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

fs/nilfs2/segment.c

+32 −1
Original line number Diff line number Diff line
@@ -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,

include/trace/events/nilfs2.h

+53 −0
Original line number Diff line number Diff line
@@ -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 */



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