From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758262Ab3APQDy (ORCPT ); Wed, 16 Jan 2013 11:03:54 -0500 Received: from youngberry.canonical.com ([91.189.89.112]:36130 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758216Ab3APQDw (ORCPT ); Wed, 16 Jan 2013 11:03:52 -0500 From: Herton Ronaldo Krzesinski To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Marek Szyprowski , Herton Ronaldo Krzesinski Subject: [PATCH 100/222] mm: dmapool: use provided gfp flags for all dma_alloc_coherent() calls Date: Wed, 16 Jan 2013 13:55:00 -0200 Message-Id: <1358351822-7675-101-git-send-email-herton.krzesinski@canonical.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1358351822-7675-1-git-send-email-herton.krzesinski@canonical.com> References: <1358351822-7675-1-git-send-email-herton.krzesinski@canonical.com> X-Extended-Stable: 3.5 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.5.7.3 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Marek Szyprowski 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 Reported-by: Thomas Petazzoni Signed-off-by: Marek Szyprowski Tested-by: Andrew Lunn Tested-by: Soeren Moch Signed-off-by: Herton Ronaldo Krzesinski --- mm/dmapool.c | 31 +++++++------------------------ 1 file changed, 7 insertions(+), 24 deletions(-) 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 @@ 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); -- 1.7.9.5