2008-01-25 17:00:02

by Myklebust, Trond

[permalink] [raw]
Subject: [PATCH 019/112] SUNRPC: Clean up the initialisation of priority queue scheduling info.

We want the default scheduling priority (priority == 0) to remain
RPC_PRIORITY_NORMAL.

Also ensure that the priority wait queue scheduling is per process id
instead of sometimes being per thread, and sometimes being per inode.

Signed-off-by: Trond Myklebust <[email protected]>
---

fs/nfs/direct.c | 10 ----------
fs/nfs/read.c | 2 --
fs/nfs/write.c | 12 +++++-------
include/linux/sunrpc/sched.h | 17 +++++++++--------
net/sunrpc/sched.c | 30 +++++++++++++++---------------
5 files changed, 29 insertions(+), 42 deletions(-)

diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c
index f9f5fc1..5bcc764 100644
--- a/fs/nfs/direct.c
+++ b/fs/nfs/direct.c
@@ -331,8 +331,6 @@ static ssize_t nfs_direct_read_schedule_segment(struct nfs_direct_req *dreq,
rpc_init_task(&data->task, &task_setup_data);
NFS_PROTO(inode)->read_setup(data);

- data->task.tk_cookie = (unsigned long) inode;
-
rpc_execute(&data->task);

dprintk("NFS: %5u initiated direct read call "
@@ -465,9 +463,6 @@ static void nfs_direct_write_reschedule(struct nfs_direct_req *dreq)
rpc_init_task(&data->task, &task_setup_data);
NFS_PROTO(inode)->write_setup(data, FLUSH_STABLE);

- data->task.tk_priority = RPC_PRIORITY_NORMAL;
- data->task.tk_cookie = (unsigned long) inode;
-
/*
* We're called via an RPC callback, so BKL is already held.
*/
@@ -534,8 +529,6 @@ static void nfs_direct_commit_schedule(struct nfs_direct_req *dreq)
rpc_init_task(&data->task, &task_setup_data);
NFS_PROTO(data->inode)->commit_setup(data, 0);

- data->task.tk_priority = RPC_PRIORITY_NORMAL;
- data->task.tk_cookie = (unsigned long)data->inode;
/* Note: task.tk_ops->rpc_release will free dreq->commit_data */
dreq->commit_data = NULL;

@@ -718,9 +711,6 @@ static ssize_t nfs_direct_write_schedule_segment(struct nfs_direct_req *dreq,
rpc_init_task(&data->task, &task_setup_data);
NFS_PROTO(inode)->write_setup(data, sync);

- data->task.tk_priority = RPC_PRIORITY_NORMAL;
- data->task.tk_cookie = (unsigned long) inode;
-
rpc_execute(&data->task);

dprintk("NFS: %5u initiated direct write call "
diff --git a/fs/nfs/read.c b/fs/nfs/read.c
index c7f0d5e..8f1eb08 100644
--- a/fs/nfs/read.c
+++ b/fs/nfs/read.c
@@ -189,8 +189,6 @@ static void nfs_read_rpcsetup(struct nfs_page *req, struct nfs_read_data *data,
rpc_init_task(&data->task, &task_setup_data);
NFS_PROTO(inode)->read_setup(data);

- data->task.tk_cookie = (unsigned long)inode;
-
dprintk("NFS: %5u initiated read call (req %s/%Ld, %u bytes @ offset %Lu)\n",
data->task.tk_pid,
inode->i_sb->s_id,
diff --git a/fs/nfs/write.c b/fs/nfs/write.c
index c437660..8d90e90 100644
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -753,7 +753,7 @@ static void nfs_writepage_release(struct nfs_page *req)
nfs_clear_page_tag_locked(req);
}

-static inline int flush_task_priority(int how)
+static int flush_task_priority(int how)
{
switch (how & (FLUSH_HIGHPRI|FLUSH_LOWPRI)) {
case FLUSH_HIGHPRI:
@@ -775,11 +775,13 @@ static void nfs_write_rpcsetup(struct nfs_page *req,
{
struct inode *inode = req->wb_context->path.dentry->d_inode;
int flags = (how & FLUSH_SYNC) ? 0 : RPC_TASK_ASYNC;
+ int priority = flush_task_priority(how);
struct rpc_task_setup task_setup_data = {
.rpc_client = NFS_CLIENT(inode),
.callback_ops = call_ops,
.callback_data = data,
.flags = flags,
+ .priority = priority,
};

/* Set up the RPC argument and reply structs
@@ -805,9 +807,6 @@ static void nfs_write_rpcsetup(struct nfs_page *req,
rpc_init_task(&data->task, &task_setup_data);
NFS_PROTO(inode)->write_setup(data, how);

