SUNRPC: switchable buffer allocation
Add RPC client transport switch support for replacing buffer management
on a per-transport basis.
In the current IPv4 socket transport implementation, RPC buffers are
allocated as needed for each RPC message that is sent. Some transport
implementations may choose to use pre-allocated buffers for encoding,
sending, receiving, and unmarshalling RPC messages, however. For
transports capable of direct data placement, the buffers can be carved
out of a pre-registered area of memory rather than from a slab cache.
Test-plan:
Millions of fsx operations. Performance characterization with "sio" and
"iozone". Use oprofile and other tools to look for significant regression
in CPU utilization.
Signed-off-by: Chuck Lever <cel@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
index b23c0d3..25cba94 100644
--- a/net/sunrpc/clnt.c
+++ b/net/sunrpc/clnt.c
@@ -644,24 +644,26 @@
/*
* 2. Allocate the buffer. For details, see sched.c:rpc_malloc.
- * (Note: buffer memory is freed in rpc_task_release).
+ * (Note: buffer memory is freed in xprt_release).
*/
static void
call_allocate(struct rpc_task *task)
{
+ struct rpc_rqst *req = task->tk_rqstp;
+ struct rpc_xprt *xprt = task->tk_xprt;
unsigned int bufsiz;
dprintk("RPC: %4d call_allocate (status %d)\n",
task->tk_pid, task->tk_status);
task->tk_action = call_bind;
- if (task->tk_buffer)
+ if (req->rq_buffer)
return;
/* FIXME: compute buffer requirements more exactly using
* auth->au_wslack */
bufsiz = task->tk_msg.rpc_proc->p_bufsiz + RPC_SLACK_SPACE;
- if (rpc_malloc(task, bufsiz << 1) != NULL)
+ if (xprt->ops->buf_alloc(task, bufsiz << 1) != NULL)
return;
printk(KERN_INFO "RPC: buffer allocation failed for task %p\n", task);
@@ -704,14 +706,14 @@
task->tk_pid, task->tk_status);
/* Default buffer setup */
- bufsiz = task->tk_bufsize >> 1;
- sndbuf->head[0].iov_base = (void *)task->tk_buffer;
+ bufsiz = req->rq_bufsize >> 1;
+ sndbuf->head[0].iov_base = (void *)req->rq_buffer;
sndbuf->head[0].iov_len = bufsiz;
sndbuf->tail[0].iov_len = 0;
sndbuf->page_len = 0;
sndbuf->len = 0;
sndbuf->buflen = bufsiz;
- rcvbuf->head[0].iov_base = (void *)((char *)task->tk_buffer + bufsiz);
+ rcvbuf->head[0].iov_base = (void *)((char *)req->rq_buffer + bufsiz);
rcvbuf->head[0].iov_len = bufsiz;
rcvbuf->tail[0].iov_len = 0;
rcvbuf->page_len = 0;