From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754466AbcEERJm (ORCPT ); Thu, 5 May 2016 13:09:42 -0400 Received: from mail-pa0-f43.google.com ([209.85.220.43]:35017 "EHLO mail-pa0-f43.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750865AbcEERJl (ORCPT ); Thu, 5 May 2016 13:09:41 -0400 Subject: Re: [PATCH] ION: Sys_heap: Makes ion buffer always alloc from page pool To: Chen Feng , yudongbin@hisilicon.com, gregkh@linuxfoundation.org, arve@android.com, riandrews@android.com, paul.gortmaker@windriver.com, bmarsh94@gmail.com, devel@driverdev.osuosl.org, linux-kernel@vger.kernel.org References: <1462418868-40454-1-git-send-email-puck.chen@hisilicon.com> Cc: suzhuangluan@hisilicon.com, dan.zhao@hisilicon.com, zhaojunmin@huawei.com, xuyiping@hisilicon.com, puck.chen@foxmail.com From: Laura Abbott Message-ID: Date: Thu, 5 May 2016 10:09:37 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.0 MIME-Version: 1.0 In-Reply-To: <1462418868-40454-1-git-send-email-puck.chen@hisilicon.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 05/04/2016 08:27 PM, Chen Feng wrote: > Makes the ion buffer always alloced from page pool, no matter > it's cached or not. In this way, it can improve the efficiency > of it. > > Currently, there is no difference from cached or non-cached buffer > for the page pool. The advantage of the uncached pool was that the pages in the pool were always clean in the cache. This is lost here with the addition of cached pages to the same pool as uncached pages I agree the cache path could benefit from pooling but we need to keep the caching model consistent. > > Signed-off-by: Chen Feng > --- > drivers/staging/android/ion/ion_system_heap.c | 19 ++----------------- > 1 file changed, 2 insertions(+), 17 deletions(-) > > diff --git a/drivers/staging/android/ion/ion_system_heap.c b/drivers/staging/android/ion/ion_system_heap.c > index b69dfc7..caf11fc 100644 > --- a/drivers/staging/android/ion/ion_system_heap.c > +++ b/drivers/staging/android/ion/ion_system_heap.c > @@ -56,24 +56,10 @@ static struct page *alloc_buffer_page(struct ion_system_heap *heap, > struct ion_buffer *buffer, > unsigned long order) > { > - bool cached = ion_buffer_cached(buffer); > struct ion_page_pool *pool = heap->pools[order_to_index(order)]; > struct page *page; > > - if (!cached) { > - page = ion_page_pool_alloc(pool); > - } else { > - gfp_t gfp_flags = low_order_gfp_flags; > - > - if (order > 4) > - gfp_flags = high_order_gfp_flags; > - page = alloc_pages(gfp_flags | __GFP_COMP, order); > - if (!page) > - return NULL; > - ion_pages_sync_for_device(NULL, page, PAGE_SIZE << order, > - DMA_BIDIRECTIONAL); > - } > - > + page = ion_page_pool_alloc(pool); > return page; > } > > @@ -81,9 +67,8 @@ static void free_buffer_page(struct ion_system_heap *heap, > struct ion_buffer *buffer, struct page *page) > { > unsigned int order = compound_order(page); > - bool cached = ion_buffer_cached(buffer); > > - if (!cached && !(buffer->private_flags & ION_PRIV_FLAG_SHRINKER_FREE)) { > + if (!(buffer->private_flags & ION_PRIV_FLAG_SHRINKER_FREE)) { > struct ion_page_pool *pool = heap->pools[order_to_index(order)]; > > ion_page_pool_free(pool, page); >