diff options
| -rw-r--r-- | mm/z3fold.c | 184 |
1 files changed, 100 insertions, 84 deletions
diff --git a/mm/z3fold.c b/mm/z3fold.c index aee9b0b8d907..7a59875d880c 100644 --- a/mm/z3fold.c +++ b/mm/z3fold.c @@ -255,10 +255,15 @@ static enum buddy handle_to_buddy(unsigned long handle) return (handle - zhdr->first_num) & BUDDY_MASK; } +static inline struct z3fold_pool *zhdr_to_pool(struct z3fold_header *zhdr) +{ + return zhdr->pool; +} + static void __release_z3fold_page(struct z3fold_header *zhdr, bool locked) { struct page *page = virt_to_page(zhdr); - struct z3fold_pool *pool = zhdr->pool; + struct z3fold_pool *pool = zhdr_to_pool(zhdr); WARN_ON(!list_empty(&zhdr->buddy)); set_bit(PAGE_STALE, &page->private); @@ -295,9 +300,10 @@ static void release_z3fold_page_locked_list(struct kref *ref) { struct z3fold_header *zhdr = container_of(ref, struct z3fold_header, refcount); - spin_lock(&zhdr->pool->lock); + struct z3fold_pool *pool = zhdr_to_pool(zhdr); + spin_lock(&pool->lock); list_del_init(&zhdr->buddy); - spin_unlock(&zhdr->pool->lock); + spin_unlock(&pool->lock); WARN_ON(z3fold_page_trylock(zhdr)); __release_z3fold_page(zhdr, true); @@ -349,6 +355,23 @@ static int num_free_chunks(struct z3fold_header *zhdr) return nfree; } +/* Add to the appropriate unbuddied list */ +static inline void add_to_unbuddied(struct z3fold_pool *pool, + struct z3fold_header *zhdr) +{ + if (zhdr->first_chunks == 0 || zhdr->last_chunks == 0 || + zhdr->middle_chunks == 0) { + struct list_head *unbuddied = get_cpu_ptr(pool->unbuddied); + + int freechunks = num_free_chunks(zhdr); + spin_lock(&pool->lock); + list_add(&zhdr->buddy, &unbuddied[freechunks]); + spin_unlock(&pool->lock); + zhdr->cpu = smp_processor_id(); + put_cpu_ptr(pool->unbuddied); + } +} + static inline void *mchunk_memmove(struct z3fold_header *zhdr, unsigned short dst_chunk) { @@ -406,10 +429,8 @@ static int z3fold_compact_page(struct z3fold_header *zhdr) static void do_compact_page(struct z3fold_header *zhdr, bool locked) { - struct z3fold_pool *pool = zhdr->pool; + struct z3fold_pool *pool = zhdr_to_pool(zhdr); struct page *page; - struct list_head *unbuddied; - int fchunks; page = virt_to_page(zhdr); if (locked) @@ -430,18 +451,7 @@ static void do_compact_page(struct z3fold_header *zhdr, bool locked) } z3fold_compact_page(zhdr); - unbuddied = get_cpu_ptr(pool->unbuddied); - fchunks = num_free_chunks(zhdr); - if (fchunks < NCHUNKS && - (!zhdr->first_chunks || !zhdr->middle_chunks || - !zhdr->last_chunks)) { - /* the page's not completely free and it's unbuddied */ - spin_lock(&pool->lock); - list_add(&zhdr->buddy, &unbuddied[fchunks]); - spin_unlock(&pool->lock); - zhdr->cpu = smp_processor_id(); - } - put_cpu_ptr(pool->unbuddied); + add_to_unbuddied(pool, zhdr); z3fold_page_unlock(zhdr); } @@ -453,6 +463,67 @@ static void compact_page_work(struct work_struct *w) do_compact_page(zhdr, false); } +/* returns _locked_ z3fold page header or NULL */ +static inline struct z3fold_header *__z3fold_alloc(struct z3fold_pool *pool, + size_t size, bool can_sleep) +{ + struct z3fold_header *zhdr = NULL; + struct page *page; + struct list_head *unbuddied; + int chunks = size_to_chunks(size), i; + +lookup: + /* First, try to find an unbuddied z3fold page. */ + unbuddied = get_cpu_ptr(pool->unbuddied); + for_each_unbuddied_list(i, chunks) { + struct list_head *l = &unbuddied[i]; + + zhdr = list_first_entry_or_null(READ_ONCE(l), + struct z3fold_header, buddy); + + if (!zhdr) + continue; + + /* Re-check under lock. */ + spin_lock(&pool->lock); + l = &unbuddied[i]; + if (unlikely(zhdr != list_first_entry(READ_ONCE(l), + struct z3fold_header, buddy)) || + !z3fold_page_trylock(zhdr)) { + spin_unlock(&pool->lock); + zhdr = NULL; + put_cpu_ptr(pool->unbuddied); + if (can_sleep) + cond_resched(); + goto lookup; + } + list_del_init(&zhdr->buddy); + zhdr->cpu = -1; + spin_unlock(&pool->lock); + + page = virt_to_page(zhdr); + if (test_bit(NEEDS_COMPACTING, &page->private)) { + z3fold_page_unlock(zhdr); + zhdr = NULL; + put_cpu_ptr(pool->unbuddied); + if (can_sleep) + cond_resched(); + goto lookup; + } + + /* + * this page could not be removed from its unbuddied + * list while pool lock was held, and then we've taken + * page lock so kref_put could not be called before + * we got here, so it's safe to just call kref_get() + */ + kref_get(&zhdr->refcount); + break; + } + put_cpu_ptr(pool->unbuddied); + + return zhdr; +} /* * API Functions @@ -546,7 +617,7 @@ static void z3fold_destroy_pool(struct z3fold_pool *pool) static int z3fold_alloc(struct z3fold_pool *pool, size_t size, gfp_t gfp, unsigned long *handle) { - int chunks = 0, i, freechunks; + int chunks = size_to_chunks(size); struct z3fold_header *zhdr = NULL; struct page *page = NULL; enum buddy bud; @@ -561,56 +632,8 @@ static int z3fold_alloc(struct z3fold_pool *pool, size_t size, gfp_t gfp, if (size > PAGE_SIZE - ZHDR_SIZE_ALIGNED - CHUNK_SIZE) bud = HEADLESS; else { - struct list_head *unbuddied; - chunks = size_to_chunks(size); - -lookup: - /* First, try to find an unbuddied z3fold page. */ - unbuddied = get_cpu_ptr(pool->unbuddied); - for_each_unbuddied_list(i, chunks) { - struct list_head *l = &unbuddied[i]; - - zhdr = list_first_entry_or_null(READ_ONCE(l), - struct z3fold_header, buddy); - - if (!zhdr) - continue; - - /* Re-check under lock. */ - spin_lock(&pool->lock); - l = &unbuddied[i]; - if (unlikely(zhdr != list_first_entry(READ_ONCE(l), - struct z3fold_header, buddy)) || - !z3fold_page_trylock(zhdr)) { - spin_unlock(&pool->lock); - put_cpu_ptr(pool->unbuddied); - goto lookup; - } - list_del_init(&zhdr->buddy); - zhdr->cpu = -1; - spin_unlock(&pool->lock); - - page = virt_to_page(zhdr); - if (test_bit(NEEDS_COMPACTING, &page->private)) { - z3fold_page_unlock(zhdr); - zhdr = NULL; - put_cpu_ptr(pool->unbuddied); - if (can_sleep) - cond_resched(); - goto lookup; - } - - /* - * this page could not be removed from its unbuddied - * list while pool lock was held, and then we've taken - * page lock so kref_put could not be called before - * we got here, so it's safe to just call kref_get() - */ - kref_get(&zhdr->refcount); - break; - } - put_cpu_ptr(pool->unbuddied); - +retry: + zhdr = __z3fold_alloc(pool, size, can_sleep); if (zhdr) { if (zhdr->first_chunks == 0) { if (zhdr->middle_chunks != 0 && @@ -630,8 +653,9 @@ lookup: z3fold_page_unlock(zhdr); pr_err("No free chunks in unbuddied\n"); WARN_ON(1); - goto lookup; + goto retry; } + page = virt_to_page(zhdr); goto found; } bud = FIRST; @@ -662,8 +686,12 @@ lookup: if (!page) return -ENOMEM; - atomic64_inc(&pool->pages_nr); zhdr = init_z3fold_page(page, pool); + if (!zhdr) { + __free_page(page); + return -ENOMEM; + } + atomic64_inc(&pool->pages_nr); if (bud == HEADLESS) { set_bit(PAGE_HEADLESS, &page->private); @@ -680,19 +708,7 @@ found: zhdr->middle_chunks = chunks; zhdr->start_middle = zhdr->first_chunks + ZHDR_CHUNKS; } - - if (zhdr->first_chunks == 0 || zhdr->last_chunks == 0 || - zhdr->middle_chunks == 0) { - struct list_head *unbuddied = get_cpu_ptr(pool->unbuddied); - - /* Add to unbuddied list */ - freechunks = num_free_chunks(zhdr); - spin_lock(&pool->lock); - list_add(&zhdr->buddy, &unbuddied[freechunks]); - spin_unlock(&pool->lock); - zhdr->cpu = smp_processor_id(); - put_cpu_ptr(pool->unbuddied); - } + add_to_unbuddied(pool, zhdr); headless: spin_lock(&pool->lock); |