Commit 1d6e8131 authored by Patrick Caulfield's avatar Patrick Caulfield Committed by Steven Whitehouse

[DLM] Use workqueues for dlm lowcomms

This patch converts the DLM TCP lowcomms to use workqueues rather than using its
own daemon functions. Simultaneously removing a lot of code and making it more
scalable on multi-processor machines.
Signed-Off-By: default avatarPatrick Caulfield <pcaulfie@redhat.com>
Signed-off-by: default avatarSteven Whitehouse <swhiteho@redhat.com>
parent 03dc6a53
......@@ -72,6 +72,8 @@ struct nodeinfo {
struct list_head writequeue; /* outgoing writequeue_entries */
spinlock_t writequeue_lock;
int nodeid;
struct work_struct swork; /* Send workqueue */
struct work_struct lwork; /* Locking workqueue */
};
static DEFINE_IDR(nodeinfo_idr);
......@@ -96,6 +98,7 @@ struct connection {
atomic_t waiting_requests;
struct cbuf cb;
int eagain_flag;
struct work_struct work; /* Send workqueue */
};
/* An entry waiting to be sent */
......@@ -137,19 +140,23 @@ static void cbuf_eat(struct cbuf *cb, int n)
static LIST_HEAD(write_nodes);
static DEFINE_SPINLOCK(write_nodes_lock);
/* Maximum number of incoming messages to process before
* doing a schedule()
*/
#define MAX_RX_MSG_COUNT 25
/* Manage daemons */
static struct task_struct *recv_task;
static struct task_struct *send_task;
static DECLARE_WAIT_QUEUE_HEAD(lowcomms_recv_wait);
/* Work queues */
static struct workqueue_struct *recv_workqueue;
static struct workqueue_struct *send_workqueue;
static struct workqueue_struct *lock_workqueue;
/* The SCTP connection */
static struct connection sctp_con;
static void process_send_sockets(struct work_struct *work);
static void process_recv_sockets(struct work_struct *work);
static void process_lock_request(struct work_struct *work);
static int nodeid_to_addr(int nodeid, struct sockaddr *retaddr)
{
......@@ -222,6 +229,8 @@ static struct nodeinfo *nodeid2nodeinfo(int nodeid, gfp_t alloc)
spin_lock_init(&ni->lock);
INIT_LIST_HEAD(&ni->writequeue);
spin_lock_init(&ni->writequeue_lock);
INIT_WORK(&ni->lwork, process_lock_request);
INIT_WORK(&ni->swork, process_send_sockets);
ni->nodeid = nodeid;
if (nodeid > max_nodeid)
......@@ -249,11 +258,8 @@ static struct nodeinfo *assoc2nodeinfo(sctp_assoc_t assoc)
/* Data or notification available on socket */
static void lowcomms_data_ready(struct sock *sk, int count_unused)
{
atomic_inc(&sctp_con.waiting_requests);
if (test_and_set_bit(CF_READ_PENDING, &sctp_con.flags))
return;
wake_up_interruptible(&lowcomms_recv_wait);
queue_work(recv_workqueue, &sctp_con.work);
}
......@@ -361,10 +367,10 @@ static void init_failed(void)
spin_lock_bh(&write_nodes_lock);
list_add_tail(&ni->write_list, &write_nodes);
spin_unlock_bh(&write_nodes_lock);
queue_work(send_workqueue, &ni->swork);
}
}
}
wake_up_process(send_task);
}
/* Something happened to an association */
......@@ -446,8 +452,8 @@ static void process_sctp_notification(struct msghdr *msg, char *buf)
spin_lock_bh(&write_nodes_lock);
list_add_tail(&ni->write_list, &write_nodes);
spin_unlock_bh(&write_nodes_lock);
queue_work(send_workqueue, &ni->swork);
}
wake_up_process(send_task);
}
break;
......@@ -580,8 +586,8 @@ static int receive_from_sock(void)
spin_lock_bh(&write_nodes_lock);
list_add_tail(&ni->write_list, &write_nodes);
spin_unlock_bh(&write_nodes_lock);
queue_work(send_workqueue, &ni->swork);
}
wake_up_process(send_task);
}
}
......@@ -590,6 +596,7 @@ static int receive_from_sock(void)
return 0;
cbuf_add(&sctp_con.cb, ret);
// PJC: TODO: Add to node's workqueue....can we ??
