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Subject[PATCH 1/4] mm: pagemap: Avoid unnecessary overhead when tracepoints are deactivated
Date
The LRU insertion and activate tracepoints take PFN as a parameter forcing
the overhead to the caller. Move the overhead to the tracepoint fast-assign
method to ensure the cost is only incurred when the tracepoint is active.

Signed-off-by: Mel Gorman <mgorman@suse.de>
---
include/trace/events/pagemap.h | 16 +++++++---------
mm/swap.c | 4 ++--
2 files changed, 9 insertions(+), 11 deletions(-)

diff --git a/include/trace/events/pagemap.h b/include/trace/events/pagemap.h
index 1c9fabd..ce0803b 100644
--- a/include/trace/events/pagemap.h
+++ b/include/trace/events/pagemap.h
@@ -28,12 +28,10 @@ TRACE_EVENT(mm_lru_insertion,

TP_PROTO(
struct page *page,
- unsigned long pfn,
- int lru,
- unsigned long flags
+ int lru
),

- TP_ARGS(page, pfn, lru, flags),
+ TP_ARGS(page, lru),

TP_STRUCT__entry(
__field(struct page *, page )
@@ -44,9 +42,9 @@ TRACE_EVENT(mm_lru_insertion,

TP_fast_assign(
__entry->page = page;
- __entry->pfn = pfn;
+ __entry->pfn = page_to_pfn(page);
__entry->lru = lru;
- __entry->flags = flags;
+ __entry->flags = trace_pagemap_flags(page);
),

/* Flag format is based on page-types.c formatting for pagemap */
@@ -64,9 +62,9 @@ TRACE_EVENT(mm_lru_insertion,

TRACE_EVENT(mm_lru_activate,

- TP_PROTO(struct page *page, unsigned long pfn),
+ TP_PROTO(struct page *page),

- TP_ARGS(page, pfn),
+ TP_ARGS(page),

TP_STRUCT__entry(
__field(struct page *, page )
@@ -75,7 +73,7 @@ TRACE_EVENT(mm_lru_activate,

TP_fast_assign(
__entry->page = page;
- __entry->pfn = pfn;
+ __entry->pfn = page_to_pfn(page);
),

/* Flag format is based on page-types.c formatting for pagemap */
diff --git a/mm/swap.c b/mm/swap.c
index 9e8e347..d10be45 100644
--- a/mm/swap.c
+++ b/mm/swap.c
@@ -501,7 +501,7 @@ static void __activate_page(struct page *page, struct lruvec *lruvec,
SetPageActive(page);
lru += LRU_ACTIVE;
add_page_to_lru_list(page, lruvec, lru);
- trace_mm_lru_activate(page, page_to_pfn(page));
+ trace_mm_lru_activate(page);

__count_vm_event(PGACTIVATE);
update_page_reclaim_stat(lruvec, file, 1);
@@ -996,7 +996,7 @@ static void __pagevec_lru_add_fn(struct page *page, struct lruvec *lruvec,
SetPageLRU(page);
add_page_to_lru_list(page, lruvec, lru);
update_page_reclaim_stat(lruvec, file, active);
- trace_mm_lru_insertion(page, page_to_pfn(page), lru, trace_pagemap_flags(page));
+ trace_mm_lru_insertion(page, lru);
}

/*
--
1.8.4.5


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