From a9cd410a3d296846a8125aa43d97a573a354c472 Mon Sep 17 00:00:00 2001 From: Arun KS Date: Tue, 5 Mar 2019 15:42:14 -0800 Subject: [PATCH] mm/page_alloc.c: memory hotplug: free pages as higher order When freeing pages are done with higher order, time spent on coalescing pages by buddy allocator can be reduced. With section size of 256MB, hot add latency of a single section shows improvement from 50-60 ms to less than 1 ms, hence improving the hot add latency by 60 times. Modify external providers of online callback to align with the change. [arunks@codeaurora.org: v11] Link: http://lkml.kernel.org/r/1547792588-18032-1-git-send-email-arunks@codeaurora.org [akpm@linux-foundation.org: remove unused local, per Arun] [akpm@linux-foundation.org: avoid return of void-returning __free_pages_core(), per Oscar] [akpm@linux-foundation.org: fix it for mm-convert-totalram_pages-and-totalhigh_pages-variables-to-atomic.patch] [arunks@codeaurora.org: v8] Link: http://lkml.kernel.org/r/1547032395-24582-1-git-send-email-arunks@codeaurora.org [arunks@codeaurora.org: v9] Link: http://lkml.kernel.org/r/1547098543-26452-1-git-send-email-arunks@codeaurora.org Link: http://lkml.kernel.org/r/1538727006-5727-1-git-send-email-arunks@codeaurora.org Signed-off-by: Arun KS Reviewed-by: Andrew Morton Acked-by: Michal Hocko Reviewed-by: Oscar Salvador Reviewed-by: Alexander Duyck Cc: K. Y. Srinivasan Cc: Haiyang Zhang Cc: Stephen Hemminger Cc: Boris Ostrovsky Cc: Juergen Gross Cc: Dan Williams Cc: Vlastimil Babka Cc: Joonsoo Kim Cc: Greg Kroah-Hartman Cc: Mathieu Malaterre Cc: "Kirill A. Shutemov" Cc: Souptick Joarder Cc: Mel Gorman Cc: Aaron Lu Cc: Srivatsa Vaddagiri Cc: Vinayak Menon Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/hv/hv_balloon.c | 7 ++++--- drivers/xen/balloon.c | 15 +++++++++----- include/linux/memory_hotplug.h | 2 +- mm/internal.h | 1 + mm/memory_hotplug.c | 37 +++++++++++++++++++++++----------- mm/page_alloc.c | 8 ++++---- 6 files changed, 45 insertions(+), 25 deletions(-) diff --git a/drivers/hv/hv_balloon.c b/drivers/hv/hv_balloon.c index 7c6349a50ef1..a50b7624b2a3 100644 --- a/drivers/hv/hv_balloon.c +++ b/drivers/hv/hv_balloon.c @@ -771,7 +771,7 @@ static void hv_mem_hot_add(unsigned long start, unsigned long size, } } -static void hv_online_page(struct page *pg) +static void hv_online_page(struct page *pg, unsigned int order) { struct hv_hotadd_state *has; unsigned long flags; @@ -780,10 +780,11 @@ static void hv_online_page(struct page *pg) spin_lock_irqsave(&dm_device.ha_lock, flags); list_for_each_entry(has, &dm_device.ha_region_list, list) { /* The page belongs to a different HAS. */ - if ((pfn < has->start_pfn) || (pfn >= has->end_pfn)) + if ((pfn < has->start_pfn) || + (pfn + (1UL << order) > has->end_pfn)) continue; - hv_page_online_one(has, pg); + hv_bring_pgs_online(has, pfn, 1UL << order); break; } spin_unlock_irqrestore(&dm_device.ha_lock, flags); diff --git a/drivers/xen/balloon.c b/drivers/xen/balloon.c index ceb5048de9a7..d107447c47de 100644 --- a/drivers/xen/balloon.c +++ b/drivers/xen/balloon.c @@ -369,14 +369,19 @@ static enum bp_state reserve_additional_memory(void) return BP_ECANCELED; } -static void xen_online_page(struct page *page) +static void xen_online_page(struct page *page, unsigned int order) { - __online_page_set_limits(page); + unsigned long i, size = (1 << order); + unsigned long start_pfn = page_to_pfn(page); + struct page *p; + pr_debug("Online %lu pages starting at pfn 0x%lx\n", size, start_pfn); mutex_lock(&balloon_mutex); - - __balloon_append(page); - + for (i = 0; i < size; i++) { + p = pfn_to_page(start_pfn + i); + __online_page_set_limits(p); + __balloon_append(p); + } mutex_unlock(&balloon_mutex); } diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h index 368267c1b71b..52869d6d38b3 100644 --- a/include/linux/memory_hotplug.h +++ b/include/linux/memory_hotplug.h @@ -89,7 +89,7 @@ extern int test_pages_in_a_zone(unsigned long start_pfn, unsigned long end_pfn, unsigned long *valid_start, unsigned long *valid_end); extern void __offline_isolated_pages(unsigned long, unsigned long); -typedef void (*online_page_callback_t)(struct page *page); +typedef void (*online_page_callback_t)(struct page *page, unsigned int order); extern int set_online_page_callback(online_page_callback_t callback); extern int restore_online_page_callback(online_page_callback_t callback); diff --git a/mm/internal.h b/mm/internal.h index f4a7bb02decf..536bc2a839b9 100644 --- a/mm/internal.h +++ b/mm/internal.h @@ -163,6 +163,7 @@ static inline struct page *pageblock_pfn_to_page(unsigned long start_pfn, extern int __isolate_free_page(struct page *page, unsigned int order); extern void memblock_free_pages(struct page *page, unsigned long pfn, unsigned int order); +extern void __free_pages_core(struct page *page, unsigned int order); extern void prep_compound_page(struct page *page, unsigned int order); extern void post_alloc_hook(struct page *page, unsigned int order, gfp_t gfp_flags); diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index 1ad28323fb9f..4f07c8ddfdd7 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -47,7 +47,7 @@ * and restore_online_page_callback() for generic callback restore. */ -static void generic_online_page(struct page *page); +static void generic_online_page(struct page *page, unsigned int order); static online_page_callback_t online_page_callback = generic_online_page; static DEFINE_MUTEX(online_page_callback_lock); @@ -656,26 +656,39 @@ void __online_page_free(struct page *page) } EXPORT_SYMBOL_GPL(__online_page_free); -static void generic_online_page(struct page *page) +static void generic_online_page(struct page *page, unsigned int order) { - __online_page_set_limits(page); - __online_page_increment_counters(page); - __online_page_free(page); + __free_pages_core(page, order); + totalram_pages_add(1UL << order); +#ifdef CONFIG_HIGHMEM + if (PageHighMem(page)) + totalhigh_pages_add(1UL << order); +#endif +} + +static int online_pages_blocks(unsigned long start, unsigned long nr_pages) +{ + unsigned long end = start + nr_pages; + int order, onlined_pages = 0; + + while (start < end) { + order = min(MAX_ORDER - 1, + get_order(PFN_PHYS(end) - PFN_PHYS(start))); + (*online_page_callback)(pfn_to_page(start), order); + + onlined_pages += (1UL << order); + start += (1UL << order); + } + return onlined_pages; } static int online_pages_range(unsigned long start_pfn, unsigned long nr_pages, void *arg) { - unsigned long i; unsigned long onlined_pages = *(unsigned long *)arg; - struct page *page; if (PageReserved(pfn_to_page(start_pfn))) - for (i = 0; i < nr_pages; i++) { - page = pfn_to_page(start_pfn + i); - (*online_page_callback)(page); - onlined_pages++; - } + onlined_pages += online_pages_blocks(start_pfn, nr_pages); online_mem_sections(start_pfn, start_pfn + nr_pages); diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 10d0f2ed9f69..5361bd078493 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -1303,7 +1303,7 @@ static void __free_pages_ok(struct page *page, unsigned int order) local_irq_restore(flags); } -static void __init __free_pages_boot_core(struct page *page, unsigned int order) +void __free_pages_core(struct page *page, unsigned int order) { unsigned int nr_pages = 1 << order; struct page *p = page; @@ -1382,7 +1382,7 @@ void __init memblock_free_pages(struct page *page, unsigned long pfn, { if (early_page_uninitialised(pfn)) return; - return __free_pages_boot_core(page, order); + __free_pages_core(page, order); } /* @@ -1472,14 +1472,14 @@ static void __init deferred_free_range(unsigned long pfn, if (nr_pages == pageblock_nr_pages && (pfn & (pageblock_nr_pages - 1)) == 0) { set_pageblock_migratetype(page, MIGRATE_MOVABLE); - __free_pages_boot_core(page, pageblock_order); + __free_pages_core(page, pageblock_order); return; } for (i = 0; i < nr_pages; i++, page++, pfn++) { if ((pfn & (pageblock_nr_pages - 1)) == 0) set_pageblock_migratetype(page, MIGRATE_MOVABLE); - __free_pages_boot_core(page, 0); + __free_pages_core(page, 0); } } -- 2.39.5