From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dave Hansen Subject: Re: [PATCHv4 26/39] ramfs: enable transparent huge page cache Date: Tue, 21 May 2013 15:43:44 -0700 Message-ID: <519BF8A0.5000103@sr71.net> References: <1368321816-17719-1-git-send-email-kirill.shutemov@linux.intel.com> <1368321816-17719-27-git-send-email-kirill.shutemov@linux.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: Andrea Arcangeli , Andrew Morton , Al Viro , Hugh Dickins , Wu Fengguang , Jan Kara , Mel Gorman , linux-mm@kvack.org, Andi Kleen , Matthew Wilcox , "Kirill A. Shutemov" , Hillf Danton , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org To: "Kirill A. Shutemov" Return-path: In-Reply-To: <1368321816-17719-27-git-send-email-kirill.shutemov@linux.intel.com> Sender: owner-linux-mm@kvack.org List-Id: linux-fsdevel.vger.kernel.org On 05/11/2013 06:23 PM, Kirill A. Shutemov wrote: > From: "Kirill A. Shutemov" > > ramfs is the most simple fs from page cache point of view. Let's start > transparent huge page cache enabling here. > > For now we allocate only non-movable huge page. ramfs pages cannot be > moved yet. > > Signed-off-by: Kirill A. Shutemov > --- > fs/ramfs/inode.c | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) > > diff --git a/fs/ramfs/inode.c b/fs/ramfs/inode.c > index c24f1e1..54d69c7 100644 > --- a/fs/ramfs/inode.c > +++ b/fs/ramfs/inode.c > @@ -61,7 +61,11 @@ struct inode *ramfs_get_inode(struct super_block *sb, > inode_init_owner(inode, dir, mode); > inode->i_mapping->a_ops = &ramfs_aops; > inode->i_mapping->backing_dev_info = &ramfs_backing_dev_info; > - mapping_set_gfp_mask(inode->i_mapping, GFP_HIGHUSER); > + /* > + * TODO: make ramfs pages movable > + */ > + mapping_set_gfp_mask(inode->i_mapping, > + GFP_TRANSHUGE & ~__GFP_MOVABLE); So, before these patches, ramfs was movable. Now, even on architectures or configurations that have no chance of using THP-pagecache, ramfs pages are no longer movable. Right? That seems unfortunate, and probably not something we want to intentionally merge in this state. Worst-case, we should at least make sure the pages remain movable in configurations where THP-pagecache is unavailable. -- 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