Use the page order as the only threshold for page reporting is not flexible and has some flaws. Because scan a long free list is not cheap, it's better to wake up the page reporting worker when there are more pages, wake it up for a sigle page may not worth. This patch add a batch size as another threshold to control the waking up of reporting worker.
Cc: Alexander Duyck <[email protected]> Cc: Mel Gorman <[email protected]> Cc: Andrea Arcangeli <[email protected]> Cc: Dan Williams <[email protected]> Cc: Dave Hansen <[email protected]> Cc: David Hildenbrand <[email protected]> Cc: Michal Hocko <[email protected]> Cc: Andrew Morton <[email protected]> Cc: Alex Williamson <[email protected]> Cc: Michael S. Tsirkin <[email protected]> Cc: Liang Li <[email protected]> Signed-off-by: Liang Li <[email protected]> --- mm/page_reporting.c | 1 + mm/page_reporting.h | 12 ++++++++++-- 2 files changed, 11 insertions(+), 2 deletions(-) diff --git a/mm/page_reporting.c b/mm/page_reporting.c index cd8e13d41df4..694df981ddd2 100644 --- a/mm/page_reporting.c +++ b/mm/page_reporting.c @@ -12,6 +12,7 @@ #define PAGE_REPORTING_DELAY (2 * HZ) static struct page_reporting_dev_info __rcu *pr_dev_info __read_mostly; +unsigned long page_report_batch_size __read_mostly = 16 * 1024 * 1024UL; enum { PAGE_REPORTING_IDLE = 0, diff --git a/mm/page_reporting.h b/mm/page_reporting.h index 2c385dd4ddbd..b8fb3bbb345f 100644 --- a/mm/page_reporting.h +++ b/mm/page_reporting.h @@ -12,6 +12,8 @@ #define PAGE_REPORTING_MIN_ORDER pageblock_order +extern unsigned long page_report_batch_size; + #ifdef CONFIG_PAGE_REPORTING DECLARE_STATIC_KEY_FALSE(page_reporting_enabled); void __page_reporting_notify(void); @@ -33,6 +35,8 @@ static inline bool page_reported(struct page *page) */ static inline void page_reporting_notify_free(unsigned int order) { + static long batch_size; + /* Called from hot path in __free_one_page() */ if (!static_branch_unlikely(&page_reporting_enabled)) return; @@ -41,8 +45,12 @@ static inline void page_reporting_notify_free(unsigned int order) if (order < PAGE_REPORTING_MIN_ORDER) return; - /* This will add a few cycles, but should be called infrequently */ - __page_reporting_notify(); + batch_size += (1 << order) << PAGE_SHIFT; + if (batch_size >= page_report_batch_size) { + batch_size = 0; + /* This add a few cycles, but should be called infrequently */ + __page_reporting_notify(); + } } #else /* CONFIG_PAGE_REPORTING */ #define page_reported(_page) false -- 2.18.2
