提交 8301a2c0 编写于 作者: C Chuck Lever 提交者: Anna Schumaker

xprtrdma: Limit work done by completion handler

Sagi Grimberg <sagig@dev.mellanox.co.il> points out that a steady
stream of CQ events could starve other work because of the boundless
loop pooling in rpcrdma_{send,recv}_poll().

Instead of a (potentially infinite) while loop, return after
collecting a budgeted number of completions.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Acked-by: NSagi Grimberg <sagig@dev.mellanox.co.il>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>
上级 1c00dd07
......@@ -165,8 +165,9 @@ static int
rpcrdma_sendcq_poll(struct ib_cq *cq, struct rpcrdma_ep *ep)
{
struct ib_wc *wcs;
int count, rc;
int budget, count, rc;
budget = RPCRDMA_WC_BUDGET / RPCRDMA_POLLSIZE;
do {
wcs = ep->rep_send_wcs;
......@@ -177,7 +178,7 @@ rpcrdma_sendcq_poll(struct ib_cq *cq, struct rpcrdma_ep *ep)
count = rc;
while (count-- > 0)
rpcrdma_sendcq_process_wc(wcs++);
} while (rc == RPCRDMA_POLLSIZE);
} while (rc == RPCRDMA_POLLSIZE && --budget);
return 0;
}
......@@ -254,8 +255,9 @@ static int
rpcrdma_recvcq_poll(struct ib_cq *cq, struct rpcrdma_ep *ep)
{
struct ib_wc *wcs;
int count, rc;
int budget, count, rc;
budget = RPCRDMA_WC_BUDGET / RPCRDMA_POLLSIZE;
do {
wcs = ep->rep_recv_wcs;
......@@ -266,7 +268,7 @@ rpcrdma_recvcq_poll(struct ib_cq *cq, struct rpcrdma_ep *ep)
count = rc;
while (count-- > 0)
rpcrdma_recvcq_process_wc(wcs++);
} while (rc == RPCRDMA_POLLSIZE);
} while (rc == RPCRDMA_POLLSIZE && --budget);
return 0;
}
......
......@@ -74,6 +74,7 @@ struct rpcrdma_ia {
* RDMA Endpoint -- one per transport instance
*/
#define RPCRDMA_WC_BUDGET (128)
#define RPCRDMA_POLLSIZE (16)
struct rpcrdma_ep {
......
Markdown is supported
0% .
You are about to add 0 people to the discussion. Proceed with caution.
先完成此消息的编辑!
想要评论请 注册