[PATCH 2/3] compcache: TLSF Allocator
From: Nitin Gupta
Date: Tue Apr 08 2008 - 05:48:23 EST
Two Level Segregate Fit (TLSF) Allocator is used to allocate memory for
variable size compressed pages. Its fast and gives low fragmentation.
Following links give details on this allocator:
- http://rtportal.upv.es/rtmalloc/files/tlsf_paper_spe_2007.pdf
In tests, it shows ~43% less memory usage than SLUB!
See: http://code.google.com/p/compcache/wiki/AllocatorsComparison
This kernel port of TLSF (v2.3.2) introduces several changes but underlying
algorithm remains the same.
Changelog TLSF v2.3.2 vs this kernel port
- Pool now dynamically expands/shrinks.
It is collection of contiguous memory regions.
- Changes to pool create interface as a result of above change.
- It is not scalable (lack of per-cpu data structures etc.)
- Collect and export stats (/proc/tlsfinfo)
- Cleanups: kernel coding style, added comments, macros -> static inline, etc.
Signed-off-by: Nitin Gupta <nitingupta910 at gmail dot com>
---
include/linux/tlsf.h | 93 +++++++
init/Kconfig | 28 ++
mm/Makefile | 1 +
mm/tlsf.c | 676 ++++++++++++++++++++++++++++++++++++++++++++++++++
mm/tlsf_int.h | 145 +++++++++++
5 files changed, 943 insertions(+), 0 deletions(-)
diff --git a/include/linux/tlsf.h b/include/linux/tlsf.h
new file mode 100644
index 0000000..bc224b5
--- /dev/null
+++ b/include/linux/tlsf.h
@@ -0,0 +1,93 @@
+/*
+ * Two Levels Segregate Fit memory allocator (TLSF)
+ * Version 2.3.2
+ *
+ * Written by Miguel Masmano Tello <mimastel@xxxxxxxxxxxxx>
+ *
+ * Thanks to Ismael Ripoll for his suggestions and reviews
+ *
+ * Copyright (C) 2007, 2006, 2005, 2004
+ *
+ * This code is released using a dual license strategy: GPL/LGPL
+ * You can choose the licence that better fits your requirements.
+ *
+ * Released under the terms of the GNU General Public License Version 2.0
+ * Released under the terms of the GNU Lesser General Public License Version 2.1
+ *
+ * This is kernel port of TLSF allocator.
+ * Original code can be found at: http://rtportal.upv.es/rtmalloc/
+ * - Nitin Gupta (nitingupta910@xxxxxxxxx)
+ */
+
+#ifndef _TLSF_H_
+#define _TLSF_H_
+
+typedef void* (get_memory)(size_t bytes);
+typedef void (put_memory)(void *ptr);
+
+/**
+ * tlsf_create_memory_pool - create dynamic memory pool
+ * @name: name of the pool
+ * @get_mem: callback function used to expand pool
+ * @put_mem: callback function used to shrink pool
+ * @init_size: inital pool size (in bytes)
+ * @max_size: maximum pool size (in bytes) - set this as 0 for no limit
+ * @grow_size: amount of memory (in bytes) added to pool whenever required
+ *
+ * All size values are rounded up to next page boundary.
+ */
+extern void *tlsf_create_memory_pool(const char *name,
+ get_memory get_mem,
+ put_memory put_mem,
+ size_t init_size,
+ size_t max_size,
+ size_t grow_size);
+/**
+ * tlsf_destory_memory_pool - cleanup given pool
+ * @mem_pool: Pool to be destroyed
+ *
+ * Data structures associated with pool are freed.
+ * All memory allocated from pool must be freed before
+ * destorying it.
+ */
+extern void tlsf_destroy_memory_pool(void *mem_pool);
+
+/**
+ * tlsf_malloc - allocate memory from given pool
+ * @size: no. of bytes
+ * @mem_pool: pool to allocate from
+ */
+extern void *tlsf_malloc(size_t size, void *mem_pool);
+
+/**
+ * tlsf_calloc - allocate and zero-out memory from given pool
+ * @size: no. of bytes
+ * @mem_pool: pool to allocate from
+ */
+extern void *tlsf_calloc(size_t nelem, size_t elem_size, void *mem_pool);
+
+/**
+ * tlsf_free - free memory from given pool
+ * @ptr: address of memory to be freed
+ * @mem_pool: pool to free from
+ */
+extern void tlsf_free(void *ptr, void *mem_pool);
+
+/**
+ * tlsf_get_used_size - get memory currently used by given pool
+ *
+ * Used memory includes stored data + metadata + internal fragmentation
+ */
+extern size_t tlsf_get_used_size(void *mem_pool);
+
+/**
+ * tlsf_get_total_size - get total memory currently allocated for given pool
+ *
+ * This is the total memory currently allocated for this pool which includes
+ * used size + free size.
