xprtrdma: Allocate MRs on demand
Frequent MR list exhaustion can impact I/O throughput, so enough MRs
are always created during transport set-up to prevent running out.
This means more MRs are created than most workloads need.
Commit 94f58c58c0b4 ("xprtrdma: Allow Read list and Reply chunk
simultaneously") introduced support for sending two chunk lists per
RPC, which consumes more MRs per RPC.
Instead of trying to provision more MRs, introduce a mechanism for
allocating MRs on demand. A few MRs are allocated during transport
set-up to kick things off.
This significantly reduces the average number of MRs per transport
while allowing the MR count to grow for workloads or devices that
need more MRs.
FRWR with mlx4 allocated almost 400 MRs per transport before this
patch. Now it starts with 32.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Tested-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
diff --git a/net/sunrpc/xprtrdma/fmr_ops.c b/net/sunrpc/xprtrdma/fmr_ops.c
index bc5f4a1..758cd1a 100644
--- a/net/sunrpc/xprtrdma/fmr_ops.c
+++ b/net/sunrpc/xprtrdma/fmr_ops.c
@@ -46,7 +46,7 @@
}
static int
-__fmr_init(struct rpcrdma_mw *mw, struct ib_pd *pd)
+fmr_op_init_mr(struct rpcrdma_ia *ia, struct rpcrdma_mw *mw)
{
static struct ib_fmr_attr fmr_attr = {
.max_pages = RPCRDMA_MAX_FMR_SGES,
@@ -66,7 +66,7 @@
sg_init_table(mw->mw_sg, RPCRDMA_MAX_FMR_SGES);
- mw->fmr.fm_mr = ib_alloc_fmr(pd, RPCRDMA_FMR_ACCESS_FLAGS,
+ mw->fmr.fm_mr = ib_alloc_fmr(ia->ri_pd, RPCRDMA_FMR_ACCESS_FLAGS,
&fmr_attr);
if (IS_ERR(mw->fmr.fm_mr))
goto out_fmr_err;
@@ -96,7 +96,7 @@
}
static void
-__fmr_release(struct rpcrdma_mw *r)
+fmr_op_release_mr(struct rpcrdma_mw *r)
{
LIST_HEAD(unmap_list);
int rc;
@@ -116,13 +116,11 @@
if (rc)
pr_err("rpcrdma: final ib_dealloc_fmr for %p returned %i\n",
r, rc);
+
+ kfree(r);
}
/* Reset of a single FMR.
- *
- * There's no recovery if this fails. The FMR is abandoned, but
- * remains in rb_all. It will be cleaned up when the transport is
- * destroyed.
*/
static void
fmr_op_recover_mr(struct rpcrdma_mw *mw)
@@ -166,41 +164,6 @@
RPCRDMA_MAX_HDR_SEGS * RPCRDMA_MAX_FMR_SGES);
}
-static int
-fmr_op_init(struct rpcrdma_xprt *r_xprt)
-{
- struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
- struct ib_pd *pd = r_xprt->rx_ia.ri_pd;
- struct rpcrdma_mw *r;
- int i, rc;
-
- spin_lock_init(&buf->rb_mwlock);
- INIT_LIST_HEAD(&buf->rb_mws);
- INIT_LIST_HEAD(&buf->rb_all);
-
- i = max_t(int, RPCRDMA_MAX_DATA_SEGS / RPCRDMA_MAX_FMR_SGES, 1);
- i += 2; /* head + tail */
- i *= buf->rb_max_requests; /* one set for each RPC slot */
- dprintk("RPC: %s: initalizing %d FMRs\n", __func__, i);
-
- while (i--) {
- r = kzalloc(sizeof(*r), GFP_KERNEL);
- if (!r)
- return -ENOMEM;
-
- rc = __fmr_init(r, pd);
- if (rc) {
- kfree(r);
- return rc;
- }
-
- r->mw_xprt = r_xprt;
- list_add(&r->mw_list, &buf->rb_mws);
- list_add(&r->mw_all, &buf->rb_all);
- }
- return 0;
-}
-
/* Use the ib_map_phys_fmr() verb to register a memory region
* for remote access via RDMA READ or RDMA WRITE.
