The patch titled
vmscan: tracing: add trace event when a page is written
has been added to the -mm tree. Its filename is
vmscan-tracing-add-trace-event-when-a-page-is-written.patch
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See http://userweb.kernel.org/~akpm/stuff/added-to-mm.txt to find
out what to do about this
The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
Subject: vmscan: tracing: add trace event when a page is written
From: Mel Gorman <mel@xxxxxxxxx>
Add a trace event for when page reclaim queues a page for IO and records
whether it is synchronous or asynchronous. Excessive synchronous IO for a
process can result in noticeable stalls during direct reclaim. Excessive
IO from page reclaim may indicate that the system is seriously under
provisioned for the amount of dirty pages that exist.
Signed-off-by: Mel Gorman <mel@xxxxxxxxx>
Acked-by: Rik van Riel <riel@xxxxxxxxxx>
Acked-by: Larry Woodman <lwoodman@xxxxxxxxxx>
Cc: Dave Chinner <david@xxxxxxxxxxxxx>
Cc: Chris Mason <chris.mason@xxxxxxxxxx>
Cc: Nick Piggin <npiggin@xxxxxxx>
Cc: Rik van Riel <riel@xxxxxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxxxxxxxxx>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
Cc: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>
Cc: Andrea Arcangeli <aarcange@xxxxxxxxxx>
Cc: Michael Rubin <mrubin@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/trace/events/vmscan.h | 23 +++++++++++++++++++++++
mm/vmscan.c | 2 ++
2 files changed, 25 insertions(+)
diff -puN include/trace/events/vmscan.h~vmscan-tracing-add-trace-event-when-a-page-is-written include/trace/events/vmscan.h
--- a/include/trace/events/vmscan.h~vmscan-tracing-add-trace-event-when-a-page-is-written
+++ a/include/trace/events/vmscan.h
@@ -155,6 +155,29 @@ TRACE_EVENT(mm_vmscan_lru_isolate,
__entry->nr_lumpy_failed)
);
+TRACE_EVENT(mm_vmscan_writepage,
+
+ TP_PROTO(struct page *page,
+ int sync_io),
+
+ TP_ARGS(page, sync_io),
+
+ TP_STRUCT__entry(
+ __field(struct page *, page)
+ __field(int, sync_io)
+ ),
+
+ TP_fast_assign(
+ __entry->page = page;
+ __entry->sync_io = sync_io;
+ ),
+
+ TP_printk("page=%p pfn=%lu sync_io=%d",
+ __entry->page,
+ page_to_pfn(__entry->page),
+ __entry->sync_io)
+);
+
#endif /* _TRACE_VMSCAN_H */
/* This part must be outside protection */
diff -puN mm/vmscan.c~vmscan-tracing-add-trace-event-when-a-page-is-written mm/vmscan.c
--- a/mm/vmscan.c~vmscan-tracing-add-trace-event-when-a-page-is-written
+++ a/mm/vmscan.c
@@ -399,6 +399,8 @@ static pageout_t pageout(struct page *pa
/* synchronous write or broken a_ops? */
ClearPageReclaim(page);
}
+ trace_mm_vmscan_writepage(page,
+ sync_writeback == PAGEOUT_IO_SYNC);
inc_zone_page_state(page, NR_VMSCAN_WRITE);
return PAGE_SUCCESS;
}
_
Patches currently in -mm which might be from mel@xxxxxxxxx are
mm-vmscan-fix-mapping-use-after-free.patch
linux-next.patch
hugetlb-call-mmu-notifiers-on-hugepage-cow.patch
mm-rename-anon_vma_lock-to-vma_lock_anon_vma.patch
mm-change-direct-call-of-spin_lockanon_vma-lock-to-inline-function.patch
mm-track-the-root-oldest-anon_vma.patch
mm-always-lock-the-root-oldest-anon_vma.patch
mm-extend-ksm-refcounts-to-the-anon_vma-root.patch
mm-extend-ksm-refcounts-to-the-anon_vma-root-fix.patch
vmscan-tracing-add-trace-events-for-kswapd-wakeup-sleeping-and-direct-reclaim.patch
vmscan-tracing-add-trace-events-for-lru-page-isolation.patch
vmscan-tracing-add-trace-events-for-lru-page-isolation-checkpatch-fixes.patch
vmscan-tracing-add-trace-event-when-a-page-is-written.patch
vmscan-tracing-add-a-postprocessing-script-for-reclaim-related-ftrace-events.patch
vmscan-kill-prev_priority-completely.patch
vmscan-remove-unnecessary-temporary-vars-in-do_try_to_free_pages.patch
vmscan-set-up-pagevec-as-late-as-possible-in-shrink_inactive_list.patch
vmscan-set-up-pagevec-as-late-as-possible-in-shrink_page_list.patch
vmscan-update-isolated-page-counters-outside-of-main-path-in-shrink_inactive_list.patch
delay-accounting-re-implement-c-for-getdelaysc-to-report-information-on-a-target-command.patch
delay-accounting-re-implement-c-for-getdelaysc-to-report-information-on-a-target-command-checkpatch-fixes.patch
add-debugging-aid-for-memory-initialisation-problems.patch
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