To ensure this allocation cannot fail and will not sleep,
pre-allocate the req_map structures per-connection.
Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
---
include/linux/sunrpc/svc_rdma.h | 8 ++-
net/sunrpc/xprtrdma/svc_rdma_sendto.c | 6 +-
net/sunrpc/xprtrdma/svc_rdma_transport.c | 85 ++++++++++++++++++++++++++----
3 files changed, 84 insertions(+), 15 deletions(-)
diff --git a/include/linux/sunrpc/svc_rdma.h b/include/linux/sunrpc/svc_rdma.h
index be2804b..05bf4fe 100644
--- a/include/linux/sunrpc/svc_rdma.h
+++ b/include/linux/sunrpc/svc_rdma.h
@@ -113,6 +113,7 @@ struct svc_rdma_fastreg_mr {
struct list_head frmr_list;
};
struct svc_rdma_req_map {
+ struct list_head free;
unsigned long count;
union {
struct kvec sge[RPCSVC_MAXPAGES];
@@ -145,6 +146,8 @@ struct svcxprt_rdma {
spinlock_t sc_ctxt_lock;
struct list_head sc_ctxts;
int sc_ctxt_used;
+ spinlock_t sc_map_lock;
+ struct list_head sc_maps;
struct list_head sc_rq_dto_q;
spinlock_t sc_rq_dto_lock;
@@ -223,8 +226,9 @@ extern int svc_rdma_create_listen(struct svc_serv *, int, struct sockaddr *);
extern struct svc_rdma_op_ctxt *svc_rdma_get_context(struct svcxprt_rdma *);
extern void svc_rdma_put_context(struct svc_rdma_op_ctxt *, int);
extern void svc_rdma_unmap_dma(struct svc_rdma_op_ctxt *ctxt);
-extern struct svc_rdma_req_map *svc_rdma_get_req_map(void);
-extern void svc_rdma_put_req_map(struct svc_rdma_req_map *);
+extern struct svc_rdma_req_map *svc_rdma_get_req_map(struct svcxprt_rdma *);
+extern void svc_rdma_put_req_map(struct svcxprt_rdma *,
+ struct svc_rdma_req_map *);
extern struct svc_rdma_fastreg_mr *svc_rdma_get_frmr(struct svcxprt_rdma *);
extern void svc_rdma_put_frmr(struct svcxprt_rdma *,
struct svc_rdma_fastreg_mr *);
diff --git a/net/sunrpc/xprtrdma/svc_rdma_sendto.c b/net/sunrpc/xprtrdma/svc_rdma_sendto.c
index bad5eaa..b75566c 100644
--- a/net/sunrpc/xprtrdma/svc_rdma_sendto.c
+++ b/net/sunrpc/xprtrdma/svc_rdma_sendto.c
@@ -598,7 +598,7 @@ int svc_rdma_sendto(struct svc_rqst *rqstp)
/* Build an req vec for the XDR */
ctxt = svc_rdma_get_context(rdma);
ctxt->direction = DMA_TO_DEVICE;
- vec = svc_rdma_get_req_map();
+ vec = svc_rdma_get_req_map(rdma);
ret = map_xdr(rdma, &rqstp->rq_res, vec);
if (ret)
goto err0;
@@ -637,14 +637,14 @@ int svc_rdma_sendto(struct svc_rqst *rqstp)
ret = send_reply(rdma, rqstp, res_page, rdma_resp, ctxt, vec,
inline_bytes);
- svc_rdma_put_req_map(vec);
+ svc_rdma_put_req_map(rdma, vec);
dprintk("svcrdma: send_reply returns %d\n", ret);
return ret;
err1:
put_page(res_page);
err0:
- svc_rdma_put_req_map(vec);
+ svc_rdma_put_req_map(rdma, vec);
svc_rdma_put_context(ctxt, 0);
return ret;
}
diff --git a/net/sunrpc/xprtrdma/svc_rdma_transport.c b/net/sunrpc/xprtrdma/svc_rdma_transport.c
index 58ed9f2..ec10ae3 100644
--- a/net/sunrpc/xprtrdma/svc_rdma_transport.c
+++ b/net/sunrpc/xprtrdma/svc_rdma_transport.c
@@ -273,23 +273,83 @@ static void svc_rdma_destroy_ctxts(struct svcxprt_rdma *xprt)
}
}
-/*
- * Temporary NFS req mappings are shared across all transport
- * instances. These are short lived and should be bounded by the number
- * of concurrent server threads * depth of the SQ.
