| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-Id: <20170104101942.4860-3-mhocko@kernel.org>
Date: Wed, 4 Jan 2017 11:19:37 +0100
From: Michal Hocko <mhocko@...nel.org>
To: Andrew Morton <akpm@...ux-foundation.org>
Cc: Mel Gorman <mgorman@...e.de>, Johannes Weiner <hannes@...xchg.org>,
Vlastimil Babka <vbabka@...e.cz>,
Minchan Kim <minchan@...nel.org>,
Hillf Danton <hillf.zj@...baba-inc.com>, <linux-mm@...ck.org>,
LKML <linux-kernel@...r.kernel.org>,
Michal Hocko <mhocko@...e.com>
Subject: [PATCH 2/7] mm, vmscan: add active list aging tracepoint
From: Michal Hocko <mhocko@...e.com>
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_scanned, nr_taken pages to tell us the LRU isolation
effectiveness.
- 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_activated 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.
Changes since v1
- report nr_taken pages as per Minchan
- report nr_activated as per Minchan
- do not report nr_freed pages because that would add a tiny overhead to
free_hot_cold_page_list which is a hot path
- do not report nr_unevictable because we can report this number via a
different and more generic tracepoint in putback_lru_page
- fix move_active_pages_to_lru to report proper page count when we hit
into large pages
- drop nr_scanned because this can be obtained from
trace_mm_vmscan_lru_isolate as per Minchan
Acked-by: Hillf Danton <hillf.zj@...baba-inc.com>
Acked-by: Mel Gorman <mgorman@...e.de>
Signed-off-by: Michal Hocko <mhocko@...e.com>
---
include/trace/events/vmscan.h | 36 ++++++++++++++++++++++++++++++++++++
mm/vmscan.c | 18 ++++++++++++++----
2 files changed, 50 insertions(+), 4 deletions(-)
diff --git a/include/trace/events/vmscan.h b/include/trace/events/vmscan.h
index 39bad8921ca1..087c0b625ba7 100644
--- a/include/trace/events/vmscan.h
+++ b/include/trace/events/vmscan.h
@@ -363,6 +363,42 @@ 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_activate, unsigned long nr_deactivated,
+ unsigned long nr_referenced, int priority, int file),
+
+ TP_ARGS(nid, nr_taken, nr_activate, nr_deactivated, nr_referenced, priority, file),
+
+ TP_STRUCT__entry(
+ __field(int, nid)
+ __field(unsigned long, nr_taken)
+ __field(unsigned long, nr_activate)
+ __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_activate = nr_activate;
+ __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_activated=%ld nr_deactivated=%ld nr_referenced=%ld priority=%d flags=%s",
+ __entry->nid,
+ __entry->nr_taken,
+ __entry->nr_activate, __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 c4abf08861d2..70d1c55463c0 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1846,9 +1846,11 @@ shrink_inactive_list(unsigned long nr_to_scan, struct lruvec *lruvec,
*
* The downside is that we have to touch page->_refcount 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)
@@ -1857,6 +1859,7 @@ 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);
@@ -1882,11 +1885,15 @@ static void move_active_pages_to_lru(struct lruvec *lruvec,
spin_lock_irq(&pgdat->lru_lock);
} else
list_add(&page->lru, pages_to_free);
+ } else {
+ nr_moved += nr_pages;
}
}
if (!is_active_lru(lru))
__count_vm_events(PGDEACTIVATE, pgmoved);
+
+ return nr_moved;
}
static void shrink_active_list(unsigned long nr_to_scan,
@@ -1902,7 +1909,8 @@ 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 pglist_data *pgdat = lruvec_pgdat(lruvec);
@@ -1980,13 +1988,15 @@ 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_node_page_state(pgdat, NR_ISOLATED_ANON + file, -nr_taken);
spin_unlock_irq(&pgdat->lru_lock);
mem_cgroup_uncharge_list(&l_hold);
free_hot_cold_page_list(&l_hold, true);
+ trace_mm_vmscan_lru_shrink_active(pgdat->node_id, nr_taken, nr_activate,
+ nr_deactivate, nr_rotated, sc->priority, file);
}
/*
--
2.11.0
Powered by blists - more mailing lists