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
Cc: Benixon Dhas <benixon.d...@wdc.com>
Cc: TK Kato <tk.k...@wdc.com>
Signed-off-by: Hitoshi Mitake <mitake.hito...@lab.ntt.co.jp>
---
fs/nilfs2/sufile.c | 8 ++++++
include/trace/events/nilfs2.h | 67 +++++++++++++++++++++++++++++++++++++++++++
2 files changed, 75 insertions(+)
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 @@ 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);
}
/**
diff --git a/include/trace/events/nilfs2.h b/include/trace/events/nilfs2.h
index e5649ac..1b65ba6 100644
--- a/include/trace/events/nilfs2.h
+++ b/include/trace/events/nilfs2.h
@@ -95,6 +95,73 @@ TRACE_EVENT(nilfs2_transaction_transition,
show_transaction_state(__entry->state))
);
+TRACE_EVENT(nilfs2_segment_usage_check,
+ TP_PROTO(struct inode *sufile,
+ __u64 segnum,
+ unsigned long cnt),
+
+ TP_ARGS(sufile, segnum, cnt),
+
+ TP_STRUCT__entry(
+ __field(struct inode *, sufile)
+ __field(__u64, segnum)
+ __field(unsigned long, cnt)
+ ),
+
+ TP_fast_assign(
+ __entry->sufile = sufile;
+ __entry->segnum = segnum;
+ __entry->cnt = cnt;
+ ),
+
+ TP_printk("sufile = %p segnum = %llu cnt = %lu",
+ __entry->sufile,
+ __entry->segnum,
+ __entry->cnt)
+);
+
+TRACE_EVENT(nilfs2_segment_usage_allocated,
+ TP_PROTO(struct inode *sufile,
+ __u64 segnum),
+
+ TP_ARGS(sufile, segnum),
+
+ TP_STRUCT__entry(
+ __field(struct inode *, sufile)
+ __field(__u64, segnum)
+ ),
+
+ TP_fast_assign(
+ __entry->sufile = sufile;
+ __entry->segnum = segnum;
+ ),
+
+ TP_printk("sufile = %p segnum = %llu",
+ __entry->sufile,
+ __entry->segnum)
+);
+
+TRACE_EVENT(nilfs2_segment_usage_freed,
+ TP_PROTO(struct inode *sufile,
+ __u64 segnum),
+
+ TP_ARGS(sufile, segnum),
+
+ TP_STRUCT__entry(
+ __field(struct inode *, sufile)
+ __field(__u64, segnum)
+ ),
+
+ TP_fast_assign(
+ __entry->sufile = sufile;
+ __entry->segnum = segnum;
+ ),
+
+ TP_printk("sufile = %p segnum = %llu",
+ __entry->sufile,
+ __entry->segnum)
+);
+
#endif /* _TRACE_NILFS2_H */
/* This part must be outside protection */
--
1.9.1
--
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