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authorJoonsoo Kim <iamjoonsoo.kim@lge.com>2015-02-11 15:27:09 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2015-02-11 17:06:04 -0800
commit24e2716f63e613cf15d3beba3faa0711bcacc427 (patch)
tree7ab8b73ff2977b76e4a3486730614999ea42e4d3
parent837d026d560c5ef26abeca0441713d82e4e82cad (diff)
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mm/compaction: add tracepoint to observe behaviour of compaction defer
Compaction deferring logic is heavy hammer that block the way to the compaction. It doesn't consider overall system state, so it could prevent user from doing compaction falsely. In other words, even if system has enough range of memory to compact, compaction would be skipped due to compaction deferring logic. This patch add new tracepoint to understand work of deferring logic. This will also help to check compaction success and fail. Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Mel Gorman <mgorman@suse.de> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--include/linux/compaction.h65
-rw-r--r--include/trace/events/compaction.h56
-rw-r--r--mm/compaction.c71
3 files changed, 132 insertions, 60 deletions
diff --git a/include/linux/compaction.h b/include/linux/compaction.h
index 501d7513aac1..a014559e4a49 100644
--- a/include/linux/compaction.h
+++ b/include/linux/compaction.h
@@ -44,66 +44,11 @@ extern void reset_isolation_suitable(pg_data_t *pgdat);
extern unsigned long compaction_suitable(struct zone *zone, int order,
int alloc_flags, int classzone_idx);
-/* Do not skip compaction more than 64 times */
-#define COMPACT_MAX_DEFER_SHIFT 6
-
-/*
- * Compaction is deferred when compaction fails to result in a page
- * allocation success. 1 << compact_defer_limit compactions are skipped up
- * to a limit of 1 << COMPACT_MAX_DEFER_SHIFT
- */
-static inline void defer_compaction(struct zone *zone, int order)
-{
- zone->compact_considered = 0;
- zone->compact_defer_shift++;
-
- if (order < zone->compact_order_failed)
- zone->compact_order_failed = order;
-
- if (zone->compact_defer_shift > COMPACT_MAX_DEFER_SHIFT)
- zone->compact_defer_shift = COMPACT_MAX_DEFER_SHIFT;
-}
-
-/* Returns true if compaction should be skipped this time */
-static inline bool compaction_deferred(struct zone *zone, int order)
-{
- unsigned long defer_limit = 1UL << zone->compact_defer_shift;
-
- if (order < zone->compact_order_failed)
- return false;
-
- /* Avoid possible overflow */
- if (++zone->compact_considered > defer_limit)
- zone->compact_considered = defer_limit;
-
- return zone->compact_considered < defer_limit;
-}
-
-/*
- * Update defer tracking counters after successful compaction of given order,
- * which means an allocation either succeeded (alloc_success == true) or is
- * expected to succeed.
- */
-static inline void compaction_defer_reset(struct zone *zone, int order,
- bool alloc_success)
-{
- if (alloc_success) {
- zone->compact_considered = 0;
- zone->compact_defer_shift = 0;
- }
- if (order >= zone->compact_order_failed)
- zone->compact_order_failed = order + 1;
-}
-
-/* Returns true if restarting compaction after many failures */
-static inline bool compaction_restarting(struct zone *zone, int order)
-{
- if (order < zone->compact_order_failed)
- return false;
-
- return zone->compact_defer_shift == COMPACT_MAX_DEFER_SHIFT &&
- zone->compact_considered >= 1UL << zone->compact_defer_shift;
-}
+extern void defer_compaction(struct zone *zone, int order);
+extern bool compaction_deferred(struct zone *zone, int order);
+extern void compaction_defer_reset(struct zone *zone, int order,
+ bool alloc_success);
+extern bool compaction_restarting(struct zone *zone, int order);
#else
static inline unsigned long try_to_compact_pages(gfp_t gfp_mask,
diff --git a/include/trace/events/compaction.h b/include/trace/events/compaction.h
index d46535801f63..9a6a3fe0fb51 100644
--- a/include/trace/events/compaction.h
