From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Wed, 13 Sep 2006 10:32:49 -0700 (PDT) From: Christoph Lameter Subject: Re: why inode creation with GFP_HIGHUSER? In-Reply-To: <34a75100609130754t24b8bde6xcebda4f0684c51cb@mail.gmail.com> Message-ID: References: <34a75100609130734m68729bdaj30258c10edfa7947@mail.gmail.com> <34a75100609130754t24b8bde6xcebda4f0684c51cb@mail.gmail.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org Return-Path: To: girish Cc: Linux-MM@kvack.org List-ID: On Wed, 13 Sep 2006, girish wrote: > 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? GFP_HIGHUSER allows the use of HIGH memory but it does not require it. If the system has no HIGHMEM then we will just use regular memory. > 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? I am not sure what you intend to do. The kernel already avoids mapping highmem pages into the kernel as much as possible. -- 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