From mboxrd@z Thu Jan 1 00:00:00 1970 Received: by py-out-1112.google.com with SMTP id c59so3084596pyc for ; Wed, 13 Sep 2006 07:54:20 -0700 (PDT) Message-ID: <34a75100609130754t24b8bde6xcebda4f0684c51cb@mail.gmail.com> Date: Wed, 13 Sep 2006 23:54:19 +0900 From: girish Subject: why inode creation with GFP_HIGHUSER? In-Reply-To: <34a75100609130734m68729bdaj30258c10edfa7947@mail.gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <34a75100609130734m68729bdaj30258c10edfa7947@mail.gmail.com> Sender: owner-linux-mm@kvack.org Return-Path: To: Linux-MM@kvack.org List-ID: [hello world. my first mail linux-mm] i am following a trail of high-memory initialization on a MIPS32 based system. i came across inode initialization. i'd like to know why page(s) for inodes are allocated with GFP_HIGHUSER & not with GFP_USER mask? is there any particular need that the address_space be set with GFP_HIGHUSER flag? (ref: http://lxr.free-electrons.com/source/fs/inode.c#150) (ref: http://lxr.free-electrons.com/source/include/linux/pagemap.h#031) i intend to allocate highmem pages strictly to user processes. my idea is to completely avoid kernel mapping for these pages. so, as a dirty hack - i changed mapping_set_gfp_mask function not to honor __GFP_HIGHMEM zone selector if __GFP_IO | __GFP_FS are set. in short i replace GFP_HIGHUSER with GFP_USER mask. with this change the kernel comes to life. but i am still confused about the effect of this change on system, that i am yet to see? any help in this regards will be greatly appreciated. thanks in advance. girish. -- 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