xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

xprtrdma: Allocate MRs on demand

Browse Source 
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 94f58c58c0 ("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>
This commit is contained in:
Chuck Lever
2016-06-29 13:54:00 -04:00
committed by Anna Schumaker
parent a54d4059e5
commit e2ac236c0b
5 changed files with 114 additions and 124 deletions
Download Patch File Download Diff File Expand all files Collapse all files

64
net/sunrpc/xprtrdma/frwr_ops.c
View File

@@ -91,12 +91,13 @@ out_not_supported:
}
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 @@ out_list_err:
}
static void
__frwr_release(struct rpcrdma_mw *r)
frwr_op_release_mr(struct rpcrdma_mw *r)
{
int rc;
@@ -132,6 +133,7 @@ __frwr_release(struct rpcrdma_mw *r)
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 @@ frwr_wc_localinv_wake(struct ib_cq *cq, struct ib_wc *wc)
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 @@ frwr_op_unmap_safe(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req,
}
}
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 @@ const struct rpcrdma_memreg_ops rpcrdma_frwr_memreg_ops = {
.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",
};