X-Git-Url: http://git.monstr.eu/?p=linux-2.6-microblaze.git;a=blobdiff_plain;f=mm%2Fz3fold.c;h=b3c0577b8095a7fa109bf0ca3b8c837d3573fd93;hp=cf71da10d04e73e5126a71443e1cc4883054c21c;hb=HEAD;hpb=b2a88c212e652e94f1e4b635910972ac57ba4e97 diff --git a/mm/z3fold.c b/mm/z3fold.c index cf71da10d04e..7ab05621052d 100644 --- a/mm/z3fold.c +++ b/mm/z3fold.c @@ -68,9 +68,6 @@ * Structures *****************/ struct z3fold_pool; -struct z3fold_ops { - int (*evict)(struct z3fold_pool *pool, unsigned long handle); -}; enum buddy { HEADLESS = 0, @@ -128,20 +125,14 @@ struct z3fold_header { /** * struct z3fold_pool - stores metadata for each z3fold pool * @name: pool name - * @lock: protects pool unbuddied/lru lists + * @lock: protects pool unbuddied lists * @stale_lock: protects pool stale page list * @unbuddied: per-cpu array of lists tracking z3fold pages that contain 2- * buddies; the list each z3fold page is added to depends on * the size of its free region. - * @lru: list tracking the z3fold pages in LRU order by most recently - * added buddy. * @stale: list of pages marked for freeing * @pages_nr: number of z3fold pages in the pool. * @c_handle: cache for z3fold_buddy_slots allocation - * @ops: pointer to a structure of user defined operations specified at - * pool creation time. - * @zpool: zpool driver - * @zpool_ops: zpool operations structure with an evict callback * @compact_wq: workqueue for page layout background optimization * @release_wq: workqueue for safe page release * @work: work_struct for safe page release @@ -154,13 +145,9 @@ struct z3fold_pool { spinlock_t lock; spinlock_t stale_lock; struct list_head *unbuddied; - struct list_head lru; struct list_head stale; atomic64_t pages_nr; struct kmem_cache *c_handle; - const struct z3fold_ops *ops; - struct zpool *zpool; - const struct zpool_ops *zpool_ops; struct workqueue_struct *compact_wq; struct workqueue_struct *release_wq; struct work_struct work; @@ -335,7 +322,6 @@ static struct z3fold_header *init_z3fold_page(struct page *page, bool headless, struct z3fold_header *zhdr = page_address(page); struct z3fold_buddy_slots *slots; - INIT_LIST_HEAD(&page->lru); clear_bit(PAGE_HEADLESS, &page->private); clear_bit(MIDDLE_CHUNK_MAPPED, &page->private); clear_bit(NEEDS_COMPACTING, &page->private); @@ -378,8 +364,9 @@ static inline int __idx(struct z3fold_header *zhdr, enum buddy bud) } /* - * Encodes the handle of a particular buddy within a z3fold page - * Pool lock should be held as this function accesses first_num + * Encodes the handle of a particular buddy within a z3fold page. + * Zhdr->page_lock should be held as this function accesses first_num + * if bud != HEADLESS. */ static unsigned long __encode_handle(struct z3fold_header *zhdr, struct z3fold_buddy_slots *slots, @@ -457,8 +444,6 @@ static void __release_z3fold_page(struct z3fold_header *zhdr, bool locked) set_bit(PAGE_STALE, &page->private); clear_bit(NEEDS_COMPACTING, &page->private); spin_lock(&pool->lock); - if (!list_empty(&page->lru)) - list_del_init(&page->lru); spin_unlock(&pool->lock); if (locked) @@ -494,6 +479,16 @@ static void release_z3fold_page_locked_list(struct kref *ref) __release_z3fold_page(zhdr, true); } +static inline int put_z3fold_locked(struct z3fold_header *zhdr) +{ + return kref_put(&zhdr->refcount, release_z3fold_page_locked); +} + +static