- */
-struct svc_rdma_req_map *svc_rdma_get_req_map(void)
+static struct svc_rdma_req_map *alloc_req_map(gfp_t flags)
{
struct svc_rdma_req_map *map;
- map = kmem_cache_alloc(svc_rdma_map_cachep,
- GFP_KERNEL | __GFP_NOFAIL);
+
+ map = kmalloc(sizeof(*map), flags);
+ if (map)
+ INIT_LIST_HEAD(&map->free);
+ return map;
+}
+
+static bool svc_rdma_prealloc_maps(struct svcxprt_rdma *xprt)
+{
+ int i;
+
+ /* One for each receive buffer on this connection. */
+ i = xprt->sc_max_requests;
+
+ while (i--) {
+ struct svc_rdma_req_map *map;
+
+ map = alloc_req_map(GFP_KERNEL);
+ if (!map) {
+ dprintk("svcrdma: No memory for request map\n");
+ return false;
+ }
+ list_add(&map->free, &xprt->sc_maps);
+ }
+ return true;
+}
+
+struct svc_rdma_req_map *svc_rdma_get_req_map(struct svcxprt_rdma *xprt)
+{
+ struct svc_rdma_req_map *map = NULL;
+
+ spin_lock(&xprt->sc_map_lock);
+ if (list_empty(&xprt->sc_maps))
+ goto out_empty;
+
+ map = list_first_entry(&xprt->sc_maps,
+ struct svc_rdma_req_map, free);
+ list_del_init(&map->free);
+ spin_unlock(&xprt->sc_map_lock);
+
+out:
map->count = 0;
return map;
+
+out_empty:
+ spin_unlock(&xprt->sc_map_lock);
+
+ /* Pre-allocation amount was incorrect */
+ map = alloc_req_map(GFP_NOIO);
+ if (map)
+ goto out;
+
+ WARN_ON_ONCE("svcrdma: empty request map list?\n");
+ return NULL;
}
-void svc_rdma_put_req_map(struct svc_rdma_req_map *map)
+void svc_rdma_put_req_map(struct svcxprt_rdma *xprt,
+ struct svc_rdma_req_map *map)
{
- kmem_cache_free(svc_rdma_map_cachep, map);
+ spin_lock(&xprt->sc_map_lock);
+ list_add(&map->free, &xprt->sc_maps);
+ spin_unlock(&xprt->sc_map_lock);
+}
+
+static void svc_rdma_destroy_maps(struct svcxprt_rdma *xprt)
+{
+ while (!list_empty(&xprt->sc_maps)) {
+ struct svc_rdma_req_map *map;
+
+ map = list_first_entry(&xprt->sc_maps,
+ struct svc_rdma_req_map, free);
+ list_del(&map->free);
+ kfree(map);
+ }
}
/* ib_cq event handler */
@@ -593,12 +653,14 @@ static struct svcxprt_rdma *rdma_create_xprt(struct svc_serv *serv,
INIT_LIST_HEAD(&cma_xprt->sc_read_complete_q);
INIT_LIST_HEAD(&cma_xprt->sc_frmr_q);
INIT_LIST_HEAD(&cma_xprt->sc_ctxts);
+ INIT_LIST_HEAD(&cma_xprt->sc_maps);
init_waitqueue_head(&cma_xprt->sc_send_wait);
spin_lock_init(&cma_xprt->sc_lock);
spin_lock_init(&cma_xprt->sc_rq_dto_lock);
spin_lock_init(&cma_xprt->sc_frmr_q_lock);
spin_lock_init(&cma_xprt->sc_ctxt_lock);
+ spin_lock_init(&cma_xprt->sc_map_lock);
if (listener)
set_bit(XPT_LISTENER, &cma_xprt->sc_xprt.xpt_flags);
@@ -988,6 +1050,8 @@ static struct svc_xprt *svc_rdma_accept(struct svc_xprt *xprt)
if (!svc_rdma_prealloc_ctxts(newxprt))
goto errout;
+ if (!svc_rdma_prealloc_maps(newxprt))
+ goto errout;
/*
* Limit ORD based on client limit, local device limit, and
@@ -1259,6 +1323,7 @@ static void __svc_rdma_free(struct work_struct *work)
rdma_dealloc_frmr_q(rdma);
svc_rdma_destroy_ctxts(rdma);
+ svc_rdma_destroy_maps(rdma);
/* Destroy the QP if present (not a listener) */
if (rdma->sc_qp && !IS_ERR(rdma->sc_qp))
--
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