diff options
| -rw-r--r-- | include/linux/mmzone.h | 3 | ||||
| -rw-r--r-- | mm/page_alloc.c | 41 |
2 files changed, 41 insertions, 3 deletions
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index 7937a1d1d166..0a86b2890a16 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -343,8 +343,9 @@ struct per_cpu_pages { int count; /* number of pages in the list */ int high; /* high watermark, emptying needed */ int batch; /* chunk size for buddy add/remove */ + short free_factor; /* batch scaling factor during free */ #ifdef CONFIG_NUMA - int expire; /* When 0, remote pagesets are drained */ + short expire; /* When 0, remote pagesets are drained */ #endif /* Lists of pages, one per migrate type stored on the pcp-lists */ diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 8d196a803820..e1d1825a2611 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -3278,18 +3278,47 @@ static bool free_unref_page_prepare(struct page *page, unsigned long pfn) return true; } +static int nr_pcp_free(struct per_cpu_pages *pcp, int high, int batch) +{ + int min_nr_free, max_nr_free; + + /* Check for PCP disabled or boot pageset */ + if (unlikely(high < batch)) + return 1; + + /* Leave at least pcp->batch pages on the list */ + min_nr_free = batch; + max_nr_free = high - batch; + + /* + * Double the number of pages freed each time there is subsequent + * freeing of pages without any allocation. + */ + batch <<= pcp->free_factor; + if (batch < max_nr_free) + pcp->free_factor++; + batch = clamp(batch, min_nr_free, max_nr_free); + + return batch; +} + static void free_unref_page_commit(struct page *page, unsigned long pfn, int migratetype) { struct zone *zone = page_zone(page); struct per_cpu_pages *pcp; + int high; __count_vm_event(PGFREE); pcp = this_cpu_ptr(zone->per_cpu_pageset); list_add(&page->lru, &pcp->lists[migratetype]); pcp->count++; - if (pcp->count >= READ_ONCE(pcp->high)) - free_pcppages_bulk(zone, READ_ONCE(pcp->batch), pcp); + high = READ_ONCE(pcp->high); + if (pcp->count >= high) { + int batch = READ_ONCE(pcp->batch); + + free_pcppages_bulk(zone, nr_pcp_free(pcp, high, batch), pcp); + } } /* @@ -3541,7 +3570,14 @@ static struct page *rmqueue_pcplist(struct zone *preferred_zone, unsigned long flags; local_lock_irqsave(&pagesets.lock, flags); + + /* + * On allocation, reduce the number of pages that are batch freed. + * See nr_pcp_free() where free_factor is increased for subsequent + * frees. + */ pcp = this_cpu_ptr(zone->per_cpu_pageset); + pcp->free_factor >>= 1; list = &pcp->lists[migratetype]; page = __rmqueue_pcplist(zone, migratetype, alloc_flags, pcp, list); local_unlock_irqrestore(&pagesets.lock, flags); @@ -6737,6 +6773,7 @@ static void per_cpu_pages_init(struct per_cpu_pages *pcp, struct per_cpu_zonesta */ pcp->high = BOOT_PAGESET_HIGH; pcp->batch = BOOT_PAGESET_BATCH; + pcp->free_factor = 0; } static void __zone_set_pageset_high_and_batch(struct zone *zone, unsigned long high, |