0,0 → 1,420 |
/* |
* Copyright (C) 2006 Ondrej Palkovsky |
* All rights reserved. |
* |
* Redistribution and use in source and binary forms, with or without |
* modification, are permitted provided that the following conditions |
* are met: |
* |
* - Redistributions of source code must retain the above copyright |
* notice, this list of conditions and the following disclaimer. |
* - Redistributions in binary form must reproduce the above copyright |
* notice, this list of conditions and the following disclaimer in the |
* documentation and/or other materials provided with the distribution. |
* - The name of the author may not be used to endorse or promote products |
* derived from this software without specific prior written permission. |
* |
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
*/ |
|
#include <synch/spinlock.h> |
#include <mm/slab.h> |
#include <list.h> |
#include <memstr.h> |
#include <align.h> |
#include <mm/heap.h> |
#include <config.h> |
#include <print.h> |
#include <arch.h> |
#include <panic.h> |
|
SPINLOCK_INITIALIZE(slab_cache_lock); |
LIST_INITIALIZE(slab_cache_list); |
|
slab_cache_t mag_cache; |
|
/**************************************/ |
/* SLAB low level functions */ |
|
|
/** |
* Return object to slab and call a destructor |
* |
* @return Number of freed pages |
*/ |
static count_t slab_obj_destroy(slab_cache_t *cache, void *obj) |
{ |
return 0; |
} |
|
|
/** |
* Take new object from slab or create new if needed |
* |
* @return Object address or null |
*/ |
static void * slab_obj_create(slab_cache_t *cache, int flags) |
{ |
return NULL; |
} |
|
/**************************************/ |
/* CPU-Cache slab functions */ |
|
/** |
* Free all objects in magazine and free memory associated with magazine |
* |
* Assume cpu->lock is locked |
* |
* @return Number of freed pages |
*/ |
static count_t magazine_destroy(slab_cache_t *cache, |
slab_magazine_t *mag) |
{ |
int i; |
count_t frames = 0; |
|
for (i=0;i < mag->busy; i++) |
frames += slab_obj_destroy(cache, mag->objs[i]); |
|
slab_free(&mag_cache, mag); |
|
return frames; |
} |
|
/** |
* Try to find object in CPU-cache magazines |
* |
* @return Pointer to object or NULL if not available |
*/ |
static void * magazine_obj_get(slab_cache_t *cache) |
{ |
slab_magazine_t *mag; |
|
spinlock_lock(&cache->mag_cache[CPU->id].lock); |
|
mag = cache->mag_cache[CPU->id].current; |
if (!mag) |
goto out; |
|
if (!mag->busy) { |
/* If current is empty && last exists && not empty, exchange */ |
if (cache->mag_cache[CPU->id].last \ |
&& cache->mag_cache[CPU->id].last->busy) { |
cache->mag_cache[CPU->id].current = cache->mag_cache[CPU->id].last; |
cache->mag_cache[CPU->id].last = mag; |
mag = cache->mag_cache[CPU->id].current; |
goto gotit; |
} |
/* If still not busy, exchange current with some frome |
* other full magazines */ |
spinlock_lock(&cache->lock); |
if (list_empty(&cache->magazines)) { |
spinlock_unlock(&cache->lock); |
goto out; |
} |
/* Free current magazine and take one from list */ |
slab_free(&mag_cache, mag); |
mag = list_get_instance(cache->magazines.next, |
slab_magazine_t, |
link); |
list_remove(&mag->link); |
|
spinlock_unlock(&cache->lock); |
} |
gotit: |
spinlock_unlock(&cache->mag_cache[CPU->id].lock); |
return mag->objs[--mag->busy]; |
out: |
spinlock_unlock(&cache->mag_cache[CPU->id].lock); |
return NULL; |
} |
|
/** |
* Put object into CPU-cache magazine |
* |
* We have 2 magazines bound to processor. |