+++ b/include/trace/events/compaction.h
@@ -238,6 +238,62 @@ DEFINE_EVENT(mm_compaction_suitable_template, mm_compaction_suitable,
TP_ARGS(zone, order, ret)
);
+#ifdef CONFIG_COMPACTION
+DECLARE_EVENT_CLASS(mm_compaction_defer_template,
+
+ TP_PROTO(struct zone *zone, int order),
+
+ TP_ARGS(zone, order),
+
+ TP_STRUCT__entry(
+ __field(int, nid)
+ __field(char *, name)
+ __field(int, order)
+ __field(unsigned int, considered)
+ __field(unsigned int, defer_shift)
+ __field(int, order_failed)
+ ),
+
+ TP_fast_assign(
+ __entry->nid = zone_to_nid(zone);
+ __entry->name = (char *)zone->name;
+ __entry->order = order;
+ __entry->considered = zone->compact_considered;
+ __entry->defer_shift = zone->compact_defer_shift;
+ __entry->order_failed = zone->compact_order_failed;
+ ),
+
+ TP_printk("node=%d zone=%-8s order=%d order_failed=%d consider=%u limit=%lu",
+ __entry->nid,
+ __entry->name,
+ __entry->order,
+ __entry->order_failed,
+ __entry->considered,
+ 1UL << __entry->defer_shift)
+);
+
+DEFINE_EVENT(mm_compaction_defer_template, mm_compaction_deferred,
+
+ TP_PROTO(struct zone *zone, int order),
+
+ TP_ARGS(zone, order)
+);
+
+DEFINE_EVENT(mm_compaction_defer_template, mm_compaction_defer_compaction,
+
+ TP_PROTO(struct zone *zone, int order),
+
+ TP_ARGS(zone, order)
+);
+
+DEFINE_EVENT(mm_compaction_defer_template, mm_compaction_defer_reset,
+
+ TP_PROTO(struct zone *zone, int order),
+
+ TP_ARGS(zone, order)
+);
+#endif
+
#endif /* _TRACE_COMPACTION_H */
/* This part must be outside protection */
diff --git a/mm/compaction.c b/mm/compaction.c
index b6ede459c1bb..b68736c8a1ce 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -124,6 +124,77 @@ static struct page *pageblock_pfn_to_page(unsigned long start_pfn,
}
#ifdef CONFIG_COMPACTION
+
+/* Do not skip compaction more than 64 times */
+#define COMPACT_MAX_DEFER_SHIFT 6
+
+/*
+ * Compaction is deferred when compaction fails to result in a page
+ * allocation success. 1 << compact_defer_limit compactions are skipped up
+ * to a limit of 1 << COMPACT_MAX_DEFER_SHIFT
+ */
+void defer_compaction(struct zone *zone, int order)
+{
+ zone->compact_considered = 0;
+ zone->compact_defer_shift++;
+
+ if (order < zone->compact_order_failed)
+ zone->compact_order_failed = order;
+
+ if (zone->compact_defer_shift > COMPACT_MAX_DEFER_SHIFT)
+ zone->compact_defer_shift = COMPACT_MAX_DEFER_SHIFT;
+
+ trace_mm_compaction_defer_compaction(zone, order);
+}
+
+/* Returns true if compaction should be skipped this time */
+bool compaction_deferred(struct zone *zone, int order)
+{
+ unsigned long defer_limit = 1UL << zone->compact_defer_shift;
+
+ if (order < zone->compact_order_failed)
+ return false;
+
+ /* Avoid possible overflow */
+ if (++zone->compact_considered > defer_limit)
+ zone->compact_considered = defer_limit;
+
+ if (zone->compact_considered >= defer_limit)
+ return false;
+
+ trace_mm_compaction_deferred(zone, order);
+
+ return true;
+}
+
+/*
+ * Update defer tracking counters after successful compaction of given order,
+ * which means an allocation either succeeded (alloc_success == true) or is
+ * expected to succeed.
+ */
+void compaction_defer_reset(struct zone *zone, int order,
+ bool alloc_success)
+{
+ if (alloc_success) {
+ zone->compact_considered = 0;
+ zone->compact_defer_shift = 0;
+ }
+ if (order >= zone->compact_order_failed)
+ zone->compact_order_failed = order + 1;
+
+ trace_mm_compaction_defer_reset(zone, order);
+}
+
+/* Returns true if restarting compaction after many failures */
+bool compaction_restarting(struct zone *zone, int order)
+{
+ if (order < zone->compact_order_failed)
+ return false;
+
+ return zone->compact_defer_shift == COMPACT_MAX_DEFER_SHIFT &&
+ zone->compact_considered >= 1UL << zone->compact_defer_shift;
+}
+
/* Returns true if the pageblock should be scanned for pages to isolate. */
static inline bool isolation_suitable(struct compact_control *cc,
struct page *page)