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>
diff --git a/fs/nilfs2/sufile.c b/fs/nilfs2/sufile.c
index 2a869c3..7ff8f15 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 @@
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 @@
nilfs_mdt_mark_dirty(sufile);
brelse(su_bh);
*segnump = segnum;
+
+ trace_nilfs2_segment_usage_allocated(sufile, segnum);
+
goto out_header;
}
@@ -490,6 +496,8 @@
NILFS_SUI(sufile)->ncleansegs++;
nilfs_mdt_mark_dirty(sufile);
+
+ trace_nilfs2_segment_usage_freed(sufile, segnum);
}
/**