[PATCH 3/4] ext4: accumulate jbd2 stats in jiffies

[Eric Sandeen <sandeen@redhat.com>]

Accumulate jbd2 stats in jiffies not msecs, per akpm's suggestion.
Convert to msecs on when displayed.

jbd2_time_diff() should still be moved to a common header file.
 
Signed-off-by: Eric Sandeen <sandeen@redhat.com>

---

Index: linux-2.6.24-rc3/fs/jbd2/checkpoint.c
===================================================================
--- linux-2.6.24-rc3.orig/fs/jbd2/checkpoint.c
+++ linux-2.6.24-rc3/fs/jbd2/checkpoint.c
@@ -326,7 +326,7 @@ int jbd2_log_do_checkpoint(journal_t *jo
 		goto out;
 	transaction = journal->j_checkpoint_transactions;
 	if (transaction->t_chp_stats.cs_chp_time == 0)
-		transaction->t_chp_stats.cs_chp_time = CURRENT_MSECS;
+		transaction->t_chp_stats.cs_chp_time = jiffies;
 	this_tid = transaction->t_tid;
 restart:
 	/*
Index: linux-2.6.24-rc3/fs/jbd2/commit.c
===================================================================
--- linux-2.6.24-rc3.orig/fs/jbd2/commit.c
+++ linux-2.6.24-rc3/fs/jbd2/commit.c
@@ -340,7 +340,7 @@ void jbd2_journal_commit_transaction(jou
 	commit_transaction->t_state = T_LOCKED;
 
 	stats.ts_wait = commit_transaction->t_max_wait;
-	stats.ts_locked = CURRENT_MSECS;
+	stats.ts_locked = jiffies;
 	stats.ts_running = jbd2_time_diff(commit_transaction->t_start,
 						stats.ts_locked);
 
@@ -414,7 +414,7 @@ void jbd2_journal_commit_transaction(jou
 	 */
 	jbd2_journal_switch_revoke_table(journal);
 
-	stats.ts_flushing = CURRENT_MSECS;
+	stats.ts_flushing = jiffies;
 	stats.ts_locked = jbd2_time_diff(stats.ts_locked, stats.ts_flushing);
 
 	commit_transaction->t_state = T_FLUSH;
@@ -508,7 +508,7 @@ void jbd2_journal_commit_transaction(jou
 	 */
 	commit_transaction->t_state = T_COMMIT;
 
-	stats.ts_logging = CURRENT_MSECS;
+	stats.ts_logging = jiffies;
 	stats.ts_flushing = jbd2_time_diff(stats.ts_flushing, stats.ts_logging);
 	stats.ts_blocks = commit_transaction->t_outstanding_credits;
 	stats.ts_blocks_logged = 0;
@@ -907,7 +907,7 @@ restart_loop:
 
 	J_ASSERT(commit_transaction->t_state == T_COMMIT);
 
-	commit_transaction->t_start = CURRENT_MSECS;
+	commit_transaction->t_start = jiffies;
 	stats.ts_logging = jbd2_time_diff(stats.ts_logging,
 						commit_transaction->t_start);
 
Index: linux-2.6.24-rc3/fs/jbd2/transaction.c
===================================================================
--- linux-2.6.24-rc3.orig/fs/jbd2/transaction.c
+++ linux-2.6.24-rc3/fs/jbd2/transaction.c
@@ -60,7 +60,7 @@ jbd2_get_transaction(journal_t *journal,
 	J_ASSERT(journal->j_running_transaction == NULL);
 	journal->j_running_transaction = transaction;
 	transaction->t_max_wait = 0;
-	transaction->t_start = CURRENT_MSECS;
+	transaction->t_start = jiffies;
 
 	return transaction;
 }
@@ -87,7 +87,7 @@ static int start_this_handle(journal_t *
 	int nblocks = handle->h_buffer_credits;
 	transaction_t *new_transaction = NULL;
 	int ret = 0;
-	unsigned long ts = CURRENT_MSECS;
+	unsigned long ts = jiffies;
 
 	if (nblocks > journal->j_max_transaction_buffers) {
 		printk(KERN_ERR "JBD: %s wants too many credits (%d > %d)\n",
Index: linux-2.6.24-rc3/include/linux/jbd2.h
===================================================================
--- linux-2.6.24-rc3.orig/include/linux/jbd2.h
+++ linux-2.6.24-rc3/include/linux/jbd2.h
@@ -626,16 +626,13 @@ struct transaction_stats_s
 #define ts_written		u.chp.cs_written
 #define ts_dropped		u.chp.cs_dropped
 
