by Mike Rapoport

[permalink] [raw]

Subject: Re: [PATCH v2 5/6] mm/slob: remove slob.c

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 <[email protected]>
> Acked-by: Hyeonggon Yoo <[email protected]>
> Acked-by: Lorenzo Stoakes <[email protected]>
> Acked-by: Roman Gushchin <[email protected]>

Acked-by: Mike Rapoport (IBM) <[email protected]>

> ---
> 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 <[email protected]> 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.