inline int put_z3fold_locked_list(struct z3fold_header *zhdr) +{ + return kref_put(&zhdr->refcount, release_z3fold_page_locked_list); +} + static void free_pages_work(struct work_struct *w) { struct z3fold_pool *pool = container_of(w, struct z3fold_pool, work); @@ -680,7 +675,7 @@ static struct z3fold_header *compact_single_buddy(struct z3fold_header *zhdr) return new_zhdr; out_fail: - if (new_zhdr && !kref_put(&new_zhdr->refcount, release_z3fold_page_locked)) { + if (new_zhdr && !put_z3fold_locked(new_zhdr)) { add_to_unbuddied(pool, new_zhdr); z3fold_page_unlock(new_zhdr); } @@ -755,7 +750,7 @@ static void do_compact_page(struct z3fold_header *zhdr, bool locked) list_del_init(&zhdr->buddy); spin_unlock(&pool->lock); - if (kref_put(&zhdr->refcount, release_z3fold_page_locked)) + if (put_z3fold_locked(zhdr)) return; if (test_bit(PAGE_STALE, &page->private) || @@ -766,7 +761,7 @@ static void do_compact_page(struct z3fold_header *zhdr, bool locked) if (!zhdr->foreign_handles && buddy_single(zhdr) && zhdr->mapped_count == 0 && compact_single_buddy(zhdr)) { - if (!kref_put(&zhdr->refcount, release_z3fold_page_locked)) { + if (!put_z3fold_locked(zhdr)) { clear_bit(PAGE_CLAIMED, &page->private); z3fold_page_unlock(zhdr); } @@ -892,7 +887,7 @@ lookup: return zhdr; out_fail: - if (!kref_put(&zhdr->refcount, release_z3fold_page_locked)) { + if (!put_z3fold_locked(zhdr)) { add_to_unbuddied(pool, zhdr); z3fold_page_unlock(zhdr); } @@ -907,13 +902,11 @@ out_fail: * z3fold_create_pool() - create a new z3fold pool * @name: pool name * @gfp: gfp flags when allocating the z3fold pool structure - * @ops: user-defined operations for the z3fold pool * * Return: pointer to the new z3fold pool or NULL if the metadata allocation * failed. */ -static struct z3fold_pool *z3fold_create_pool(const char *name, gfp_t gfp, - const struct z3fold_ops *ops) +static struct z3fold_pool *z3fold_create_pool(const char *name, gfp_t gfp) { struct z3fold_pool *pool = NULL; int i, cpu; @@ -938,7 +931,6 @@ static struct z3fold_pool *z3fold_create_pool(const char *name, gfp_t gfp, for_each_unbuddied_list(i, 0) INIT_LIST_HEAD(&unbuddied[i]); } - INIT_LIST_HEAD(&pool->lru); INIT_LIST_HEAD(&pool->stale); atomic64_set(&pool->pages_nr, 0); pool->name = name; @@ -949,7 +941,6 @@ static struct z3fold_pool *z3fold_create_pool(const char *name, gfp_t gfp, if (!pool->release_wq) goto out_wq; INIT_WORK(&pool->work, free_pages_work); - pool->ops = ops; return pool; out_wq: @@ -1030,8 +1021,7 @@ retry: if (zhdr) { bud = get_free_buddy(zhdr, chunks); if (bud == HEADLESS) { - if (!kref_put(&zhdr->refcount, - release_z3fold_page_locked)) + if (!put_z3fold_locked(zhdr)) z3fold_page_unlock(zhdr); pr_err("No free chunks in unbuddied\n"); WARN_ON(1); @@ -1082,12 +1072,6 @@ found: headless: spin_lock(&pool->lock); - /* Add/move z3fold page to beginning of LRU */ - if (!list_empty(&page->lru)) - list_del(&page->lru); - - list_add(&page->lru, &pool->lru); - *handle = encode_handle(zhdr, bud); spin_unlock(&pool->lock); if (bud != HEADLESS) @@ -1124,9 +1108,6 @@ static void z3fold_free(struct z3fold_pool *pool, unsigned long handle) * immediately so we don't care about its value any more. */ if (!page_claimed) { - spin_lock(&pool->lock); - list_del(&page->lru); - spin_unlock(&pool->lock); put_z3fold_header(zhdr); free_z3fold_page(page, true); atomic64_dec(&pool->pages_nr); @@ -1156,7 +1137,7 @@ static void z3fold_free(struct z3fold_pool *pool, unsigned long handle) if (!page_claimed) free_handle(handle, zhdr); - if (kref_put(&zhdr->refcount, release_z3fold_page_locked_list)) + if (put_z3fold_locked_list(zhdr)) return; if (page_claimed) { /* the page has not been claimed by us */ @@ -1181,198 +1162,6 @@ static void z3fold_free(struct z3fold_pool *pool, unsigned long handle) put_z3fold_header(zhdr); } -/** - * z3fold_reclaim_page() - evicts allocations from a pool page and frees it - * @pool: pool from which a page will attempt to be evicted - * @retries: number of pages on the LRU list for which eviction will - * be attempted before failing - * - * z3fold reclaim is different from normal system reclaim in that it is done - * from the bottom, up. This is because only the bottom layer, z3fold, has - * information on how the allocations are organized within each z3fold page. - * This has the potential to create interesting locking situations between - * z3fold and the user, however. - * - * To avoid these, this is how z3fold_reclaim_page() should be called: - * - * The user detects a page should be reclaimed and calls z3fold_reclaim_page(). - * z3fold_reclaim_page() will remove a z3fold page from the pool LRU list and - * call the user-defined eviction handler with the pool and handle as - * arguments. - * - * If the handle can not be evicted, the eviction handler should return - * non-zero. z3fold_reclaim_page() will add the z3fold page back to the - * appropriate list and try the next z3fold page on the LRU up to - * a user defined number of retries. - * - * If the handle is successfully evicted, the eviction handler should - * return 0 _and_ should have called z3fold_free() on the handle. z3fold_free() - * contains logic to delay freeing the page if the page is under reclaim, - * as indicated by the setting of the PG_reclaim flag on the underlying page. - * - * If all buddies in the z3fold page are successfully evicted, then the - * z3fold page can be freed. - * - * Returns: 0 if page is successfully freed, otherwise -EINVAL if there are - * no pages to evict or an eviction handler is not registered, -EAGAIN if - * the retry limit was hit. - */ -static int z3fold_reclaim_page(struct z3fold_pool *pool, unsigned int retries) -{ - int i, ret = -1; - struct z3fold_header *zhdr = NULL; - struct page *page = NULL; - struct list_head *pos; - unsigned long first_handle = 0, middle_handle = 0, last_handle = 0; - struct z3fold_buddy_slots slots __attribute__((aligned(SLOTS_ALIGN))); - - rwlock_init(&slots.lock); - slots.pool = (unsigned long)pool | (1 << HANDLES_NOFREE); - - spin_lock(&pool->lock); - if (!pool->ops || !pool->ops->evict || retries == 0) { - spin_unlock(&pool->lock); - return -EINVAL; - } - for (i = 0; i < retries; i++) { - if (list_empty(&pool->lru)) { - spin_unlock(&pool->lock); - return -EINVAL; - } - list_for_each_prev(pos, &pool->lru) { - page = list_entry(pos, struct page, lru); - - zhdr = page_address(page); - if (test_bit(PAGE_HEADLESS, &page->private)) { - /* - * For non-headless pages, we wait to do this - * until we have the page lock to avoid racing - * with __z3fold_alloc(). Headless pages don't - * have a lock (and __z3fold_alloc() will