+ *
+ * (Total - Used) is good indicator of memory efficiency of allocator.
+ */
+extern size_t tlsf_get_total_size(void *mem_pool);
+
+#endif
diff --git a/init/Kconfig b/init/Kconfig
index a97924b..d51d476 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -734,6 +734,34 @@ config SLOB
endchoice
+config TLSF
+ depends on EMBEDDED
+ tristate "TLSF Allocator"
+ help
+ Two Level Segregate Fit Allocator. Its fast and gives low
+ fragmentation. See:
+ http://rtportal.upv.es/rtmalloc/
+ http://code.google.com/p/compcache/wiki/TLSFAllocator
+ for more information.
+
+config TLSF_DEBUG
+ default y
+ depends on TLSF
+ bool "Enable TLSF allocator debugging" if EMBEDDED
+ help
+ Enable TLSF debugging.
+ This causes negligible performance loss and size increase.
+ If unusure, say Y.
+
+config TLSF_STATS
+ default N
+ depends on TLSF
+ bool "Collect TLSF statistics" if EMBEDDED
+ help
+ Creates /proc/tlsfinfo to export various tlsf statistics.
+ This adds about 30K to size with significant performance loss.
+ If unsure, say N.
+
config PROFILING
bool "Profiling support (EXPERIMENTAL)"
help
diff --git a/mm/Makefile b/mm/Makefile
index a5b0dd9..4e2398f 100644
--- a/mm/Makefile
+++ b/mm/Makefile
@@ -27,6 +27,7 @@ obj-$(CONFIG_TINY_SHMEM) += tiny-shmem.o
obj-$(CONFIG_SLOB) += slob.o
obj-$(CONFIG_SLAB) += slab.o
obj-$(CONFIG_SLUB) += slub.o
+obj-$(CONFIG_TLSF) += tlsf.o
obj-$(CONFIG_MEMORY_HOTPLUG) += memory_hotplug.o
obj-$(CONFIG_FS_XIP) += filemap_xip.o
obj-$(CONFIG_MIGRATION) += migrate.o
diff --git a/mm/tlsf.c b/mm/tlsf.c
new file mode 100644
index 0000000..e3b517d
--- /dev/null
+++ b/mm/tlsf.c
@@ -0,0 +1,676 @@
+/*
+ * Two Levels Segregate Fit memory allocator (TLSF)
+ * Version 2.3.2
+ *
+ * Written by Miguel Masmano Tello <mimastel@xxxxxxxxxxxxx>
+ *
+ * Thanks to Ismael Ripoll for his suggestions and reviews
+ *
+ * Copyright (C) 2007, 2006, 2005, 2004
+ *
+ * This code is released using a dual license strategy: GPL/LGPL
+ * You can choose the licence that better fits your requirements.
+ *
+ * Released under the terms of the GNU General Public License Version 2.0
+ * Released under the terms of the GNU Lesser General Public License Version 2.1
+ *
+ * This is kernel port of TLSF allocator.
+ * Original code can be found at: http://rtportal.upv.es/rtmalloc/
+ * - Nitin Gupta (nitingupta910@xxxxxxxxx)
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+#include <linux/string.h>
+#include <linux/tlsf.h>
+
+#include "tlsf_int.h"
+
+static struct mutex pool_list_lock;
+static struct list_head pool_list_head;
+
+#if defined(CONFIG_TLSF_STATS)
+static struct proc_dir_entry *proc;
+
+/* Print in format similar to /proc/slabinfo -- easy to awk */
+static void print_tlsfinfo_header(struct seq_file *tlsf)
+{
+ seq_puts(tlsf, "# Size in kB\n");
+ seq_puts(tlsf, "# name <init_size> <max_size> <grow_size>"
+ " <used_size> <total_size> <extra>");
+#if defined(CONFIG_TLSF_STATS)
+ seq_puts(tlsf, " <peak_used> <peak_total> <peak_extra>"
+ " <count_alloc> <count_free> <count_region_alloc>"
+ " <count_region_free> <failed_alloc>");
+#endif
+#if defined(CONFIG_TLSF_DEBUG)
+ seq_puts(tlsf, " <valid>");
+#endif
+
+ seq_putc(tlsf, '\n');
+}
+
+/* Get pool no. (*pos) from pool list */
+static void *tlsf_start(struct seq_file *tlsf, loff_t *pos)
+{
+ struct list_head *lp;
+ loff_t p = *pos;
+
+ mutex_lock(&pool_list_lock);
+ if (!p)
+ return SEQ_START_TOKEN;
+
+ list_for_each(lp, &pool_list_head) {
+ if (!--p)
