2008-02-26 23:38:51

by Myklebust, Trond

[permalink] [raw]
Subject: [PATCH 10/10] SUNRPC: Remove now-redundant RCU-safe rpc_task free path

Now that we've tightened up the locking rules for RPC queue wakeups, we can
remove the RCU-safe kfree calls...

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

fs/nfs/read.c | 8 +-------
fs/nfs/write.c | 16 ++--------------
include/linux/sunrpc/sched.h | 2 --
net/sunrpc/sched.c | 37 ++++++++++++-------------------------
4 files changed, 15 insertions(+), 48 deletions(-)

diff --git a/fs/nfs/read.c b/fs/nfs/read.c
index 87546cd..be9e827 100644
--- a/fs/nfs/read.c
+++ b/fs/nfs/read.c
@@ -58,19 +58,13 @@ struct nfs_read_data *nfs_readdata_alloc(unsigned int pagecount)
return p;
}

-static void nfs_readdata_rcu_free(struct rcu_head *head)
+static void nfs_readdata_free(struct nfs_read_data *p)
{
- struct nfs_read_data *p = container_of(head, struct nfs_read_data, task.u.tk_rcu);
if (p && (p->pagevec != &p->page_array[0]))
kfree(p->pagevec);
mempool_free(p, nfs_rdata_mempool);
}

-static void nfs_readdata_free(struct nfs_read_data *rdata)
-{
- call_rcu_bh(&rdata->task.u.tk_rcu, nfs_readdata_rcu_free);
-}
-
void nfs_readdata_release(void *data)
{
struct nfs_read_data *rdata = data;
diff --git a/fs/nfs/write.c b/fs/nfs/write.c
index 84495ef..3051302 100644
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -58,19 +58,13 @@ struct nfs_write_data *nfs_commit_alloc(void)
return p;
}

-static void nfs_commit_rcu_free(struct rcu_head *head)
+void nfs_commit_free(struct nfs_write_data *p)
{
- struct nfs_write_data *p = container_of(head, struct nfs_write_data, task.u.tk_rcu);
if (p && (p->pagevec != &p->page_array[0]))
kfree(p->pagevec);
mempool_free(p, nfs_commit_mempool);
}

-void nfs_commit_free(struct nfs_write_data *wdata)
-{
- call_rcu_bh(&wdata->task.u.tk_rcu, nfs_commit_rcu_free);
-}
-
struct nfs_write_data *nfs_writedata_alloc(unsigned int pagecount)
{
struct nfs_write_data *p = mempool_alloc(nfs_wdata_mempool, GFP_NOFS);
@@ -92,19 +86,13 @@ struct nfs_write_data *nfs_writedata_alloc(unsigned int pagecount)
return p;
}

-static void nfs_writedata_rcu_free(struct rcu_head *head)
+static void nfs_writedata_free(struct nfs_write_data *p)
{
- struct nfs_write_data *p = container_of(head, struct nfs_write_data, task.u.tk_rcu);
if (p && (p->pagevec != &p->page_array[0]))
kfree(p->pagevec);
mempool_free(p, nfs_wdata_mempool);
}

-static void nfs_writedata_free(struct nfs_write_data *wdata)
-{
- call_rcu_bh(&wdata->task.u.tk_rcu, nfs_writedata_rcu_free);
-}
-
void nfs_writedata_release(void *data)
{
struct nfs_write_data *wdata = data;
diff --git a/include/linux/sunrpc/sched.h b/include/linux/sunrpc/sched.h
index bf69fce..d1a5c8c 100644
--- a/include/linux/sunrpc/sched.h
+++ b/include/linux/sunrpc/sched.h
@@ -11,7 +11,6 @@

