mm: dmapool: use provided gfp flags for all dma_alloc_coherent() calls
dmapool always calls dma_alloc_coherent() with GFP_ATOMIC flag,
regardless the flags provided by the caller. This causes excessive
pruning of emergency memory pools without any good reason. Additionaly,
on ARM architecture any driver which is using dmapools will sooner or
later trigger the following error:
"ERROR: 256 KiB atomic DMA coherent pool is too small!
Please increase it with coherent_pool= kernel parameter!".
Increasing the coherent pool size usually doesn't help much and only
delays such error, because all GFP_ATOMIC DMA allocations are always
served from the special, very limited memory pool.
This patch changes the dmapool code to correctly use gfp flags provided
by the dmapool caller.
Reported-by: Soeren Moch <smoch@web.de>
Reported-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Tested-by: Andrew Lunn <andrew@lunn.ch>
Tested-by: Soeren Moch <smoch@web.de>
Cc: stable@vger.kernel.org
diff --git a/mm/dmapool.c b/mm/dmapool.c
index c5ab33b..da1b0f0 100644
--- a/mm/dmapool.c
+++ b/mm/dmapool.c
@@ -50,7 +50,6 @@
size_t allocation;
size_t boundary;
char name[32];
- wait_queue_head_t waitq;
struct list_head pools;
};
@@ -62,8 +61,6 @@
unsigned int offset;
};
-#define POOL_TIMEOUT_JIFFIES ((100 /* msec */ * HZ) / 1000)
-
static DEFINE_MUTEX(pools_lock);
static ssize_t
@@ -172,7 +169,6 @@
retval->size = size;
retval->boundary = boundary;
retval->allocation = allocation;
- init_waitqueue_head(&retval->waitq);
if (dev) {
int ret;
@@ -227,7 +223,6 @@
memset(page->vaddr, POOL_POISON_FREED, pool->allocation);
#endif
pool_initialise_page(pool, page);
- list_add(&page->page_list, &pool->page_list);
page->in_use = 0;
page->offset = 0;
} else {
@@ -315,30 +310,21 @@
might_sleep_if(mem_flags & __GFP_WAIT);
spin_lock_irqsave(&pool->lock, flags);
- restart:
list_for_each_entry(page, &pool->page_list, page_list) {
if (page->offset < pool->allocation)
goto ready;
}
- page = pool_alloc_page(pool, GFP_ATOMIC);
- if (!page) {
- if (mem_flags & __GFP_WAIT) {
- DECLARE_WAITQUEUE(wait, current);
- __set_current_state(TASK_UNINTERRUPTIBLE);
- __add_wait_queue(&pool->waitq, &wait);
- spin_unlock_irqrestore(&pool->lock, flags);
+ /* pool_alloc_page() might sleep, so temporarily drop &pool->lock */
+ spin_unlock_irqrestore(&pool->lock, flags);
- schedule_timeout(POOL_TIMEOUT_JIFFIES);
+ page = pool_alloc_page(pool, mem_flags);
+ if (!page)
+ return NULL;
- spin_lock_irqsave(&pool->lock, flags);
- __remove_wait_queue(&pool->waitq, &wait);
- goto restart;
- }
- retval = NULL;
- goto done;
- }
+ spin_lock_irqsave(&pool->lock, flags);
+ list_add(&page->page_list, &pool->page_list);
ready:
page->in_use++;
offset = page->offset;
@@ -348,7 +334,6 @@
#ifdef DMAPOOL_DEBUG
memset(retval, POOL_POISON_ALLOCATED, pool->size);
#endif
- done:
spin_unlock_irqrestore(&pool->lock, flags);
return retval;
}
@@ -435,8 +420,6 @@
page->in_use--;
*(int *)vaddr = page->offset;
page->offset = offset;
- if (waitqueue_active(&pool->waitq))
- wake_up_locked(&pool->waitq);
/*
* Resist a temptation to do
* if (!is_page_busy(page)) pool_free_page(pool, page);