+ return lp;
+ }
+
+ return NULL;
+}
+
+/* Get pool next to the one given by tlsf_start()/previous tlsf_next() */
+static void *tlsf_next(struct seq_file *tlsf, void *v, loff_t *pos)
+{
+ struct list_head *lp;
+
+ if (v == SEQ_START_TOKEN)
+ lp = &pool_list_head;
+ else
+ lp = v;
+
+ lp = lp->next;
+ if (lp == &pool_list_head)
+ return NULL;
+
+ ++*pos;
+ return lp;
+}
+
+static void tlsf_stop(struct seq_file *tlsf, void *v)
+{
+ mutex_unlock(&pool_list_lock);
+}
+
+/* Display stats for pool given by tlsf_next() */
+static int tlsf_show(struct seq_file *tlsf, void *v)
+{
+ struct pool *pool;
+ size_t used, total;
+ if (v == SEQ_START_TOKEN) {
+ print_tlsfinfo_header(tlsf);
+ return 0;
+ }
+
+ pool = list_entry(v, struct pool, list);
+ used = tlsf_get_used_size(pool);
+ total = tlsf_get_total_size(pool);
+#define K(x) ((x) >> 10)
+ seq_printf(tlsf, "%-16s %6zu %6zu %6zu %6zu %6zu %6zu",
+ pool->name,
+ K(pool->init_size),
+ K(pool->max_size),
+ K(pool->grow_size),
+ K(used),
+ K(total),
+ K(total - used));
+
+#if defined(CONFIG_TLSF_STATS)
+ seq_printf(tlsf, " %6zu %6zu %6zu %6zu %6zu %6zu %6zu %6zu",
+ K(pool->peak_used),
+ K(pool->peak_total),
+ K(pool->peak_extra),
+ pool->count_alloc,
+ pool->count_free,
+ pool->count_region_alloc,
+ pool->count_region_free,
+ pool->count_failed_alloc);
+#endif
+
+#if defined(CONFIG_TLSF_DEBUG)
+ seq_printf(tlsf, " %u", pool->valid);
+#endif
+
+ seq_putc(tlsf, '\n');
+ return 0;
+}
+
+static struct seq_operations tlsfinfo_op = {
+ .start = tlsf_start,
+ .next = tlsf_next,
+ .stop = tlsf_stop,
+ .show = tlsf_show,
+};
+
+static int tlsfinfo_open(struct inode *inode, struct file *file)
+{
+ return seq_open(file, &tlsfinfo_op);
+}
+
+static const struct file_operations proc_tlsfinfo_operations = {
+ .open = tlsfinfo_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = seq_release,
+};
+#endif /* CONFIG_TLSF_STATS */
+
+/*
+ * Helping functions
+ */
+
+/**
+ * Returns indexes (fl, sl) of the list used to serve request of size r
+ */
+static inline void MAPPING_SEARCH(size_t *r, int *fl, int *sl)
+{
+ int t;
+
+ if (*r < SMALL_BLOCK) {
+ *fl = 0;
+ *sl = *r / (SMALL_BLOCK / MAX_SLI);
+ } else {
+ t = (1 << (fls(*r) - 1 - MAX_LOG2_SLI)) - 1;
+ *r = *r + t;
+ *fl = fls(*r) - 1;
+ *sl = (*r >> (*fl - MAX_LOG2_SLI)) - MAX_SLI;
+ *fl -= FLI_OFFSET;
+ /*if ((*fl -= FLI_OFFSET) < 0) // FL will be always >0!
+ *fl = *sl = 0;
+ */
+ *r &= ~t;
+ }
+}
+
+/**
+ * Returns indexes (fl, sl) which is used as starting point to search
+ * for a block of size r. It also rounds up requested size(r) to the
+ * next list.
+ */
+static inline void MAPPING_INSERT(size_t r, int *fl, int *sl)
+{
+ if (r < SMALL_BLOCK) {
+ *fl = 0;
+ *sl = r / (SMALL_BLOCK / MAX_SLI);
+ } else {
+ *fl = fls(r) - 1;
+ *sl = (r >> (*fl - MAX_LOG2_SLI)) - MAX_SLI;
+ *fl -= FLI_OFFSET;
+ }
+}
+
+/**
+ * Returns first block from a list that hold blocks larger than or
+ * equal to the one pointed by the indexes (fl, sl)
+ */
+static inline struct bhdr *FIND_SUITABLE_BLOCK(struct pool *p, int *fl,
+ int *sl)
+{
+ u32 tmp = p->sl_bitmap[*fl] & (~0 << *sl);
+ struct bhdr *b = NULL;
+
+ if (tmp) {
+ *sl = ffs(tmp) - 1;
+ b = p->matrix[*fl][*sl];
+ } else {
+ *fl = ffs(p->fl_bitmap & (~0 << (*fl + 1))) - 1;
+ if (*fl > 0) { /* likely */
+ *sl = ffs(p->sl_bitmap[*fl]) - 1;
+ b = p->matrix[*fl][*sl];
+ }
+ }
+ return b;
+}
+
+/**
+ * Remove first free block(b) from free list with indexes (fl, sl).