ret = dlm_process_incoming_buffer(cpu_to_le32(sinfo->sinfo_ppid),
page_address(sctp_con.rx_page),
sctp_con.cb.base, sctp_con.cb.len,
......@@ -820,7 +827,8 @@ void dlm_lowcomms_commit_buffer(void *arg)
spin_lock_bh(&write_nodes_lock);
list_add_tail(&ni->write_list, &write_nodes);
spin_unlock_bh(&write_nodes_lock);
wake_up_process(send_task);
queue_work(send_workqueue, &ni->swork);
}
return;
......@@ -1088,101 +1096,75 @@ int dlm_lowcomms_close(int nodeid)
return 0;
}
static int write_list_empty(void)
// PJC: The work queue function for receiving.
static void process_recv_sockets(struct work_struct *work)
{
int status;
if (test_and_clear_bit(CF_READ_PENDING, &sctp_con.flags)) {
int ret;
int count = 0;
spin_lock_bh(&write_nodes_lock);
status = list_empty(&write_nodes);
spin_unlock_bh(&write_nodes_lock);
do {
ret = receive_from_sock();
return status;
/* Don't starve out everyone else */
if (++count >= MAX_RX_MSG_COUNT) {
cond_resched();
count = 0;
}
} while (!kthread_should_stop() && ret >=0);
}
cond_resched();
}
static int dlm_recvd(void *data)
// PJC: the work queue function for sending
static void process_send_sockets(struct work_struct *work)
{
DECLARE_WAITQUEUE(wait, current);
while (!kthread_should_stop()) {
int count = 0;
set_current_state(TASK_INTERRUPTIBLE);
add_wait_queue(&lowcomms_recv_wait, &wait);
if (!test_bit(CF_READ_PENDING, &sctp_con.flags))
schedule();
remove_wait_queue(&lowcomms_recv_wait, &wait);
set_current_state(TASK_RUNNING);
if (test_and_clear_bit(CF_READ_PENDING, &sctp_con.flags)) {
int ret;
do {
ret = receive_from_sock();
/* Don't starve out everyone else */
if (++count >= MAX_RX_MSG_COUNT) {
cond_resched();
count = 0;
}
} while (!kthread_should_stop() && ret >=0);
}
cond_resched();
if (sctp_con.eagain_flag) {
sctp_con.eagain_flag = 0;
refill_write_queue();
}
return 0;
process_output_queue();
}
static int dlm_sendd(void *data)
// PJC: Process lock requests from a particular node.
// TODO: can we optimise this out on UP ??
static void process_lock_request(struct work_struct *work)
{
DECLARE_WAITQUEUE(wait, current);
add_wait_queue(sctp_con.sock->sk->sk_sleep, &wait);
while (!kthread_should_stop()) {
set_current_state(TASK_INTERRUPTIBLE);
if (write_list_empty())
schedule();
set_current_state(TASK_RUNNING);
if (sctp_con.eagain_flag) {
sctp_con.eagain_flag = 0;
refill_write_queue();
}
process_output_queue();
}
remove_wait_queue(sctp_con.sock->sk->sk_sleep, &wait);
return 0;
}
static void daemons_stop(void)
{
kthread_stop(recv_task);
kthread_stop(send_task);
destroy_workqueue(recv_workqueue);
destroy_workqueue(send_workqueue);
destroy_workqueue(lock_workqueue);
}
static int daemons_start(void)
{
struct task_struct *p;
int error;
recv_workqueue = create_workqueue("dlm_recv");
error = IS_ERR(recv_workqueue);
if (error) {
log_print("can't start dlm_recv %d", error);
return error;
}
p = kthread_run(dlm_recvd, NULL, "dlm_recvd");
error = IS_ERR(p);
send_workqueue = create_singlethread_workqueue("dlm_send");
error = IS_ERR(send_workqueue);
if (error) {
log_print("can't start dlm_recvd %d", error);
log_print("can't start dlm_send %d", error);
destroy_workqueue(recv_workqueue);
