Commit 44fda114 authored by Hitoshi Mitake's avatar Hitoshi Mitake Committed by Linus Torvalds

nilfs2: add a tracepoint for transaction events

This patch adds a tracepoint for transaction events of nilfs.  With the
tracepoint, these events can be tracked: begin, abort, commit, trylock,
lock, and unlock.  Basically, these events have corresponding functions
e.g.  begin event corresponds nilfs_transaction_begin().  The unlock event
is an exception.  It corresponds to the iteration in
nilfs_transaction_lock().

Only one tracepoint is introcued: nilfs2_transaction_transition.  The
above events are distinguished with newly introduced enum.  With this
tracepoint, we can analyse a critical section of segment constructoin.

Sample output by tpoint of perf-tools:
              cp-4457  [000] ...1    63.266220: nilfs2_transaction_transition: sb = ffff8802112b8800 ti = ffff8800bf5ccc58 count = 1 flags = 9 state = BEGIN
              cp-4457  [000] ...1    63.266221: nilfs2_transaction_transition: sb = ffff8802112b8800 ti = ffff8800bf5ccc58 count = 0 flags = 9 state = COMMIT
              cp-4457  [000] ...1    63.266221: nilfs2_transaction_transition: sb = ffff8802112b8800 ti = ffff8800bf5ccc58 count = 0 flags = 9 state = COMMIT
        segctord-4371  [001] ...1    68.261196: nilfs2_transaction_transition: sb = ffff8802112b8800 ti = ffff8800b889bdf8 count = 0 flags = 10 state = TRYLOCK
        segctord-4371  [001] ...1    68.261280: nilfs2_transaction_transition: sb = ffff8802112b8800 ti = ffff8800b889bdf8 count = 0 flags = 10 state = LOCK
        segctord-4371  [001] ...1    68.261877: nilfs2_transaction_transition: sb = ffff8802112b8800 ti = ffff8800b889bdf8 count = 1 flags = 10 state = BEGIN
        segctord-4371  [001] ...1    68.262116: nilfs2_transaction_transition: sb = ffff8802112b8800 ti = ffff8800b889bdf8 count = 0 flags = 18 state = COMMIT
        segctord-4371  [001] ...1    68.265032: nilfs2_transaction_transition: sb = ffff8802112b8800 ti = ffff8800b889bdf8 count = 0 flags = 18 state = UNLOCK
        segctord-4371  [001] ...1   132.376847: nilfs2_transaction_transition: sb = ffff8802112b8800 ti = ffff8800b889bdf8 count = 0 flags = 10 state = TRYLOCK

