From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mel Gorman Message-Id: <20060412232036.18862.84118.sendpatchset@skynet> Subject: [PATCH 0/7] [RFC] Sizing zones and holes in an architecture independent manner V2 Date: Thu, 13 Apr 2006 00:20:36 +0100 (IST) Sender: owner-linux-mm@kvack.org Return-Path: To: davej@codemonkey.org.uk, tony.luck@intel.com, linuxppc-dev@ozlabs.org, linux-kernel@vger.kernel.org, bob.picco@hp.com, ak@suse.de, linux-mm@kvack.org Cc: Mel Gorman List-ID: This is V2 of the patchset. They have been boot tested on x86, ppc64 and x86_64 but I still need to do a double check that zones are the same size before and after the patch on all arches. IA64 passed a basic compile-test. a driver program that fed in the values generated by IA64 to add_active_range(), zone_present_pages_in_node() and zone_absent_pages_in_node() seemed to generate expected values. Changelog since V1 o Correctly convert virtual and physical addresses to PFNs on ia64 o Correctly convert physical addresses to PFN on older ppc o When add_active_range() is called with overlapping pfn ranges, merge them o When a zone boundary occurs within a memory hole, account correctly o Minor whitespace damage cleanup o Debugging patch temporarily included At a basic level, architectures define structures to record where active ranges of page frames are located. Once located, the code to calculate zone sizes and holes in each architecture is very similar. Some of this zone and hole sizing code is difficult to read for no good reason. This set of patches eliminates the similar-looking architecture-specific code. The patches introduce a mechanism where architectures register where the active ranges of page frames are with add_active_range(). When all areas have been discovered, free_area_init_nodes() is called to initialise the pgdat and zones. The zone sizes and holes are then calculated in an architecture independent manner. Patch 1 introduces the mechanism for registering and initialising PFN ranges Patch 2 changes ppc to use the mechanism - 128 arch-specific LOC removed Patch 3 changes x86 to use the mechanism - 150 arch-specific LOC removed Patch 4 changes x86_64 to use the mechanism - 34 arch-specific LOC removed Patch 5 changes ia64 to use the mechanism - 57 arch-specific LOC removed At this point, there is a net reduction of 27 lines of code and the arch-independent code is a lot easier to read in comparison to some of the arch-specific stuff, particularly in arch/i386/ . For Patch 6, it was also noted that page_alloc.c has a *lot* of initialisation code which makes the file harder to read than it needs to be. Patch 6 creates a new file mem_init.c and moves a lot of initialisation code from page_alloc.c to it. After the patch is applied, there is still a net reduction of 6 lines of code. The patches have been successfully boot tested on o x86, flatmem o x86, NUMAQ o PPC64, NUMA o PPC64, CONFIG_NUMA=n o x86_64, NUMA with SRAT The patches have been compile tested for ia64 for flatmem and sparsemem configurations. At attempt was made to boot test on an ancient RS/6000 but the vanilla kernel does not boot so I have to investigate there. The net reduction seems small but the big benefit of this set of patches is the reduction of 380 lines of architecture-specific code, some of which is very hairy. There should be a greater net reduction when other architectures use the same mechanisms for zone and hole sizing but I lack the hardware to test on. Comments? Additional credit; Dave Hansen for the initial suggestion and comments on early patches Andy Whitcroft for reviewing early versions and catching numerous errors Tony Luck and Bob Picco for testing and debugging on IA64 arch/i386/Kconfig | 8 arch/i386/kernel/setup.c | 19 arch/i386/kernel/srat.c | 98 ---- arch/i386/mm/discontig.c | 59 -- arch/ia64/Kconfig | 3 arch/ia64/mm/contig.c | 60 -- arch/ia64/mm/discontig.c | 41 - arch/ia64/mm/init.c | 12 arch/powerpc/Kconfig | 13 arch/powerpc/mm/mem.c | 53 -- arch/powerpc/mm/numa.c | 157 ------ arch/ppc/Kconfig | 3 arch/ppc/mm/init.c | 26 - arch/x86_64/Kconfig | 3 arch/x86_64/kernel/e820.c | 19 arch/x86_64/mm/init.c | 60 -- arch/x86_64/mm/numa.c | 15 include/asm-ia64/meminit.h | 1 include/asm-x86_64/e820.h | 1 include/asm-x86_64/proto.h | 2 include/linux/mm.h | 14 include/linux/mmzone.h | 15 mm/Makefile | 2 mm/mem_init.c | 1014 +++++++++++++++++++++++++++++++++++++++++++++ mm/page_alloc.c | 678 ------------------------------ 25 files changed, 1185 insertions(+), 1191 deletions(-) -- -- Mel Gorman Part-time Phd Student Linux Technology Center University of Limerick IBM Dublin Software Lab -- 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