+ */
+static inline void EXTRACT_BLOCK_HDR(struct bhdr *b, struct pool *p, int fl,
+ int sl)
+{
+ p->matrix[fl][sl] = b->ptr.free_ptr.next;
+ if (p->matrix[fl][sl])
+ p->matrix[fl][sl]->ptr.free_ptr.prev = NULL;
+ else {
+ clear_bit(sl, (void *)&p->sl_bitmap[fl]);
+ if(!p->sl_bitmap[fl])
+ clear_bit (fl, (void *)&p->fl_bitmap);
+ }
+ b->ptr.free_ptr = (struct free_ptr) {NULL, NULL};
+}
+
+/**
+ * Removes block(b) from free list with indexes (fl, sl)
+ */
+static inline void EXTRACT_BLOCK(struct bhdr *b, struct pool *p, int fl,
+ int sl)
+{
+ if (b->ptr.free_ptr.next)
+ b->ptr.free_ptr.next->ptr.free_ptr.prev =
+ b->ptr.free_ptr.prev;
+ if (b->ptr.free_ptr.prev)
+ b->ptr.free_ptr.prev->ptr.free_ptr.next =
+ b->ptr.free_ptr.next;
+ if (p->matrix[fl][sl] == b) {
+ p->matrix[fl][sl] = b->ptr.free_ptr.next;
+ if (!p->matrix[fl][sl]) {
+ clear_bit(sl, (void *)&p->sl_bitmap[fl]);
+ if (!p->sl_bitmap[fl])
+ clear_bit (fl, (void *)&p->fl_bitmap);
+ }
+ }
+ b->ptr.free_ptr = (struct free_ptr) {NULL, NULL};
+}
+
+/**
+ * Insert block(b) in free list with indexes (fl, sl)
+ */
+static inline void INSERT_BLOCK(struct bhdr *b, struct pool *p, int fl, int sl)
+{
+ b->ptr.free_ptr = (struct free_ptr) {NULL, p->matrix[fl][sl]};
+ if (p->matrix[fl][sl])
+ p->matrix[fl][sl]->ptr.free_ptr.prev = b;
+ p->matrix[fl][sl] = b;
+ set_bit(sl, (void *)&p->sl_bitmap[fl]);
+ set_bit(fl, (void *)&p->fl_bitmap);
+}
+
+/**
+ * Region is a virtually contiguous memory region and Pool is
+ * collection of such regions
+ */
+static inline void ADD_REGION(void *region, size_t region_size,
+ struct pool *pool)
+{
+ int fl, sl;
+ struct bhdr *b, *lb;
+
+ b = (struct bhdr *)(region);
+ b->prev_hdr = NULL;
+ b->size = ROUNDDOWN_SIZE(region_size - 2 * BHDR_OVERHEAD)
+ | FREE_BLOCK | PREV_USED;
+ MAPPING_INSERT(b->size & BLOCK_SIZE_MASK, &fl, &sl);
+ INSERT_BLOCK(b, pool, fl, sl);
+ /* The sentinel block: allows us to know when we're in the last block */
+ lb = GET_NEXT_BLOCK(b->ptr.buffer, b->size & BLOCK_SIZE_MASK);
+ lb->prev_hdr = b;
+ lb->size = 0 | USED_BLOCK | PREV_FREE;
+ pool->used_size += BHDR_OVERHEAD; /* only sentinel block is "used" */
+ pool->num_regions++;
+ stat_inc(pool->count_region_alloc);
+}
+
+/*
+ * Allocator code start
+ */
+
+/**
+ * tlsf_create_memory_pool - create dynamic memory pool
+ * @name: name of the pool
+ * @get_mem: callback function used to expand pool
+ * @put_mem: callback function used to shrink pool
+ * @init_size: inital pool size (in bytes)
+ * @max_size: maximum pool size (in bytes) - set this as 0 for no limit
+ * @grow_size: amount of memory (in bytes) added to pool whenever required
+ *
+ * All size values are rounded up to next page boundary.
