[Devel] [PATCH RHEL7 COMMIT] ms/mm, vmscan: add active list aging tracepoint
Konstantin Khorenko
khorenko at virtuozzo.com
Wed Jan 31 18:29:31 MSK 2018
The commit is pushed to "branch-rh7-3.10.0-693.11.6.vz7.42.x-ovz" and will appear at https://src.openvz.org/scm/ovz/vzkernel.git
after rh7-3.10.0-693.11.6.vz7.42.4
------>
commit 4080c5a6e3398ba43de798e30e7ef69018abd2e3
Author: Michal Hocko <mhocko at suse.com>
Date: Wed Jan 31 18:29:30 2018 +0300
ms/mm, vmscan: add active list aging tracepoint
Our reclaim process has several tracepoints to tell us more about how
things are progressing. We are, however, missing a tracepoint to track
active list aging. Introduce mm_vmscan_lru_shrink_active which reports
the number of
- nr_taken is number of isolated pages from the active list
- nr_referenced pages which tells us that we are hitting referenced
pages which are deactivated. If this is a large part of the
reported nr_deactivated pages then we might be hitting into
the active list too early because they might be still part of
the working set. This might help to debug performance issues.
- nr_active pages which tells us how many pages are kept on the
active list - mostly exec file backed pages. A high number can
indicate that we might be trashing on executables.
[mhocko at suse.com: update]
Link: http://lkml.kernel.org/r/20170104135244.GJ25453@dhcp22.suse.cz
Link: http://lkml.kernel.org/r/20170104101942.4860-3-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko at suse.com>
Acked-by: Hillf Danton <hillf.zj at alibaba-inc.com>
Acked-by: Mel Gorman <mgorman at suse.de>
Acked-by: Minchan Kim <minchan at kernel.org>
Acked-by: Vlastimil Babka <vbabka at suse.cz>
Signed-off-by: Andrew Morton <akpm at linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds at linux-foundation.org>
https://jira.sw.ru/browse/PSBM-61409
(cherry-picked from 9d998b4f1e39abd69441d29a1ef3250514479267)
Signed-off-by: Andrey Ryabinin <aryabinin at virtuozzo.com>
---
include/trace/events/vmscan.h | 36 ++++++++++++++++++++++++++++++++++++
mm/vmscan.c | 19 +++++++++++++++----
2 files changed, 51 insertions(+), 4 deletions(-)
diff --git a/include/trace/events/vmscan.h b/include/trace/events/vmscan.h
index d98fb0ab1831..9b64323db0e0 100644
--- a/include/trace/events/vmscan.h
+++ b/include/trace/events/vmscan.h
@@ -374,6 +374,42 @@ TRACE_EVENT(mm_vmscan_lru_shrink_inactive,
show_reclaim_flags(__entry->reclaim_flags))
);
+TRACE_EVENT(mm_vmscan_lru_shrink_active,
+
+ TP_PROTO(int nid, unsigned long nr_taken,
+ unsigned long nr_active, unsigned long nr_deactivated,
+ unsigned long nr_referenced, int priority, int file),
+
+ TP_ARGS(nid, nr_taken, nr_active, nr_deactivated, nr_referenced, priority, file),
+
+ TP_STRUCT__entry(
+ __field(int, nid)
+ __field(unsigned long, nr_taken)
+ __field(unsigned long, nr_active)
+ __field(unsigned long, nr_deactivated)
+ __field(unsigned long, nr_referenced)
+ __field(int, priority)
+ __field(int, reclaim_flags)
+ ),
+
+ TP_fast_assign(
+ __entry->nid = nid;
+ __entry->nr_taken = nr_taken;
+ __entry->nr_active = nr_active;
+ __entry->nr_deactivated = nr_deactivated;
+ __entry->nr_referenced = nr_referenced;
+ __entry->priority = priority;
+ __entry->reclaim_flags = trace_shrink_flags(file);
+ ),
+
+ TP_printk("nid=%d nr_taken=%ld nr_active=%ld nr_deactivated=%ld nr_referenced=%ld priority=%d flags=%s",
+ __entry->nid,
+ __entry->nr_taken,
+ __entry->nr_active, __entry->nr_deactivated, __entry->nr_referenced,
+ __entry->priority,
+ show_reclaim_flags(__entry->reclaim_flags))
+);
+
#endif /* _TRACE_VMSCAN_H */
/* This part must be outside protection */
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 0856721124c9..3f0a7a1e27ff 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1685,9 +1685,11 @@ shrink_inactive_list(unsigned long nr_to_scan, struct lruvec *lruvec,
*
* The downside is that we have to touch page->_count against each page.
* But we had to alter page->flags anyway.
+ *
+ * Returns the number of pages moved to the given lru.
*/
-static void move_active_pages_to_lru(struct lruvec *lruvec,
+static unsigned move_active_pages_to_lru(struct lruvec *lruvec,
struct list_head *list,
struct list_head *pages_to_free,
enum lru_list lru)
@@ -1696,6 +1698,7 @@ static void move_active_pages_to_lru(struct lruvec *lruvec,
unsigned long pgmoved = 0;
struct page *page;
int nr_pages;
+ int nr_moved = 0;
while (!list_empty(list)) {
page = lru_to_page(list);
@@ -1721,11 +1724,15 @@ static void move_active_pages_to_lru(struct lruvec *lruvec,
spin_lock_irq(&zone->lru_lock);
} else
list_add(&page->lru, pages_to_free);
+ } else {
+ nr_moved += nr_pages;
}
}
__mod_zone_page_state(zone, NR_LRU_BASE + lru, pgmoved);
if (!is_active_lru(lru))
__count_vm_events(PGDEACTIVATE, pgmoved);
+
+ return nr_moved;
}
static void shrink_active_list(unsigned long nr_to_scan,
@@ -1741,7 +1748,8 @@ static void shrink_active_list(unsigned long nr_to_scan,
LIST_HEAD(l_inactive);
struct page *page;
struct zone_reclaim_stat *reclaim_stat = &lruvec->reclaim_stat;
- unsigned long nr_rotated = 0;
+ unsigned nr_deactivate, nr_activate;
+ unsigned nr_rotated = 0;
isolate_mode_t isolate_mode = 0;
int file = is_file_lru(lru);
struct zone *zone = lruvec_zone(lruvec);
@@ -1821,8 +1829,8 @@ static void shrink_active_list(unsigned long nr_to_scan,
*/
reclaim_stat->recent_rotated[file] += nr_rotated;
- move_active_pages_to_lru(lruvec, &l_active, &l_hold, lru);
- move_active_pages_to_lru(lruvec, &l_inactive, &l_hold, lru - LRU_ACTIVE);
+ nr_activate = move_active_pages_to_lru(lruvec, &l_active, &l_hold, lru);
+ nr_deactivate = move_active_pages_to_lru(lruvec, &l_inactive, &l_hold, lru - LRU_ACTIVE);
__mod_zone_page_state(zone, NR_ISOLATED_ANON + file, -nr_taken);
spin_unlock_irq(&zone->lru_lock);
@@ -1830,6 +1838,9 @@ static void shrink_active_list(unsigned long nr_to_scan,
free_hot_cold_page_list(&l_hold, true);
KSTAT_PERF_LEAVE(refill_inact);
+
+ trace_mm_vmscan_lru_shrink_active(zone_to_nid(zone), nr_taken, nr_activate,
+ nr_deactivate, nr_rotated, sc->priority, file);
}
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