mm/compaction: enhance tracepoint output for compaction begin/end

We now have tracepoint for begin event of compaction and it prints start
position of both scanners, but, tracepoint for end event of compaction
doesn't print finish position of both scanners.  It'd be also useful to
know finish position of both scanners so this patch add it.  It will help
to find odd behavior or problem on compaction internal logic.

And mode is added to both begin/end tracepoint output, since according to
mode, compaction behavior is quite different.

And lastly, status format is changed to string rather than status number
for readability.

[akpm@linux-foundation.org: fix sparse warning]
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Mel Gorman <mgorman@suse.de>
Cc: David Rientjes <rientjes@google.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 1 insertions, 0 deletions

diff --git a/include/linux/compaction.h b/include/linux/compaction.h
index f2efda2e6ac6..db64cae06530 100644
--- a/include/linux/compaction.h
+++ b/include/linux/compaction.h
@@ -12,6 +12,7 @@
 #define COMPACT_PARTIAL		3
 /* The full zone was compacted */
 #define COMPACT_COMPLETE	4
+/* When adding new state, please change compaction_status_string, too */
 
 /* Used to signal whether compaction detected need_sched() or lock contention */
 /* No contention detected */