[Drbd-dev] [PATCH 08/23] drbd: track timing details of peer_requests
Philipp Reisner
philipp.reisner at linbit.com
Thu Jul 3 10:43:00 CEST 2014
From: Lars Ellenberg <lars.ellenberg at linbit.com>
To be able to present timing details in debugfs,
we need to track preparation/submit times of peer requests.
Track peer request flags early,
before they are put on the epoch_entry lists.
Waiting for activity log transactions may be a major latency factor.
We want to be able to present the peer_request state accurately in
debugfs, and what it is waiting for.
Consistently mark/unmark peer requests with EE_CALL_AL_COMPLETE_IO.
Set it only *after* calling drbd_al_begin_io(),
clear it as soon as we call drbd_al_complete_io().
Signed-off-by: Philipp Reisner <philipp.reisner at linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg at linbit.com>
---
drivers/block/drbd/drbd_int.h | 15 ++++++++
drivers/block/drbd/drbd_receiver.c | 78 +++++++++++++++++++++++---------------
drivers/block/drbd/drbd_worker.c | 1 +
3 files changed, 64 insertions(+), 30 deletions(-)
diff --git a/drivers/block/drbd/drbd_int.h b/drivers/block/drbd/drbd_int.h
index 81f4af4..c7a409f 100644
--- a/drivers/block/drbd/drbd_int.h
+++ b/drivers/block/drbd/drbd_int.h
@@ -422,6 +422,7 @@ struct drbd_peer_request {
struct drbd_interval i;
/* see comments on ee flag bits below */
unsigned long flags;
+ unsigned long submit_jif;
union {
u64 block_id;
struct digest_info *digest;
@@ -464,6 +465,17 @@ enum {
/* Is set when net_conf had two_primaries set while creating this peer_req */
__EE_IN_INTERVAL_TREE,
+
+ /* for debugfs: */
+ /* has this been submitted, or does it still wait for something else? */
+ __EE_SUBMITTED,
+
+ /* this is/was a write request */
+ __EE_WRITE,
+
+ /* this originates from application on peer
+ * (not some resync or verify or other DRBD internal request) */
+ __EE_APPLICATION,
};
#define EE_CALL_AL_COMPLETE_IO (1<<__EE_CALL_AL_COMPLETE_IO)
#define EE_MAY_SET_IN_SYNC (1<<__EE_MAY_SET_IN_SYNC)
@@ -475,6 +487,9 @@ enum {
#define EE_RESTART_REQUESTS (1<<__EE_RESTART_REQUESTS)
#define EE_SEND_WRITE_ACK (1<<__EE_SEND_WRITE_ACK)
#define EE_IN_INTERVAL_TREE (1<<__EE_IN_INTERVAL_TREE)
+#define EE_SUBMITTED (1<<__EE_SUBMITTED)
+#define EE_WRITE (1<<__EE_WRITE)
+#define EE_APPLICATION (1<<__EE_APPLICATION)
/* flag bits per device */
enum {
diff --git a/drivers/block/drbd/drbd_receiver.c b/drivers/block/drbd/drbd_receiver.c
index 0d3cbd8..2f67dc0 100644
--- a/drivers/block/drbd/drbd_receiver.c
+++ b/drivers/block/drbd/drbd_receiver.c
@@ -389,11 +389,16 @@ drbd_alloc_peer_req(struct drbd_peer_device *peer_device, u64 id, sector_t secto
void __drbd_free_peer_req(struct drbd_device *device, struct drbd_peer_request *peer_req,
int is_net)
{
+ might_sleep();
if (peer_req->flags & EE_HAS_DIGEST)
kfree(peer_req->digest);
drbd_free_pages(device, peer_req->pages, is_net);
D_ASSERT(device, atomic_read(&peer_req->pending_bios) == 0);
D_ASSERT(device, drbd_interval_empty(&peer_req->i));
+ if (!expect(!(peer_req->flags & EE_CALL_AL_COMPLETE_IO))) {
+ peer_req->flags &= ~EE_CALL_AL_COMPLETE_IO;
+ drbd_al_complete_io(device, &peer_req->i);
+ }
mempool_free(peer_req, drbd_ee_mempool);
}
@@ -1372,6 +1377,8 @@ int drbd_submit_peer_request(struct drbd_device *device,
conn_wait_active_ee_empty(first_peer_device(device)->connection);
/* add it to the active list now,
* so we can find it to present it in debugfs */
+ peer_req->submit_jif = jiffies;
+ peer_req->flags |= EE_SUBMITTED;
spin_lock_irq(&device->resource->req_lock);
list_add_tail(&peer_req->w.list, &device->active_ee);
spin_unlock_irq(&device->resource->req_lock);
@@ -1443,6 +1450,9 @@ submit:
D_ASSERT(device, page == NULL);
atomic_set(&peer_req->pending_bios, n_bios);
+ /* for debugfs: update timestamp, mark as submitted */
+ peer_req->submit_jif = jiffies;
+ peer_req->flags |= EE_SUBMITTED;
do {
bio = bios;
bios = bios->bi_next;
@@ -1624,6 +1634,7 @@ read_in_block(struct drbd_peer_device *peer_device, u64 id, sector_t sector,
if (!peer_req)
return NULL;
+ peer_req->flags |= EE_WRITE;
if (trim)
return peer_req;
@@ -1780,6 +1791,7 @@ static int recv_resync_read(struct drbd_peer_device *peer_device, sector_t secto
* respective _drbd_clear_done_ee */
peer_req->w.cb = e_end_resync_block;
+ peer_req->submit_jif = jiffies;
spin_lock_irq(&device->resource->req_lock);
list_add_tail(&peer_req->w.list, &device->sync_ee);
@@ -2196,7 +2208,6 @@ static int handle_write_conflicts(struct drbd_device *device,
(unsigned long long)sector, size,
superseded ? "local" : "remote");
- inc_unacked(device);
peer_req->w.cb = superseded ? e_send_superseded :
e_send_retry_write;
list_add_tail(&peer_req->w.list, &device->done_ee);
@@ -2255,6 +2266,7 @@ static int receive_Data(struct drbd_connection *connection, struct packet_info *
{
struct drbd_peer_device *peer_device;
struct drbd_device *device;
+ struct net_conf *nc;
sector_t sector;
struct drbd_peer_request *peer_req;
struct p_data *p = pi->data;
@@ -2294,6 +2306,8 @@ static int receive_Data(struct drbd_connection *connection, struct packet_info *
}
peer_req->w.cb = e_end_block;
+ peer_req->submit_jif = jiffies;
+ peer_req->flags |= EE_APPLICATION;
dp_flags = be32_to_cpu(p->dp_flags);
rw |= wire_flags_to_bio(dp_flags);
@@ -2320,9 +2334,36 @@ static int receive_Data(struct drbd_connection *connection, struct packet_info *
spin_unlock(&connection->epoch_lock);
rcu_read_lock();
- tp = rcu_dereference(peer_device->connection->net_conf)->two_primaries;
+ nc = rcu_dereference(peer_device->connection->net_conf);
+ tp = nc->two_primaries;
+ if (peer_device->connection->agreed_pro_version < 100) {
+ switch (nc->wire_protocol) {
+ case DRBD_PROT_C:
+ dp_flags |= DP_SEND_WRITE_ACK;
+ break;
+ case DRBD_PROT_B:
+ dp_flags |= DP_SEND_RECEIVE_ACK;
+ break;
+ }
+ }
rcu_read_unlock();
+
+ if (dp_flags & DP_SEND_WRITE_ACK) {
+ peer_req->flags |= EE_SEND_WRITE_ACK;
+ inc_unacked(device);
+ /* corresponding dec_unacked() in e_end_block()
+ * respective _drbd_clear_done_ee */
+ }
+
+ if (dp_flags & DP_SEND_RECEIVE_ACK) {
+ /* I really don't like it that the receiver thread
