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drm/ttm: Allocate the page pool manager in the heap.

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Repeated ttm_page_alloc_init/fini fails noisily because the pool
manager kobj isn't zeroed out between uses (we could do just that but
statically allocated kobjects are generally considered a bad thing).
Move it to kzalloc'ed memory.

Note that this patch drops the refcounting behavior of the pool
allocator init/fini functions: it would have led to a race condition
in its current form, and anyway it was never exploited.

This fixes a regression with reloading kms modules at runtime, since
page allocator was introduced.

Signed-off-by: Francisco Jerez <currojerez@riseup.net>
Signed-off-by: Dave Airlie <airlied@redhat.com>
This commit is contained in:
Francisco Jerez 2010-07-04 04:03:07 +02:00 committed by Dave Airlie
parent 123f94f22e
commit 5870a4d97d
2 changed files with 33 additions and 39 deletions
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68
drivers/gpu/drm/ttm/ttm_page_alloc.c
View file

@ -104,7 +104,6 @@ struct ttm_pool_opts {
struct ttm_pool_manager { struct ttm_pool_manager {
struct kobject kobj; struct kobject kobj;
struct shrinker mm_shrink; struct shrinker mm_shrink;
atomic_t page_alloc_inited;
struct ttm_pool_opts options; struct ttm_pool_opts options;
union { union {
@ -142,7 +141,7 @@ static void ttm_pool_kobj_release(struct kobject *kobj)
{ {
struct ttm_pool_manager *m = struct ttm_pool_manager *m =
container_of(kobj, struct ttm_pool_manager, kobj); container_of(kobj, struct ttm_pool_manager, kobj);
(void)m; kfree(m);
} }
static ssize_t ttm_pool_store(struct kobject *kobj, static ssize_t ttm_pool_store(struct kobject *kobj,
@ -214,9 +213,7 @@ static struct kobj_type ttm_pool_kobj_type = {
.default_attrs = ttm_pool_attrs, .default_attrs = ttm_pool_attrs,
}; };
static struct ttm_pool_manager _manager = { static struct ttm_pool_manager *_manager;
.page_alloc_inited = ATOMIC_INIT(0)
};
#ifndef CONFIG_X86 #ifndef CONFIG_X86
static int set_pages_array_wb(struct page **pages, int addrinarray) static int set_pages_array_wb(struct page **pages, int addrinarray)
@ -271,7 +268,7 @@ static struct ttm_page_pool *ttm_get_pool(int flags,
if (flags & TTM_PAGE_FLAG_DMA32) if (flags & TTM_PAGE_FLAG_DMA32)
pool_index |= 0x2; pool_index |= 0x2;
return &_manager.pools[pool_index]; return &_manager->pools[pool_index];
} }
/* set memory back to wb and free the pages. */ /* set memory back to wb and free the pages. */
@ -387,7 +384,7 @@ static int ttm_pool_get_num_unused_pages(void)
unsigned i; unsigned i;
int total = 0; int total = 0;
for (i = 0; i < NUM_POOLS; ++i) for (i = 0; i < NUM_POOLS; ++i)
total += _manager.pools[i].npages; total += _manager->pools[i].npages;
return total; return total;
} }
@ -408,7 +405,7 @@ static int ttm_pool_mm_shrink(int shrink_pages, gfp_t gfp_mask)
unsigned nr_free = shrink_pages; unsigned nr_free = shrink_pages;
if (shrink_pages == 0) if (shrink_pages == 0)
break; break;
pool = &_manager.pools[(i + pool_offset)%NUM_POOLS]; pool = &_manager->pools[(i + pool_offset)%NUM_POOLS];
shrink_pages = ttm_page_pool_free(pool, nr_free); shrink_pages = ttm_page_pool_free(pool, nr_free);
} }
/* return estimated number of unused pages in pool */ /* return estimated number of unused pages in pool */
@ -576,10 +573,10 @@ static void ttm_page_pool_fill_locked(struct ttm_page_pool *pool,
/* If allocation request is small and there is not enough /* If allocation request is small and there is not enough
* pages in pool we fill the pool first */ * pages in pool we fill the pool first */
if (count < _manager.options.small if (count < _manager->options.small
&& count > pool->npages) { && count > pool->npages) {
struct list_head new_pages; struct list_head new_pages;
unsigned alloc_size = _manager.options.alloc_size; unsigned alloc_size = _manager->options.alloc_size;
/** /**
* Can't change page caching if in irqsave context. We have to * Can't change page caching if in irqsave context. We have to
@ -759,8 +756,8 @@ void ttm_put_pages(struct list_head *pages, unsigned page_count, int flags,
pool->npages += page_count; pool->npages += page_count;
/* Check that we don't go over the pool limit */ /* Check that we don't go over the pool limit */
page_count = 0; page_count = 0;
