The page allocator already has mm_page_pcpu_drain to trace pages drained from the per-cpu page lists back to the buddy allocator. There is no matching tracepoint for the opposite direction, where rmqueue_bulk() refills a PCP list from the buddy allocator.
mm_page_alloc_zone_locked is not a good substitute for this. It is emitted from __rmqueue_smallest(), which is used both by rmqueue_bulk() and by the direct buddy allocation path. Its percpu_refill field is derived from the allocation order and migratetype, so it does not reliably identify whether the allocation came from a PCP refill. Add mm_page_pcpu_refill and emit it from rmqueue_bulk() for each page added to the PCP list. The new tracepoint uses the same page, order and migratetype fields as mm_page_pcpu_drain, making refill and drain activity directly comparable. Signed-off-by: Bunyod Suvonov <[email protected]> --- include/trace/events/kmem.h | 23 +++++++++++++++++++++++ mm/page_alloc.c | 1 + 2 files changed, 24 insertions(+) diff --git a/include/trace/events/kmem.h b/include/trace/events/kmem.h index cd7920c81f85..16985604fc51 100644 --- a/include/trace/events/kmem.h +++ b/include/trace/events/kmem.h @@ -243,6 +243,29 @@ DEFINE_EVENT(mm_page, mm_page_alloc_zone_locked, TP_ARGS(page, order, migratetype, percpu_refill) ); +TRACE_EVENT(mm_page_pcpu_refill, + + TP_PROTO(struct page *page, unsigned int order, int migratetype), + + TP_ARGS(page, order, migratetype), + + TP_STRUCT__entry( + __field( unsigned long, pfn ) + __field( unsigned int, order ) + __field( int, migratetype ) + ), + + TP_fast_assign( + __entry->pfn = page ? page_to_pfn(page) : -1UL; + __entry->order = order; + __entry->migratetype = migratetype; + ), + + TP_printk("page=%p pfn=0x%lx order=%d migratetype=%d", + pfn_to_page(__entry->pfn), __entry->pfn, + __entry->order, __entry->migratetype) +); + TRACE_EVENT(mm_page_pcpu_drain, TP_PROTO(struct page *page, unsigned int order, int migratetype), diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 65e205111553..a60b73ed39a4 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -2544,6 +2544,7 @@ static int rmqueue_bulk(struct zone *zone, unsigned int order, * pages are ordered properly. */ list_add_tail(&page->pcp_list, list); + trace_mm_page_pcpu_refill(page, order, migratetype); } spin_unlock_irqrestore(&zone->lock, flags); -- 2.53.0