return error;
}
recv_task = p;
p = kthread_run(dlm_sendd, NULL, "dlm_sendd");
error = IS_ERR(p);
lock_workqueue = create_workqueue("dlm_rlock");
error = IS_ERR(lock_workqueue);
if (error) {
log_print("can't start dlm_sendd %d", error);
kthread_stop(recv_task);
log_print("can't start dlm_rlock %d", error);
destroy_workqueue(send_workqueue);
destroy_workqueue(recv_workqueue);
return error;
}
send_task = p;
return 0;
}
......@@ -1194,6 +1176,8 @@ int dlm_lowcomms_start(void)
{
int error;
INIT_WORK(&sctp_con.work, process_recv_sockets);
error = init_sock();
if (error)
goto fail_sock;
......@@ -1224,4 +1208,3 @@ void dlm_lowcomms_stop(void)
for (i = 0; i < dlm_local_count; i++)
kfree(dlm_local_addr[i]);
}
......@@ -115,6 +115,8 @@ struct connection {
atomic_t waiting_requests;
#define MAX_CONNECT_RETRIES 3
struct connection *othercon;
struct work_struct rwork; /* Receive workqueue */
struct work_struct swork; /* Send workqueue */
};
#define sock2con(x) ((struct connection *)(x)->sk_user_data)
......@@ -131,14 +133,9 @@ struct writequeue_entry {
static struct sockaddr_storage dlm_local_addr;
/* Manage daemons */
static struct task_struct *recv_task;
static struct task_struct *send_task;
static wait_queue_t lowcomms_send_waitq_head;
static DECLARE_WAIT_QUEUE_HEAD(lowcomms_send_waitq);
static wait_queue_t lowcomms_recv_waitq_head;
static DECLARE_WAIT_QUEUE_HEAD(lowcomms_recv_waitq);
/* Work queues */
static struct workqueue_struct *recv_workqueue;
static struct workqueue_struct *send_workqueue;
/* An array of pointers to connections, indexed by NODEID */
static struct connection **connections;
......@@ -146,17 +143,8 @@ static DECLARE_MUTEX(connections_lock);
static struct kmem_cache *con_cache;
static int conn_array_size;
/* List of sockets that have reads pending */
static LIST_HEAD(read_sockets);
static DEFINE_SPINLOCK(read_sockets_lock);
/* List of sockets which have writes pending */
static LIST_HEAD(write_sockets);
static DEFINE_SPINLOCK(write_sockets_lock);
/* List of sockets which have connects pending */
static LIST_HEAD(state_sockets);
static DEFINE_SPINLOCK(state_sockets_lock);
static void process_recv_sockets(struct work_struct *work);
static void process_send_sockets(struct work_struct *work);
static struct connection *nodeid2con(int nodeid, gfp_t allocation)
{
......@@ -189,6 +177,8 @@ static struct connection *nodeid2con(int nodeid, gfp_t allocation)
init_rwsem(&con->sock_sem);
INIT_LIST_HEAD(&con->writequeue);
spin_lock_init(&con->writequeue_lock);
INIT_WORK(&con->swork, process_send_sockets);
INIT_WORK(&con->rwork, process_recv_sockets);
connections[nodeid] = con;
}
......@@ -203,41 +193,22 @@ static void lowcomms_data_ready(struct sock *sk, int count_unused)
{
struct connection *con = sock2con(sk);
atomic_inc(&con->waiting_requests);
if (test_and_set_bit(CF_READ_PENDING, &con->flags))
return;
spin_lock_bh(&read_sockets_lock);
list_add_tail(&con->read_list, &read_sockets);
spin_unlock_bh(&read_sockets_lock);
wake_up_interruptible(&lowcomms_recv_waitq);
if (!test_and_set_bit(CF_READ_PENDING, &con->flags))
queue_work(recv_workqueue, &con->rwork);
}