if (pool->npages > _manager.options.max_size) { if (pool->npages > _manager->options.max_size) {
page_count = pool->npages - _manager.options.max_size; page_count = pool->npages - _manager->options.max_size;
/* free at least NUM_PAGES_TO_ALLOC number of pages /* free at least NUM_PAGES_TO_ALLOC number of pages
* to reduce calls to set_memory_wb */ * to reduce calls to set_memory_wb */
if (page_count < NUM_PAGES_TO_ALLOC) if (page_count < NUM_PAGES_TO_ALLOC)
@ -785,33 +782,36 @@ static void ttm_page_pool_init_locked(struct ttm_page_pool *pool, int flags,
int ttm_page_alloc_init(struct ttm_mem_global *glob, unsigned max_pages) int ttm_page_alloc_init(struct ttm_mem_global *glob, unsigned max_pages)
{ {
int ret; int ret;
if (atomic_add_return(1, &_manager.page_alloc_inited) > 1)
return 0; WARN_ON(_manager);
printk(KERN_INFO TTM_PFX "Initializing pool allocator.\n"); printk(KERN_INFO TTM_PFX "Initializing pool allocator.\n");
ttm_page_pool_init_locked(&_manager.wc_pool, GFP_HIGHUSER, "wc"); _manager = kzalloc(sizeof(*_manager), GFP_KERNEL);
ttm_page_pool_init_locked(&_manager.uc_pool, GFP_HIGHUSER, "uc"); ttm_page_pool_init_locked(&_manager->wc_pool, GFP_HIGHUSER, "wc");
ttm_page_pool_init_locked(&_manager.wc_pool_dma32, GFP_USER | GFP_DMA32, ttm_page_pool_init_locked(&_manager->uc_pool, GFP_HIGHUSER, "uc");
"wc dma");
ttm_page_pool_init_locked(&_manager.uc_pool_dma32, GFP_USER | GFP_DMA32, ttm_page_pool_init_locked(&_manager->wc_pool_dma32,
"uc dma"); GFP_USER | GFP_DMA32, "wc dma");
_manager.options.max_size = max_pages; ttm_page_pool_init_locked(&_manager->uc_pool_dma32,
_manager.options.small = SMALL_ALLOCATION; GFP_USER | GFP_DMA32, "uc dma");
_manager.options.alloc_size = NUM_PAGES_TO_ALLOC;
kobject_init(&_manager.kobj, &ttm_pool_kobj_type); _manager->options.max_size = max_pages;
ret = kobject_add(&_manager.kobj, &glob->kobj, "pool"); _manager->options.small = SMALL_ALLOCATION;
_manager->options.alloc_size = NUM_PAGES_TO_ALLOC;
ret = kobject_init_and_add(&_manager->kobj, &ttm_pool_kobj_type,
&glob->kobj, "pool");
if (unlikely(ret != 0)) { if (unlikely(ret != 0)) {
kobject_put(&_manager.kobj); kobject_put(&_manager->kobj);
_manager = NULL;
return ret; return ret;
} }
ttm_pool_mm_shrink_init(&_manager); ttm_pool_mm_shrink_init(_manager);
return 0; return 0;
} }
@ -820,16 +820,14 @@ void ttm_page_alloc_fini()
{ {
int i; int i;
if (atomic_sub_return(1, &_manager.page_alloc_inited) > 0)
return;
printk(KERN_INFO TTM_PFX "Finalizing pool allocator.\n"); printk(KERN_INFO TTM_PFX "Finalizing pool allocator.\n");
ttm_pool_mm_shrink_fini(&_manager); ttm_pool_mm_shrink_fini(_manager);
for (i = 0; i < NUM_POOLS; ++i) for (i = 0; i < NUM_POOLS; ++i)
ttm_page_pool_free(&_manager.pools[i], FREE_ALL_PAGES); ttm_page_pool_free(&_manager->pools[i], FREE_ALL_PAGES);
kobject_put(&_manager.kobj); kobject_put(&_manager->kobj);
_manager = NULL;
} }
int ttm_page_alloc_debugfs(struct seq_file *m, void *data) int ttm_page_alloc_debugfs(struct seq_file *m, void *data)
@ -837,14 +835,14 @@ int ttm_page_alloc_debugfs(struct seq_file *m, void *data)
struct ttm_page_pool *p; struct ttm_page_pool *p;
unsigned i; unsigned i;
char *h[] = {"pool", "refills", "pages freed", "size"}; char *h[] = {"pool", "refills", "pages freed", "size"};
if (atomic_read(&_manager.page_alloc_inited) == 0) { if (!_manager) {
seq_printf(m, "No pool allocator running.\n"); seq_printf(m, "No pool allocator running.\n");
return 0; return 0;
} }
seq_printf(m, "%6s %12s %13s %8s\n", seq_printf(m, "%6s %12s %13s %8s\n",
h[0], h[1], h[2], h[3]); h[0], h[1], h[2], h[3]);
for (i = 0; i < NUM_POOLS; ++i) { for (i = 0; i < NUM_POOLS; ++i) {
p = &_manager.pools[i]; p = &_manager->pools[i];
seq_printf(m, "%6s %12ld %13ld %8d\n", seq_printf(m, "%6s %12ld %13ld %8d\n",
p->name, p->nrefills, p->name, p->nrefills,

4
include/drm/ttm/ttm_page_alloc.h
View file

@ -56,10 +56,6 @@ void ttm_put_pages(struct list_head *pages,
enum ttm_caching_state cstate); enum ttm_caching_state cstate);
/** /**
* Initialize pool allocator. * Initialize pool allocator.
*
* Pool allocator is internaly reference counted so it can be initialized
* multiple times but ttm_page_alloc_fini has to be called same number of
* times.
*/ */
int ttm_page_alloc_init(struct ttm_mem_global *glob, unsigned max_pages); int ttm_page_alloc_init(struct ttm_mem_global *glob, unsigned max_pages);
/** /**