From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx124.postini.com [74.125.245.124]) by kanga.kvack.org (Postfix) with SMTP id 8613E6B000D for ; Tue, 5 Mar 2013 01:59:03 -0500 (EST) Received: from epcpsbgm2.samsung.com (epcpsbgm2 [203.254.230.27]) by mailout3.samsung.com (Oracle Communications Messaging Server 7u4-24.01(7.0.4.24.0) 64bit (built Nov 17 2011)) with ESMTP id <0MJ6003GFE1TOQR0@mailout3.samsung.com> for linux-mm@kvack.org; Tue, 05 Mar 2013 15:58:46 +0900 (KST) From: Marek Szyprowski Subject: [RFC/PATCH 5/5] media: vb2: use FOLL_DURABLE and __get_user_pages() to avoid CMA migration issues Date: Tue, 05 Mar 2013 07:57:59 +0100 Message-id: <1362466679-17111-6-git-send-email-m.szyprowski@samsung.com> In-reply-to: <1362466679-17111-1-git-send-email-m.szyprowski@samsung.com> References: <1362466679-17111-1-git-send-email-m.szyprowski@samsung.com> Sender: owner-linux-mm@kvack.org List-ID: To: linux-mm@kvack.org, linaro-mm-sig@lists.linaro.org, linux-kernel@vger.kernel.org Cc: Marek Szyprowski , Kyungmin Park , Arnd Bergmann , Andrew Morton , Mel Gorman , Michal Nazarewicz , Minchan Kim , Bartlomiej Zolnierkiewicz V4L2 devices usually grab additional references to user pages for a very long period of time, what causes permanent migration failures if the given page has been allocated from CMA pageblock. By setting FOLL_DURABLE flag, videobuf2 will instruct __get_user_pages() to migrate user pages out of CMA pageblocks before blocking them with an additional reference. Signed-off-by: Marek Szyprowski Signed-off-by: Kyungmin Park --- drivers/media/v4l2-core/videobuf2-dma-contig.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/media/v4l2-core/videobuf2-dma-contig.c b/drivers/media/v4l2-core/videobuf2-dma-contig.c index 10beaee..70649ab 100644 --- a/drivers/media/v4l2-core/videobuf2-dma-contig.c +++ b/drivers/media/v4l2-core/videobuf2-dma-contig.c @@ -443,9 +443,13 @@ static int vb2_dc_get_user_pages(unsigned long start, struct page **pages, } } else { int n; + int flags = FOLL_TOUCH | FOLL_GET | FOLL_FORCE | FOLL_DURABLE; - n = get_user_pages(current, current->mm, start & PAGE_MASK, - n_pages, write, 1, pages, NULL); + if (write) + flags |= FOLL_WRITE; + + n = __get_user_pages(current, current->mm, start & PAGE_MASK, + n_pages, flags, pages, NULL, NULL); /* negative error means that no page was pinned */ n = max(n, 0); if (n != n_pages) { -- 1.7.9.5 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org