+ * sends on the msock, but anyways */
+ drbd_send_ack(first_peer_device(device), P_RECV_ACK, peer_req);
+ }
+
if (tp) {
+ /* two primaries implies protocol C */
+ D_ASSERT(device, dp_flags & DP_SEND_WRITE_ACK);
peer_req->flags |= EE_IN_INTERVAL_TREE;
err = wait_for_and_update_peer_seq(peer_device, peer_seq);
if (err)
@@ -2352,38 +2393,12 @@ static int receive_Data(struct drbd_connection *connection, struct packet_info *
if (device->state.conn == C_SYNC_TARGET)
wait_event(device->ee_wait, !overlapping_resync_write(device, peer_req));
- if (peer_device->connection->agreed_pro_version < 100) {
- rcu_read_lock();
- switch (rcu_dereference(peer_device->connection->net_conf)->wire_protocol) {
- case DRBD_PROT_C:
- dp_flags |= DP_SEND_WRITE_ACK;
- break;
- case DRBD_PROT_B:
- dp_flags |= DP_SEND_RECEIVE_ACK;
- break;
- }
- rcu_read_unlock();
- }
-
- if (dp_flags & DP_SEND_WRITE_ACK) {
- peer_req->flags |= EE_SEND_WRITE_ACK;
- inc_unacked(device);
- /* corresponding dec_unacked() in e_end_block()
- * respective _drbd_clear_done_ee */
- }
-
- if (dp_flags & DP_SEND_RECEIVE_ACK) {
- /* I really don't like it that the receiver thread
- * sends on the msock, but anyways */
- drbd_send_ack(first_peer_device(device), P_RECV_ACK, peer_req);
- }
-
if (device->state.pdsk < D_INCONSISTENT) {
/* In case we have the only disk of the cluster, */
drbd_set_out_of_sync(device, peer_req->i.sector, peer_req->i.size);
- peer_req->flags |= EE_CALL_AL_COMPLETE_IO;
peer_req->flags &= ~EE_MAY_SET_IN_SYNC;
drbd_al_begin_io(device, &peer_req->i);
+ peer_req->flags |= EE_CALL_AL_COMPLETE_IO;
}
err = drbd_submit_peer_request(device, peer_req, rw, DRBD_FAULT_DT_WR);
@@ -2396,8 +2411,10 @@ static int receive_Data(struct drbd_connection *connection, struct packet_info *
list_del(&peer_req->w.list);
drbd_remove_epoch_entry_interval(device, peer_req);
spin_unlock_irq(&device->resource->req_lock);
- if (peer_req->flags & EE_CALL_AL_COMPLETE_IO)
+ if (peer_req->flags & EE_CALL_AL_COMPLETE_IO) {
+ peer_req->flags &= ~EE_CALL_AL_COMPLETE_IO;
drbd_al_complete_io(device, &peer_req->i);
+ }
out_interrupted:
drbd_may_finish_epoch(connection, peer_req->epoch, EV_PUT + EV_CLEANUP);
@@ -2561,6 +2578,7 @@ static int receive_DataRequest(struct drbd_connection *connection, struct packet
peer_req->w.cb = w_e_end_data_req;
fault_type = DRBD_FAULT_DT_RD;
/* application IO, don't drbd_rs_begin_io */
+ peer_req->flags |= EE_APPLICATION;
goto submit;
case P_RS_DATA_REQUEST:
diff --git a/drivers/block/drbd/drbd_worker.c b/drivers/block/drbd/drbd_worker.c
index 48975a2..b908e9b 100644
--- a/drivers/block/drbd/drbd_worker.c
+++ b/drivers/block/drbd/drbd_worker.c
@@ -132,6 +132,7 @@ void drbd_endio_write_sec_final(struct drbd_peer_request *peer_req) __releases(l
i = peer_req->i;
do_al_complete_io = peer_req->flags & EE_CALL_AL_COMPLETE_IO;
block_id = peer_req->block_id;
+ peer_req->flags &= ~EE_CALL_AL_COMPLETE_IO;
spin_lock_irqsave(&device->resource->req_lock, flags);
device->writ_cnt += peer_req->i.size >> 9;
--
1.9.1
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