[PATCH 12/12] hv_balloon: trace post_status

From: kys
Date: Sun Feb 11 2018 - 19:39:30 EST


From: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>

Hyper-V balloon driver makes non-trivial calculations to convert Linux's
representation of free/used memory to what Hyper-V host expects to see. Add
a tracepoint to see what's being sent and where the data comes from.

Signed-off-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
Signed-off-by: K. Y. Srinivasan <kys@xxxxxxxxxxxxx>
---
drivers/hv/Makefile | 1 +
drivers/hv/hv_balloon.c | 6 ++++++
drivers/hv/hv_trace_balloon.h | 48 +++++++++++++++++++++++++++++++++++++++++++
3 files changed, 55 insertions(+)
create mode 100644 drivers/hv/hv_trace_balloon.h

diff --git a/drivers/hv/Makefile b/drivers/hv/Makefile
index 14c22786b519..a1eec7177c2d 100644
--- a/drivers/hv/Makefile
+++ b/drivers/hv/Makefile
@@ -4,6 +4,7 @@ obj-$(CONFIG_HYPERV_UTILS) += hv_utils.o
obj-$(CONFIG_HYPERV_BALLOON) += hv_balloon.o

CFLAGS_hv_trace.o = -I$(src)
+CFLAGS_hv_balloon.o = -I$(src)

hv_vmbus-y := vmbus_drv.o \
hv.o connection.o channel.o \
diff --git a/drivers/hv/hv_balloon.c b/drivers/hv/hv_balloon.c
index 7514a32d0de4..b3e9f13f8bc3 100644
--- a/drivers/hv/hv_balloon.c
+++ b/drivers/hv/hv_balloon.c
@@ -34,6 +34,9 @@

#include <linux/hyperv.h>

+#define CREATE_TRACE_POINTS
+#include "hv_trace_balloon.h"
+
/*
* We begin with definitions supporting the Dynamic Memory protocol
* with the host.
@@ -1159,6 +1162,9 @@ static void post_status(struct hv_dynmem_device *dm)
dm->num_pages_added - dm->num_pages_onlined : 0) +
compute_balloon_floor();

+ trace_balloon_status(status.num_avail, status.num_committed,
+ vm_memory_committed(), dm->num_pages_ballooned,
+ dm->num_pages_added, dm->num_pages_onlined);
/*
* If our transaction ID is no longer current, just don't
* send the status. This can happen if we were interrupted
diff --git a/drivers/hv/hv_trace_balloon.h b/drivers/hv/hv_trace_balloon.h
new file mode 100644
index 000000000000..93082888aec3
--- /dev/null
+++ b/drivers/hv/hv_trace_balloon.h
@@ -0,0 +1,48 @@
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM hyperv
+
+#if !defined(_HV_TRACE_BALLOON_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _HV_TRACE_BALLOON_H
+
+#include <linux/tracepoint.h>
+
+TRACE_EVENT(balloon_status,
+ TP_PROTO(u64 available, u64 committed,
+ unsigned long vm_memory_committed,
+ unsigned long pages_ballooned,
+ unsigned long pages_added,
+ unsigned long pages_onlined),
+ TP_ARGS(available, committed, vm_memory_committed,
+ pages_ballooned, pages_added, pages_onlined),
+ TP_STRUCT__entry(
+ __field(u64, available)
+ __field(u64, committed)
+ __field(unsigned long, vm_memory_committed)
+ __field(unsigned long, pages_ballooned)
+ __field(unsigned long, pages_added)
+ __field(unsigned long, pages_onlined)
+ ),
+ TP_fast_assign(
+ __entry->available = available;
+ __entry->committed = committed;
+ __entry->vm_memory_committed = vm_memory_committed;
+ __entry->pages_ballooned = pages_ballooned;
+ __entry->pages_added = pages_added;
+ __entry->pages_onlined = pages_onlined;
+ ),
+ TP_printk("available %lld, committed %lld; vm_memory_committed %ld;"
+ " pages_ballooned %ld, pages_added %ld, pages_onlined %ld",
+ __entry->available, __entry->committed,
+ __entry->vm_memory_committed, __entry->pages_ballooned,
+ __entry->pages_added, __entry->pages_onlined
+ )
+ );
+
+#undef TRACE_INCLUDE_PATH
+#define TRACE_INCLUDE_PATH .
+#undef TRACE_INCLUDE_FILE
+#define TRACE_INCLUDE_FILE hv_trace_balloon
+#endif /* _HV_TRACE_BALLOON_H */
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>
--
2.15.1