Hi,
This patch changes the log_flush kernel trace point so that it
actually gives you meaningful statistics about the journal:
Output looks like this:
gfs2_logd-10580 [009] .... 1390.398627: gfs2_log_flush: 253,8 log flush
start 8532 r:0 cr:0 v:0 f:5002 n:6153 h:5570/5570 t:2380 a1:2 a2:0 o:1 l:0 i:1
r: sd_log_blks_reserved
cr: sd_log_commited_revoke
v: sd_log_num_revoke
f: sd_log_blks_free
n: sd_log_blks_needed
h: sd_log_head / sd_log_flush_head
t: sd_log_tail
a1: count of items on the sd_ail1_list
a2: count of items on the sd_ail2_list
o: count of items on the sd_log_le_ordered list
l: sd_log_in_flight
i: sd_log_idle
Signed-off-by: Bob Peterson <rpete...@redhat.com>
---
diff --git a/fs/gfs2/trace_gfs2.h b/fs/gfs2/trace_gfs2.h
index 49ac55d..cdecd1c 100644
--- a/fs/gfs2/trace_gfs2.h
+++ b/fs/gfs2/trace_gfs2.h
@@ -73,6 +73,16 @@ static inline u8 glock_trace_state(unsigned int state)
}
return DLM_LOCK_NL;
}
+
+static inline const unsigned int list_count(const struct list_head *head)
+{
+ const struct list_head *tmp;
+ unsigned int count = 0;
+ list_for_each(tmp, head)
+ count++;
+ return count;
+}
+
#endif
/* Section 1 - Locking
@@ -359,18 +369,58 @@ TRACE_EVENT(gfs2_log_flush,
__field( dev_t, dev )
__field( int, start )
__field( u64, log_seq )
+ __field( unsigned int, sd_log_blks_reserved )
+ __field( int, sd_log_commited_revoke )
+ __field( unsigned int, sd_log_num_revoke )
+ __field( int, sd_log_blks_free )
+ __field( int, sd_log_blks_needed )
+ __field( unsigned int, sd_log_head )
+ __field( unsigned int, sd_log_flush_head )
+ __field( unsigned int, sd_log_tail )
+ __field( unsigned int, ail1_count )
+ __field( unsigned int, ail2_count )
+ __field( unsigned int, ordered_count )
+ __field( int, sd_log_in_flight )
+ __field( int, sd_log_idle )
),
TP_fast_assign(
__entry->dev = sdp->sd_vfs->s_dev;
__entry->start = start;
__entry->log_seq = sdp->sd_log_sequence;
+ __entry->sd_log_blks_reserved = sdp->sd_log_blks_reserved;
+ __entry->sd_log_commited_revoke = sdp->sd_log_commited_revoke;
+ __entry->sd_log_num_revoke = sdp->sd_log_num_revoke;
+ __entry->sd_log_blks_free =
atomic_read(&sdp->sd_log_blks_free);
+ __entry->sd_log_blks_needed =
atomic_read(&sdp->sd_log_blks_needed);
+ __entry->sd_log_head = sdp->sd_log_head;
+ __entry->sd_log_flush_head = sdp->sd_log_flush_head;
+ __entry->sd_log_tail = sdp->sd_log_tail;
+ __entry->ail1_count = list_count(&sdp->sd_ail1_list);
+ __entry->ail2_count = list_count(&sdp->sd_ail2_list);
+ __entry->ordered_count = list_count(&sdp->sd_log_le_ordered);
+ __entry->sd_log_in_flight = atomic_read(&sdp->sd_log_in_flight);
+ __entry->sd_log_idle = sdp->sd_log_idle;
),
- TP_printk("%u,%u log flush %s %llu",
+ TP_printk("%u,%u log flush %s %llu r:%u cr:%d v:%u "
+ "f:%d n:%d h:%u/%u t:%u a1:%u a2:%u o:%u l:%d i:%d",
MAJOR(__entry->dev), MINOR(__entry->dev),
__entry->start ? "start" : "end",
- (unsigned long long)__entry->log_seq)
+ (unsigned long long)__entry->log_seq,
+ __entry->sd_log_blks_reserved,
+ __entry->sd_log_commited_revoke,
+ __entry->sd_log_num_revoke,
+ __entry->sd_log_blks_free,
+ __entry->sd_log_blks_needed,
+ __entry->sd_log_head,
+ __entry->sd_log_flush_head,
+ __entry->sd_log_tail,
+ __entry->ail1_count,
+ __entry->ail2_count,
+ __entry->ordered_count,
+ __entry->sd_log_in_flight,
+ __entry->sd_log_idle)
);
/* Reserving/releasing blocks in the log */