+ */
+void *tlsf_create_memory_pool(const char *name,
+ get_memory get_mem,
+ put_memory put_mem,
+ size_t init_size,
+ size_t max_size,
+ size_t grow_size)
+{
+ struct pool *pool;
+ void *region;
+#if defined(CONFIG_TLSF_STATS)
+ size_t used, total;
+#endif
+
+ if (max_size)
+ BUG_ON(max_size < init_size);
+
+ pool = get_mem(ROUNDUP_SIZE(sizeof(*pool)));
+ if (pool == NULL)
+ goto out;
+ memset(pool, 0, ROUNDUP_SIZE(sizeof(*pool)));
+
+ /* Round to next page boundary */
+ init_size = ROUNDUP_PAGE(init_size);
+ max_size = ROUNDUP_PAGE(max_size);
+ grow_size = ROUNDUP_PAGE(grow_size);
+ pr_info(T "pool: %p, init_size=%zu, max_size=%zu, grow_size=%zu\n",
+ pool, init_size, max_size, grow_size);
+
+ /* pool global overhead not included in used size */
+ pool->used_size = 0;
+
+ pool->init_size = init_size;
+ pool->max_size = max_size;
+ pool->grow_size = grow_size;
+ pool->get_mem = get_mem;
+ pool->put_mem = put_mem;
+ strncpy(pool->name, name, MAX_POOL_NAME_LEN);
+ pool->name[MAX_POOL_NAME_LEN - 1] = '\0';
+#if defined(CONFIG_TLSF_DEBUG)
+ pool->valid = 1;
+#endif
+ region = get_mem(init_size);
+ if (region == NULL)
+ goto out_region;
+ ADD_REGION(region, init_size, pool);
+ pool->init_region = region;
+
+ mutex_init(&pool->lock);
+
+ mutex_lock(&pool_list_lock);
+ list_add_tail(&pool->list, &pool_list_head);
+ mutex_unlock(&pool_list_lock);
+
+ /* Pool created: update stats */
+ stat_set(used, tlsf_get_used_size(pool));
+ stat_set(total, tlsf_get_total_size(pool));
+ stat_inc(pool->count_alloc);
+ stat_setmax(pool->peak_extra, total - used);
+ stat_setmax(pool->peak_used, used);
+ stat_setmax(pool->peak_total, total);
+
+ return pool;
+
+out_region:
+ put_mem(pool);
+
+out:
+ return NULL;
+}
+EXPORT_SYMBOL_GPL(tlsf_create_memory_pool);
+
+/**
+ * tlsf_get_used_size - get memory currently used by given pool
+ *
+ * Used memory includes stored data + metadata + internal fragmentation
+ */
+size_t tlsf_get_used_size(void *mem_pool)
+{
+ struct pool *pool = (struct pool *)mem_pool;
+ return pool->used_size;
+}
+EXPORT_SYMBOL_GPL(tlsf_get_used_size);
+
+/**
+ * tlsf_get_total_size - get total memory currently allocated for given pool
+ *
+ * This is the total memory currently allocated for this pool which includes
+ * used size + free size.
+ *
+ * (Total - Used) is good indicator of memory efficiency of allocator.
+ */
+size_t tlsf_get_total_size(void *mem_pool)
+{
+ size_t total;
+ struct pool *pool = (struct pool *)mem_pool;
+ total = ROUNDUP_SIZE(sizeof(*pool))
+ + pool->init_size
+ + (pool->num_regions - 1) * pool->grow_size;
+ return total;
+}
+EXPORT_SYMBOL_GPL(tlsf_get_total_size);
+
+/**
+ * tlsf_destory_memory_pool - cleanup given pool
+ * @mem_pool: Pool to be destroyed
+ *
+ * Data structures associated with pool are freed.
+ * All memory allocated from pool must be freed before
+ * destorying it.
