From 44fda114601fa5edebeacecb265f09d802670bc0 Mon Sep 17 00:00:00 2001 From: Hitoshi Mitake Date: Fri, 6 Nov 2015 16:32:02 -0800 Subject: 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: Hitoshi Mitake Signed-off-by: Ryusuke Konishi Cc: Steven Rostedt Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/nilfs2/segment.c | 33 ++++++++++++++++++++++++++++++++- 1 file changed, 32 insertions(+), 1 deletion(-) (limited to 'fs/nilfs2') diff --git a/fs/nilfs2/segment.c b/fs/nilfs2/segment.c index ef354043b87c..3fc47326fbe1 100644 --- a/fs/nilfs2/segment.c +++ b/fs/nilfs2/segment.c @@ -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, -- cgit v1.2.3