Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753153Ab0GNIOi (ORCPT ); Wed, 14 Jul 2010 04:14:38 -0400 Received: from fgwmail7.fujitsu.co.jp ([192.51.44.37]:44543 "EHLO fgwmail7.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752702Ab0GNIOf (ORCPT ); Wed, 14 Jul 2010 04:14:35 -0400 X-SecurityPolicyCheck-FJ: OK by FujitsuOutboundMailChecker v1.3.1 Date: Wed, 14 Jul 2010 17:09:48 +0900 From: KAMEZAWA Hiroyuki To: Kukjin Kim Cc: "'Minchan Kim'" , "'Dave Hansen'" , "'Johannes Weiner'" , linux@arm.linux.org.uk, "'Yinghai Lu'" , "'H. Peter Anvin'" , "'Andrew Morton'" , "'Shaohua Li'" , "'Yakui Zhao'" , linux-kernel@vger.kernel.org, linux-mm@kvack.org, arm-kernel@lists.infradead.org, "'Mel Gorman'" Subject: Re: [RFC] Tight check of pfn_valid on sparsemem Message-Id: <20100714170948.3eac9132.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: <000e01cb2329$3d8c5770$b8a50650$%kim@samsung.com> References: <20100712155348.GA2815@barrios-desktop> <20100713093006.GB14504@cmpxchg.org> <20100713154335.GB2815@barrios-desktop> <1279038933.10995.9.camel@nimitz> <20100713164423.GC2815@barrios-desktop> <20100714092301.69e7e628.kamezawa.hiroyu@jp.fujitsu.com> <000e01cb2329$3d8c5770$b8a50650$%kim@samsung.com> Organization: FUJITSU Co. LTD. X-Mailer: Sylpheed 3.0.3 (GTK+ 2.10.14; i686-pc-mingw32) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6313 Lines: 198 On Wed, 14 Jul 2010 16:50:25 +0900 Kukjin Kim wrote: > KAMEZAWA Hiroyuki wrote: > > > > On Wed, 14 Jul 2010 01:44:23 +0900 > > Minchan Kim wrote: > > > > > > If you _really_ can't make the section size smaller, and the vast > > > > majority of the sections are fully populated, you could hack something > > > > in. We could, for instance, have a global list that's mostly readonly > > > > which tells you which sections need to be have their sizes closely > > > > inspected. That would work OK if, for instance, you only needed to > > > > check a couple of memory sections in the system. It'll start to suck > if > > > > you made the lists very long. > > > > > > Thanks for advise. As I say, I hope Russell accept 16M section. > > > > Hi, > > Thanks for your inputs. > > > > It seems what I needed was good sleep.... > > How about this if 16M section is not acceptable ? > > > > == NOT TESTED AT ALL, EVEN NOT COMPILED == > > Yeah... > > Couldn't build with s5pv210_defconfig when used mmotm tree, > And couldn't apply your patch against latest mainline 35-rc5. > > Could you please remake your patch against mainline 35-rc5? > Or...please let me know how I can test on my board(smdkv210). > Ahh..how brave you are. my patch was against mmotm-07-01. select SPARSEMEM_HAS_PIT in config. (in menuconfig it will appear under Processor type and features.) This is a fixed one, maybe mm/sparce.o can be compiled. At least, arch-generic part is compiled. (This config should be selected automatically via arm's config. this patch is just for test.) Signed-off-by: KAMEZAWA hiroyuki --- arch/arm/mm/init.c | 11 ++++++++++- include/linux/mmzone.h | 19 ++++++++++++++++++- mm/Kconfig | 5 +++++ mm/sparse.c | 38 +++++++++++++++++++++++++++++++++++++- 4 files changed, 70 insertions(+), 3 deletions(-) Index: mmotm-2.6.35-0701/include/linux/mmzone.h =================================================================== --- mmotm-2.6.35-0701.orig/include/linux/mmzone.h +++ mmotm-2.6.35-0701/include/linux/mmzone.h @@ -1047,11 +1047,28 @@ static inline struct mem_section *__pfn_ return __nr_to_section(pfn_to_section_nr(pfn)); } +#ifdef CONFIG_SPARSEMEM_HAS_PIT +void mark_memmap_pit(unsigned long start, unsigned long end, bool