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Commit acb9da7a authored by Chuck Lever's avatar Chuck Lever Committed by Anna Schumaker
Browse files

xprtrdma: Stack relief in fmr_op_map() 



fmr_op_map() declares a 64 element array of u64 in automatic
storage. This is 512 bytes (8 * 64) on the stack.

Instead, when FMR memory registration is in use, pre-allocate a
physaddr array for each rpcrdma_mw.

This is a pre-requisite for increasing the r/wsize maximum for
FMR on platforms with 4KB pages.

Signed-off-by: default avatarChuck Lever <chuck.lever@oracle.com>
Reviewed-by: default avatarSteve Wise <swise@opengridcomputing.com>
Reviewed-by: default avatarSagi Grimberg <sagig@mellanox.com>
Reviewed-by: default avatarDevesh Sharma <devesh.sharma@avagotech.com>
Tested-By: default avatarDevesh Sharma <devesh.sharma@avagotech.com>
Reviewed-by: default avatarDoug Ledford <dledford@redhat.com>
Signed-off-by: default avatarAnna Schumaker <Anna.Schumaker@Netapp.com>
parent 58d1dcf5

net/sunrpc/xprtrdma/fmr_ops.c

+22 −10
Original line number Diff line number Diff line
@@ -72,13 +72,19 @@ fmr_op_init(struct rpcrdma_xprt *r_xprt) 
	i = (buf->rb_max_requests + 1) * RPCRDMA_MAX_SEGS;

	dprintk("RPC:       %s: initializing %d FMRs\n", __func__, i);



	rc = -ENOMEM;

	while (i--) {

		r = kzalloc(sizeof(*r), GFP_KERNEL);

		if (!r)

			return -ENOMEM;

			goto out;



		r->r.fmr.physaddrs = kmalloc(RPCRDMA_MAX_FMR_SGES *

					     sizeof(u64), GFP_KERNEL);

		if (!r->r.fmr.physaddrs)

			goto out_free;



		r->r.fmr = ib_alloc_fmr(pd, mr_access_flags, &fmr_attr);

		if (IS_ERR(r->r.fmr))

		r->r.fmr.fmr = ib_alloc_fmr(pd, mr_access_flags, &fmr_attr);

		if (IS_ERR(r->r.fmr.fmr))

			goto out_fmr_err;



		list_add(&r->mw_list, &buf->rb_mws);
@@ -87,9 +93,12 @@ fmr_op_init(struct rpcrdma_xprt *r_xprt) 
	return 0;



out_fmr_err:

	rc = PTR_ERR(r->r.fmr);

	rc = PTR_ERR(r->r.fmr.fmr);

	dprintk("RPC:       %s: ib_alloc_fmr status %i\n", __func__, rc);

	kfree(r->r.fmr.physaddrs);

out_free:

	kfree(r);

out:

	return rc;

}
@@ -98,7 +107,7 @@ __fmr_unmap(struct rpcrdma_mw *r) 
{

	LIST_HEAD(l);



	list_add(&r->r.fmr->list, &l);

	list_add(&r->r.fmr.fmr->list, &l);

	return ib_unmap_fmr(&l);

}
@@ -113,7 +122,6 @@ fmr_op_map(struct rpcrdma_xprt *r_xprt, struct rpcrdma_mr_seg *seg, 
	struct ib_device *device = ia->ri_device;

	enum dma_data_direction direction = rpcrdma_data_dir(writing);

	struct rpcrdma_mr_seg *seg1 = seg;

	u64 physaddrs[RPCRDMA_MAX_DATA_SEGS];

	int len, pageoff, i, rc;

	struct rpcrdma_mw *mw;
@@ -138,7 +146,7 @@ fmr_op_map(struct rpcrdma_xprt *r_xprt, struct rpcrdma_mr_seg *seg, 
		nsegs = RPCRDMA_MAX_FMR_SGES;

	for (i = 0; i < nsegs;) {

		rpcrdma_map_one(device, seg, direction);

		physaddrs[i] = seg->mr_dma;

		mw->r.fmr.physaddrs[i] = seg->mr_dma;

		len += seg->mr_len;

		++seg;

		++i;
@@ -148,12 +156,13 @@ fmr_op_map(struct rpcrdma_xprt *r_xprt, struct rpcrdma_mr_seg *seg, 
			break;

	}



	rc = ib_map_phys_fmr(mw->r.fmr, physaddrs, i, seg1->mr_dma);

	rc = ib_map_phys_fmr(mw->r.fmr.fmr, mw->r.fmr.physaddrs,

			     i, seg1->mr_dma);

	if (rc)

		goto out_maperr;



	seg1->rl_mw = mw;

	seg1->mr_rkey = mw->r.fmr->rkey;

	seg1->mr_rkey = mw->r.fmr.fmr->rkey;

	seg1->mr_base = seg1->mr_dma + pageoff;

	seg1->mr_nsegs = i;

	seg1->mr_len = len;
@@ -207,10 +216,13 @@ fmr_op_destroy(struct rpcrdma_buffer *buf) 
	while (!list_empty(&buf->rb_all)) {

		r = list_entry(buf->rb_all.next, struct rpcrdma_mw, mw_all);

		list_del(&r->mw_all);

		rc = ib_dealloc_fmr(r->r.fmr);

		kfree(r->r.fmr.physaddrs);



		rc = ib_dealloc_fmr(r->r.fmr.fmr);

		if (rc)

			dprintk("RPC:       %s: ib_dealloc_fmr failed %i\n",

				__func__, rc);



		kfree(r);

	}

}

net/sunrpc/xprtrdma/xprt_rdma.h

+6 −1
Original line number Diff line number Diff line
@@ -206,9 +206,14 @@ struct rpcrdma_frmr { 
	struct rpcrdma_xprt		*fr_xprt;

};



struct rpcrdma_fmr {

	struct ib_fmr		*fmr;

	u64			*physaddrs;

};



struct rpcrdma_mw {

	union {

		struct ib_fmr		*fmr;

		struct rpcrdma_fmr	fmr;

		struct rpcrdma_frmr	frmr;

	} r;

	void			(*mw_sendcompletion)(struct ib_wc *);