+ */
+void tlsf_destroy_memory_pool(void *mem_pool)
+{
+ struct pool *pool;
+
+ if (mem_pool == NULL)
+ return;
+
+ pool = (struct pool *)mem_pool;
+
+ /* User is destorying without ever allocating from this pool */
+ if (tlsf_get_used_size(pool) == BHDR_OVERHEAD) {
+ pool->put_mem(pool->init_region);
+ pool->used_size -= BHDR_OVERHEAD;
+ stat_inc(pool->count_region_free);
+ }
+
+ /* Check for memory leaks in this pool */
+ if (tlsf_get_used_size(pool)) {
+ pr_warning(T "memory leak in pool: %s (%p). "
+ "%zu bytes still in use.\n",
+ pool->name, pool, tlsf_get_used_size(pool));
+
+#if defined(CONFIG_TLSF_DEBUG)
+ pool->valid = 0;
+ /* Invalid pools stay in list for debugging purpose */
+ return;
+#endif
+ }
+ mutex_lock(&pool_list_lock);
+ list_del_init(&pool->list);
+ mutex_unlock(&pool_list_lock);
+ pool->put_mem(pool);
+}
+EXPORT_SYMBOL_GPL(tlsf_destroy_memory_pool);
+
+/**
+ * tlsf_malloc - allocate memory from given pool
+ * @size: no. of bytes
+ * @mem_pool: pool to allocate from
+ */
+void *tlsf_malloc(size_t size, void *mem_pool)
+{
+ struct pool *pool = (struct pool *)mem_pool;
+ struct bhdr *b, *b2, *next_b, *region;
+ int fl, sl;
+ size_t tmp_size;
+#if defined(CONFIG_TLSF_STATS)
+ size_t used, total;
+#endif
+
+#if defined(CONFIG_TLSF_DEBUG)
+ unsigned int retries = 0;
+#endif
+
+ size = (size < MIN_BLOCK_SIZE) ? MIN_BLOCK_SIZE : ROUNDUP_SIZE(size);
+ /* Rounding up the requested size and calculating fl and sl */
+
+ mutex_lock(&pool->lock);
+retry_find:
+ MAPPING_SEARCH(&size, &fl, &sl);
+
+ /* Searching a free block */
+ if (!(b = FIND_SUITABLE_BLOCK(pool, &fl, &sl))) {
+#if defined(CONFIG_TLSF_DEBUG)
+ /*
+ * This can happen if there are too many users
+ * allocating from this pool simultaneously.
+ */
+ if (unlikely(retries == MAX_RETRY_EXPAND))
+ goto out_locked;
+ retries++;
+#endif
+ /* Not found */
+ if (size > (pool->grow_size - 2 * BHDR_OVERHEAD))
+ goto out_locked;
+ if (pool->max_size && (pool->init_size +
+ pool->num_regions * pool->grow_size
+ > pool->max_size))
+ goto out_locked;
+ mutex_unlock(&pool->lock);
+ if ((region = pool->get_mem(pool->grow_size)) == NULL)
+ goto out;
+ mutex_lock(&pool->lock);
+ ADD_REGION(region, pool->grow_size, pool);
+ goto retry_find;
+ }
+ EXTRACT_BLOCK_HDR(b, pool, fl, sl);
+
+ /*-- found: */
+ next_b = GET_NEXT_BLOCK(b->ptr.buffer, b->size & BLOCK_SIZE_MASK);
+ /* Should the block be split? */
+ tmp_size = (b->size & BLOCK_SIZE_MASK) - size;
+ if (tmp_size >= sizeof(struct bhdr) ) {
+ tmp_size -= BHDR_OVERHEAD;
+ b2 = GET_NEXT_BLOCK(b->ptr.buffer, size);
+
+ b2->size = tmp_size | FREE_BLOCK | PREV_USED;
+ b2->prev_hdr = b;
+
+ next_b->prev_hdr = b2;
+
+ MAPPING_INSERT(tmp_size, &fl, &sl);
+ INSERT_BLOCK(b2, pool, fl, sl);
+
+ b->size = size | (b->size & PREV_STATE);
+ } else {
+ next_b->size &= (~PREV_FREE);
+ b->size &= (~FREE_BLOCK); /* Now it's used */
+ }
+
+ pool->used_size += (b->size & BLOCK_SIZE_MASK) + BHDR_OVERHEAD;
+
+ /* Successful alloc: update stats. */
+ stat_set(used, tlsf_get_used_size(pool));
+ stat_set(total, tlsf_get_total_size(pool));
+ stat_inc(pool->count_alloc);
+ stat_setmax(pool->peak_extra, total - used);
+ stat_setmax(pool->peak_used, used);
+ stat_setmax(pool->peak_total, total);
+
+ mutex_unlock(&pool->lock);
+ return (void *)b->ptr.buffer;
+
+ /* Failed alloc */
+out_locked:
+ mutex_unlock(&pool->lock);
+
+out:
+ stat_inc(pool->count_failed_alloc);
+ return NULL;
+}
+EXPORT_SYMBOL_GPL(tlsf_malloc);
+
+/**
+ * tlsf_free - free memory from given pool
+ * @ptr: address of memory to be freed
+ * @mem_pool: pool to free from
+ */
+void tlsf_free(void *ptr, void *mem_pool)
+{
+ struct pool *pool = (struct pool *)mem_pool;
+ struct bhdr *b, *tmp_b;
+ int fl = 0, sl = 0;
+#if defined(CONFIG_TLSF_STATS)
+ size_t used, total;
+#endif
+ if (unlikely(ptr == NULL))
+ return;
+
+ b = (struct bhdr *) ((char *) ptr - BHDR_OVERHEAD);
+
+ mutex_lock(&pool->lock);
+ b->size |= FREE_BLOCK;
+ pool->used_size -= (b->size & BLOCK_SIZE_MASK) + BHDR_OVERHEAD;
+ b->ptr.free_ptr = (struct free_ptr) { NULL, NULL};
+ tmp_b = GET_NEXT_BLOCK(b->ptr.buffer, b->size & BLOCK_SIZE_MASK);
+ if (tmp_b->size & FREE_BLOCK) {
+ MAPPING_INSERT(tmp_b->size & BLOCK_SIZE_MASK, &fl, &sl);
+ EXTRACT_BLOCK(tmp_b, pool, fl, sl);
+ b->size += (tmp_b->size & BLOCK_SIZE_MASK) + BHDR_OVERHEAD;
+ }
+ if (b->size & PREV_FREE) {
+ tmp_b = b->prev_hdr;
+ MAPPING_INSERT(tmp_b->size & BLOCK_SIZE_MASK, &fl, &sl);
+ EXTRACT_BLOCK(tmp_b, pool, fl, sl);
+ tmp_b->size += (b->size & BLOCK_SIZE_MASK) + BHDR_OVERHEAD;
+ b = tmp_b;
+ }
+ tmp_b = GET_NEXT_BLOCK(b->ptr.buffer, b->size & BLOCK_SIZE_MASK);
+ tmp_b->prev_hdr = b;
+
+ MAPPING_INSERT(b->size & BLOCK_SIZE_MASK, &fl, &sl);
+
+ if ((b->prev_hdr == NULL) && ((tmp_b->size & BLOCK_SIZE_MASK) == 0)) {
+ pool->put_mem(b);
+ pool->num_regions--;
+ pool->used_size -= BHDR_OVERHEAD; /* sentinel block header */
+ stat_inc(pool->count_region_free);
+ goto out;
+ }
+
+ INSERT_BLOCK(b, pool, fl, sl);
+
+ tmp_b->size |= PREV_FREE;
+ tmp_b->prev_hdr = b;
+out:
+ /* Update stats */
+ stat_set(used, tlsf_get_used_size(pool));
+ stat_set(total, tlsf_get_total_size(pool));
+ stat_inc(pool->count_free);
+ stat_setmax(pool->peak_extra, total - used);
+ stat_setmax(pool->peak_used, used);
+ stat_setmax(pool->peak_total, total);
+
+ mutex_unlock(&pool->lock);
+}
+EXPORT_SYMBOL_GPL(tlsf_free);
+
+/**
+ * tlsf_calloc - allocate and zero-out memory from given pool
+ * @size: no. of bytes
+ * @mem_pool: pool to allocate from
+ */
+void *tlsf_calloc(size_t nelem, size_t elem_size, void *mem_pool)
+{
+ void *ptr;
+
+ if (nelem == 0 || elem_size == 0)
+ return NULL;
+
+ if ((ptr = tlsf_malloc(nelem * elem_size, mem_pool)) == NULL)
+ return NULL;
+ memset(ptr, 0, nelem * elem_size);
+
+ return ptr;
+}
+EXPORT_SYMBOL_GPL(tlsf_calloc);
+
+static int __init tlsf_init(void)
+{
+ INIT_LIST_HEAD(&pool_list_head);
+ mutex_init(&pool_list_lock);
+#if defined(CONFIG_TLSF_STATS)
+ proc = create_proc_entry("tlsfinfo", S_IRUGO, NULL);
+ if (proc)
+ proc->proc_fops = &proc_tlsfinfo_operations;
+ else
+ pr_warning(T "error creating proc entry\n");
+#endif
+ return 0;
+}
+
+static void __exit tlsf_exit(void)
+{
+#if defined(CONFIG_TLSF_STATS)
+ if (proc)
+ remove_proc_entry("tlsfinfo", &proc_root);
+#endif
+ return;
+}
+
+module_init(tlsf_init);
+module_exit(tlsf_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Nitin Gupta <nitingupta910@xxxxxxxxx>");
+MODULE_DESCRIPTION("TLSF Memory Allocator");
diff --git a/mm/tlsf_int.h b/mm/tlsf_int.h
new file mode 100644
index 0000000..377eb8a
--- /dev/null
+++ b/mm/tlsf_int.h
@@ -0,0 +1,145 @@
+/*
+ * To be used internally by TLSF allocator.
