From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ingo Molnar Subject: Re: [PATCH 06/20] early_res: seperate common memmap func from e820.c to fw_memmap.cy Date: Tue, 23 Mar 2010 09:02:52 +0100 Message-ID: <20100323080252.GA4848@elte.hu> References: <20100322193720.GA2844@elte.hu> <4BA7CE1B.9070109@kernel.org> <4BA7EE72.7000507@kernel.org> <4BA80019.5000900@kernel.org> <4BA813A4.1010704@kernel.org> <4BA8594F.8090205@kernel.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mx2.mail.elte.hu ([157.181.151.9]:35464 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751721Ab0CWIDJ (ORCPT ); Tue, 23 Mar 2010 04:03:09 -0400 Content-Disposition: inline In-Reply-To: <4BA8594F.8090205@kernel.org> Sender: linux-arch-owner@vger.kernel.org List-ID: To: Yinghai Lu Cc: Thomas Gleixner , David Miller , Andrew Morton , Linus Torvalds , benh@kernel.crashing.org, hpa@zytor.com, jbarnes@virtuousgeek.org, ebiederm@xmission.com, linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org * Yinghai Lu wrote: > please check > > [PATCH 01/20] x86: add find_e820_area_node > > > [RFC PATCH] x86: use lmb to replace early_res > > still keep kernel/early_res.c for the extension. > > should move those file to lib/lmb.c later? > > Signed-off-by: Yinghai Lu > > --- > arch/x86/Kconfig | 1 > arch/x86/include/asm/e820.h | 38 +- > arch/x86/include/asm/lmb.h | 8 > arch/x86/kernel/e820.c | 163 +---------- > arch/x86/kernel/head.c | 2 > arch/x86/kernel/head32.c | 4 > arch/x86/kernel/head64.c | 2 > arch/x86/kernel/setup.c | 2 > arch/x86/kernel/setup_percpu.c | 6 > include/linux/early_res.h | 9 > include/linux/lmb.h | 5 > kernel/early_res.c | 594 ++++++++++++++++------------------------- > lib/lmb.c | 9 > mm/page_alloc.c | 2 > mm/sparse-vmemmap.c | 4 > 15 files changed, 321 insertions(+), 528 deletions(-) That looks like a very promising direction! There's several things to do to make the approach fully clean: 1) I think we want to shape this as a series of simpler (and bisectable) patches. 2) I think we also need to concentrate the changes back into LMB: > Index: linux-2.6/include/linux/early_res.h > =================================================================== > --- linux-2.6.orig/include/linux/early_res.h > +++ linux-2.6/include/linux/early_res.h > @@ -5,15 +5,18 @@ > extern void reserve_early(u64 start, u64 end, char *name); > extern void reserve_early_overlap_ok(u64 start, u64 end, char *name); > extern void free_early(u64 start, u64 end); > -void free_early_partial(u64 start, u64 end); > extern void early_res_to_bootmem(u64 start, u64 end); > > -void reserve_early_without_check(u64 start, u64 end, char *name); > u64 find_early_area(u64 ei_start, u64 ei_last, u64 start, u64 end, > u64 size, u64 align); > u64 find_early_area_size(u64 ei_start, u64 ei_last, u64 start, > u64 *sizep, u64 align); > -u64 find_fw_memmap_area(u64 start, u64 end, u64 size, u64 align); > +u64 find_lmb_area(u64 start, u64 end, u64 size, u64 align); > +u64 find_lmb_area_size(u64 start, u64 *sizep, u64 align); > +u64 find_lmb_area_node(int nid, u64 start, u64 end, u64 size, u64 align); > +void lmb_register_active_regions(int nid, unsigned long start_pfn, > + unsigned long last_pfn); > +u64 lmb_hole_size(u64 start, u64 end); > u64 get_max_mapped(void); > #include > int get_free_all_memory_range(struct range **rangep, int nodeid); those new lmb_*() APIs should go into lmb.h. 3) Furthermore, i think all of early_res.c should move into lmb.c as well and we should eliminate kernel/early_res.c. early_res.h will go away as well and all the new APIs will be in lmb.h. 4) Also, we should move lib/lmb.c to mm/lmb.c, as now it's not just some optional library but _the_ main early-reserve memory subsystem used by the biggest Linux architectures. 5) Could we perhaps also try to eliminate e820_*() method uses in arch/x86/, and replace them by lmb_*() API uses? (that too should be a step by step method, for bisectability) > +++ linux-2.6/include/linux/lmb.h > @@ -26,7 +26,8 @@ struct lmb_property { > struct lmb_region { > unsigned long cnt; > u64 size; > - struct lmb_property region[MAX_LMB_REGIONS+1]; > + struct lmb_property *region; > + unsigned long region_array_size; > }; I suspect this should keep current LMB architectures still working, right? Ingo