From: Chuck Lever <[email protected]>
Performance regression reported with NFS/RDMA using Omnipath.
Tracing on the server reports:
nfsd-7771 [060] 1758.891809: svcrdma_sq_post_err:
cq.id=205 cid=226 sc_sq_avail=13643/851 status=-12
sq_post_err reports ENOMEM, and the rdma->sc_sq_avail (13643) is
larger than rdma->sc_sq_depth (851). The number of available Send
Queue entries is always supposed to be smaller than the Send Queue
depth. That seems like a Send Queue accounting bug in svcrdma.
As it's getting to be late in the 6.9-rc cycle, revert this commit.
It can be revisited in a subsequent kernel release.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=218743
Fixes: e084ee673c77 ("svcrdma: Add Write chunk WRs to the RPC's Send WR chain")
Signed-off-by: Chuck Lever <[email protected]>
---
include/linux/sunrpc/svc_rdma.h | 13 +----
net/sunrpc/xprtrdma/svc_rdma_rw.c | 86 ++++++++-------------------------
net/sunrpc/xprtrdma/svc_rdma_sendto.c | 5 --
3 files changed, 26 insertions(+), 78 deletions(-)
diff --git a/include/linux/sunrpc/svc_rdma.h b/include/linux/sunrpc/svc_rdma.h
index 24cd199dd6f3..d33bab33099a 100644
--- a/include/linux/sunrpc/svc_rdma.h
+++ b/include/linux/sunrpc/svc_rdma.h
@@ -210,7 +210,6 @@ struct svc_rdma_recv_ctxt {
*/
struct svc_rdma_write_info {
struct svcxprt_rdma *wi_rdma;
- struct list_head wi_list;
const struct svc_rdma_chunk *wi_chunk;
@@ -239,10 +238,7 @@ struct svc_rdma_send_ctxt {
struct ib_cqe sc_cqe;
struct xdr_buf sc_hdrbuf;
struct xdr_stream sc_stream;
-
- struct list_head sc_write_info_list;
struct svc_rdma_write_info sc_reply_info;
-
void *sc_xprt_buf;
int sc_page_count;
int sc_cur_sge_no;
@@ -274,14 +270,11 @@ extern void svc_rdma_cc_init(struct svcxprt_rdma *rdma,
extern void svc_rdma_cc_release(struct svcxprt_rdma *rdma,
struct svc_rdma_chunk_ctxt *cc,
enum dma_data_direction dir);
-extern void svc_rdma_write_chunk_release(struct svcxprt_rdma *rdma,
- struct svc_rdma_send_ctxt *ctxt);
extern void svc_rdma_reply_chunk_release(struct svcxprt_rdma *rdma,
struct svc_rdma_send_ctxt *ctxt);
-extern int svc_rdma_prepare_write_list(struct svcxprt_rdma *rdma,
- const struct svc_rdma_pcl *write_pcl,
- struct svc_rdma_send_ctxt *sctxt,
- const struct xdr_buf *xdr);
+extern int svc_rdma_send_write_list(struct svcxprt_rdma *rdma,
+ const struct svc_rdma_recv_ctxt *rctxt,
+ const struct xdr_buf *xdr);
extern int svc_rdma_prepare_reply_chunk(struct svcxprt_rdma *rdma,
const struct svc_rdma_pcl *write_pcl,
const struct svc_rdma_pcl *reply_pcl,
diff --git a/net/sunrpc/xprtrdma/svc_rdma_rw.c b/net/sunrpc/xprtrdma/svc_rdma_rw.c
index f2a100c4c81f..40797114d50a 100644
--- a/net/sunrpc/xprtrdma/svc_rdma_rw.c
+++ b/net/sunrpc/xprtrdma/svc_rdma_rw.c
@@ -230,28 +230,6 @@ static void svc_rdma_write_info_free(struct svc_rdma_write_info *info)
queue_work(svcrdma_wq, &info->wi_work);
}
-/**
- * svc_rdma_write_chunk_release - Release Write chunk I/O resources
- * @rdma: controlling transport
- * @ctxt: Send context that is being released
- */
-void svc_rdma_write_chunk_release(struct svcxprt_rdma *rdma,
- struct svc_rdma_send_ctxt *ctxt)
-{
- struct svc_rdma_write_info *info;
- struct svc_rdma_chunk_ctxt *cc;
-
- while (!list_empty(&ctxt->sc_write_info_list)) {
- info = list_first_entry(&ctxt->sc_write_info_list,
- struct svc_rdma_write_info, wi_list);
- list_del(&info->wi_list);
-
- cc = &info->wi_cc;
- svc_rdma_wake_send_waiters(rdma, cc->cc_sqecount);
- svc_rdma_write_info_free(info);
- }
-}
-
/**
* svc_rdma_reply_chunk_release - Release Reply chunk I/O resources
* @rdma: controlling transport
@@ -308,11 +286,13 @@ static void svc_rdma_write_done(struct ib_cq *cq, struct ib_wc *wc)
struct ib_cqe *cqe = wc->wr_cqe;
struct svc_rdma_chunk_ctxt *cc =
container_of(cqe, struct svc_rdma_chunk_ctxt, cc_cqe);
+ struct svc_rdma_write_info *info =
+ container_of(cc, struct svc_rdma_write_info, wi_cc);
switch (wc->status) {
case IB_WC_SUCCESS:
trace_svcrdma_wc_write(&cc->cc_cid);
- return;
+ break;
case IB_WC_WR_FLUSH_ERR:
trace_svcrdma_wc_write_flush(wc, &cc->cc_cid);
break;
@@ -320,11 +300,12 @@ static void svc_rdma_write_done(struct ib_cq *cq, struct ib_wc *wc)
trace_svcrdma_wc_write_err(wc, &cc->cc_cid);
}
- /* The RDMA Write has flushed, so the client won't get
- * some of the outgoing RPC message. Signal the loss
- * to the client by closing the connection.
- */
- svc_xprt_deferred_close(&rdma->sc_xprt);
+ svc_rdma_wake_send_waiters(rdma, cc->cc_sqecount);
+
+ if (unlikely(wc->status != IB_WC_SUCCESS))
+ svc_xprt_deferred_close(&rdma->sc_xprt);
+
+ svc_rdma_write_info_free(info);
}
/**
@@ -620,19 +601,13 @@ static int svc_rdma_xb_write(const struct xdr_buf *xdr, void *data)
return xdr->len;
}
-/* Link Write WRs for @chunk onto @sctxt's WR chain.
- */
-static int svc_rdma_prepare_write_chunk(struct svcxprt_rdma *rdma,
- struct svc_rdma_send_ctxt *sctxt,
- const struct svc_rdma_chunk *chunk,
- const struct xdr_buf *xdr)
+static int svc_rdma_send_write_chunk(struct svcxprt_rdma *rdma,
+ const struct svc_rdma_chunk *chunk,
+ const struct xdr_buf *xdr)
{
struct svc_rdma_write_info *info;
struct svc_rdma_chunk_ctxt *cc;
- struct ib_send_wr *first_wr;
struct xdr_buf payload;
- struct list_head *pos;
- struct ib_cqe *cqe;
int ret;
if (xdr_buf_subsegment(xdr, &payload, chunk->ch_position,
@@ -648,25 +623,10 @@ static int svc_rdma_prepare_write_chunk(struct svcxprt_rdma *rdma,
if (ret != payload.len)
goto out_err;
- ret = -EINVAL;
- if (unlikely(cc->cc_sqecount > rdma->sc_sq_depth))
- goto out_err;
-
- first_wr = sctxt->sc_wr_chain;
- cqe = &cc->cc_cqe;
- list_for_each(pos, &cc->cc_rwctxts) {
- struct svc_rdma_rw_ctxt *rwc;
-
- rwc = list_entry(pos, struct svc_rdma_rw_ctxt, rw_list);
- first_wr = rdma_rw_ctx_wrs(&rwc->rw_ctx, rdma->sc_qp,
- rdma->sc_port_num, cqe, first_wr);
- cqe = NULL;
- }
- sctxt->sc_wr_chain = first_wr;
- sctxt->sc_sqecount += cc->cc_sqecount;
- list_add(&info->wi_list, &sctxt->sc_write_info_list);
-
trace_svcrdma_post_write_chunk(&cc->cc_cid, cc->cc_sqecount);
+ ret = svc_rdma_post_chunk_ctxt(rdma, cc);
+ if (ret < 0)
+ goto out_err;
return 0;
out_err:
@@ -675,27 +635,25 @@ static int svc_rdma_prepare_write_chunk(struct svcxprt_rdma *rdma,
}
/**
- * svc_rdma_prepare_write_list - Construct WR chain for sending Write list
+ * svc_rdma_send_write_list - Send all chunks on the Write list
* @rdma: controlling RDMA transport
- * @write_pcl: Write list provisioned by the client
- * @sctxt: Send WR resources
+ * @rctxt: Write list provisioned by the client
* @xdr: xdr_buf containing an RPC Reply message
*
* Returns zero on success, or a negative errno if one or more
* Write chunks could not be sent.
*/
-int svc_rdma_prepare_write_list(struct svcxprt_rdma *rdma,
- const struct svc_rdma_pcl *write_pcl,
- struct svc_rdma_send_ctxt *sctxt,
- const struct xdr_buf *xdr)
+int svc_rdma_send_write_list(struct svcxprt_rdma *rdma,
+ const struct svc_rdma_recv_ctxt *rctxt,
+ const struct xdr_buf *xdr)
{
struct svc_rdma_chunk *chunk;
int ret;
- pcl_for_each_chunk(chunk, write_pcl) {
+ pcl_for_each_chunk(chunk, &rctxt->rc_write_pcl) {
if (!chunk->ch_payload_length)
break;
- ret = svc_rdma_prepare_write_chunk(rdma, sctxt, chunk, xdr);
+ ret = svc_rdma_send_write_chunk(rdma, chunk, xdr);
if (ret < 0)
return ret;
}
diff --git a/net/sunrpc/xprtrdma/svc_rdma_sendto.c b/net/sunrpc/xprtrdma/svc_rdma_sendto.c
index dfca39abd16c..bb5436b719e0 100644
--- a/net/sunrpc/xprtrdma/svc_rdma_sendto.c
+++ b/net/sunrpc/xprtrdma/svc_rdma_sendto.c
@@ -142,7 +142,6 @@ svc_rdma_send_ctxt_alloc(struct svcxprt_rdma *rdma)
ctxt->sc_send_wr.sg_list = ctxt->sc_sges;
ctxt->sc_send_wr.send_flags = IB_SEND_SIGNALED;
ctxt->sc_cqe.done = svc_rdma_wc_send;
- INIT_LIST_HEAD(&ctxt->sc_write_info_list);
ctxt->sc_xprt_buf = buffer;
xdr_buf_init(&ctxt->sc_hdrbuf, ctxt->sc_xprt_buf,
rdma->sc_max_req_size);
@@ -228,7 +227,6 @@ static void svc_rdma_send_ctxt_release(struct svcxprt_rdma *rdma,
struct ib_device *device = rdma->sc_cm_id->device;
unsigned int i;
- svc_rdma_write_chunk_release(rdma, ctxt);
svc_rdma_reply_chunk_release(rdma, ctxt);
if (ctxt->sc_page_count)
@@ -1015,8 +1013,7 @@ int svc_rdma_sendto(struct svc_rqst *rqstp)
if (!p)
goto put_ctxt;
- ret = svc_rdma_prepare_write_list(rdma, &rctxt->rc_write_pcl, sctxt,
- &rqstp->rq_res);
+ ret = svc_rdma_send_write_list(rdma, rctxt, &rqstp->rq_res);
if (ret < 0)
goto put_ctxt;