#include <linux/timer.h>
#include <linux/sunrpc/types.h>
-#include <linux/rcupdate.h>
#include <linux/spinlock.h>
#include <linux/wait.h>
#include <linux/workqueue.h>
@@ -77,7 +76,6 @@ struct rpc_task {
union {
struct work_struct tk_work; /* Async task work queue */
struct rpc_wait tk_wait; /* RPC wait */
- struct rcu_head tk_rcu; /* for task deletion */
} u;

unsigned short tk_timeouts; /* maj timeouts */
diff --git a/net/sunrpc/sched.c b/net/sunrpc/sched.c
index 0c6fb50..872da12 100644
--- a/net/sunrpc/sched.c
+++ b/net/sunrpc/sched.c
@@ -385,11 +385,9 @@ static void rpc_wake_up_task_queue_locked(struct rpc_wait_queue *queue, struct r
*/
void rpc_wake_up_queued_task(struct rpc_wait_queue *queue, struct rpc_task *task)
{
- rcu_read_lock_bh();
- spin_lock(&queue->lock);
+ spin_lock_bh(&queue->lock);
rpc_wake_up_task_queue_locked(queue, task);
- spin_unlock(&queue->lock);
- rcu_read_unlock_bh();
+ spin_unlock_bh(&queue->lock);
}
EXPORT_SYMBOL_GPL(rpc_wake_up_queued_task);

@@ -462,16 +460,14 @@ struct rpc_task * rpc_wake_up_next(struct rpc_wait_queue *queue)

dprintk("RPC: wake_up_next(%p \"%s\")\n",
queue, rpc_qname(queue));
- rcu_read_lock_bh();
- spin_lock(&queue->lock);
+ spin_lock_bh(&queue->lock);
if (RPC_IS_PRIORITY(queue))
task = __rpc_wake_up_next_priority(queue);
else {
task_for_first(task, &queue->tasks[0])
rpc_wake_up_task_queue_locked(queue, task);
}
- spin_unlock(&queue->lock);
- rcu_read_unlock_bh();
+ spin_unlock_bh(&queue->lock);

return task;
}
@@ -488,8 +484,7 @@ void rpc_wake_up(struct rpc_wait_queue *queue)
struct rpc_task *task, *next;
struct list_head *head;

- rcu_read_lock_bh();
- spin_lock(&queue->lock);
+ spin_lock_bh(&queue->lock);
head = &queue->tasks[queue->maxpriority];
for (;;) {
list_for_each_entry_safe(task, next, head, u.tk_wait.list)
@@ -498,8 +493,7 @@ void rpc_wake_up(struct rpc_wait_queue *queue)
break;
head--;
}
- spin_unlock(&queue->lock);
- rcu_read_unlock_bh();
+ spin_unlock_bh(&queue->lock);
}
EXPORT_SYMBOL_GPL(rpc_wake_up);

@@ -515,8 +509,7 @@ void rpc_wake_up_status(struct rpc_wait_queue *queue, int status)
struct rpc_task *task, *next;
struct list_head *head;

- rcu_read_lock_bh();
- spin_lock(&queue->lock);
+ spin_lock_bh(&queue->lock);
head = &queue->tasks[queue->maxpriority];
for (;;) {
list_for_each_entry_safe(task, next, head, u.tk_wait.list) {
@@ -527,8 +520,7 @@ void rpc_wake_up_status(struct rpc_wait_queue *queue, int status)
break;
head--;
}
- spin_unlock(&queue->lock);
- rcu_read_unlock_bh();
+ spin_unlock_bh(&queue->lock);
}
EXPORT_SYMBOL_GPL(rpc_wake_up_status);

@@ -843,13 +835,6 @@ rpc_alloc_task(void)
return (struct rpc_task *)mempool_alloc(rpc_task_mempool, GFP_NOFS);
}

-static void rpc_free_task_rcu(struct rcu_head *rcu)
-{
- struct rpc_task *task = container_of(rcu, struct rpc_task, u.tk_rcu);
- dprintk("RPC: %5u freeing task\n", task->tk_pid);
- mempool_free(task, rpc_task_mempool);
-}
-
/*
* Create a new task for the specified client.
*/
@@ -878,8 +863,10 @@ static void rpc_free_task(struct rpc_task *task)
const struct rpc_call_ops *tk_ops = task->tk_ops;
void *calldata = task->tk_calldata;

- if (task->tk_flags & RPC_TASK_DYNAMIC)
- call_rcu_bh(&task->u.tk_rcu, rpc_free_task_rcu);
+ if (task->tk_flags & RPC_TASK_DYNAMIC) {
+ dprintk("RPC: %5u freeing task\n", task->tk_pid);
+ mempool_free(task, rpc_task_mempool);
+ }
rpc_release_calldata(tk_ops, calldata);
}