*/
@@ -374,19 +337,6 @@
}
}
-static void
-fmr_op_destroy(struct rpcrdma_buffer *buf)
-{
- struct rpcrdma_mw *r;
-
- while (!list_empty(&buf->rb_all)) {
- r = list_entry(buf->rb_all.next, struct rpcrdma_mw, mw_all);
- list_del(&r->mw_all);
- __fmr_release(r);
- kfree(r);
- }
-}
-
const struct rpcrdma_memreg_ops rpcrdma_fmr_memreg_ops = {
.ro_map = fmr_op_map,
.ro_unmap_sync = fmr_op_unmap_sync,
@@ -394,7 +344,7 @@
.ro_recover_mr = fmr_op_recover_mr,
.ro_open = fmr_op_open,
.ro_maxpages = fmr_op_maxpages,
- .ro_init = fmr_op_init,
- .ro_destroy = fmr_op_destroy,
+ .ro_init_mr = fmr_op_init_mr,
+ .ro_release_mr = fmr_op_release_mr,
.ro_displayname = "fmr",
};
diff --git a/net/sunrpc/xprtrdma/frwr_ops.c b/net/sunrpc/xprtrdma/frwr_ops.c
index f3a06fa..e77776b 100644
--- a/net/sunrpc/xprtrdma/frwr_ops.c
+++ b/net/sunrpc/xprtrdma/frwr_ops.c
@@ -91,12 +91,13 @@
}
static int
-__frwr_init(struct rpcrdma_mw *r, struct ib_pd *pd, unsigned int depth)
+frwr_op_init_mr(struct rpcrdma_ia *ia, struct rpcrdma_mw *r)
{
+ unsigned int depth = ia->ri_max_frmr_depth;
struct rpcrdma_frmr *f = &r->frmr;
int rc;
- f->fr_mr = ib_alloc_mr(pd, IB_MR_TYPE_MEM_REG, depth);
+ f->fr_mr = ib_alloc_mr(ia->ri_pd, IB_MR_TYPE_MEM_REG, depth);
if (IS_ERR(f->fr_mr))
goto out_mr_err;
@@ -123,7 +124,7 @@
}
static void
-__frwr_release(struct rpcrdma_mw *r)
+frwr_op_release_mr(struct rpcrdma_mw *r)
{
int rc;
@@ -132,6 +133,7 @@
pr_err("rpcrdma: final ib_dereg_mr for %p returned %i\n",
r, rc);
kfree(r->mw_sg);
+ kfree(r);
}
static int
@@ -319,45 +321,6 @@
complete_all(&frmr->fr_linv_done);
}
-static int
-frwr_op_init(struct rpcrdma_xprt *r_xprt)
-{
- struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
- unsigned int depth = r_xprt->rx_ia.ri_max_frmr_depth;
- struct ib_pd *pd = r_xprt->rx_ia.ri_pd;
- int i;
-
- spin_lock_init(&buf->rb_mwlock);
- INIT_LIST_HEAD(&buf->rb_mws);
- INIT_LIST_HEAD(&buf->rb_all);
-
- i = max_t(int, RPCRDMA_MAX_DATA_SEGS / depth, 1);
- i += 2; /* head + tail */
- i *= buf->rb_max_requests; /* one set for each RPC slot */
- dprintk("RPC: %s: initalizing %d FRMRs\n", __func__, i);
-
- while (i--) {
- struct rpcrdma_mw *r;
- int rc;
-
- r = kzalloc(sizeof(*r), GFP_KERNEL);
- if (!r)
- return -ENOMEM;
-
- rc = __frwr_init(r, pd, depth);
- if (rc) {
- kfree(r);
- return rc;
- }
-
- r->mw_xprt = r_xprt;
- list_add(&r->mw_list, &buf->rb_mws);
- list_add(&r->mw_all, &buf->rb_all);
- }
-
- return 0;
-}
-
/* Post a REG_MR Work Request to register a memory region
* for remote access via RDMA READ or RDMA WRITE.