valid); +static inline int page_valid(struct mem_section *ms, unsigned long pfn) +{ + struct page *page = pfn_to_page(pfn); + struct page *__pg = virt_to_page(page); + return __pg->private == ms; +} +#else +static inline int page_valid(struct mem_section *ms, unsigned long pfn) +{ + return 1; +} +#endif + static inline int pfn_valid(unsigned long pfn) { + struct mem_section *ms; if (pfn_to_section_nr(pfn) >= NR_MEM_SECTIONS) return 0; - return valid_section(__nr_to_section(pfn_to_section_nr(pfn))); + ms = __nr_to_section(pfn_to_section_nr(pfn)); + return valid_section(ms) && page_valid(ms, pfn); } static inline int pfn_present(unsigned long pfn) Index: mmotm-2.6.35-0701/mm/sparse.c =================================================================== --- mmotm-2.6.35-0701.orig/mm/sparse.c +++ mmotm-2.6.35-0701/mm/sparse.c @@ -13,7 +13,6 @@ #include #include #include - /* * Permanent SPARSEMEM data: * @@ -615,6 +614,43 @@ void __init sparse_init(void) free_bootmem(__pa(usemap_map), size); } +#ifdef CONFIG_SPARSEMEM_HAS_PIT +/* + * Fill memmap's pg->private with a pointer to mem_section. + * pfn_valid() will check this later. (see include/linux/mmzone.h) + * The caller should call + * mark_memmap_pit(start, end, true) # for all allocated mem_map + * and, after that, + * mark_memmap_pit(start, end, false) # for all pits in mem_map. + * please see usage in ARM. + */ +void mark_memmap_pit(unsigned long start, unsigned long end, bool valid) +{ + struct mem_section *ms; + unsigned long pos, next; + struct page *pg; + void *memmap, *mapend; + + for (pos = start; + pos < end; pos = next) { + next = (pos + PAGES_PER_SECTION) & PAGE_SECTION_MASK; + ms = __pfn_to_section(pos); + if (!valid_section(ms)) + continue; + for (memmap = (void*)pfn_to_page(pos), + mapend = pfn_to_page(next-1); /* the last page in section*/ + memmap < mapend; + memmap += PAGE_SIZE) { + pg = virt_to_page(memmap); + if (valid) + pg->private = (unsigned long)ms; + else + pg->private = 0; + } + } +} +#endif + #ifdef CONFIG_MEMORY_HOTPLUG #ifdef CONFIG_SPARSEMEM_VMEMMAP static inline struct page *kmalloc_section_memmap(unsigned long pnum, int nid, Index: mmotm-2.6.35-0701/arch/arm/mm/init.c =================================================================== --- mmotm-2.6.35-0701.orig/arch/arm/mm/init.c +++ mmotm-2.6.35-0701/arch/arm/mm/init.c @@ -234,6 +234,13 @@ static void __init arm_bootmem_free(stru arch_adjust_zones(zone_size, zhole_size); free_area_init_node(0, zone_size, min, zhole_size); + +#ifdef CONFIG_SPARSEMEM + for_each_bank(i, mi) { + mark_memmap_pit(bank_start_pfn(mi->bank[i]), + bank_end_pfn(mi->bank[i]), true); + } +#endif } #ifndef CONFIG_SPARSEMEM @@ -386,8 +393,10 @@ free_memmap(unsigned long start_pfn, uns * If there are free pages between these, * free the section of the memmap array. */ - if (pg < pgend) + if (pg < pgend) { + mark_memap_pit(pg >> PAGE_SHIFT, pgend >> PAGE_SHIFT, false); free_bootmem(pg, pgend - pg); + } } /* Index: mmotm-2.6.35-0701/mm/Kconfig =================================================================== --- mmotm-2.6.35-0701.orig/mm/Kconfig +++ mmotm-2.6.35-0701/mm/Kconfig @@ -128,6 +128,11 @@ config SPARSEMEM_VMEMMAP pfn_to_page and page_to_pfn operations. This is the most efficient option when sufficient kernel resources are available. +config SPAESEMEM_HAS_PIT + bool "allow holes in sparsemem's memmap" + depends on SPARSEMEM && !SPARSEMEM_VMEMMAP + default n + # eventually, we can have this option just 'select SPARSEMEM' config MEMORY_HOTPLUG bool "Allow for memory hot-add" -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/