[PATCH v2 2/3] mm, compaction: export tracepoints zone names to userspace

From: Vlastimil Babka
Date: Tue Sep 22 2015 - 05:33:37 EST


Some compaction tracepoints use zone->name to print which zone is being
compacted. This works for in-kernel printing, but not userspace trace printing
of raw captured trace such as via trace-cmd report.

This patch uses zone_idx() instead of zone->name as the raw value, and when
printing, converts the zone_type to string using the appropriate EM() macros
and some ugly tricks to overcome the problem that half the values depend on
CONFIG_ options and one does not simply use #ifdef inside of #define.

trace-cmd output before:
transhuge-stres-4235 [000] 453.149280: mm_compaction_finished: node=0
zone=ffffffff81815d7a order=9 ret=partial

after:
transhuge-stres-4235 [000] 453.149280: mm_compaction_finished: node=0
zone=Normal order=9 ret=partial

Signed-off-by: Vlastimil Babka <vbabka@xxxxxxx>
Reviewed-by: Steven Rostedt <rostedt@xxxxxxxxxxx>
Cc: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Mel Gorman <mgorman@xxxxxxx>
Cc: David Rientjes <rientjes@xxxxxxxxxx>
---
v2: add Reviewed-by.

include/trace/events/compaction.h | 38 ++++++++++++++++++++++++++++++++------
1 file changed, 32 insertions(+), 6 deletions(-)

diff --git a/include/trace/events/compaction.h b/include/trace/events/compaction.h
index 1275a55..8daa8fa 100644
--- a/include/trace/events/compaction.h
+++ b/include/trace/events/compaction.h
@@ -18,6 +18,31 @@
EM( COMPACT_NO_SUITABLE_PAGE, "no_suitable_page") \
EMe(COMPACT_NOT_SUITABLE_ZONE, "not_suitable_zone")

+#ifdef CONFIG_ZONE_DMA
+#define IFDEF_ZONE_DMA(X) X
+#else
+#define IFDEF_ZONE_DMA(X)
+#endif
+
+#ifdef CONFIG_ZONE_DMA32
+#define IFDEF_ZONE_DMA32(X) X
+#else
+#define IFDEF_ZONE_DMA32(X)
+#endif
+
+#ifdef CONFIG_ZONE_HIGHMEM_
+#define IFDEF_ZONE_HIGHMEM(X) X
+#else
+#define IFDEF_ZONE_HIGHMEM(X)
+#endif
+
+#define ZONE_TYPE \
+ IFDEF_ZONE_DMA( EM (ZONE_DMA, "DMA")) \
+ IFDEF_ZONE_DMA32( EM (ZONE_DMA32, "DMA32")) \
+ EM (ZONE_NORMAL, "Normal") \
+ IFDEF_ZONE_HIGHMEM( EM (ZONE_HIGHMEM,"HighMem")) \
+ EMe(ZONE_MOVABLE,"Movable")
+
/*
* First define the enums in the above macros to be exported to userspace
* via TRACE_DEFINE_ENUM().
@@ -28,6 +53,7 @@
#define EMe(a, b) TRACE_DEFINE_ENUM(a);

COMPACTION_STATUS
+ZONE_TYPE

/*
* Now redefine the EM() and EMe() macros to map the enums to the strings
@@ -230,21 +256,21 @@ DECLARE_EVENT_CLASS(mm_compaction_suitable_template,

TP_STRUCT__entry(
__field(int, nid)
- __field(char *, name)
+ __field(enum zone_type, idx)
__field(int, order)
__field(int, ret)
),

TP_fast_assign(
__entry->nid = zone_to_nid(zone);
- __entry->name = (char *)zone->name;
+ __entry->idx = zone_idx(zone);
__entry->order = order;
__entry->ret = ret;
),

TP_printk("node=%d zone=%-8s order=%d ret=%s",
__entry->nid,
- __entry->name,
+ __print_symbolic(__entry->idx, ZONE_TYPE),
__entry->order,
__print_symbolic(__entry->ret, COMPACTION_STATUS))
);
@@ -276,7 +302,7 @@ DECLARE_EVENT_CLASS(mm_compaction_defer_template,

TP_STRUCT__entry(
__field(int, nid)
- __field(char *, name)
+ __field(enum zone_type, idx)
__field(int, order)
__field(unsigned int, considered)
__field(unsigned int, defer_shift)
@@ -285,7 +311,7 @@ DECLARE_EVENT_CLASS(mm_compaction_defer_template,

TP_fast_assign(
__entry->nid = zone_to_nid(zone);
- __entry->name = (char *)zone->name;
+ __entry->idx = zone_idx(zone);
__entry->order = order;
__entry->considered = zone->compact_considered;
__entry->defer_shift = zone->compact_defer_shift;
@@ -294,7 +320,7 @@ DECLARE_EVENT_CLASS(mm_compaction_defer_template,

TP_printk("node=%d zone=%-8s order=%d order_failed=%d consider=%u limit=%lu",
__entry->nid,
- __entry->name,
+ __print_symbolic(__entry->idx, ZONE_TYPE),
__entry->order,
__entry->order_failed,
__entry->considered,
--
2.5.1

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