*/
@@ -618,19 +581,6 @@
}
}
-static void
-frwr_op_destroy(struct rpcrdma_buffer *buf)
-{
- struct rpcrdma_mw *r;
-
- while (!list_empty(&buf->rb_all)) {
- r = list_entry(buf->rb_all.next, struct rpcrdma_mw, mw_all);
- list_del(&r->mw_all);
- __frwr_release(r);
- kfree(r);
- }
-}
-
const struct rpcrdma_memreg_ops rpcrdma_frwr_memreg_ops = {
.ro_map = frwr_op_map,
.ro_unmap_sync = frwr_op_unmap_sync,
@@ -638,7 +588,7 @@
.ro_recover_mr = frwr_op_recover_mr,
.ro_open = frwr_op_open,
.ro_maxpages = frwr_op_maxpages,
- .ro_init = frwr_op_init,
- .ro_destroy = frwr_op_destroy,
+ .ro_init_mr = frwr_op_init_mr,
+ .ro_release_mr = frwr_op_release_mr,
.ro_displayname = "frwr",
};
diff --git a/net/sunrpc/xprtrdma/transport.c b/net/sunrpc/xprtrdma/transport.c
index be4dd2c..b1dd42a 100644
--- a/net/sunrpc/xprtrdma/transport.c
+++ b/net/sunrpc/xprtrdma/transport.c
@@ -682,9 +682,10 @@
r_xprt->rx_stats.failed_marshal_count,
r_xprt->rx_stats.bad_reply_count,
r_xprt->rx_stats.nomsg_call_count);
- seq_printf(seq, "%lu %lu\n",
+ seq_printf(seq, "%lu %lu %lu\n",
r_xprt->rx_stats.mrs_recovered,
- r_xprt->rx_stats.mrs_orphaned);
+ r_xprt->rx_stats.mrs_orphaned,
+ r_xprt->rx_stats.mrs_allocated);
}
static int
diff --git a/net/sunrpc/xprtrdma/verbs.c b/net/sunrpc/xprtrdma/verbs.c
index db935ed..e8677ea 100644
--- a/net/sunrpc/xprtrdma/verbs.c
+++ b/net/sunrpc/xprtrdma/verbs.c
@@ -782,6 +782,55 @@
schedule_delayed_work(&buf->rb_recovery_worker, 0);
}
+static void
+rpcrdma_create_mrs(struct rpcrdma_xprt *r_xprt)
+{
+ struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
+ struct rpcrdma_ia *ia = &r_xprt->rx_ia;
+ unsigned int count;
+ LIST_HEAD(free);
+ LIST_HEAD(all);
+
+ for (count = 0; count < 32; count++) {
+ struct rpcrdma_mw *mw;
+ int rc;
+
+ mw = kzalloc(sizeof(*mw), GFP_KERNEL);
+ if (!mw)
+ break;
+
+ rc = ia->ri_ops->ro_init_mr(ia, mw);
+ if (rc) {
+ kfree(mw);
+ break;
+ }
+
+ mw->mw_xprt = r_xprt;
+
+ list_add(&mw->mw_list, &free);
+ list_add(&mw->mw_all, &all);
+ }
+
+ spin_lock(&buf->rb_mwlock);
+ list_splice(&free, &buf->rb_mws);
+ list_splice(&all, &buf->rb_all);
+ r_xprt->rx_stats.mrs_allocated += count;
+ spin_unlock(&buf->rb_mwlock);
+
+ dprintk("RPC: %s: created %u MRs\n", __func__, count);
+}
+
+static void
+rpcrdma_mr_refresh_worker(struct work_struct *work)
+{
+ struct rpcrdma_buffer *buf = container_of(work, struct rpcrdma_buffer,
+ rb_refresh_worker.work);
+ struct rpcrdma_xprt *r_xprt = container_of(buf, struct rpcrdma_xprt,
+ rx_buf);
+
+ rpcrdma_create_mrs(r_xprt);
+}
+
struct rpcrdma_req *
rpcrdma_create_req(struct rpcrdma_xprt *r_xprt)
{
@@ -837,21 +886,23 @@
rpcrdma_buffer_create(struct rpcrdma_xprt *r_xprt)
{
struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
- struct rpcrdma_ia *ia = &r_xprt->rx_ia;
int i, rc;
