The patch titled
Subject: mm, vmscan: show the number of skipped pages in mm_vmscan_lru_isolate
has been added to the -mm tree. Its filename is
mm-vmscan-show-the-number-of-skipped-pages-in-mm_vmscan_lru_isolate.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/mm-vmscan-show-the-number-of-skipped-pages-in-mm_vmscan_lru_isolate.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/mm-vmscan-show-the-number-of-skipped-pages-in-mm_vmscan_lru_isolate.patch
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From: Michal Hocko <mhocko@xxxxxxxx>
Subject: mm, vmscan: show the number of skipped pages in mm_vmscan_lru_isolate
mm_vmscan_lru_isolate shows the number of requested, scanned and taken
pages. This is mostly OK but on 32b systems the number of scanned pages
is quite misleading because it includes both the scanned and skipped
pages. Moreover the skipped part is scaled based on the number of taken
pages. Let's report the exact numbers without any additional logic and
add the number of skipped pages. This should make the reported data much
more easier to interpret.
Link: http://lkml.kernel.org/r/20170104101942.4860-4-mhocko@xxxxxxxxxx
Signed-off-by: Michal Hocko <mhocko@xxxxxxxx>
Acked-by: Minchan Kim <minchan@xxxxxxxxxx>
Acked-by: Mel Gorman <mgorman@xxxxxxx>
Acked-by: Vlastimil Babka <vbabka@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/trace/events/vmscan.h | 8 ++++++--
mm/vmscan.c | 10 +++++-----
2 files changed, 11 insertions(+), 7 deletions(-)
diff -puN include/trace/events/vmscan.h~mm-vmscan-show-the-number-of-skipped-pages-in-mm_vmscan_lru_isolate include/trace/events/vmscan.h
--- a/include/trace/events/vmscan.h~mm-vmscan-show-the-number-of-skipped-pages-in-mm_vmscan_lru_isolate
+++ a/include/trace/events/vmscan.h
@@ -274,17 +274,19 @@ TRACE_EVENT(mm_vmscan_lru_isolate,
int order,
unsigned long nr_requested,
unsigned long nr_scanned,
+ unsigned long nr_skipped,
unsigned long nr_taken,
isolate_mode_t isolate_mode,
int file),
- TP_ARGS(classzone_idx, order, nr_requested, nr_scanned, nr_taken, isolate_mode, file),
+ TP_ARGS(classzone_idx, order, nr_requested, nr_scanned, nr_skipped, nr_taken, isolate_mode, file),
TP_STRUCT__entry(
__field(int, classzone_idx)
__field(int, order)
__field(unsigned long, nr_requested)
__field(unsigned long, nr_scanned)
+ __field(unsigned long, nr_skipped)
__field(unsigned long, nr_taken)
__field(isolate_mode_t, isolate_mode)
__field(int, file)
@@ -295,17 +297,19 @@ TRACE_EVENT(mm_vmscan_lru_isolate,
__entry->order = order;
__entry->nr_requested = nr_requested;
__entry->nr_scanned = nr_scanned;
+ __entry->nr_skipped = nr_skipped;
__entry->nr_taken = nr_taken;
__entry->isolate_mode = isolate_mode;
__entry->file = file;
),
- TP_printk("isolate_mode=%d classzone=%d order=%d nr_requested=%lu nr_scanned=%lu nr_taken=%lu file=%d",
+ TP_printk("isolate_mode=%d classzone=%d order=%d nr_requested=%lu nr_scanned=%lu nr_skipped=%lu nr_taken=%lu file=%d",
__entry->isolate_mode,
__entry->classzone_idx,
__entry->order,
__entry->nr_requested,
__entry->nr_scanned,
+ __entry->nr_skipped,
__entry->nr_taken,
__entry->file)
);
diff -puN mm/vmscan.c~mm-vmscan-show-the-number-of-skipped-pages-in-mm_vmscan_lru_isolate mm/vmscan.c
--- a/mm/vmscan.c~mm-vmscan-show-the-number-of-skipped-pages-in-mm_vmscan_lru_isolate
+++ a/mm/vmscan.c
@@ -1428,6 +1428,7 @@ static unsigned long isolate_lru_pages(u
unsigned long nr_taken = 0;
unsigned long nr_zone_taken[MAX_NR_ZONES] = { 0 };
unsigned long nr_skipped[MAX_NR_ZONES] = { 0, };
+ unsigned long skipped = 0, total_skipped = 0;
unsigned long scan, nr_pages;
LIST_HEAD(pages_skipped);
@@ -1479,14 +1480,13 @@ static unsigned long isolate_lru_pages(u
*/
if (!list_empty(&pages_skipped)) {
int zid;
- unsigned long total_skipped = 0;
for (zid = 0; zid < MAX_NR_ZONES; zid++) {
if (!nr_skipped[zid])
continue;
__count_zid_vm_events(PGSCAN_SKIP, zid, nr_skipped[zid]);
- total_skipped += nr_skipped[zid];
+ skipped += nr_skipped[zid];
}
/*
@@ -1494,13 +1494,13 @@ static unsigned long isolate_lru_pages(u
* close to unreclaimable. If the LRU list is empty, account
* skipped pages as a full scan.
*/
- scan += list_empty(src) ? total_skipped : total_skipped >> 2;
+ total_skipped = list_empty(src) ? skipped : skipped >> 2;
list_splice(&pages_skipped, src);
}
- *nr_scanned = scan;
+ *nr_scanned = scan + total_skipped;
trace_mm_vmscan_lru_isolate(sc->reclaim_idx, sc->order, nr_to_scan, scan,
- nr_taken, mode, is_file_lru(lru));
+ skipped, nr_taken, mode, is_file_lru(lru));
update_lru_sizes(lruvec, lru, nr_zone_taken, nr_taken);
return nr_taken;
}
_
Patches currently in -mm which might be from mhocko@xxxxxxxx are
mm-slab-make-sure-that-kmalloc_max_size-will-fit-into-max_order.patch
bpf-do-not-use-kmalloc_shift_max.patch
mm-fix-remote-numa-hits-statistics.patch
mm-get-rid-of-__gfp_other_node.patch
mm-throttle-show_mem-from-warn_alloc.patch
mm-trace-extract-compaction_status-and-zone_type-to-a-common-header.patch
oom-trace-add-oom-detection-tracepoints.patch
oom-trace-add-compaction-retry-tracepoint.patch
mm-vmscan-remove-unused-mm_vmscan_memcg_isolate.patch
mm-vmscan-add-active-list-aging-tracepoint.patch
mm-vmscan-add-active-list-aging-tracepoint-update.patch
mm-vmscan-show-the-number-of-skipped-pages-in-mm_vmscan_lru_isolate.patch
mm-vmscan-show-lru-name-in-mm_vmscan_lru_isolate-tracepoint.patch
mm-vmscan-extract-shrink_page_list-reclaim-counters-into-a-struct.patch
mm-vmscan-enhance-mm_vmscan_lru_shrink_inactive-tracepoint.patch
mm-vmscan-add-mm_vmscan_inactive_list_is_low-tracepoint.patch
trace-vmscan-postprocess-sync-with-tracepoints-updates.patch
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