- data->task.tk_priority = flush_task_priority(how);
- data->task.tk_cookie = (unsigned long)inode;
-
dprintk("NFS: %5u initiated write call "
"(req %s/%Ld, %u bytes @ offset %Lu)\n",
data->task.tk_pid,
@@ -1152,11 +1151,13 @@ static void nfs_commit_rpcsetup(struct list_head *head,
struct nfs_page *first = nfs_list_entry(head->next);
struct inode *inode = first->wb_context->path.dentry->d_inode;
int flags = (how & FLUSH_SYNC) ? 0 : RPC_TASK_ASYNC;
+ int priority = flush_task_priority(how);
struct rpc_task_setup task_setup_data = {
.rpc_client = NFS_CLIENT(inode),
.callback_ops = &nfs_commit_ops,
.callback_data = data,
.flags = flags,
+ .priority = priority,
};

/* Set up the RPC argument and reply structs
@@ -1180,9 +1181,6 @@ static void nfs_commit_rpcsetup(struct list_head *head,
rpc_init_task(&data->task, &task_setup_data);
NFS_PROTO(inode)->commit_setup(data, how);

- data->task.tk_priority = flush_task_priority(how);
- data->task.tk_cookie = (unsigned long)inode;
-
dprintk("NFS: %5u initiated commit call\n", data->task.tk_pid);
}

diff --git a/include/linux/sunrpc/sched.h b/include/linux/sunrpc/sched.h
index d974421..c9444fd 100644
--- a/include/linux/sunrpc/sched.h
+++ b/include/linux/sunrpc/sched.h
@@ -56,8 +56,6 @@ struct rpc_task {
__u8 tk_garb_retry;
__u8 tk_cred_retry;

- unsigned long tk_cookie; /* Cookie for batching tasks */
-
/*
* timeout_fn to be executed by timer bottom half
* callback to be executed after waking up
@@ -78,7 +76,6 @@ struct rpc_task {
struct timer_list tk_timer; /* kernel timer */
unsigned long tk_timeout; /* timeout for rpc_sleep() */
unsigned short tk_flags; /* misc flags */
- unsigned char tk_priority : 2;/* Task priority */
unsigned long tk_runstate; /* Task run status */
struct workqueue_struct *tk_workqueue; /* Normally rpciod, but could
* be any workqueue
@@ -94,6 +91,9 @@ struct rpc_task {
unsigned long tk_start; /* RPC task init timestamp */
long tk_rtt; /* round-trip time (jiffies) */

+ pid_t tk_owner; /* Process id for batching tasks */
+ unsigned char tk_priority : 2;/* Task priority */
+
#ifdef RPC_DEBUG
unsigned short tk_pid; /* debugging aid */
#endif
@@ -123,6 +123,7 @@ struct rpc_task_setup {
const struct rpc_call_ops *callback_ops;
void *callback_data;
unsigned short flags;
+ signed char priority;
};

/*
@@ -187,10 +188,10 @@ struct rpc_task_setup {
* Note: if you change these, you must also change
* the task initialization definitions below.
*/
-#define RPC_PRIORITY_LOW 0
-#define RPC_PRIORITY_NORMAL 1
-#define RPC_PRIORITY_HIGH 2
-#define RPC_NR_PRIORITY (RPC_PRIORITY_HIGH+1)
+#define RPC_PRIORITY_LOW (-1)
+#define RPC_PRIORITY_NORMAL (0)
+#define RPC_PRIORITY_HIGH (1)
+#define RPC_NR_PRIORITY (1 + RPC_PRIORITY_HIGH - RPC_PRIORITY_LOW)

/*
* RPC synchronization objects
@@ -198,7 +199,7 @@ struct rpc_task_setup {
struct rpc_wait_queue {
spinlock_t lock;
struct list_head tasks[RPC_NR_PRIORITY]; /* task queue for each priority level */
- unsigned long cookie; /* cookie of last task serviced */
+ pid_t owner; /* process id of last task serviced */
unsigned char maxpriority; /* maximum priority (0 if queue is not a priority queue) */
unsigned char priority; /* current priority */
unsigned char count; /* # task groups remaining serviced so far */
diff --git a/net/sunrpc/sched.c b/net/sunrpc/sched.c
index 2bcaef5..0adbddb 100644
--- a/net/sunrpc/sched.c
+++ b/net/sunrpc/sched.c
@@ -135,7 +135,7 @@ static void __rpc_add_wait_queue_priority(struct rpc_wait_queue *queue, struct r
if (unlikely(task->tk_priority > queue->maxpriority))
q = &queue->tasks[queue->maxpriority];
list_for_each_entry(t, q, u.tk_wait.list) {
- if (t->tk_cookie == task->tk_cookie) {
+ if (t->tk_owner == task->tk_owner) {
list_add_tail(&task->u.tk_wait.list, &t->u.tk_wait.links);
return;
}
@@ -208,26 +208,26 @@ static inline void rpc_set_waitqueue_priority(struct rpc_wait_queue *queue, int
queue->count = 1 << (priority * 2);
}