buf->rb_max_requests = r_xprt->rx_data.max_requests;
buf->rb_bc_srv_max_requests = 0;
atomic_set(&buf->rb_credits, 1);
+ spin_lock_init(&buf->rb_mwlock);
spin_lock_init(&buf->rb_lock);
spin_lock_init(&buf->rb_recovery_lock);
+ INIT_LIST_HEAD(&buf->rb_mws);
+ INIT_LIST_HEAD(&buf->rb_all);
INIT_LIST_HEAD(&buf->rb_stale_mrs);
+ INIT_DELAYED_WORK(&buf->rb_refresh_worker,
+ rpcrdma_mr_refresh_worker);
INIT_DELAYED_WORK(&buf->rb_recovery_worker,
rpcrdma_mr_recovery_worker);
- rc = ia->ri_ops->ro_init(r_xprt);
- if (rc)
- goto out;
+ rpcrdma_create_mrs(r_xprt);
INIT_LIST_HEAD(&buf->rb_send_bufs);
INIT_LIST_HEAD(&buf->rb_allreqs);
@@ -927,6 +978,32 @@
kfree(req);
}
+static void
+rpcrdma_destroy_mrs(struct rpcrdma_buffer *buf)
+{
+ struct rpcrdma_xprt *r_xprt = container_of(buf, struct rpcrdma_xprt,
+ rx_buf);
+ struct rpcrdma_ia *ia = rdmab_to_ia(buf);
+ struct rpcrdma_mw *mw;
+ unsigned int count;
+
+ count = 0;
+ spin_lock(&buf->rb_mwlock);
+ while (!list_empty(&buf->rb_all)) {
+ mw = list_entry(buf->rb_all.next, struct rpcrdma_mw, mw_all);
+ list_del(&mw->mw_all);
+
+ spin_unlock(&buf->rb_mwlock);
+ ia->ri_ops->ro_release_mr(mw);
+ count++;
+ spin_lock(&buf->rb_mwlock);
+ }
+ spin_unlock(&buf->rb_mwlock);
+ r_xprt->rx_stats.mrs_allocated = 0;
+
+ dprintk("RPC: %s: released %u MRs\n", __func__, count);
+}
+
void
rpcrdma_buffer_destroy(struct rpcrdma_buffer *buf)
{
@@ -955,7 +1032,7 @@
}
spin_unlock(&buf->rb_reqslock);
- ia->ri_ops->ro_destroy(buf);
+ rpcrdma_destroy_mrs(buf);
}
struct rpcrdma_mw *
@@ -973,8 +1050,17 @@
spin_unlock(&buf->rb_mwlock);
if (!mw)
- pr_err("RPC: %s: no MWs available\n", __func__);
+ goto out_nomws;
return mw;
+
+out_nomws:
+ dprintk("RPC: %s: no MWs available\n", __func__);
+ schedule_delayed_work(&buf->rb_refresh_worker, 0);
+
+ /* Allow the reply handler and refresh worker to run */
+ cond_resched();
+
+ return NULL;
}
void
diff --git a/net/sunrpc/xprtrdma/xprt_rdma.h b/net/sunrpc/xprtrdma/xprt_rdma.h
index 08d441d..649d01d 100644
--- a/net/sunrpc/xprtrdma/xprt_rdma.h
+++ b/net/sunrpc/xprtrdma/xprt_rdma.h
@@ -339,6 +339,7 @@
spinlock_t rb_recovery_lock; /* protect rb_stale_mrs */
struct list_head rb_stale_mrs;
struct delayed_work rb_recovery_worker;
+ struct delayed_work rb_refresh_worker;
};
#define rdmab_to_ia(b) (&container_of((b), struct rpcrdma_xprt, rx_buf)->rx_ia)
@@ -387,6 +388,7 @@
unsigned long bcall_count;
unsigned long mrs_recovered;
unsigned long mrs_orphaned;
+ unsigned long mrs_allocated;
};
/*
@@ -405,8 +407,9 @@
struct rpcrdma_ep *,
struct rpcrdma_create_data_internal *);
size_t (*ro_maxpages)(struct rpcrdma_xprt *);
- int (*ro_init)(struct rpcrdma_xprt *);
- void (*ro_destroy)(struct rpcrdma_buffer *);
+ int (*ro_init_mr)(struct rpcrdma_ia *,
+ struct rpcrdma_mw *);
+ void (*ro_release_mr)(struct rpcrdma_mw *);
const char *ro_displayname;
};