From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752206AbaEWMN0 (ORCPT ); Fri, 23 May 2014 08:13:26 -0400 Received: from mail-ee0-f43.google.com ([74.125.83.43]:40569 "EHLO mail-ee0-f43.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751238AbaEWMNY (ORCPT ); Fri, 23 May 2014 08:13:24 -0400 From: David Herrmann To: linux-kernel@vger.kernel.org Cc: Andrew Morton , Wanpeng Li , Naoya Horiguchi , David Rientjes , Vladimir Cernov , linux-mm@kvack.org, David Herrmann Subject: [PATCH] mm/madvise: fix WILLNEED on SHM/ANON to actually do something Date: Fri, 23 May 2014 14:12:15 +0200 Message-Id: <1400847135-22291-1-git-send-email-dh.herrmann@gmail.com> X-Mailer: git-send-email 1.9.3 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Currently, madvise(MADV_WILLNEED) on shmem with swap enabled is a no-op. Problem is, we use find_get_page() to lookup shmem pages in the given range. However, what we're actually interested in is swapped-out pages. Therefore, our current code is a no-op: page = find_get_page(mapping, index); if (!radix_tree_exceptional_entry(page)) bail-out; find_get_page() never returns exceptional entries. Fix this by using find_get_entry(). This was probably meant to be used right from the beginning. Signed-off-by: David Herrmann --- mm/madvise.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/madvise.c b/mm/madvise.c index 539eeb9..a402f8f 100644 --- a/mm/madvise.c +++ b/mm/madvise.c @@ -195,7 +195,7 @@ static void force_shm_swapin_readahead(struct vm_area_struct *vma, for (; start < end; start += PAGE_SIZE) { index = ((start - vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff; - page = find_get_page(mapping, index); + page = find_get_entry(mapping, index); if (!radix_tree_exceptional_entry(page)) { if (page) page_cache_release(page); -- 1.9.3