xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

SUNRPC: Support dynamic slot allocation for TCP connections

Browse Source 
Allow the number of available slots to grow with the TCP window size.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This commit is contained in:
Trond Myklebust
2011-07-17 18:11:30 -04:00
parent 21de0a955f
commit d9ba131d8f
4 changed files with 109 additions and 20 deletions
Download Patch File Download Diff File Expand all files Collapse all files

70
net/sunrpc/xprt.c
View File

@@ -935,25 +935,66 @@ void xprt_transmit(struct rpc_task *task)
spin_unlock_bh(&xprt->transport_lock);
}
static struct rpc_rqst *xprt_dynamic_alloc_slot(struct rpc_xprt *xprt, gfp_t gfp_flags)
{
struct rpc_rqst *req = ERR_PTR(-EAGAIN);
if (!atomic_add_unless(&xprt->num_reqs, 1, xprt->max_reqs))
goto out;
req = kzalloc(sizeof(struct rpc_rqst), gfp_flags);
if (req != NULL)
goto out;
atomic_dec(&xprt->num_reqs);
req = ERR_PTR(-ENOMEM);
out:
return req;
}
static bool xprt_dynamic_free_slot(struct rpc_xprt *xprt, struct rpc_rqst *req)
{
if (atomic_add_unless(&xprt->num_reqs, -1, xprt->min_reqs)) {
kfree(req);
return true;
}
return false;
}
static void xprt_alloc_slot(struct rpc_task *task)
{
struct rpc_xprt *xprt = task->tk_xprt;
struct rpc_rqst *req;
task->tk_status = 0;
if (!list_empty(&xprt->free)) {
struct rpc_rqst *req = list_entry(xprt->free.next, struct rpc_rqst, rq_list);
list_del_init(&req->rq_list);
task->tk_rqstp = req;
xprt_request_init(task, xprt);
return;
req = list_entry(xprt->free.next, struct rpc_rqst, rq_list);
list_del(&req->rq_list);
goto out_init_req;
}
req = xprt_dynamic_alloc_slot(xprt, GFP_NOWAIT);
if (!IS_ERR(req))
goto out_init_req;
switch (PTR_ERR(req)) {
case -ENOMEM:
rpc_delay(task, HZ >> 2);
dprintk("RPC: dynamic allocation of request slot "
"failed! Retrying\n");
break;
case -EAGAIN:
rpc_sleep_on(&xprt->backlog, task, NULL);
dprintk("RPC: waiting for request slot\n");
}
dprintk("RPC: waiting for request slot\n");
task->tk_status = -EAGAIN;
rpc_sleep_on(&xprt->backlog, task, NULL);
return;
out_init_req:
task->tk_status = 0;
task->tk_rqstp = req;
xprt_request_init(task, xprt);
}
static void xprt_free_slot(struct rpc_xprt *xprt, struct rpc_rqst *req)
{
if (xprt_dynamic_free_slot(xprt, req))
return;
memset(req, 0, sizeof(*req)); /* mark unused */
spin_lock(&xprt->reserve_lock);
@@ -972,7 +1013,9 @@ static void xprt_free_all_slots(struct rpc_xprt *xprt)
}
}
struct rpc_xprt *xprt_alloc(struct net *net, int size, int num_prealloc)
struct rpc_xprt *xprt_alloc(struct net *net, size_t size,
unsigned int num_prealloc,
unsigned int max_alloc)
{
struct rpc_xprt *xprt;
struct rpc_rqst *req;
@@ -992,7 +1035,12 @@ struct rpc_xprt *xprt_alloc(struct net *net, int size, int num_prealloc)
}
if (i < num_prealloc)
goto out_free;
xprt->max_reqs = num_prealloc;
if (max_alloc > num_prealloc)
xprt->max_reqs = max_alloc;
else
xprt->max_reqs = num_prealloc;
xprt->min_reqs = num_prealloc;
atomic_set(&xprt->num_reqs, num_prealloc);
return xprt;
@@ -1036,7 +1084,6 @@ void xprt_reserve(struct rpc_task *task)
if (!xprt_lock_write(xprt, task))
return;
task->tk_status = -EIO;
spin_lock(&xprt->reserve_lock);
xprt_alloc_slot(task);
spin_unlock(&xprt->reserve_lock);
@@ -1057,6 +1104,7 @@ static void xprt_request_init(struct rpc_task *task, struct rpc_xprt *xprt)
{
struct rpc_rqst *req = task->tk_rqstp;
INIT_LIST_HEAD(&req->rq_list);
req->rq_timeout = task->tk_client->cl_timeout->to_initval;
req->rq_task = task;
req->rq_xprt = xprt;