This patch also does trivial cleaning of comma usage in collection stage
transition event for consistent coding style.
Signed-off-by: default avatarHitoshi Mitake <mitake.hitoshi@lab.ntt.co.jp>
Signed-off-by: default avatarRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 58497703
......@@ -214,11 +214,18 @@ int nilfs_transaction_begin(struct super_block *sb,
{
struct the_nilfs *nilfs;
int ret = nilfs_prepare_segment_lock(ti);
struct nilfs_transaction_info *trace_ti;
if (unlikely(ret < 0))
return ret;
if (ret > 0)
if (ret > 0) {
trace_ti = current->journal_info;
trace_nilfs2_transaction_transition(sb, trace_ti,
trace_ti->ti_count, trace_ti->ti_flags,
TRACE_NILFS2_TRANSACTION_BEGIN);
return 0;
}
sb_start_intwrite(sb);
......@@ -229,6 +236,11 @@ int nilfs_transaction_begin(struct super_block *sb,
ret = -ENOSPC;
goto failed;
}
trace_ti = current->journal_info;
trace_nilfs2_transaction_transition(sb, trace_ti, trace_ti->ti_count,
trace_ti->ti_flags,
TRACE_NILFS2_TRANSACTION_BEGIN);
return 0;
failed:
......@@ -261,6 +273,8 @@ int nilfs_transaction_commit(struct super_block *sb)
ti->ti_flags |= NILFS_TI_COMMIT;
if (ti->ti_count > 0) {
ti->ti_count--;
trace_nilfs2_transaction_transition(sb, ti, ti->ti_count,
ti->ti_flags, TRACE_NILFS2_TRANSACTION_COMMIT);
return 0;
}
if (nilfs->ns_writer) {
......@@ -272,6 +286,9 @@ int nilfs_transaction_commit(struct super_block *sb)
nilfs_segctor_do_flush(sci, 0);
}
up_read(&nilfs->ns_segctor_sem);
trace_nilfs2_transaction_transition(sb, ti, ti->ti_count,
ti->ti_flags, TRACE_NILFS2_TRANSACTION_COMMIT);
current->journal_info = ti->ti_save;
if (ti->ti_flags & NILFS_TI_SYNC)
......@@ -290,10 +307,15 @@ void nilfs_transaction_abort(struct super_block *sb)
BUG_ON(ti == NULL || ti->ti_magic != NILFS_TI_MAGIC);
if (ti->ti_count > 0) {
ti->ti_count--;
trace_nilfs2_transaction_transition(sb, ti, ti->ti_count,
ti->ti_flags, TRACE_NILFS2_TRANSACTION_ABORT);
return;
}
up_read(&nilfs->ns_segctor_sem);
trace_nilfs2_transaction_transition(sb, ti, ti->ti_count,
ti->ti_flags, TRACE_NILFS2_TRANSACTION_ABORT);
current->journal_info = ti->ti_save;
if (ti->ti_flags & NILFS_TI_DYNAMIC_ALLOC)
kmem_cache_free(nilfs_transaction_cachep, ti);
......@@ -339,6 +361,9 @@ static void nilfs_transaction_lock(struct super_block *sb,
current->journal_info = ti;
for (;;) {
trace_nilfs2_transaction_transition(sb, ti, ti->ti_count,
ti->ti_flags, TRACE_NILFS2_TRANSACTION_TRYLOCK);
down_write(&nilfs->ns_segctor_sem);
if (!test_bit(NILFS_SC_PRIOR_FLUSH, &sci->sc_flags))
break;
......@@ -350,6 +375,9 @@ static void nilfs_transaction_lock(struct super_block *sb,
}
if (gcflag)
ti->ti_flags |= NILFS_TI_GC;
trace_nilfs2_transaction_transition(sb, ti, ti->ti_count,
ti->ti_flags, TRACE_NILFS2_TRANSACTION_LOCK);
}
static void nilfs_transaction_unlock(struct super_block *sb)
......@@ -362,6 +390,9 @@ static void nilfs_transaction_unlock(struct super_block *sb)
up_write(&nilfs->ns_segctor_sem);
current->journal_info = ti->ti_save;
trace_nilfs2_transaction_transition(sb, ti, ti->ti_count,
ti->ti_flags, TRACE_NILFS2_TRANSACTION_UNLOCK);
}
static void *nilfs_segctor_map_segsum_entry(struct nilfs_sc_info *sci,
......
......@@ -42,6 +42,59 @@ TRACE_EVENT(nilfs2_collection_stage_transition,
show_collection_stage(__entry->stage))
);
#ifndef TRACE_HEADER_MULTI_READ
enum nilfs2_transaction_transition_state {
TRACE_NILFS2_TRANSACTION_BEGIN,
TRACE_NILFS2_TRANSACTION_COMMIT,
TRACE_NILFS2_TRANSACTION_ABORT,
TRACE_NILFS2_TRANSACTION_TRYLOCK,
TRACE_NILFS2_TRANSACTION_LOCK,
TRACE_NILFS2_TRANSACTION_UNLOCK,
};
#endif
#define show_transaction_state(type) \
__print_symbolic(type, \
{ TRACE_NILFS2_TRANSACTION_BEGIN, "BEGIN" }, \
{ TRACE_NILFS2_TRANSACTION_COMMIT, "COMMIT" }, \
{ TRACE_NILFS2_TRANSACTION_ABORT, "ABORT" }, \
{ TRACE_NILFS2_TRANSACTION_TRYLOCK, "TRYLOCK" }, \
{ TRACE_NILFS2_TRANSACTION_LOCK, "LOCK" }, \
{ TRACE_NILFS2_TRANSACTION_UNLOCK, "UNLOCK" })
TRACE_EVENT(nilfs2_transaction_transition,
TP_PROTO(struct super_block *sb,
struct nilfs_transaction_info *ti,
int count,
unsigned int flags,
enum nilfs2_transaction_transition_state state),
TP_ARGS(sb, ti, count, flags, state),
TP_STRUCT__entry(
__field(void *, sb)
__field(void *, ti)
__field(int, count)
__field(unsigned int, flags)
__field(int, state)
),
TP_fast_assign(
__entry->sb = sb;
__entry->ti = ti;
__entry->count = count;
__entry->flags = flags;
__entry->state = state;
),
TP_printk("sb = %p ti = %p count = %d flags = %x state = %s",
__entry->sb,
__entry->ti,
__entry->count,
__entry->flags,
show_transaction_state(__entry->state))
);
#endif /* _TRACE_NILFS2_H */
/* This part must be outside protection */
......
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