Added optional container checkpointing statistics

This adds the parameter '--print-stats' to 'podman container checkpoint'.
With '--print-stats' Podman will measure how long Podman itself, the OCI
runtime and CRIU requires to create a checkpoint and print out these
information. CRIU already creates checkpointing statistics which are
just read in addition to the added measurements. In contrast to just
printing out the ID of the checkpointed container, Podman will now print
out JSON:

 # podman container checkpoint --latest --print-stats
 {
     "podman_checkpoint_duration": 360749,
     "container_statistics": [
         {
             "Id": "25244244bf2efbef30fb6857ddea8cb2e5489f07eb6659e20dda117f0c466808",
             "runtime_checkpoint_duration": 177222,
             "criu_statistics": {
                 "freezing_time": 100657,
                 "frozen_time": 60700,
                 "memdump_time": 8162,
                 "memwrite_time": 4224,
                 "pages_scanned": 20561,
                 "pages_written": 2129
             }
         }
     ]
 }

The output contains 'podman_checkpoint_duration' which contains the
number of microseconds Podman required to create the checkpoint. The
output also includes 'runtime_checkpoint_duration' which is the time
the runtime needed to checkpoint that specific container. Each container
also includes 'criu_statistics' which displays the timing information
collected by CRIU.

Signed-off-by: Adrian Reber <areber@redhat.com>

1 files changed, 32 insertions, 0 deletions

diff --git a/libpod/define/checkpoint_restore.go b/libpod/define/checkpoint_restore.go
new file mode 100644
index 000000000..536bdde9a
--- /dev/null
+++ b/libpod/define/checkpoint_restore.go
@@ -0,0 +1,32 @@
+package define
+
+// This contains values reported by CRIU during
+// checkpointing or restoring.
+// All names are the same as reported by CRIU.
+type CRIUCheckpointRestoreStatistics struct {
+	// Checkpoint values
+	// Time required to freeze/pause/quiesce the processes
+	FreezingTime uint32 `json:"freezing_time,omitempty"`
+	// Time the processes are actually not running during checkpointing
+	FrozenTime uint32 `json:"frozen_time,omitempty"`
+	// Time required to extract memory pages from the processes
+	MemdumpTime uint32 `json:"memdump_time,omitempty"`
+	// Time required to write memory pages to disk
+	MemwriteTime uint32 `json:"memwrite_time,omitempty"`
+	// Number of memory pages CRIU analyzed
+	PagesScanned uint64 `json:"pages_scanned,omitempty"`
+	// Number of memory pages written
+	PagesWritten uint64 `json:"pages_written,omitempty"`
+
+	// Restore values
+	// Number of pages compared during restore
+	PagesCompared uint64 `json:"pages_compared,omitempty"`
+	// Number of COW pages skipped during restore
+	PagesSkippedCow uint64 `json:"pages_skipped_cow,omitempty"`
+	// Time required to fork processes
+	ForkingTime uint32 `json:"forking_time,omitempty"`
+	// Time required to restore
+	RestoreTime uint32 `json:"restore_time,omitempty"`
+	// Number of memory pages restored
+	PagesRestored uint64 `json:"pages_restored,omitempty"`
+}