[PATCH] mm: dmapool: use provided gfp flags for all dma_alloc_coherent() calls
From: Jason Cooper <hidden>
Date: 2012-11-19 00:19:11
Also in:
linux-mm, lkml
Marek, I've added the maintainers for mm/*. Hopefully they can let us know if this is good for v3.8... thx, Jason. On Thu, Nov 08, 2012 at 07:38:57AM +0100, Marek Szyprowski wrote:
quoted hunk ↗ jump to hunk
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. This patch changes the code to correctly use gfp flags provided by the dmapool caller. This should solve the dmapool usage on ARM architecture, where GFP_ATOMIC DMA allocations can be served only from the special, very limited memory pool. Reported-by: Soren Moch <redacted> Reported-by: Thomas Petazzoni <redacted> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> --- mm/dmapool.c | 27 +++++++-------------------- 1 file changed, 7 insertions(+), 20 deletions(-)diff --git a/mm/dmapool.c b/mm/dmapool.c index c5ab33b..86de9b2 100644 --- a/mm/dmapool.c +++ b/mm/dmapool.c@@ -62,8 +62,6 @@ 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@@ -227,7 +225,6 @@ 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 +312,21 @@ 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 +336,6 @@ 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; }-- 1.7.9.5 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel at lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel