From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f199.google.com (mail-pf0-f199.google.com [209.85.192.199]) by kanga.kvack.org (Postfix) with ESMTP id 0487F6B0279 for ; Mon, 3 Jul 2017 05:09:15 -0400 (EDT) Received: by mail-pf0-f199.google.com with SMTP id e3so195382864pfc.4 for ; Mon, 03 Jul 2017 02:09:14 -0700 (PDT) Received: from szxga03-in.huawei.com (szxga03-in.huawei.com. [45.249.212.189]) by mx.google.com with ESMTP id g3si3624733plb.210.2017.07.03.02.09.11 for ; Mon, 03 Jul 2017 02:09:13 -0700 (PDT) Subject: Re: [PATCH mm] introduce reverse buddy concept to reduce buddy fragment References: <1498821941-55771-1-git-send-email-zhouxianrong@huawei.com> <20170703074829.GD3217@dhcp22.suse.cz> From: zhouxianrong Message-ID: Date: Mon, 3 Jul 2017 17:01:20 +0800 MIME-Version: 1.0 In-Reply-To: <20170703074829.GD3217@dhcp22.suse.cz> Content-Type: text/plain; charset="windows-1252"; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Michal Hocko Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, akpm@linux-foundation.org, vbabka@suse.cz, alexander.h.duyck@intel.com, mgorman@suse.de, l.stach@pengutronix.de, vdavydov.dev@gmail.com, hannes@cmpxchg.org, minchan@kernel.org, npiggin@gmail.com, kirill.shutemov@linux.intel.com, gi-oh.kim@profitbricks.com, luto@kernel.org, keescook@chromium.org, mark.rutland@arm.com, mingo@kernel.org, heiko.carstens@de.ibm.com, iamjoonsoo.kim@lge.com, rientjes@google.com, ming.ling@spreadtrum.com, jack@suse.cz, ebru.akagunduz@gmail.com, bigeasy@linutronix.de, Mi.Sophia.Wang@huawei.com, zhouxiyu@huawei.com, weidu.du@huawei.com, fanghua3@huawei.com, won.ho.park@huawei.com On 2017/7/3 15:48, Michal Hocko wrote: > On Fri 30-06-17 19:25:41, zhouxianrong@huawei.com wrote: >> From: zhouxianrong >> >> when buddy is under fragment i find that still there are some pages >> just like AFFA mode. A is allocated, F is free, AF is buddy pair for >> oder n, FA is buddy pair for oder n as well. > > Could you quantify how often does this happen and how much of a problem > this actually is? Is there any specific workload that would suffer from > such an artificial fragmentation? > >> I want to compse the >> FF as oder n + 1 and align to n other than n + 1. this patch broke >> the rules of buddy stated as alignment to its length of oder. i think >> we can do so except for kernel stack because the requirement comes from >> buddy attribution rather than user. > > Why do you think the stack is a problem here? > >> for kernel stack requirement i add >> __GFP_NOREVERSEBUDDY for this purpose. >> >> a sample just like blow. >> >> Node 0, zone DMA >> 1389 1765 342 272 2 0 0 0 0 0 0 >> 0 75 4398 1560 379 27 2 0 0 0 0 >> Node 0, zone Normal >> 20 24 14 2 0 0 0 0 0 0 0 >> 0 6 228 3 0 0 0 0 0 0 0 >> at the sample moment if we have not this patch, the aspect should like below: Node 0, zone DMA (1389 + 75 * 2) (1765 + 4398 * 2) (342 + 1560 * 2) (272 + 379 * 2) (2 + 27 * 2) (0 + 2 * 2) 0 0 0 0 0 Node 0, zone Normal (20 + 6 * 2) (24 + 228 * 2) (14 + 3 * 2) 2 0 0 0 0 0 0 0 i find out AFFA mode in lower order free_list and move FF into higher order free_list_reverse. >> the patch does not consider fallback allocation for now. > > The path is missing the crucial information required for any > optimization. Some numbers to compare how much it helps. The above > output of buddyinfo is pointless without any base to compare to. Also > which workloads would benefit from this change and how much? It is also > a non trivial amount of code in the guts of the page allocator so this > really needs _much_ better explanation. > > I haven't looked closely on the code yet but a quick look at > set_reverse_free_area scared me away. > >> Signed-off-by: zhouxianrong >> --- >> include/linux/gfp.h | 8 +- >> include/linux/mmzone.h | 2 + >> include/linux/page-flags.h | 9 ++ >> include/linux/thread_info.h | 5 +- >> mm/compaction.c | 17 ++++ >> mm/internal.h | 7 ++ >> mm/page_alloc.c | 222 +++++++++++++++++++++++++++++++++++++++---- >> mm/vmstat.c | 5 +- >> 8 files changed, 251 insertions(+), 24 deletions(-) >> >> diff --git a/include/linux/gfp.h b/include/linux/gfp.h >> index db373b9..f63d4d9 100644 >> --- a/include/linux/gfp.h >> +++ b/include/linux/gfp.h >> @@ -40,6 +40,7 @@ >> #define ___GFP_DIRECT_RECLAIM 0x400000u >> #define ___GFP_WRITE 0x800000u >> #define ___GFP_KSWAPD_RECLAIM 0x1000000u >> +#define ___GFP_NOREVERSEBUDDY 0x2000000u >> /* If the above are modified, __GFP_BITS_SHIFT may need updating */ >> >> /* >> @@ -171,6 +172,10 @@ >> * __GFP_NOTRACK_FALSE_POSITIVE is an alias of __GFP_NOTRACK. It's a means of >> * distinguishing in the source between false positives and allocations that >> * cannot be supported (e.g. page tables). >> + * >> + * __GFP_NOREVERSEBUDDY does not allocate pages from reverse buddy list >> + * of current order. It make sure that allocation is alignment to same order >> + * with length order. >> */ >> #define __GFP_COLD ((__force gfp_t)___GFP_COLD) >> #define __GFP_NOWARN ((__force gfp_t)___GFP_NOWARN) >> @@ -178,9 +183,10 @@ >> #define __GFP_ZERO ((__force gfp_t)___GFP_ZERO) >> #define __GFP_NOTRACK ((__force gfp_t)___GFP_NOTRACK) >> #define __GFP_NOTRACK_FALSE_POSITIVE (__GFP_NOTRACK) >> +#define __GFP_NOREVERSEBUDDY ((__force gfp_t)___GFP_NOREVERSEBUDDY) >> >> /* Room for N __GFP_FOO bits */ >> -#define __GFP_BITS_SHIFT 25 >> +#define __GFP_BITS_SHIFT 26 >> #define __GFP_BITS_MASK ((__force gfp_t)((1 << __GFP_BITS_SHIFT) - 1)) >> >> /* >> diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h >> index 8e02b37..94237fe 100644 >> --- a/include/linux/mmzone.h >> +++ b/include/linux/mmzone.h >> @@ -89,7 +89,9 @@ enum { >> >> struct free_area { >> struct list_head free_list[MIGRATE_TYPES]; >> + struct list_head free_list_reverse[MIGRATE_TYPES]; >> unsigned long nr_free; >> + unsigned long nr_free_reverse; >> }; >> >> struct pglist_data; >> diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h >> index 6b5818d..39d17d7 100644 >> --- a/include/linux/page-flags.h >> +++ b/include/linux/page-flags.h >> @@ -675,6 +675,15 @@ static inline int TestClearPageDoubleMap(struct page *page) >> #define PAGE_KMEMCG_MAPCOUNT_VALUE (-512) >> PAGE_MAPCOUNT_OPS(Kmemcg, KMEMCG) >> >> +/* >> + * ReverseBuddy is enabled for the buddy allocator that allow allocating >> + * two adjacent same free order blocks other than buddy blocks and >> + * composing them as a order + 1 block. It is for reducing buddy >> + * fragment. >> + */ >> +#define PAGE_REVERSE_BUDDY_MAPCOUNT_VALUE (-1024) >> +PAGE_MAPCOUNT_OPS(ReverseBuddy, REVERSE_BUDDY) >> + >> extern bool is_free_buddy_page(struct page *page); >> >> __PAGEFLAG(Isolated, isolated, PF_ANY); >> diff --git a/include/linux/thread_info.h b/include/linux/thread_info.h >> index 5837387..b4a1605 100644 >> --- a/include/linux/thread_info.h >> +++ b/include/linux/thread_info.h >> @@ -28,9 +28,10 @@ >> >> #ifdef CONFIG_DEBUG_STACK_USAGE >> # define THREADINFO_GFP (GFP_KERNEL_ACCOUNT | __GFP_NOTRACK | \ >> - __GFP_ZERO) >> + __GFP_NOREVERSEBUDDY | __GFP_ZERO) >> #else >> -# define THREADINFO_GFP (GFP_KERNEL_ACCOUNT | __GFP_NOTRACK) >> +# define THREADINFO_GFP (GFP_KERNEL_ACCOUNT | __GFP_NOTRACK | \ >> + __GFP_NOREVERSEBUDDY) >> #endif >> >> /* >> diff --git a/mm/compaction.c b/mm/compaction.c >> index 0fdfde0..a43f169 100644 >> --- a/mm/compaction.c >> +++ b/mm/compaction.c >> @@ -768,6 +768,20 @@ static bool too_many_isolated(struct zone *zone) >> continue; >> } >> >> + if (PageReverseBuddy(page)) { >> + unsigned long freepage_order = page_order_unsafe(page); >> + >> + /* >> + * Without lock, we cannot be sure that what we got is >> + * a valid page order. Consider only values in the >> + * valid order range to prevent low_pfn overflow. >> + */ >> + if (freepage_order > 0 && >> + freepage_order < MAX_ORDER - 1) >> + low_pfn += (1UL << (freepage_order + 1)) - 1; >> + continue; >> + } >> + >> /* >> * Regardless of being on LRU, compound pages such as THP and >> * hugetlbfs are not to be compacted. We can potentially save >> @@ -1005,6 +1019,9 @@ static bool suitable_migration_target(struct compact_control *cc, >> return false; >> } >> >> + if (PageReverseBuddy(page)) >> + return false; >> + >> /* If the block is MIGRATE_MOVABLE or MIGRATE_CMA, allow migration */ >> if (migrate_async_suitable(get_pageblock_migratetype(page))) >> return true; >> diff --git a/mm/internal.h b/mm/internal.h >> index ccfc2a2..439b0a8 100644 >> --- a/mm/internal.h >> +++ b/mm/internal.h >> @@ -143,6 +143,13 @@ struct alloc_context { >> return page_pfn ^ (1 << order); >> } >> >> +static inline unsigned long >> +__find_reverse_buddy_pfn(unsigned long page_pfn, unsigned int order) >> +{ >> + return (page_pfn & (1 << order)) ? page_pfn + (1 << order) : >> + page_pfn - (1 << order); >> +} >> + >> extern struct page *__pageblock_pfn_to_page(unsigned long start_pfn, >> unsigned long end_pfn, struct zone *zone); >> >> diff --git a/mm/page_alloc.c b/mm/page_alloc.c >> index 9f9623d..ee1dc1b 100644 >> --- a/mm/page_alloc.c >> +++ b/mm/page_alloc.c >> @@ -715,6 +715,18 @@ static inline void rmv_page_order(struct page *page) >> set_page_private(page, 0); >> } >> >> +static inline void set_reverse_page_order(struct page *page, unsigned int order) >> +{ >> + set_page_private(page, order); >> + __SetPageReverseBuddy(page); >> +} >> + >> +static inline void rmv_reverse_page_order(struct page *page) >> +{ >> + __ClearPageReverseBuddy(page); >> + set_page_private(page, 0); >> +} >> + >> /* >> * This function checks whether a page is free && is the buddy >> * we can do coalesce a page and its buddy if >> @@ -758,6 +770,120 @@ static inline int page_is_buddy(struct page *page, struct page *buddy, >> return 0; >> } >> >> +static inline int page_is_reverse_buddy(struct page *page, struct page *buddy, >> + unsigned int order) >> +{ >> + if (PageReverseBuddy(buddy) && page_order(buddy) == order) { >> + /* >> + * zone check is done late to avoid uselessly >> + * calculating zone/node ids for pages that could >> + * never merge. >> + */ >> + if (page_zone_id(page) != page_zone_id(buddy)) >> + return 0; >> + >> + VM_BUG_ON_PAGE(page_count(buddy) != 0, buddy); >> + >> + return 1; >> + } >> + return 0; >> +} >> + >> +static inline >> +void set_reverse_free_area(struct zone *zone, struct page *page, >> + unsigned int order, int migratetype) >> +{ >> + unsigned long buddy_pfn; >> + unsigned long reserve_buddy_pfn; >> + struct page *reverse_buddy; >> + struct free_area *area; >> + >> + if (order > MAX_ORDER - 3) >> + return; >> + if (unlikely(is_migrate_isolate(migratetype))) >> + return; >> + buddy_pfn = page_to_pfn(page); >> + reserve_buddy_pfn = __find_reverse_buddy_pfn(buddy_pfn, order); >> + if ((buddy_pfn ^ reserve_buddy_pfn) & ~(pageblock_nr_pages - 1)) >> + return; >> + if (!pfn_valid_within(reserve_buddy_pfn)) >> + return; >> + reverse_buddy = pfn_to_page(reserve_buddy_pfn); >> + if (page_zone_id(page) != page_zone_id(reverse_buddy)) >> + return; >> + if (PageBuddy(reverse_buddy) && >> + page_order(reverse_buddy) == order) { >> + area = &zone->free_area[order]; >> + list_del(&page->lru); >> + rmv_page_order(page); >> + area->nr_free--; >> + set_pcppage_migratetype(page, migratetype); >> + list_del(&reverse_buddy->lru); >> + rmv_page_order(reverse_buddy); >> + area->nr_free--; >> + set_pcppage_migratetype(reverse_buddy, migratetype); >> + area++; >> + if (buddy_pfn < reserve_buddy_pfn) { >> + list_add(&page->lru, >> + &area->free_list_reverse[migratetype]); >> + area->nr_free_reverse++; >> + set_reverse_page_order(page, order); >> + set_reverse_page_order(reverse_buddy, order); >> + } else { >> + list_add(&reverse_buddy->lru, >> + &area->free_list_reverse[migratetype]); >> + area->nr_free_reverse++; >> + set_reverse_page_order(reverse_buddy, order); >> + set_reverse_page_order(page, order); >> + } >> + } >> +} >> + >> +static inline >> +void rmv_reverse_free_area(struct zone *zone, struct page *page, >> + unsigned int order, int migratetype) >> +{ >> + unsigned long pfn, buddy_pfn; >> + unsigned long reserve_buddy_pfn; >> + struct page *buddy, *reverse_buddy; >> + struct free_area *area; >> + >> + pfn = page_to_pfn(page); >> + buddy_pfn = __find_buddy_index(pfn, order); >> + buddy = page + (buddy_pfn - pfn); >> + if (!pfn_valid_within(buddy_pfn)) >> + return; >> + if (!page_is_reverse_buddy(page, buddy, order)) >> + return; >> + >> + area = &zone->free_area[order]; >> + reserve_buddy_pfn = __find_reverse_buddy_pfn(buddy_pfn, order); >> + reverse_buddy = pfn_to_page(reserve_buddy_pfn); >> + VM_BUG_ON_PAGE(!PageReverseBuddy(reverse_buddy) || >> + page_order(reverse_buddy) != order, reverse_buddy); >> + if (buddy_pfn < reserve_buddy_pfn) { >> + list_move(&buddy->lru, &area->free_list[migratetype]); >> + rmv_reverse_page_order(buddy); >> + area[1].nr_free_reverse--; >> + area->nr_free++; >> + set_page_order(buddy, order); >> + rmv_reverse_page_order(reverse_buddy); >> + list_add(&reverse_buddy->lru, &area->free_list[migratetype]); >> + area->nr_free++; >> + set_page_order(reverse_buddy, order); >> + } else { >> + list_move(&reverse_buddy->lru, &area->free_list[migratetype]); >> + rmv_reverse_page_order(reverse_buddy); >> + area[1].nr_free_reverse--; >> + area->nr_free++; >> + set_page_order(reverse_buddy, order); >> + rmv_reverse_page_order(buddy); >> + list_add(&buddy->lru, &area->free_list[migratetype]); >> + area->nr_free++; >> + set_page_order(buddy, order); >> + } >> +} >> + >> /* >> * Freeing function for a buddy system allocator. >> * >> @@ -805,6 +931,7 @@ static inline void __free_one_page(struct page *page, >> VM_BUG_ON_PAGE(pfn & ((1 << order) - 1), page); >> VM_BUG_ON_PAGE(bad_range(zone, page), page); >> >> + rmv_reverse_free_area(zone, page, order, migratetype); >> continue_merging: >> while (order < max_order - 1) { >> buddy_pfn = __find_buddy_pfn(pfn, order); >> @@ -882,6 +1009,7 @@ static inline void __free_one_page(struct page *page, >> list_add(&page->lru, &zone->free_area[order].free_list[migratetype]); >> out: >> zone->free_area[order].nr_free++; >> + set_reverse_free_area(zone, page, order, migratetype); >> } >> >> /* >> @@ -1238,14 +1366,24 @@ void __meminit reserve_bootmem_region(phys_addr_t start, phys_addr_t end) >> >> static void __free_pages_ok(struct page *page, unsigned int order) >> { >> + bool reverse_buddy; >> int migratetype; >> unsigned long pfn = page_to_pfn(page); >> >> if (!free_pages_prepare(page, order, true)) >> return; >> >> + reverse_buddy = order && >> + ((pfn & ((1 << order) - 1)) == (1 << (order - 1))); >> migratetype = get_pfnblock_migratetype(page, pfn); >> - free_one_page(page_zone(page), page, pfn, order, migratetype); >> + if (!reverse_buddy) >> + free_one_page(page_zone(page), page, pfn, order, migratetype); >> + else { >> + free_one_page(page_zone(page), page, >> + pfn, order - 1, migratetype); >> + free_one_page(page_zone(page), page + (1 << (order - 1)), >> + pfn + (1 << (order - 1)), order - 1, migratetype); >> + } >> } >> >> static void __init __free_pages_boot_core(struct page *page, unsigned int order) >> @@ -1651,6 +1789,25 @@ static inline void expand(struct zone *zone, struct page *page, >> } >> } >> >> +static inline void expand_reverse(struct zone *zone, struct page *page, >> + int low, int high, struct free_area *area, >> + int migratetype) >> +{ >> + struct page *reverse_buddy; >> + >> + reverse_buddy = page + (1 << (high - 1)); >> + rmv_reverse_page_order(reverse_buddy); >> + set_pcppage_migratetype(reverse_buddy, migratetype); >> + if (high > low) { >> + area--; >> + high--; >> + expand(zone, page, low, high, area, migratetype); >> + list_add(&reverse_buddy->lru, &area->free_list[migratetype]); >> + area->nr_free++; >> + set_page_order(reverse_buddy, high); >> + } >> +} >> + >> static void check_new_page_bad(struct page *page) >> { >> const char *bad_reason = NULL; >> @@ -1785,25 +1942,45 @@ static void prep_new_page(struct page *page, unsigned int order, gfp_t gfp_flags >> */ >> static inline >> struct page *__rmqueue_smallest(struct zone *zone, unsigned int order, >> - int migratetype) >> + int migratetype, gfp_t gfp_flags) >> { >> + bool reverse_buddy; >> unsigned int current_order; >> struct free_area *area; >> struct page *page; >> >> + reverse_buddy = !!(gfp_flags & __GFP_NOREVERSEBUDDY); >> /* Find a page of the appropriate size in the preferred list */ >> for (current_order = order; current_order < MAX_ORDER; ++current_order) { >> area = &(zone->free_area[current_order]); >> page = list_first_entry_or_null(&area->free_list[migratetype], >> struct page, lru); >> - if (!page) >> + if (page) { >> + list_del(&page->lru); >> + rmv_page_order(page); >> + area->nr_free--; >> + expand(zone, page, order, >> + current_order, area, migratetype); >> + set_pcppage_migratetype(page, migratetype); >> + return page; >> + } >> + if (current_order + reverse_buddy == 0 || >> + current_order + reverse_buddy > MAX_ORDER - 2) >> continue; >> - list_del(&page->lru); >> - rmv_page_order(page); >> - area->nr_free--; >> - expand(zone, page, order, current_order, area, migratetype); >> - set_pcppage_migratetype(page, migratetype); >> - return page; >> + area += reverse_buddy; >> + page = list_first_entry_or_null( >> + &area->free_list_reverse[migratetype], >> + struct page, lru); >> + if (page) { >> + list_del(&page->lru); >> + rmv_reverse_page_order(page); >> + area->nr_free_reverse--; >> + expand_reverse(zone, page, order, >> + current_order + reverse_buddy, >> + area, migratetype); >> + set_pcppage_migratetype(page, migratetype); >> + return page; >> + } >> } >> >> return NULL; >> @@ -1828,13 +2005,13 @@ struct page *__rmqueue_smallest(struct zone *zone, unsigned int order, >> >> #ifdef CONFIG_CMA >> static struct page *__rmqueue_cma_fallback(struct zone *zone, >> - unsigned int order) >> + unsigned int order, gfp_t gfp_flags) >> { >> - return __rmqueue_smallest(zone, order, MIGRATE_CMA); >> + return __rmqueue_smallest(zone, order, MIGRATE_CMA, gfp_flags); >> } >> #else >> static inline struct page *__rmqueue_cma_fallback(struct zone *zone, >> - unsigned int order) { return NULL; } >> + unsigned int order, gfp_t gfp_flags) { return NULL; } >> #endif >> >> /* >> @@ -2136,7 +2313,8 @@ static bool unreserve_highatomic_pageblock(const struct alloc_context *ac, >> >> /* Remove an element from the buddy allocator from the fallback list */ >> static inline struct page * >> -__rmqueue_fallback(struct zone *zone, unsigned int order, int start_migratetype) >> +__rmqueue_fallback(struct zone *zone, unsigned int order, int start_migratetype, >> + gfp_t gfp_flags) >> { >> struct free_area *area; >> unsigned int current_order; >> @@ -2190,17 +2368,18 @@ static bool unreserve_highatomic_pageblock(const struct alloc_context *ac, >> * Call me with the zone->lock already held. >> */ >> static struct page *__rmqueue(struct zone *zone, unsigned int order, >> - int migratetype) >> + int migratetype, gfp_t gfp_flags) >> { >> struct page *page; >> >> - page = __rmqueue_smallest(zone, order, migratetype); >> + page = __rmqueue_smallest(zone, order, migratetype, gfp_flags); >> if (unlikely(!page)) { >> if (migratetype == MIGRATE_MOVABLE) >> - page = __rmqueue_cma_fallback(zone, order); >> + page = __rmqueue_cma_fallback(zone, order, gfp_flags); >> >> if (!page) >> - page = __rmqueue_fallback(zone, order, migratetype); >> + page = __rmqueue_fallback(zone, order, migratetype, >> + gfp_flags); >> } >> >> trace_mm_page_alloc_zone_locked(page, order, migratetype); >> @@ -2221,7 +2400,7 @@ static int rmqueue_bulk(struct zone *zone, unsigned int order, >> >> spin_lock_irqsave(&zone->lock, flags); >> for (i = 0; i < count; ++i) { >> - struct page *page = __rmqueue(zone, order, migratetype); >> + struct page *page = __rmqueue(zone, order, migratetype, 0); >> if (unlikely(page == NULL)) >> break; >> >> @@ -2718,12 +2897,13 @@ struct page *rmqueue(struct zone *preferred_zone, >> do { >> page = NULL; >> if (alloc_flags & ALLOC_HARDER) { >> - page = __rmqueue_smallest(zone, order, MIGRATE_HIGHATOMIC); >> + page = __rmqueue_smallest(zone, order, >> + MIGRATE_HIGHATOMIC, gfp_flags); >> if (page) >> trace_mm_page_alloc_zone_locked(page, order, migratetype); >> } >> if (!page) >> - page = __rmqueue(zone, order, migratetype); >> + page = __rmqueue(zone, order, migratetype, gfp_flags); >> } while (page && check_new_pages(page, order)); >> spin_unlock(&zone->lock); >> if (!page) >> @@ -5286,7 +5466,9 @@ static void __meminit zone_init_free_lists(struct zone *zone) >> unsigned int order, t; >> for_each_migratetype_order(order, t) { >> INIT_LIST_HEAD(&zone->free_area[order].free_list[t]); >> + INIT_LIST_HEAD(&zone->free_area[order].free_list_reverse[t]); >> zone->free_area[order].nr_free = 0; >> + zone->free_area[order].nr_free_reverse = 0; >> } >> } >> >> diff --git a/mm/vmstat.c b/mm/vmstat.c >> index 69f9aff..26007df 100644 >> --- a/mm/vmstat.c >> +++ b/mm/vmstat.c >> @@ -1146,10 +1146,13 @@ static void frag_show_print(struct seq_file *m, pg_data_t *pgdat, >> { >> int order; >> >> - seq_printf(m, "Node %d, zone %8s ", pgdat->node_id, zone->name); >> + seq_printf(m, "Node %d, zone %8s\n", pgdat->node_id, zone->name); >> for (order = 0; order < MAX_ORDER; ++order) >> seq_printf(m, "%6lu ", zone->free_area[order].nr_free); >> seq_putc(m, '\n'); >> + for (order = 0; order < MAX_ORDER; ++order) >> + seq_printf(m, "%6lu ", zone->free_area[order].nr_free_reverse); >> + seq_putc(m, '\n'); >> } >> >> /* >> -- >> 1.7.9.5 >> > -- 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