never - * see them), but we still need to test and set - * PAGE_CLAIMED to avoid racing with - * z3fold_free(), so just do it now before - * leaving the loop. - */ - if (test_and_set_bit(PAGE_CLAIMED, &page->private)) - continue; - - break; - } - - if (!z3fold_page_trylock(zhdr)) { - zhdr = NULL; - continue; /* can't evict at this point */ - } - - /* test_and_set_bit is of course atomic, but we still - * need to do it under page lock, otherwise checking - * that bit in __z3fold_alloc wouldn't make sense - */ - if (zhdr->foreign_handles || - test_and_set_bit(PAGE_CLAIMED, &page->private)) { - z3fold_page_unlock(zhdr); - zhdr = NULL; - continue; /* can't evict such page */ - } - list_del_init(&zhdr->buddy); - zhdr->cpu = -1; - /* See comment in __z3fold_alloc. */ - kref_get(&zhdr->refcount); - break; - } - - if (!zhdr) - break; - - list_del_init(&page->lru); - spin_unlock(&pool->lock); - - if (!test_bit(PAGE_HEADLESS, &page->private)) { - /* - * We need encode the handles before unlocking, and - * use our local slots structure because z3fold_free - * can zero out zhdr->slots and we can't do much - * about that - */ - first_handle = 0; - last_handle = 0; - middle_handle = 0; - memset(slots.slot, 0, sizeof(slots.slot)); - if (zhdr->first_chunks) - first_handle = __encode_handle(zhdr, &slots, - FIRST); - if (zhdr->middle_chunks) - middle_handle = __encode_handle(zhdr, &slots, - MIDDLE); - if (zhdr->last_chunks) - last_handle = __encode_handle(zhdr, &slots, - LAST); - /* - * it's safe to unlock here because we hold a - * reference to this page - */ - z3fold_page_unlock(zhdr); - } else { - first_handle = encode_handle(zhdr, HEADLESS); - last_handle = middle_handle = 0; - } - /* Issue the eviction callback(s) */ - if (middle_handle) { - ret = pool->ops->evict(pool, middle_handle); - if (ret) - goto next; - } - if (first_handle) { - ret = pool->ops->evict(pool, first_handle); - if (ret) - goto next; - } - if (last_handle) { - ret = pool->ops->evict(pool, last_handle); - if (ret) - goto next; - } -next: - if (test_bit(PAGE_HEADLESS, &page->private)) { - if (ret == 0) { - free_z3fold_page(page, true); - atomic64_dec(&pool->pages_nr); - return 0; - } - spin_lock(&pool->lock); - list_add(&page->lru, &pool->lru); - spin_unlock(&pool->lock); - clear_bit(PAGE_CLAIMED, &page->private); - } else { - struct z3fold_buddy_slots *slots = zhdr->slots; - z3fold_page_lock(zhdr); - if (kref_put(&zhdr->refcount, - release_z3fold_page_locked)) { - kmem_cache_free(pool->c_handle, slots); - return 0; - } - /* - * if we are here, the page is still not completely - * free. Take the global pool lock then to be able - * to add it back to the lru list - */ - spin_lock(&pool->lock); - list_add(&page->lru, &pool->lru); - spin_unlock(&pool->lock); - if (list_empty(&zhdr->buddy)) - add_to_unbuddied(pool, zhdr); - clear_bit(PAGE_CLAIMED, &page->private); - z3fold_page_unlock(zhdr); - } - - /* We started off locked to we need to lock the pool back */ - spin_lock(&pool->lock); - } - spin_unlock(&pool->lock); - return -EAGAIN; -} - /** * z3fold_map() - maps the allocation associated with the given handle * @pool: pool in which the allocation resides @@ -1463,7 +1252,6 @@ static bool z3fold_page_isolate(struct page *page, isolate_mode_t mode) struct z3fold_header *zhdr; struct z3fold_pool *pool; - VM_BUG_ON_PAGE(!PageMovable(page), page); VM_BUG_ON_PAGE(PageIsolated(page), page); if (test_bit(PAGE_HEADLESS, &page->private)) @@ -1484,8 +1272,6 @@ static bool z3fold_page_isolate(struct page *page, isolate_mode_t mode) spin_lock(&pool->lock); if (!list_empty(&zhdr->buddy)) list_del_init(&zhdr->buddy); - if (!list_empty(&page->lru)) - list_del_init(&page->lru); spin_unlock(&pool->lock); kref_get(&zhdr->refcount); @@ -1503,7 +1289,6 @@ static int z3fold_page_migrate(struct page *newpage, struct page *page, struct z3fold_header *zhdr, *new_zhdr; struct z3fold_pool *pool; - VM_BUG_ON_PAGE(!PageMovable(page), page); VM_BUG_ON_PAGE(!PageIsolated(page), page); VM_BUG_ON_PAGE(!test_bit(PAGE_CLAIMED, &page->private), page); VM_BUG_ON_PAGE(!PageLocked(newpage), newpage); @@ -1546,9 +1331,6 @@ static int z3fold_page_migrate(struct page *newpage, struct page *page, encode_handle(new_zhdr, MIDDLE); set_bit(NEEDS_COMPACTING, &newpage->private); new_zhdr->cpu = smp_processor_id(); - spin_lock(&pool->lock); - list_add(&newpage->lru, &pool->lru); - spin_unlock(&pool->lock); __SetPageMovable(newpage, &z3fold_mops); z3fold_page_unlock(new_zhdr); @@ -1572,11 +1354,8 @@ static void z3fold_page_putback(struct page *page) if (!list_empty(&zhdr->buddy)) list_del_init(&zhdr->buddy); INIT_LIST_HEAD(&page->lru); - if (kref_put(&zhdr->refcount, release_z3fold_page_locked)) + if (put_z3fold_locked(zhdr)) return; - spin_lock(&pool->lock); - list_add(&page->lru, &pool->lru); - spin_unlock(&pool->lock); if (list_empty(&zhdr->buddy)) add_to_unbuddied(pool, zhdr); clear_bit(PAGE_CLAIMED, &page->private); @@ -1593,31 +1372,9 @@ static const struct movable_operations z3fold_mops = { * zpool ****************/ -static int z3fold_zpool_evict(struct z3fold_pool *pool, unsigned long handle) +static void *z3fold_zpool_create(const char *name, gfp_t gfp) { - if (pool->zpool && pool->zpool_ops && pool->zpool_ops->evict) - return pool->zpool_ops->evict(pool->zpool, handle); - else - return -ENOENT; -} - -static const struct z3fold_ops z3fold_zpool_ops = { - .evict = z3fold_zpool_evict -}; - -static void *z3fold_zpool_create(const char *name, gfp_t gfp, - const struct zpool_ops *zpool_ops, - struct zpool *zpool) -{ - struct z3fold_pool *pool; - - pool = z3fold_create_pool(name, gfp, - zpool_ops ? &z3fold_zpool_ops : NULL); - if (pool) { - pool->zpool = zpool; - pool->zpool_ops = zpool_ops; - } - return pool; + return z3fold_create_pool(name, gfp); } static void z3fold_zpool_destroy(void *pool) @@ -1635,25 +1392,6 @@ static void z3fold_zpool_free(void *pool, unsigned long handle) z3fold_free(pool, handle); } -static int z3fold_zpool_shrink(void *pool, unsigned int pages, - unsigned int *reclaimed) -{ - unsigned int total = 0; - int ret = -EINVAL; - - while (total < pages) { - ret = z3fold_reclaim_page(pool, 8); - if (ret < 0) - break; - total++; - } - - if (reclaimed) - *reclaimed = total; - - return ret; -} - static void *z3fold_zpool_map(void *pool, unsigned long handle, enum zpool_mapmode mm) { @@ -1677,7 +1415,6 @@ static struct zpool_driver z3fold_zpool_driver = { .destroy = z3fold_zpool_destroy, .malloc = z3fold_zpool_malloc, .free = z3fold_zpool_free, - .shrink = z3fold_zpool_shrink, .map = z3fold_zpool_map, .unmap = z3fold_zpool_unmap, .total_size = z3fold_zpool_total_size,