Awesome.
Thanks I will pull the patches build and test.
Regards
Laurence
Laurence Oberman
Red Hat Global Support Service
SEG Team
----- Original Message -----
From: "Mikulas Patocka" <mpatocka@xxxxxxxxxx>
To: "Alasdair G. Kergon" <agk@xxxxxxxxxx>, "Mike Snitzer" <msnitzer@xxxxxxxxxx>, "Coly Li" <colyli@xxxxxxxxx>
Cc: dm-devel@xxxxxxxxxx, "Tao Ma" <boyu.mt@xxxxxxxxxx>, "Robin Dong" <sanbai@xxxxxxxxxxxxxxx>, "Laurence Oberman" <loberman@xxxxxxxxxx>
Sent: Tuesday, June 9, 2015 5:22:49 PM
Subject: [PATCH 4/4] dm stats: support statistics on requests-based devices
This patch makes it possible to use dm stats on multipath.
Signed-off-by: Mikulas Patocka <mpatocka@xxxxxxxxxx>
---
drivers/md/dm-stats.c | 5 -----
drivers/md/dm.c | 27 +++++++++++++++++++++++++++
2 files changed, 27 insertions(+), 5 deletions(-)
Index: linux-4.1-rc7/drivers/md/dm-stats.c
===================================================================
--- linux-4.1-rc7.orig/drivers/md/dm-stats.c 2015-06-09 13:53:26.000000000 +0200
+++ linux-4.1-rc7/drivers/md/dm-stats.c 2015-06-09 13:53:35.000000000 +0200
@@ -1155,11 +1155,6 @@ int dm_stats_message(struct mapped_devic
{
int r;
- if (dm_request_based(md)) {
- DMWARN("Statistics are only supported for bio-based devices");
- return -EOPNOTSUPP;
- }
-
/* All messages here must start with '@' */
if (!strcasecmp(argv[0], "@stats_create"))
r = message_stats_create(md, argc, argv, result, maxlen);
Index: linux-4.1-rc7/drivers/md/dm.c
===================================================================
--- linux-4.1-rc7.orig/drivers/md/dm.c 2015-06-09 13:53:50.000000000 +0200
+++ linux-4.1-rc7/drivers/md/dm.c 2015-06-09 16:07:35.000000000 +0200
@@ -86,6 +86,9 @@ struct dm_rq_target_io {
struct kthread_work work;
int error;
union map_info info;
+ struct dm_stats_aux stats_aux;
+ unsigned long duration_jiffies;
+ unsigned n_sectors;
};
/*
@@ -1084,6 +1087,17 @@ static struct dm_rq_target_io *tio_from_
return (rq->q->mq_ops ? blk_mq_rq_to_pdu(rq) : rq->special);
}
+static void rq_end_stats(struct mapped_device *md, struct request *orig)
+{
+ if (unlikely(dm_stats_used(&md->stats))) {
+ struct dm_rq_target_io *tio = tio_from_request(orig);
+ tio->duration_jiffies = jiffies - tio->duration_jiffies;
+ dm_stats_account_io(&md->stats, orig->cmd_flags, blk_rq_pos(orig),
+ tio->n_sectors, true, tio->duration_jiffies,
+ &tio->stats_aux);
+ }
+}
+
/*
* Don't touch any member of the md after calling this function because
* the md may be freed in dm_put() at the end of this function.
@@ -1169,6 +1183,7 @@ static void dm_end_request(struct reques
}
free_rq_clone(clone);
+ rq_end_stats(md, rq);
if (!rq->q->mq_ops)
blk_end_request_all(rq, error);
else
@@ -1211,6 +1226,7 @@ static void dm_requeue_unmapped_original
dm_unprep_request(rq);
+ rq_end_stats(md, rq);
if (!rq->q->mq_ops)
old_requeue_request(rq);
else {
@@ -1309,6 +1325,7 @@ static void dm_softirq_done(struct reque
int rw;
if (!clone) {
+ rq_end_stats(tio->md, rq);
rw = rq_data_dir(rq);
if (!rq->q->mq_ops) {
blk_end_request_all(rq, tio->error);
@@ -2120,6 +2137,15 @@ static void dm_start_request(struct mapp
md->last_rq_start_time = ktime_get();
}
+ if (unlikely(dm_stats_used(&md->stats))) {
+ struct dm_rq_target_io *tio = tio_from_request(orig);
+ tio->duration_jiffies = jiffies;
+ tio->n_sectors = blk_rq_sectors(orig);
+ dm_stats_account_io(&md->stats, orig->cmd_flags, blk_rq_pos(orig),
+ tio->n_sectors, false, 0,
+ &tio->stats_aux);
+ }
+
/*
* Hold the md reference here for the in-flight I/O.
* We can't rely on the reference count by device opener,
@@ -2853,6 +2879,7 @@ static int dm_mq_queue_rq(struct blk_mq_
/* Direct call is fine since .queue_rq allows allocations */
if (map_request(tio, rq, md) == DM_MAPIO_REQUEUE) {
/* Undo dm_start_request() before requeuing */
+ rq_end_stats(md, rq);
rq_completed(md, rq_data_dir(rq), false);
return BLK_MQ_RQ_QUEUE_BUSY;
}
--
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