static void lowcomms_write_space(struct sock *sk)
{
struct connection *con = sock2con(sk);
if (test_and_set_bit(CF_WRITE_PENDING, &con->flags))
return;
spin_lock_bh(&write_sockets_lock);
list_add_tail(&con->write_list, &write_sockets);
spin_unlock_bh(&write_sockets_lock);
wake_up_interruptible(&lowcomms_send_waitq);
if (!test_and_set_bit(CF_WRITE_PENDING, &con->flags))
queue_work(send_workqueue, &con->swork);
}
static inline void lowcomms_connect_sock(struct connection *con)
{
if (test_and_set_bit(CF_CONNECT_PENDING, &con->flags))
return;
spin_lock_bh(&state_sockets_lock);
list_add_tail(&con->state_list, &state_sockets);
spin_unlock_bh(&state_sockets_lock);
wake_up_interruptible(&lowcomms_send_waitq);
if (!test_and_set_bit(CF_CONNECT_PENDING, &con->flags))
queue_work(send_workqueue, &con->swork);
}
static void lowcomms_state_change(struct sock *sk)
......@@ -388,7 +359,8 @@ static int receive_from_sock(struct connection *con)
return 0;
out_resched:
lowcomms_data_ready(con->sock->sk, 0);
if (!test_and_set_bit(CF_READ_PENDING, &con->flags))
queue_work(recv_workqueue, &con->rwork);
up_read(&con->sock_sem);
cond_resched();
return 0;
......@@ -477,6 +449,8 @@ static int accept_from_sock(struct connection *con)
othercon->nodeid = nodeid;
othercon->rx_action = receive_from_sock;
init_rwsem(&othercon->sock_sem);
INIT_WORK(&othercon->swork, process_send_sockets);
INIT_WORK(&othercon->rwork, process_recv_sockets);
set_bit(CF_IS_OTHERCON, &othercon->flags);
newcon->othercon = othercon;
}
......@@ -498,7 +472,8 @@ static int accept_from_sock(struct connection *con)
* beween processing the accept adding the socket
* to the read_sockets list
*/
lowcomms_data_ready(newsock->sk, 0);
if (!test_and_set_bit(CF_READ_PENDING, &newcon->flags))
queue_work(recv_workqueue, &newcon->rwork);
up_read(&con->sock_sem);
return 0;
......@@ -757,12 +732,8 @@ void dlm_lowcomms_commit_buffer(void *mh)
kunmap(e->page);
spin_unlock(&con->writequeue_lock);
if (test_and_set_bit(CF_WRITE_PENDING, &con->flags) == 0) {
spin_lock_bh(&write_sockets_lock);
list_add_tail(&con->write_list, &write_sockets);
spin_unlock_bh(&write_sockets_lock);
wake_up_interruptible(&lowcomms_send_waitq);
if (!test_and_set_bit(CF_WRITE_PENDING, &con->flags)) {
queue_work(send_workqueue, &con->swork);
}
return;
......@@ -803,6 +774,7 @@ static void send_to_sock(struct connection *con)
offset = e->offset;
BUG_ON(len == 0 && e->users == 0);
spin_unlock(&con->writequeue_lock);
kmap(e->page);
ret = 0;
if (len) {
......@@ -884,85 +856,29 @@ int dlm_lowcomms_close(int nodeid)
}
/* Look for activity on active sockets */
static void process_sockets(void)
static void process_recv_sockets(struct work_struct *work)
{
struct list_head *list;
struct list_head *temp;
int count = 0;
spin_lock_bh(&read_sockets_lock);
list_for_each_safe(list, temp, &read_sockets) {
struct connection *con =
list_entry(list, struct connection, read_list);
list_del(&con->read_list);
clear_bit(CF_READ_PENDING, &con->flags);
spin_unlock_bh(&read_sockets_lock);
struct connection *con = container_of(work, struct connection, rwork);
int err;
/* This can reach zero if we are processing requests
* as they come in.
