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authorMarek Szyprowski <m.szyprowski@samsung.com>2012-11-07 15:37:07 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2012-12-17 10:37:44 -0800
commitead8c6b3697c9d45c16ecad17e5b4101573767f9 (patch)
tree5d79b88f792e5ac5a027ae1197bebc196e4cd530
parentd7ba8dff3e8afc83efe19c52ac7bd9ee2b65720b (diff)
downloadlinux-linaro-stable-ead8c6b3697c9d45c16ecad17e5b4101573767f9.tar.gz
mm: dmapool: use provided gfp flags for all dma_alloc_coherent() calls
commit 387870f2d6d679746020fa8e25ef786ff338dc98 upstream. 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--mm/dmapool.c31
1 files changed, 7 insertions, 24 deletions
diff --git a/mm/dmapool.c b/mm/dmapool.c
index c5ab33bca0a8..da1b0f0b8709 100644
--- a/mm/dmapool.c
+++ b/mm/dmapool.c
@@ -50,7 +50,6 @@ struct dma_pool { /* the pool */
size_t allocation;
size_t boundary;
char name[32];
- wait_queue_head_t waitq;
struct list_head pools;
};
@@ -62,8 +61,6 @@ struct dma_page { /* cacheable header for 'allocation' bytes */
unsigned int offset;
};
-#define POOL_TIMEOUT_JIFFIES ((100 /* msec */ * HZ) / 1000)
-
static DEFINE_MUTEX(pools_lock);
static ssize_t
@@ -172,7 +169,6 @@ struct dma_pool *dma_pool_create(const char *name, struct device *dev,
retval->size = size;
retval->boundary = boundary;
retval->allocation = allocation;
- init_waitqueue_head(&retval->waitq);
if (dev) {
int ret;
@@ -227,7 +223,6 @@ static struct dma_page *pool_alloc_page(struct dma_pool *pool, gfp_t mem_flags)
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 @@ void *dma_pool_alloc(struct dma_pool *pool, gfp_t mem_flags,
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 @@ void *dma_pool_alloc(struct dma_pool *pool, gfp_t mem_flags,
#ifdef DMAPOOL_DEBUG
memset(retval, POOL_POISON_ALLOCATED, pool->size);
#endif
- done:
spin_unlock_irqrestore(&pool->lock, flags);
return retval;
}
@@ -435,8 +420,6 @@ void dma_pool_free(struct dma_pool *pool, void *vaddr, dma_addr_t dma)
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);