-#define CURRENT_MSECS		(jiffies_to_msecs(jiffies))
-
-static inline unsigned int
-jbd2_time_diff(unsigned int start, unsigned int end)
+static inline unsigned long
+jbd2_time_diff(unsigned long start, unsigned long end)
 {
-	if (unlikely(start > end))
-		end = end + (~0UL - start);
-	else
-		end -= start;
-	return end;
+	if (end >= start)
+		return end - start;
+
+	return end + (MAX_JIFFY_OFFSET - start);
 }
 
 /**
Index: linux-2.6.24-rc3/fs/jbd2/journal.c
===================================================================
--- linux-2.6.24-rc3.orig/fs/jbd2/journal.c
+++ linux-2.6.24-rc3/fs/jbd2/journal.c
@@ -712,15 +712,19 @@ static int jbd2_seq_history_show(struct 
 		return 0;
 	}
 	if (ts->ts_type == JBD2_STATS_RUN)
-		seq_printf(seq, "%-4s %-5lu %-5lu %-5lu %-5lu %-5lu %-5lu "
+		seq_printf(seq, "%-4s %-5lu %-5u %-5u %-5u %-5u %-5u "
 				"%-6lu %-5lu %-5lu\n", "R", ts->ts_tid,
-				ts->ts_wait, ts->ts_running, ts->ts_locked,
-				ts->ts_flushing, ts->ts_logging,
+				jiffies_to_msecs(ts->ts_wait),
+				jiffies_to_msecs(ts->ts_running),
+				jiffies_to_msecs(ts->ts_locked),
+				jiffies_to_msecs(ts->ts_flushing),
+				jiffies_to_msecs(ts->ts_logging),
 				ts->ts_handle_count, ts->ts_blocks,
 				ts->ts_blocks_logged);
 	else if (ts->ts_type == JBD2_STATS_CHECKPOINT)
-		seq_printf(seq, "%-4s %-5lu %48s %-5lu %-5lu %-5lu %-5lu\n",
-				"C", ts->ts_tid, " ", ts->ts_chp_time,
+		seq_printf(seq, "%-4s %-5lu %48s %-5u %-5lu %-5lu %-5lu\n",
+				"C", ts->ts_tid, " ",
+				jiffies_to_msecs(ts->ts_chp_time),
 				ts->ts_written, ts->ts_dropped,
 				ts->ts_forced_to_close);
 	else
@@ -812,21 +816,21 @@ static int jbd2_seq_info_show(struct seq
 	if (s->stats->ts_tid == 0)
 		return 0;
 	seq_printf(seq, "average: \n  %lums waiting for transaction\n",
-			s->stats->ts_wait / s->stats->ts_tid);
+		   jiffies_to_msecs(s->stats->ts_wait / s->stats->ts_tid));
 	seq_printf(seq, "  %lums running transaction\n",
-			s->stats->ts_running / s->stats->ts_tid);
+		   jiffies_to_msecs(s->stats->ts_running / s->stats->ts_tid));
 	seq_printf(seq, "  %lums transaction was being locked\n",
-			s->stats->ts_locked / s->stats->ts_tid);
+		   jiffies_to_msecs(s->stats->ts_locked / s->stats->ts_tid));
 	seq_printf(seq, "  %lums flushing data (in ordered mode)\n",
-			s->stats->ts_flushing / s->stats->ts_tid);
+		   jiffies_to_msecs(s->stats->ts_flushing / s->stats->ts_tid));
 	seq_printf(seq, "  %lums logging transaction\n",
-			s->stats->ts_logging / s->stats->ts_tid);
+		   jiffies_to_msecs(s->stats->ts_logging / s->stats->ts_tid));
 	seq_printf(seq, "  %lu handles per transaction\n",
-			s->stats->ts_handle_count / s->stats->ts_tid);
+		   s->stats->ts_handle_count / s->stats->ts_tid);
 	seq_printf(seq, "  %lu blocks per transaction\n",
-			s->stats->ts_blocks / s->stats->ts_tid);
+		   s->stats->ts_blocks / s->stats->ts_tid);
 	seq_printf(seq, "  %lu logged blocks per transaction\n",
-			s->stats->ts_blocks_logged / s->stats->ts_tid);
+		   s->stats->ts_blocks_logged / s->stats->ts_tid);
 	return 0;
 }