*/
if (atomic_read(&con->waiting_requests) == 0) {
spin_lock_bh(&read_sockets_lock);
continue;
}
do {
con->rx_action(con);
/* Don't starve out everyone else */
if (++count >= MAX_RX_MSG_COUNT) {
cond_resched();
count = 0;
}
} while (!atomic_dec_and_test(&con->waiting_requests) &&
!kthread_should_stop());
spin_lock_bh(&read_sockets_lock);
}
spin_unlock_bh(&read_sockets_lock);
clear_bit(CF_READ_PENDING, &con->flags);
do {
err = con->rx_action(con);
} while (!err);
}
/* Try to send any messages that are pending
*/
static void process_output_queue(void)
{
struct list_head *list;
struct list_head *temp;
spin_lock_bh(&write_sockets_lock);
list_for_each_safe(list, temp, &write_sockets) {
struct connection *con =
list_entry(list, struct connection, write_list);
clear_bit(CF_WRITE_PENDING, &con->flags);
list_del(&con->write_list);
spin_unlock_bh(&write_sockets_lock);
send_to_sock(con);
spin_lock_bh(&write_sockets_lock);
}
spin_unlock_bh(&write_sockets_lock);
}
static void process_state_queue(void)
static void process_send_sockets(struct work_struct *work)
{
struct list_head *list;
struct list_head *temp;
spin_lock_bh(&state_sockets_lock);
list_for_each_safe(list, temp, &state_sockets) {
struct connection *con =
list_entry(list, struct connection, state_list);
list_del(&con->state_list);
clear_bit(CF_CONNECT_PENDING, &con->flags);
spin_unlock_bh(&state_sockets_lock);
struct connection *con = container_of(work, struct connection, swork);
if (test_and_clear_bit(CF_CONNECT_PENDING, &con->flags)) {
connect_to_sock(con);
spin_lock_bh(&state_sockets_lock);
}
spin_unlock_bh(&state_sockets_lock);
if (test_and_clear_bit(CF_WRITE_PENDING, &con->flags)) {
send_to_sock(con);
}
}
......@@ -979,97 +895,29 @@ static void clean_writequeues(void)
}
}
static int read_list_empty(void)
{
int status;
spin_lock_bh(&read_sockets_lock);
status = list_empty(&read_sockets);
spin_unlock_bh(&read_sockets_lock);
return status;
}
/* DLM Transport comms receive daemon */
static int dlm_recvd(void *data)
static void work_stop(void)
{
init_waitqueue_entry(&lowcomms_recv_waitq_head, current);
add_wait_queue(&lowcomms_recv_waitq, &lowcomms_recv_waitq_head);
while (!kthread_should_stop()) {
set_current_state(TASK_INTERRUPTIBLE);
if (read_list_empty())
schedule();
set_current_state(TASK_RUNNING);
process_sockets();
}
return 0;
destroy_workqueue(recv_workqueue);
destroy_workqueue(send_workqueue);
}
static int write_and_state_lists_empty(void)
static int work_start(void)
{
int status;
spin_lock_bh(&write_sockets_lock);
status = list_empty(&write_sockets);
spin_unlock_bh(&write_sockets_lock);
spin_lock_bh(&state_sockets_lock);
if (list_empty(&state_sockets) == 0)
status = 0;
spin_unlock_bh(&state_sockets_lock);
return status;
}
/* DLM Transport send daemon */
static int dlm_sendd(void *data)
{
init_waitqueue_entry(&lowcomms_send_waitq_head, current);
add_wait_queue(&lowcomms_send_waitq, &lowcomms_send_waitq_head);
while (!kthread_should_stop()) {
set_current_state(TASK_INTERRUPTIBLE);
if (write_and_state_lists_empty())
schedule();
set_current_state(TASK_RUNNING);
process_state_queue();
process_output_queue();
}
return 0;
}
static void daemons_stop(void)
{
kthread_stop(recv_task);
kthread_stop(send_task);
}
static int daemons_start(void)
{
struct task_struct *p;
int error;
p = kthread_run(dlm_recvd, NULL, "dlm_recvd");
error = IS_ERR(p);
recv_workqueue = create_workqueue("dlm_recv");
error = IS_ERR(recv_workqueue);
if (error) {
log_print("can't start dlm_recvd %d", error);
log_print("can't start dlm_recv %d", error);
return error;
}
recv_task = p;
p = kthread_run(dlm_sendd, NULL, "dlm_sendd");
error = IS_ERR(p);
send_workqueue = create_singlethread_workqueue("dlm_send");
error = IS_ERR(send_workqueue);
if (error) {
log_print("can't start dlm_sendd %d", error);
kthread_stop(recv_task);
log_print("can't start dlm_send %d", error);
destroy_workqueue(recv_workqueue);
return error;
}
send_task = p;
return 0;
}
......@@ -1086,7 +934,7 @@ void dlm_lowcomms_stop(void)
connections[i]->flags |= 0xFF;
}
daemons_stop();
work_stop();
clean_writequeues();
for (i = 0; i < conn_array_size; i++) {
......@@ -1138,7 +986,7 @@ int dlm_lowcomms_start(void)
if (error)
goto fail_unlisten;
error = daemons_start();
error = work_start();
if (error)
goto fail_unlisten;
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment