Spread NFSD completion handling across CPUs, and replace
BH-friendly spin locking with plain spin locks.
iozone -i0 -i1 -s128m -y1k -az -I -N
Microseconds/op Mode. Output is in microseconds per operation.
Before:
KB reclen write rewrite read reread
131072 1 51 51 43 43
131072 2 53 52 42 43
131072 4 53 52 43 43
131072 8 55 54 44 44
131072 16 62 59 49 47
131072 32 72 69 53 53
131072 64 92 87 66 66
131072 128 144 130 94 93
131072 256 225 216 146 145
131072 512 485 474 251 251
131072 1024 573 540 514 512
131072 2048 1007 941 624 618
131072 4096 1672 1699 976 969
131072 8192 3179 3158 1660 1649
131072 16384 5836 5659 3062 3041
After:
KB reclen write rewrite read reread
131072 1 54 54 43 43
131072 2 55 55 43 43
131072 4 56 57 44 45
131072 8 59 58 45 45
131072 16 64 62 47 47
131072 32 76 74 54 54
131072 64 96 91 67 66
131072 128 148 133 97 97
131072 256 229 227 148 147
131072 512 488 445 252 255
131072 1024 582 534 511 540
131072 2048 998 988 614 620
131072 4096 1685 1679 946 965
131072 8192 3113 3048 1650 1644
131072 16384 6010 5745 3046 3053
NFS READ is roughly the same, NFS WRITE is marginally worse.
Before:
GETATTR:
242 ops (0%)
avg bytes sent per op: 127
avg bytes received per op: 112
backlog wait: 0.000000
RTT: 0.041322
total execute time: 0.049587 (milliseconds)
After:
GETATTR:
242 ops (0%)
avg bytes sent per op: 127
avg bytes received per op: 112
backlog wait: 0.000000
RTT: 0.045455
total execute time: 0.053719 (milliseconds)
Small op latency increased by 4usec.
Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
---
net/sunrpc/xprtrdma/svc_rdma_recvfrom.c | 6 +++---
net/sunrpc/xprtrdma/svc_rdma_transport.c | 26 +++++++++++++-------------
2 files changed, 16 insertions(+), 16 deletions(-)
diff --git a/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c b/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c
index 41adbe7..6159ae6 100644
--- a/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c
+++ b/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c
@@ -586,13 +586,13 @@ int svc_rdma_recvfrom(struct svc_rqst *rqstp)
dprintk("svcrdma: rqstp=%p\n", rqstp);
- spin_lock_bh(&rdma_xprt->sc_rq_dto_lock);
+ spin_lock(&rdma_xprt->sc_rq_dto_lock);
if (!list_empty(&rdma_xprt->sc_read_complete_q)) {
ctxt = list_entry(rdma_xprt->sc_read_complete_q.next,
struct svc_rdma_op_ctxt,
dto_q);
list_del_init(&ctxt->dto_q);
- spin_unlock_bh(&rdma_xprt->sc_rq_dto_lock);
+ spin_unlock(&rdma_xprt->sc_rq_dto_lock);
rdma_read_complete(rqstp, ctxt);
goto complete;
} else if (!list_empty(&rdma_xprt->sc_rq_dto_q)) {
@@ -605,7 +605,7 @@ int svc_rdma_recvfrom(struct svc_rqst *rqstp)
clear_bit(XPT_DATA, &xprt->xpt_flags);
ctxt = NULL;
}
- spin_unlock_bh(&rdma_xprt->sc_rq_dto_lock);
+ spin_unlock(&rdma_xprt->sc_rq_dto_lock);
if (!ctxt) {
/* This is the EAGAIN path. The svc_recv routine will
* return -EAGAIN, the nfsd thread will go to call into
diff --git a/net/sunrpc/xprtrdma/svc_rdma_transport.c b/net/sunrpc/xprtrdma/svc_rdma_transport.c
index dd94401..8850a5f 100644
--- a/net/sunrpc/xprtrdma/svc_rdma_transport.c
+++ b/net/sunrpc/xprtrdma/svc_rdma_transport.c
@@ -186,7 +186,7 @@ struct svc_rdma_op_ctxt *svc_rdma_get_context(struct svcxprt_rdma *xprt)
{
struct svc_rdma_op_ctxt *ctxt = NULL;
- spin_lock_bh(&xprt->sc_ctxt_lock);
+ spin_lock(&xprt->sc_ctxt_lock);
xprt->sc_ctxt_used++;
if (list_empty(&xprt->sc_ctxts))
goto out_empty;
@@ -194,7 +194,7 @@ struct svc_rdma_op_ctxt *svc_rdma_get_context(struct svcxprt_rdma *xprt)
ctxt = list_first_entry(&xprt->sc_ctxts,
struct svc_rdma_op_ctxt, free);
list_del_init(&ctxt->free);
- spin_unlock_bh(&xprt->sc_ctxt_lock);
+ spin_unlock(&xprt->sc_ctxt_lock);
out:
ctxt->count = 0;
@@ -205,15 +205,15 @@ out_empty:
/* Either pre-allocation missed the mark, or send
* queue accounting is broken.
*/
- spin_unlock_bh(&xprt->sc_ctxt_lock);
+ spin_unlock(&xprt->sc_ctxt_lock);
ctxt = alloc_ctxt(xprt, GFP_NOIO);
if (ctxt)
goto out;
- spin_lock_bh(&xprt->sc_ctxt_lock);
+ spin_lock(&xprt->sc_ctxt_lock);
xprt->sc_ctxt_used--;
- spin_unlock_bh(&xprt->sc_ctxt_lock);
+ spin_unlock(&xprt->sc_ctxt_lock);
WARN_ONCE(1, "svcrdma: empty RDMA ctxt list?\n");
return NULL;
}
@@ -248,10 +248,10 @@ void svc_rdma_put_context(struct svc_rdma_op_ctxt *ctxt, int free_pages)
for (i = 0; i < ctxt->count; i++)
put_page(ctxt->pages[i]);
- spin_lock_bh(&xprt->sc_ctxt_lock);
+ spin_lock(&xprt->sc_ctxt_lock);
xprt->sc_ctxt_used--;
list_add(&ctxt->free, &xprt->sc_ctxts);
- spin_unlock_bh(&xprt->sc_ctxt_lock);
+ spin_unlock(&xprt->sc_ctxt_lock);
}
static void svc_rdma_destroy_ctxts(struct svcxprt_rdma *xprt)
@@ -897,14 +897,14 @@ struct svc_rdma_fastreg_mr *svc_rdma_get_frmr(struct svcxprt_rdma *rdma)
{
struct svc_rdma_fastreg_mr *frmr = NULL;
- spin_lock_bh(&rdma->sc_frmr_q_lock);
+ spin_lock(&rdma->sc_frmr_q_lock);
if (!list_empty(&rdma->sc_frmr_q)) {
frmr = list_entry(rdma->sc_frmr_q.next,
struct svc_rdma_fastreg_mr, frmr_list);
list_del_init(&frmr->frmr_list);
frmr->sg_nents = 0;
}
- spin_unlock_bh(&rdma->sc_frmr_q_lock);
+ spin_unlock(&rdma->sc_frmr_q_lock);
if (frmr)
return frmr;
@@ -918,10 +918,10 @@ void svc_rdma_put_frmr(struct svcxprt_rdma *rdma,
ib_dma_unmap_sg(rdma->sc_cm_id->device,
frmr->sg, frmr->sg_nents, frmr->direction);
atomic_dec(&rdma->sc_dma_used);
- spin_lock_bh(&rdma->sc_frmr_q_lock);
+ spin_lock(&rdma->sc_frmr_q_lock);
WARN_ON_ONCE(!list_empty(&frmr->frmr_list));
list_add(&frmr->frmr_list, &rdma->sc_frmr_q);
- spin_unlock_bh(&rdma->sc_frmr_q_lock);
+ spin_unlock(&rdma->sc_frmr_q_lock);
}
}
@@ -999,13 +999,13 @@ static struct svc_xprt *svc_rdma_accept(struct svc_xprt *xprt)
goto errout;
}
newxprt->sc_sq_cq = ib_alloc_cq(dev, newxprt, newxprt->sc_sq_depth,
- 0, IB_POLL_SOFTIRQ);
+ 0, IB_POLL_WORKQUEUE);
if (IS_ERR(newxprt->sc_sq_cq)) {
dprintk("svcrdma: error creating SQ CQ for connect request\n");
goto errout;
}
newxprt->sc_rq_cq = ib_alloc_cq(dev, newxprt, newxprt->sc_rq_depth,
- 0, IB_POLL_SOFTIRQ);
+ 0, IB_POLL_WORKQUEUE);
if (IS_ERR(newxprt->sc_rq_cq)) {
dprintk("svcrdma: error creating RQ CQ for connect request\n");
goto errout;
--
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