_SYMBOL(__kmalloc_node);
> -
> -void *kmem_cache_alloc_node(struct kmem_cache *cachep, gfp_t gfp, int node)
> -{
> -	return slob_alloc_node(cachep, gfp, node);
> -}
> -EXPORT_SYMBOL(kmem_cache_alloc_node);
> -
> -static void __kmem_cache_free(void *b, int size)
> -{
> -	if (size < PAGE_SIZE)
> -		slob_free(b, size);
> -	else
> -		slob_free_pages(b, get_order(size));
> -}
> -
> -static void kmem_rcu_free(struct rcu_head *head)
> -{
> -	struct slob_rcu *slob_rcu = (struct slob_rcu *)head;
> -	void *b = (void *)slob_rcu - (slob_rcu->size - sizeof(struct slob_rcu));
> -
> -	__kmem_cache_free(b, slob_rcu->size);
> -}
> -
> -void kmem_cache_free(struct kmem_cache *c, void *b)
> -{
> -	kmemleak_free_recursive(b, c->flags);
> -	trace_kmem_cache_free(_RET_IP_, b, c);
> -	if (unlikely(c->flags & SLAB_TYPESAFE_BY_RCU)) {
> -		struct slob_rcu *slob_rcu;
> -		slob_rcu = b + (c->size - sizeof(struct slob_rcu));
> -		slob_rcu->size = c->size;
> -		call_rcu(&slob_rcu->head, kmem_rcu_free);
> -	} else {
> -		__kmem_cache_free(b, c->size);
> -	}
> -}
> -EXPORT_SYMBOL(kmem_cache_free);
> -
> -void kmem_cache_free_bulk(struct kmem_cache *s, size_t nr, void **p)
> -{
> -	size_t i;
> -
> -	for (i = 0; i < nr; i++) {
> -		if (s)
> -			kmem_cache_free(s, p[i]);
> -		else
> -			kfree(p[i]);
> -	}
> -}
> -EXPORT_SYMBOL(kmem_cache_free_bulk);
> -
> -int kmem_cache_alloc_bulk(struct kmem_cache *s, gfp_t flags, size_t nr,
> -								void **p)
> -{
> -	size_t i;
> -
> -	for (i = 0; i < nr; i++) {
> -		void *x = p[i] = kmem_cache_alloc(s, flags);
> -
> -		if (!x) {
> -			kmem_cache_free_bulk(s, i, p);
> -			return 0;
> -		}
> -	}
> -	return i;
> -}
> -EXPORT_SYMBOL(kmem_cache_alloc_bulk);
> -
> -int __kmem_cache_shutdown(struct kmem_cache *c)
> -{
> -	/* No way to check for remaining objects */
> -	return 0;
> -}
> -
> -void __kmem_cache_release(struct kmem_cache *c)
> -{
> -}
> -
> -int __kmem_cache_shrink(struct kmem_cache *d)
> -{
> -	return 0;
> -}
> -
> -static struct kmem_cache kmem_cache_boot = {
> -	.name = "kmem_cache",
> -	.size = sizeof(struct kmem_cache),
> -	.flags = SLAB_PANIC,
> -	.align = ARCH_KMALLOC_MINALIGN,
> -};
> -
> -void __init kmem_cache_init(void)
> -{
> -	kmem_cache = &kmem_cache_boot;
> -	slab_state = UP;
> -}
> -
> -void __init kmem_cache_init_late(void)
> -{
> -	slab_state = FULL;
> -}
> -- 
> 2.39.2
> 

-- 
Sincerely yours,
Mike.