RE: [PATCHv2, RFC 20/30] ramfs: enable transparent huge page cache

From: Kirill A. Shutemov
Date: Tue Apr 02 2013 - 12:26:33 EST


Kirill A. Shutemov wrote:
> From: "Kirill A. Shutemov" <kirill.shutemov@xxxxxxxxxxxxxxx>
>
> 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. It's not yet clear if
> movable page is safe here and what need to be done to make it safe.
>
> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
> ---
> 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..da30b4f 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: what should be done to make movable safe?
> + */
> + mapping_set_gfp_mask(inode->i_mapping,
> + GFP_TRANSHUGE & ~__GFP_MOVABLE);

Hugh, I've found old thread with the reason why we have GFP_HIGHUSER here, not
GFP_HIGHUSER_MOVABLE:

http://lkml.org/lkml/2006/11/27/156

It seems the origin reason is not longer valid, correct?

--
Kirill A. Shutemov
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