lkml.org 
[lkml]   [2016]   [Dec]   [28]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 2/7] mm, vmscan: add active list aging tracepoint
Date
From: Michal Hocko <mhocko@suse.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 scanned, rotated, deactivated and freed pages from the
particular node's active list.

Signed-off-by: Michal Hocko <mhocko@suse.com>
---
include/linux/gfp.h | 2 +-
include/trace/events/vmscan.h | 38 ++++++++++++++++++++++++++++++++++++++
mm/page_alloc.c | 6 +++++-
mm/vmscan.c | 22 +++++++++++++++++-----
4 files changed, 61 insertions(+), 7 deletions(-)

diff --git a/include/linux/gfp.h b/include/linux/gfp.h
index 4175dca4ac39..61aa9b49e86d 100644
--- a/include/linux/gfp.h
+++ b/include/linux/gfp.h
@@ -503,7 +503,7 @@ void * __meminit alloc_pages_exact_nid(int nid, size_t size, gfp_t gfp_mask);
extern void __free_pages(struct page *page, unsigned int order);
extern void free_pages(unsigned long addr, unsigned int order);
extern void free_hot_cold_page(struct page *page, bool cold);
-extern void free_hot_cold_page_list(struct list_head *list, bool cold);
+extern int free_hot_cold_page_list(struct list_head *list, bool cold);

struct page_frag_cache;
extern void __page_frag_drain(struct page *page, unsigned int order,
diff --git a/include/trace/events/vmscan.h b/include/trace/events/vmscan.h
index 39bad8921ca1..d34cc0ced2be 100644
--- a/include/trace/events/vmscan.h
+++ b/include/trace/events/vmscan.h
@@ -363,6 +363,44 @@ 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_scanned, unsigned long nr_freed,
+ unsigned long nr_unevictable, unsigned long nr_deactivated,
+ unsigned long nr_rotated, int priority, int file),
+
+ TP_ARGS(nid, nr_scanned, nr_freed, nr_unevictable, nr_deactivated, nr_rotated, priority, file),
+
+ TP_STRUCT__entry(
+ __field(int, nid)
+ __field(unsigned long, nr_scanned)
+ __field(unsigned long, nr_freed)
+ __field(unsigned long, nr_unevictable)
+ __field(unsigned long, nr_deactivated)
+ __field(unsigned long, nr_rotated)
+ __field(int, priority)
+ __field(int, reclaim_flags)
+ ),
+
+ TP_fast_assign(
+ __entry->nid = nid;
+ __entry->nr_scanned = nr_scanned;
+ __entry->nr_freed = nr_freed;
+ __entry->nr_unevictable = nr_unevictable;
+ __entry->nr_deactivated = nr_deactivated;
+ __entry->nr_rotated = nr_rotated;
+ __entry->priority = priority;
+ __entry->reclaim_flags = trace_shrink_flags(file);
+ ),
+
+ TP_printk("nid=%d nr_scanned=%ld nr_freed=%ld nr_unevictable=%ld nr_deactivated=%ld nr_rotated=%ld priority=%d flags=%s",
+ __entry->nid,
+ __entry->nr_scanned, __entry->nr_freed, __entry->nr_unevictable,
+ __entry->nr_deactivated, __entry->nr_rotated,
+ __entry->priority,
+ show_reclaim_flags(__entry->reclaim_flags))
+);
+
#endif /* _TRACE_VMSCAN_H */

/* This part must be outside protection */
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 1c24112308d6..77d204660857 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -2487,14 +2487,18 @@ void free_hot_cold_page(struct page *page, bool cold)
/*
* Free a list of 0-order pages
*/
-void free_hot_cold_page_list(struct list_head *list, bool cold)
+int free_hot_cold_page_list(struct list_head *list, bool cold)
{
struct page *page, *next;
+ int ret = 0;

list_for_each_entry_safe(page, next, list, lru) {
trace_mm_page_free_batched(page, cold);
free_hot_cold_page(page, cold);
+ ret++;
}
+
+ return ret;
}

/*
diff --git a/mm/vmscan.c b/mm/vmscan.c
index c4abf08861d2..2302a1a58c6e 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 int 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++;
}
}

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 long nr_rotated = 0, nr_unevictable = 0;
+ unsigned long nr_freed, nr_deactivate, nr_activate;
isolate_mode_t isolate_mode = 0;
int file = is_file_lru(lru);
struct pglist_data *pgdat = lruvec_pgdat(lruvec);
@@ -1935,6 +1943,7 @@ static void shrink_active_list(unsigned long nr_to_scan,

if (unlikely(!page_evictable(page))) {
putback_lru_page(page);
+ nr_unevictable++;
continue;
}

@@ -1980,13 +1989,16 @@ 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);
+ nr_freed = free_hot_cold_page_list(&l_hold, true);
+ trace_mm_vmscan_lru_shrink_active(pgdat->node_id, nr_scanned, nr_freed,
+ nr_unevictable, nr_deactivate, nr_rotated,
+ sc->priority, file);
}

/*
--
2.10.2
\
 
 \ /
  Last update: 2016-12-28 16:32    [W:0.600 / U:0.108 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site