With one trivial change (taking the lock slightly earlier on wakeup from schedule), all uses of the waitq are under the pool lock, so we can use the locked (or __) versions of the wait queue functions, and avoid the extra spinlock.
Signed-off-by: Matthew Wilcox <[EMAIL PROTECTED]> --- mm/dmapool.c | 9 +++++---- 1 files changed, 5 insertions(+), 4 deletions(-) diff --git a/mm/dmapool.c b/mm/dmapool.c index 6201371..a359b5e 100644 --- a/mm/dmapool.c +++ b/mm/dmapool.c @@ -273,8 +273,8 @@ void *dma_pool_alloc(struct dma_pool *pool, gfp_t mem_flags, size_t offset; void *retval; - restart: spin_lock_irqsave(&pool->lock, flags); + restart: list_for_each_entry(page, &pool->page_list, page_list) { int i; /* only cachable accesses here ... */ @@ -296,12 +296,13 @@ void *dma_pool_alloc(struct dma_pool *pool, gfp_t mem_flags, DECLARE_WAITQUEUE(wait, current); current->state = TASK_INTERRUPTIBLE; - add_wait_queue(&pool->waitq, &wait); + __add_wait_queue(&pool->waitq, &wait); spin_unlock_irqrestore(&pool->lock, flags); schedule_timeout(POOL_TIMEOUT_JIFFIES); - remove_wait_queue(&pool->waitq, &wait); + spin_lock_irqsave(&pool->lock, flags); + __remove_wait_queue(&pool->waitq, &wait); goto restart; } retval = NULL; @@ -401,7 +402,7 @@ void dma_pool_free(struct dma_pool *pool, void *vaddr, dma_addr_t dma) page->in_use--; set_bit(block, &page->bitmap[map]); if (waitqueue_active(&pool->waitq)) - wake_up(&pool->waitq); + wake_up_locked(&pool->waitq); /* * Resist a temptation to do * if (!is_page_busy(bpp, page->bitmap)) pool_free_page(pool, page); -- 1.5.3.1 - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/