* First try the current. |
* If full, try the last. |
* If full, put to magazines list. |
* allocate new, exchange last & current |
* |
* @return 0 - success, -1 - could not get memory |
*/ |
static int magazine_obj_put(slab_cache_t *cache, void *obj) |
{ |
slab_magazine_t *mag; |
|
spinlock_lock(&cache->mag_cache[CPU->id].lock); |
|
mag = cache->mag_cache[CPU->id].current; |
if (!mag) { |
/* We do not want to sleep just because of caching */ |
/* Especially we do not want reclaiming to start, as |
* this would deadlock */ |
mag = slab_alloc(&mag_cache, SLAB_ATOMIC | SLAB_NO_RECLAIM); |
if (!mag) /* Allocation failed, give up on caching */ |
goto errout; |
|
cache->mag_cache[CPU->id].current = mag; |
mag->size = SLAB_MAG_SIZE; |
mag->busy = 0; |
} else if (mag->busy == mag->size) { |
/* If the last is full | empty, allocate new */ |
mag = cache->mag_cache[CPU->id].last; |
if (!mag || mag->size == mag->busy) { |
if (mag) |
list_prepend(&cache->magazines, &mag->link); |
|
mag = slab_alloc(&mag_cache, SLAB_ATOMIC | SLAB_NO_RECLAIM); |
if (!mag) |
goto errout; |
|
mag->size = SLAB_MAG_SIZE; |
mag->busy = 0; |
cache->mag_cache[CPU->id].last = mag; |
} |
/* Exchange the 2 */ |
cache->mag_cache[CPU->id].last = cache->mag_cache[CPU->id].current; |
cache->mag_cache[CPU->id].current = mag; |
} |
mag->objs[mag->busy++] = obj; |
|
spinlock_unlock(&cache->mag_cache[CPU->id].lock); |
return 0; |
errout: |
spinlock_unlock(&cache->mag_cache[CPU->id].lock); |
return -1; |
} |
|
|
/**************************************/ |
/* Top level SLAB functions */ |
|
/** Initialize allocated memory as a slab cache */ |
static void |
_slab_cache_create(slab_cache_t *cache, |
char *name, |
size_t size, |
size_t align, |
int (*constructor)(void *obj, int kmflag), |
void (*destructor)(void *obj), |
int flags) |
{ |
int i; |
|
memsetb((__address)cache, sizeof(*cache), 0); |
cache->name = name; |
cache->align = align; |
|
cache->size = ALIGN_UP(size, align); |
|
cache->constructor = constructor; |
cache->destructor = destructor; |
cache->flags = flags; |
|
list_initialize(&cache->full_slabs); |
list_initialize(&cache->partial_slabs); |
list_initialize(&cache->magazines); |
spinlock_initialize(&cache->lock, "cachelock"); |
if (! cache->flags & SLAB_CACHE_NOMAGAZINE) { |
for (i=0; i< config.cpu_count; i++) |
spinlock_initialize(&cache->mag_cache[i].lock, |
"cpucachelock"); |
} |
|
/* Compute slab sizes, object counts in slabs etc. */ |
if (cache->size < SLAB_INSIDE_SIZE) |
cache->flags |= SLAB_CACHE_SLINSIDE; |
|
|
|
spinlock_lock(&slab_cache_lock); |
|
list_append(&cache->link, &slab_cache_list); |
|
spinlock_unlock(&slab_cache_lock); |
} |
|
/** Create slab cache */ |
slab_cache_t * slab_cache_create(char *name, |
size_t size, |
size_t align, |
int (*constructor)(void *obj, int kmflag), |
void (*destructor)(void *obj), |
int flags) |
{ |
slab_cache_t *cache; |
|
cache = malloc(sizeof(*cache) + config.cpu_count*sizeof(cache->mag_cache[0])); |
_slab_cache_create(cache, name, size, align, constructor, destructor, |
flags); |
return cache; |
} |
|
/** |
* Reclaim space occupied by objects that are already free |
* |
* @param flags If contains SLAB_RECLAIM_ALL, do aggressive freeing |
* @return Number of freed pages |
*/ |
static count_t _slab_reclaim(slab_cache_t *cache, int flags) |
{ |
int i; |
slab_magazine_t *mag; |
link_t *cur; |
count_t frames = 0; |
|
if (cache->flags & SLAB_CACHE_NOMAGAZINE) |
return 0; /* Nothing to do */ |
|
/* First lock all cpu caches, then the complete cache lock */ |
for (i=0; i < config.cpu_count; i++) |
spinlock_lock(&cache->mag_cache[i].lock); |
spinlock_lock(&cache->lock); |
|
if (flags & SLAB_RECLAIM_ALL) { |
/* Destroy CPU magazines */ |
for (i=0; i<config.cpu_count; i++) { |
mag = cache->mag_cache[i].current; |
if (mag) |
frames += magazine_destroy(cache, mag); |
cache->mag_cache[i].current = NULL; |
|
mag = cache->mag_cache[i].last; |
if (mag) |
frames += magazine_destroy(cache, mag); |
cache->mag_cache[i].last = NULL; |
} |
/* Destroy full magazines */ |
cur=cache->magazines.next; |
while (cur!=&cache->magazines) { |
mag = list_get_instance(cur, slab_magazine_t, link); |
|
cur = cur->next; |
list_remove(cur->prev); |
frames += magazine_destroy(cache,mag); |
} |
} |
|
spinlock_unlock(&cache->lock); |
for (i=0; i < config.cpu_count; i++) |
spinlock_unlock(&cache->mag_cache[i].lock); |
|
return frames; |
} |
|
/** Check that there are no slabs and remove cache from system */ |
void slab_cache_destroy(slab_cache_t *cache) |
{ |
/* Do not lock anything, we assume the software is correct and |
* does not touch the cache when it decides to destroy it */ |
|
/* Destroy all magazines */ |
_slab_reclaim(cache, SLAB_RECLAIM_ALL); |
|
/* All slabs must be empty */ |
if (!list_empty(&cache->full_slabs) \ |
|| !list_empty(&cache->partial_slabs)) |
panic("Destroying cache that is not empty."); |
|
spinlock_lock(&slab_cache_lock); |
list_remove(&cache->link); |
spinlock_unlock(&slab_cache_lock); |
|
free(cache); |
} |
|
/** Allocate new object from cache - if no flags given, always returns |
memory */ |
void * slab_alloc(slab_cache_t *cache, int flags) |
{ |
ipl_t ipl; |
void *result = NULL; |
|
/* Disable interrupts to avoid deadlocks with interrupt handlers */ |
ipl = interrupts_disable(); |
|
if (!cache->flags & SLAB_CACHE_NOMAGAZINE) |
result = magazine_obj_get(cache); |
|
if (!result) |
result = slab_obj_create(cache, flags); |
|
interrupts_restore(ipl); |
|
return result; |
} |
|
/** Return object to cache */ |
void slab_free(slab_cache_t *cache, void *obj) |
{ |
ipl_t ipl; |
|
ipl = interrupts_disable(); |
|
if (cache->flags & SLAB_CACHE_NOMAGAZINE) |
slab_obj_destroy(cache, obj); |
else { |
if (magazine_obj_put(cache, obj)) /* If magazine put failed */ |
slab_obj_destroy(cache, obj); |
} |
interrupts_restore(ipl); |
} |
|
/* Go through all caches and reclaim what is possible */ |
count_t slab_reclaim(int flags) |
{ |
slab_cache_t *cache; |
link_t *cur; |
count_t frames = 0; |
|
spinlock_lock(&slab_cache_lock); |
|
for (cur = slab_cache_list.next;cur!=&slab_cache_list; cur=cur->next) { |
cache = list_get_instance(cur, slab_cache_t, link); |
frames += _slab_reclaim(cache, flags); |
} |
|
spinlock_unlock(&slab_cache_lock); |
|
return frames; |
} |
|
|
/* Print list of slabs */ |
void slab_print_list(void) |
{ |
slab_cache_t *cache; |
link_t *cur; |
|
spinlock_lock(&slab_cache_lock); |
printf("SLAB name\tObj size\n"); |
for (cur = slab_cache_list.next;cur!=&slab_cache_list; cur=cur->next) { |
cache = list_get_instance(cur, slab_cache_t, link); |
printf("%s\t%d\n", cache->name, cache->size); |
} |
spinlock_unlock(&slab_cache_lock); |
} |
|
void slab_cache_init(void) |
{ |
/* Initialize magazine cache */ |
_slab_cache_create(&mag_cache, |
"slab_magazine", |
sizeof(slab_magazine_t)+SLAB_MAG_SIZE*sizeof(void*), |
sizeof(__address), |
NULL, NULL, |
SLAB_CACHE_NOMAGAZINE); |
|
/* Initialize structures for malloc */ |
} |