From 83eec5e6dd10f0b1ab83ee660c8be883b3da7ba8 Mon Sep 17 00:00:00 2001
From: Hitoshi Mitake <mitake.hitoshi@lab.ntt.co.jp>
Date: Fri, 6 Nov 2015 16:32:05 -0800
Subject: nilfs2: add tracepoints for analyzing sufile manipulation

This patch adds tracepoints which would be useful for analyzing segment
usage from a perspective of high level sufile manipulation (check, alloc,
free).  sufile is an important in-place updated metadata file, so
analyzing the behavior would be useful for performance turning.

example of usage (a case of allocation):

$ sudo bin/tpoint nilfs2:nilfs2_segment_usage_allocated
Tracing nilfs2:nilfs2_segment_usage_allocated. Ctrl-C to end.
        segctord-17800 [002] ...1 10671.867294: nilfs2_segment_usage_allocated: sufile = ffff880054f908a8 segnum = 2
        segctord-17800 [002] ...1 10675.073477: nilfs2_segment_usage_allocated: sufile = ffff880054f908a8 segnum = 3

Signed-off-by: Hitoshi Mitake <mitake.hitoshi@lab.ntt.co.jp>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Benixon Dhas <benixon.dhas@wdc.com>
Cc: TK Kato <TK.Kato@wdc.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
 fs/nilfs2/sufile.c | 8 ++++++++
 1 file changed, 8 insertions(+)

(limited to 'fs')

diff --git a/fs/nilfs2/sufile.c b/fs/nilfs2/sufile.c
index 2a869c35c362..7ff8f15207ab 100644
--- a/fs/nilfs2/sufile.c
+++ b/fs/nilfs2/sufile.c
@@ -30,6 +30,8 @@
 #include "mdt.h"
 #include "sufile.h"
 
+#include <trace/events/nilfs2.h>
+
 /**
  * struct nilfs_sufile_info - on-memory private data of sufile
  * @mi: on-memory private data of metadata file
@@ -358,6 +360,7 @@ int nilfs_sufile_alloc(struct inode *sufile, __u64 *segnump)
 				break; /* never happens */
 			}
 		}
+		trace_nilfs2_segment_usage_check(sufile, segnum, cnt);
 		ret = nilfs_sufile_get_segment_usage_block(sufile, segnum, 1,
 							   &su_bh);
 		if (ret < 0)
@@ -388,6 +391,9 @@ int nilfs_sufile_alloc(struct inode *sufile, __u64 *segnump)
 			nilfs_mdt_mark_dirty(sufile);
 			brelse(su_bh);
 			*segnump = segnum;
+
+			trace_nilfs2_segment_usage_allocated(sufile, segnum);
+
 			goto out_header;
 		}
 
@@ -490,6 +496,8 @@ void nilfs_sufile_do_free(struct inode *sufile, __u64 segnum,
 	NILFS_SUI(sufile)->ncleansegs++;
 
 	nilfs_mdt_mark_dirty(sufile);
+
+	trace_nilfs2_segment_usage_freed(sufile, segnum);
 }
 
 /**
-- 
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