+ */
+
+#ifndef _TLSF_INT_H_
+#define _TLSF_INT_H_
+
+#include <linux/tlsf.h>
+#include <asm/types.h>
+
+/* Debugging and Stats */
+#define NOP do { } while(0)
+
+#if defined(CONFIG_TLSF_STATS)
+#define stat_inc(stat) (stat++)
+#define stat_set(stat, val) (stat = val)
+#define stat_setmax(stat, curr) (stat = (curr) > stat ? (curr) : stat)
+
+#else /* STATS */
+#define stat_inc(x) NOP
+#define stat_dec(x) NOP
+#define stat_set(x, v) NOP
+#define stat_setmax(x, v) NOP
+#endif /* STATS */
+
+/* Messsage prefix */
+#define T "TLSF: "
+
+#define MAX_POOL_NAME_LEN 16
+
+/*-- TLSF structures */
+
+/* Some IMPORTANT TLSF parameters */
+#define MEM_ALIGN (sizeof(void *) * 2)
+#define MEM_ALIGN_MASK (~(MEM_ALIGN - 1))
+
+#define MAX_FLI (30)
+#define MAX_LOG2_SLI (5)
+#define MAX_SLI (1 << MAX_LOG2_SLI)
+
+#define FLI_OFFSET (6)
+/* tlsf structure just will manage blocks bigger than 128 bytes */
+#define SMALL_BLOCK (128)
+#define REAL_FLI (MAX_FLI - FLI_OFFSET)
+#define MIN_BLOCK_SIZE (sizeof(struct free_ptr))
+#define BHDR_OVERHEAD (sizeof(struct bhdr) - MIN_BLOCK_SIZE)
+
+#define PTR_MASK (sizeof(void *) - 1)
+#define BLOCK_SIZE_MASK (0xFFFFFFFF - PTR_MASK)
+
+#define GET_NEXT_BLOCK(addr, r) ((struct bhdr *) \
+ ((char *)(addr) + (r)))
+#define ROUNDUP_SIZE(r) (((r) + MEM_ALIGN - 1) & MEM_ALIGN_MASK)
+#define ROUNDDOWN_SIZE(r) ((r) & MEM_ALIGN_MASK)
+#define ROUNDUP_PAGE(r) (((r) + PAGE_SIZE - 1) & PAGE_MASK)
+
+#define BLOCK_STATE (0x1)
+#define PREV_STATE (0x2)
+
+/* bit 0 of the block size */
+#define FREE_BLOCK (0x1)
+#define USED_BLOCK (0x0)
+
+/* bit 1 of the block size */
+#define PREV_FREE (0x2)
+#define PREV_USED (0x0)
+
+#if defined(CONFIG_TLSF_DEBUG)
+#define MAX_RETRY_EXPAND 10
+#endif
+
+struct free_ptr {
+ struct bhdr *prev;
+ struct bhdr *next;
+};
+
+struct bhdr {
+ /* All blocks in a region are linked in order of physical address */
+ struct bhdr *prev_hdr;
+ /*
+ * The size is stored in bytes
+ * bit 0: block is free, if set
+ * bit 1: previous block is free, if set
+ */
+ u32 size;
+ /* Free blocks in individual freelists are linked */
+ union {
+ struct free_ptr free_ptr;
+ u8 buffer[sizeof(struct free_ptr)];
+ } ptr;
+};
+
+struct pool {
+ /* First level bitmap (REAL_FLI bits) */
+ u32 fl_bitmap;
+
+ /* Second level bitmap */
+ u32 sl_bitmap[REAL_FLI];
+
+ /* Free lists */
+ struct bhdr *matrix[REAL_FLI][MAX_SLI];
+
+ struct mutex lock;
+
+ size_t init_size;
+ size_t max_size;
+ size_t grow_size;
+
+ /* Basic stats */
+ size_t used_size;
+ size_t num_regions;
+
+ /* User provided functions for expanding/shrinking pool */
+ get_memory *get_mem;
+ put_memory *put_mem;
+
+ struct list_head list;
+
+#if defined(CONFIG_TLSF_STATS)
+ /* Extra stats */
+ size_t peak_used;
+ size_t peak_total;
+ size_t peak_extra; /* MAX(Total - Used) */
+ size_t count_alloc;
+ size_t count_free;
+ size_t count_region_alloc;
+ size_t count_region_free;
+ size_t count_failed_alloc;
+#endif
+
+#if defined(CONFIG_TLSF_DEBUG)
+ /*
+ * Pool used size must be 0 when its destroyed.
+ * When non-empty pool is destroyed, it suggests
+ * memory leak. Such pools are marked invalid
+ * and kept in pool list for later debugging.
+ */
+ unsigned int valid;
+#endif
+ void *init_region;
+ char name[MAX_POOL_NAME_LEN];
+};
+/*-- TLSF structures end */
+
+#endif
--
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