Commit 10e0f753 authored by Wonhyuk Yang's avatar Wonhyuk Yang Committed by Andrew Morton
Browse files

mm/page_alloc: fix tracepoint mm_page_alloc_zone_locked() 

Currently, trace point mm_page_alloc_zone_locked() doesn't show correct
information.

First, when alloc_flag has ALLOC_HARDER/ALLOC_CMA, page can be allocated
from MIGRATE_HIGHATOMIC/MIGRATE_CMA.  Nevertheless, tracepoint use
requested migration type not MIGRATE_HIGHATOMIC and MIGRATE_CMA.

Second, after commit 44042b44 ("mm/page_alloc: allow high-order pages
to be stored on the per-cpu lists") percpu-list can store high order
pages.  But trace point determine whether it is a refiil of percpu-list by
comparing requested order and 0.

To handle these problems, make mm_page_alloc_zone_locked() only be called
by __rmqueue_smallest with correct migration type.  With a new argument
called percpu_refill, it can show roughly whether it is a refill of
percpu-list.

Link: https://lkml.kernel.org/r/20220512025307.57924-1-vvghjk1234@gmail.com


Signed-off-by: default avatarWonhyuk Yang <vvghjk1234@gmail.com>
Acked-by: default avatarMel Gorman <mgorman@suse.de>
Cc: Baik Song An <bsahn@etri.re.kr>
Cc: Hong Yeon Kim <kimhy@etri.re.kr>
Cc: Taeung Song <taeung@reallinux.co.kr>
Cc: <linuxgeek@linuxgeek.io>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 3645b5ec

include/trace/events/kmem.h

+9 −5
Original line number Diff line number Diff line
@@ -229,20 +229,23 @@ TRACE_EVENT(mm_page_alloc, 


DECLARE_EVENT_CLASS(mm_page,



	TP_PROTO(struct page *page, unsigned int order, int migratetype),

	TP_PROTO(struct page *page, unsigned int order, int migratetype,

		 int percpu_refill),



	TP_ARGS(page, order, migratetype),

	TP_ARGS(page, order, migratetype, percpu_refill),



	TP_STRUCT__entry(

		__field(	unsigned long,	pfn		)

		__field(	unsigned int,	order		)

		__field(	int,		migratetype	)

		__field(	int,		percpu_refill	)

	),



	TP_fast_assign(

		__entry->pfn		= page ? page_to_pfn(page) : -1UL;

		__entry->order		= order;

		__entry->migratetype	= migratetype;

		__entry->percpu_refill	= percpu_refill;

	),



	TP_printk("page=%p pfn=0x%lx order=%u migratetype=%d percpu_refill=%d",
@@ -250,14 +253,15 @@ DECLARE_EVENT_CLASS(mm_page, 
		__entry->pfn != -1UL ? __entry->pfn : 0,

		__entry->order,

		__entry->migratetype,

		__entry->order == 0)

		__entry->percpu_refill)

);



DEFINE_EVENT(mm_page, mm_page_alloc_zone_locked,



	TP_PROTO(struct page *page, unsigned int order, int migratetype),

	TP_PROTO(struct page *page, unsigned int order, int migratetype,

		 int percpu_refill),



	TP_ARGS(page, order, migratetype)

	TP_ARGS(page, order, migratetype, percpu_refill)

);



TRACE_EVENT(mm_page_pcpu_drain,

mm/page_alloc.c

+5 −8
Original line number Diff line number Diff line
@@ -2466,6 +2466,9 @@ struct page *__rmqueue_smallest(struct zone *zone, unsigned int order, 
		del_page_from_free_list(page, zone, current_order);

		expand(zone, page, order, current_order, migratetype);

		set_pcppage_migratetype(page, migratetype);

		trace_mm_page_alloc_zone_locked(page, order, migratetype,

				pcp_allowed_order(order) &&

				migratetype < MIGRATE_PCPTYPES);

		return page;

	}
@@ -2989,7 +2992,7 @@ __rmqueue(struct zone *zone, unsigned int order, int migratetype, 
		    zone_page_state(zone, NR_FREE_PAGES) / 2) {

			page = __rmqueue_cma_fallback(zone, order);

			if (page)

				goto out;

				return page;

		}

	}

retry:
@@ -3002,9 +3005,6 @@ __rmqueue(struct zone *zone, unsigned int order, int migratetype, 
								alloc_flags))

			goto retry;

	}

out:

	if (page)

		trace_mm_page_alloc_zone_locked(page, order, migratetype);

	return page;

}
@@ -3723,11 +3723,8 @@ struct page *rmqueue(struct zone *preferred_zone, 
		 * reserved for high-order atomic allocation, so order-0

		 * request should skip it.

		 */

		if (order > 0 && alloc_flags & ALLOC_HARDER) {

		if (order > 0 && alloc_flags & ALLOC_HARDER)

			page = __rmqueue_smallest(zone, order, MIGRATE_HIGHATOMIC);

			if (page)

				trace_mm_page_alloc_zone_locked(page, order, migratetype);

		}

		if (!page) {

			page = __rmqueue(zone, order, migratetype, alloc_flags);

			if (!page)