Commit a91576d7 authored by Tetsuo Handa's avatar Tetsuo Handa Committed by Dave Airlie

drm/ttm: Pass GFP flags in order to avoid deadlock.

Commit 7dc19d5a "drivers: convert shrinkers to new count/scan API" added
deadlock warnings that ttm_page_pool_free() and ttm_dma_page_pool_free()
are currently doing GFP_KERNEL allocation.

But these functions did not get updated to receive gfp_t argument.
This patch explicitly passes sc->gfp_mask or GFP_KERNEL to these functions,
and removes the deadlock warning.
Signed-off-by: default avatarTetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: stable <stable@kernel.org> [2.6.35+]
Signed-off-by: default avatarDave Airlie <airlied@redhat.com>
parent 71336e01
...@@ -297,8 +297,10 @@ static void ttm_pool_update_free_locked(struct ttm_page_pool *pool, ...@@ -297,8 +297,10 @@ static void ttm_pool_update_free_locked(struct ttm_page_pool *pool,
* *
* @pool: to free the pages from * @pool: to free the pages from
* @free_all: If set to true will free all pages in pool * @free_all: If set to true will free all pages in pool
* @gfp: GFP flags.
**/ **/
static int ttm_page_pool_free(struct ttm_page_pool *pool, unsigned nr_free) static int ttm_page_pool_free(struct ttm_page_pool *pool, unsigned nr_free,
gfp_t gfp)
{ {
unsigned long irq_flags; unsigned long irq_flags;
struct page *p; struct page *p;
...@@ -309,8 +311,7 @@ static int ttm_page_pool_free(struct ttm_page_pool *pool, unsigned nr_free) ...@@ -309,8 +311,7 @@ static int ttm_page_pool_free(struct ttm_page_pool *pool, unsigned nr_free)
if (NUM_PAGES_TO_ALLOC < nr_free) if (NUM_PAGES_TO_ALLOC < nr_free)
npages_to_free = NUM_PAGES_TO_ALLOC; npages_to_free = NUM_PAGES_TO_ALLOC;
pages_to_free = kmalloc(npages_to_free * sizeof(struct page *), pages_to_free = kmalloc(npages_to_free * sizeof(struct page *), gfp);
GFP_KERNEL);
if (!pages_to_free) { if (!pages_to_free) {
pr_err("Failed to allocate memory for pool free operation\n"); pr_err("Failed to allocate memory for pool free operation\n");
return 0; return 0;
...@@ -382,9 +383,7 @@ static int ttm_page_pool_free(struct ttm_page_pool *pool, unsigned nr_free) ...@@ -382,9 +383,7 @@ static int ttm_page_pool_free(struct ttm_page_pool *pool, unsigned nr_free)
* *
* XXX: (dchinner) Deadlock warning! * XXX: (dchinner) Deadlock warning!
* *
* ttm_page_pool_free() does memory allocation using GFP_KERNEL. that means * We need to pass sc->gfp_mask to ttm_page_pool_free().
* this can deadlock when called a sc->gfp_mask that is not equal to
* GFP_KERNEL.
* *
* This code is crying out for a shrinker per pool.... * This code is crying out for a shrinker per pool....
*/ */
...@@ -408,7 +407,8 @@ ttm_pool_shrink_scan(struct shrinker *shrink, struct shrink_control *sc) ...@@ -408,7 +407,8 @@ ttm_pool_shrink_scan(struct shrinker *shrink, struct shrink_control *sc)
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,
sc->gfp_mask);
freed += nr_free - shrink_pages; freed += nr_free - shrink_pages;
} }
mutex_unlock(&lock); mutex_unlock(&lock);
...@@ -710,7 +710,7 @@ static void ttm_put_pages(struct page **pages, unsigned npages, int flags, ...@@ -710,7 +710,7 @@ static void ttm_put_pages(struct page **pages, unsigned npages, int flags,
} }
spin_unlock_irqrestore(&pool->lock, irq_flags); spin_unlock_irqrestore(&pool->lock, irq_flags);
if (npages) if (npages)
ttm_page_pool_free(pool, npages); ttm_page_pool_free(pool, npages, GFP_KERNEL);
} }
/* /*
...@@ -850,7 +850,8 @@ void ttm_page_alloc_fini(void) ...@@ -850,7 +850,8 @@ void ttm_page_alloc_fini(void)
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,
GFP_KERNEL);
kobject_put(&_manager->kobj); kobject_put(&_manager->kobj);
_manager = NULL; _manager = NULL;
......
...@@ -411,8 +411,10 @@ static void ttm_dma_page_put(struct dma_pool *pool, struct dma_page *d_page) ...@@ -411,8 +411,10 @@ static void ttm_dma_page_put(struct dma_pool *pool, struct dma_page *d_page)
