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 566869e58fa3e ("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: Wonhyuk Yang <vvghjk1234@gmail.com>
Acked-by: Mel 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: Andrew Morton <akpm@linux-foundation.org>

diff --git a/include/trace/events/kmem.h b/include/trace/events/kmem.h
index 71c1418042226930653c023c5695df360c62aaae..f76668305ac503c23790b5e1a93842a81692543a 100644 (file)
--- a/include/trace/events/kmem.h
+++ b/include/trace/events/kmem.h
@@ -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,

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index a4a8fbbd6217fe603de2cd2177cacd3fef608c3d..10305b10fe93d55ad8a4dc5d5035a361ca0db8eb 100644 (file)
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -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 @@ retry:
                                                                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)