From acb9da7a57d7905c46d0b69d30fcf944eae261de Mon Sep 17 00:00:00 2001 From: Chuck Lever Date: Tue, 26 May 2015 11:53:23 -0400 Subject: [PATCH] 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: Chuck Lever Reviewed-by: Steve Wise Reviewed-by: Sagi Grimberg Reviewed-by: Devesh Sharma Tested-By: Devesh Sharma Reviewed-by: Doug Ledford Signed-off-by: Anna Schumaker --- net/sunrpc/xprtrdma/fmr_ops.c | 32 ++++++++++++++++++++++---------- net/sunrpc/xprtrdma/xprt_rdma.h | 7 ++++++- 2 files changed, 28 insertions(+), 11 deletions(-) diff --git a/net/sunrpc/xprtrdma/fmr_ops.c b/net/sunrpc/xprtrdma/fmr_ops.c index 52f9ad5..4a53ad5 100644 --- a/net/sunrpc/xprtrdma/fmr_ops.c +++ b/net/sunrpc/xprtrdma/fmr_ops.c @@ -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); } } diff --git a/net/sunrpc/xprtrdma/xprt_rdma.h b/net/sunrpc/xprtrdma/xprt_rdma.h index df92884..110d685 100644 --- a/net/sunrpc/xprtrdma/xprt_rdma.h +++ b/net/sunrpc/xprtrdma/xprt_rdma.h @@ -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 *); -- 2.7.4