* *
* @pool: to free the pages from * @pool: to free the pages from
* @nr_free: If set to true will free all pages in pool * @nr_free: If set to true will free all pages in pool
* @gfp: GFP flags.
**/ **/
static unsigned ttm_dma_page_pool_free(struct dma_pool *pool, unsigned nr_free) static unsigned ttm_dma_page_pool_free(struct dma_pool *pool, unsigned nr_free,
gfp_t gfp)
{ {
unsigned long irq_flags; unsigned long irq_flags;
struct dma_page *dma_p, *tmp; struct dma_page *dma_p, *tmp;
...@@ -430,8 +432,7 @@ static unsigned ttm_dma_page_pool_free(struct dma_pool *pool, unsigned nr_free) ...@@ -430,8 +432,7 @@ static unsigned ttm_dma_page_pool_free(struct dma_pool *pool, unsigned nr_free)
npages_to_free, nr_free); npages_to_free, nr_free);
} }
#endif #endif
pages_to_free = kmalloc(npages_to_free * sizeof(struct page *), pages_to_free = kmalloc(npages_to_free * sizeof(struct page *), gfp);
GFP_KERNEL);
if (!pages_to_free) { if (!pages_to_free) {
pr_err("%s: Failed to allocate memory for pool free operation\n", pr_err("%s: Failed to allocate memory for pool free operation\n",
...@@ -530,7 +531,7 @@ static void ttm_dma_free_pool(struct device *dev, enum pool_type type) ...@@ -530,7 +531,7 @@ static void ttm_dma_free_pool(struct device *dev, enum pool_type type)
if (pool->type != type) if (pool->type != type)
continue; continue;
/* Takes a spinlock.. */ /* Takes a spinlock.. */
ttm_dma_page_pool_free(pool, FREE_ALL_PAGES); ttm_dma_page_pool_free(pool, FREE_ALL_PAGES, GFP_KERNEL);
WARN_ON(((pool->npages_in_use + pool->npages_free) != 0)); WARN_ON(((pool->npages_in_use + pool->npages_free) != 0));
/* This code path is called after _all_ references to the /* This code path is called after _all_ references to the
* struct device has been dropped - so nobody should be * struct device has been dropped - so nobody should be
...@@ -983,7 +984,7 @@ void ttm_dma_unpopulate(struct ttm_dma_tt *ttm_dma, struct device *dev) ...@@ -983,7 +984,7 @@ void ttm_dma_unpopulate(struct ttm_dma_tt *ttm_dma, struct device *dev)
/* shrink pool if necessary (only on !is_cached pools)*/ /* shrink pool if necessary (only on !is_cached pools)*/
if (npages) if (npages)
ttm_dma_page_pool_free(pool, npages); ttm_dma_page_pool_free(pool, npages, GFP_KERNEL);
ttm->state = tt_unpopulated; ttm->state = tt_unpopulated;
} }
EXPORT_SYMBOL_GPL(ttm_dma_unpopulate); EXPORT_SYMBOL_GPL(ttm_dma_unpopulate);
...@@ -993,10 +994,7 @@ EXPORT_SYMBOL_GPL(ttm_dma_unpopulate); ...@@ -993,10 +994,7 @@ EXPORT_SYMBOL_GPL(ttm_dma_unpopulate);
* *
* XXX: (dchinner) Deadlock warning! * XXX: (dchinner) Deadlock warning!
* *
* ttm_dma_page_pool_free() does GFP_KERNEL memory allocation, and so attention * We need to pass sc->gfp_mask to ttm_dma_page_pool_free().
* needs to be paid to sc->gfp_mask to determine if this can be done or not.
* GFP_KERNEL memory allocation in a GFP_ATOMIC reclaim context woul dbe really
* bad.
* *
* I'm getting sadder as I hear more pathetical whimpers about needing per-pool * I'm getting sadder as I hear more pathetical whimpers about needing per-pool
* shrinkers * shrinkers
...@@ -1030,7 +1028,8 @@ ttm_dma_pool_shrink_scan(struct shrinker *shrink, struct shrink_control *sc) ...@@ -1030,7 +1028,8 @@ ttm_dma_pool_shrink_scan(struct shrinker *shrink, struct shrink_control *sc)
if (++idx < pool_offset) if (++idx < pool_offset)
continue; continue;
nr_free = shrink_pages; nr_free = shrink_pages;
shrink_pages = ttm_dma_page_pool_free(p->pool, nr_free); shrink_pages = ttm_dma_page_pool_free(p->pool, nr_free,
sc->gfp_mask);
freed += nr_free - shrink_pages; freed += nr_free - shrink_pages;
pr_debug("%s: (%s:%d) Asked to shrink %d, have %d more to go\n", pr_debug("%s: (%s:%d) Asked to shrink %d, have %d more to go\n",
......
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