-static inline void rpc_set_waitqueue_cookie(struct rpc_wait_queue *queue, unsigned long cookie)
+static inline void rpc_set_waitqueue_owner(struct rpc_wait_queue *queue, pid_t pid)
{
- queue->cookie = cookie;
+ queue->owner = pid;
queue->nr = RPC_BATCH_COUNT;
}

static inline void rpc_reset_waitqueue_priority(struct rpc_wait_queue *queue)
{
rpc_set_waitqueue_priority(queue, queue->maxpriority);
- rpc_set_waitqueue_cookie(queue, 0);
+ rpc_set_waitqueue_owner(queue, 0);
}

-static void __rpc_init_priority_wait_queue(struct rpc_wait_queue *queue, const char *qname, int maxprio)
+static void __rpc_init_priority_wait_queue(struct rpc_wait_queue *queue, const char *qname, unsigned char nr_queues)
{
int i;

spin_lock_init(&queue->lock);
for (i = 0; i < ARRAY_SIZE(queue->tasks); i++)
INIT_LIST_HEAD(&queue->tasks[i]);
- queue->maxpriority = maxprio;
+ queue->maxpriority = nr_queues - 1;
rpc_reset_waitqueue_priority(queue);
#ifdef RPC_DEBUG
queue->name = qname;
@@ -236,12 +236,12 @@ static void __rpc_init_priority_wait_queue(struct rpc_wait_queue *queue, const c

void rpc_init_priority_wait_queue(struct rpc_wait_queue *queue, const char *qname)
{
- __rpc_init_priority_wait_queue(queue, qname, RPC_PRIORITY_HIGH);
+ __rpc_init_priority_wait_queue(queue, qname, RPC_NR_PRIORITY);
}

void rpc_init_wait_queue(struct rpc_wait_queue *queue, const char *qname)
{
- __rpc_init_priority_wait_queue(queue, qname, 0);
+ __rpc_init_priority_wait_queue(queue, qname, 1);
}
EXPORT_SYMBOL_GPL(rpc_init_wait_queue);

@@ -456,12 +456,12 @@ static struct rpc_task * __rpc_wake_up_next_priority(struct rpc_wait_queue *queu
struct rpc_task *task;

/*
- * Service a batch of tasks from a single cookie.
+ * Service a batch of tasks from a single owner.
*/
q = &queue->tasks[queue->priority];
if (!list_empty(q)) {
task = list_entry(q->next, struct rpc_task, u.tk_wait.list);
- if (queue->cookie == task->tk_cookie) {
+ if (queue->owner == task->tk_owner) {
if (--queue->nr)
goto out;
list_move_tail(&task->u.tk_wait.list, q);
@@ -470,7 +470,7 @@ static struct rpc_task * __rpc_wake_up_next_priority(struct rpc_wait_queue *queu
* Check if we need to switch queues.
*/
if (--queue->count)
- goto new_cookie;
+ goto new_owner;
}

/*
@@ -492,8 +492,8 @@ static struct rpc_task * __rpc_wake_up_next_priority(struct rpc_wait_queue *queu

new_queue:
rpc_set_waitqueue_priority(queue, (unsigned int)(q - &queue->tasks[0]));
-new_cookie:
- rpc_set_waitqueue_cookie(queue, task->tk_cookie);
+new_owner:
+ rpc_set_waitqueue_owner(queue, task->tk_owner);
out:
__rpc_wake_up_task(task);
return task;
@@ -831,8 +831,8 @@ void rpc_init_task(struct rpc_task *task, const struct rpc_task_setup *task_setu
task->tk_garb_retry = 2;
task->tk_cred_retry = 2;

- task->tk_priority = RPC_PRIORITY_NORMAL;
- task->tk_cookie = (unsigned long)current;
+ task->tk_priority = task_setup_data->priority - RPC_PRIORITY_LOW;
+ task->tk_owner = current->tgid;

/* Initialize workqueue for async tasks */
task->tk_workqueue = rpciod_workqueue;