From d15cc043d7e450cb759ca997c618d4bb06b17836 Mon Sep 17 00:00:00 2001 From: Bart Van Assche Date: Thu, 21 Jul 2016 13:03:47 -0700 Subject: [PATCH] IB/srpt: Limit the number of SG elements per work request commit 30c6d8773de06878f920666d8c945f81cb2081b3 upstream. Limit the number of SG elements per work request to what the HCA and the queue pair support. Fixes: 34693573fde0 ("IB/srpt: Reduce QP buffer size") Reported-by: Parav Pandit Signed-off-by: Bart Van Assche Cc: Christoph Hellwig Cc: Sagi Grimberg Cc: Steve Wise Cc: Parav Pandit Cc: Nicholas Bellinger Cc: Laurence Oberman Reviewed-by: Christoph Hellwig Signed-off-by: Doug Ledford Signed-off-by: Greg Kroah-Hartman --- drivers/infiniband/ulp/srpt/ib_srpt.c | 3 ++- drivers/infiniband/ulp/srpt/ib_srpt.h | 6 +++++- 2 files changed, 7 insertions(+), 2 deletions(-) diff --git a/drivers/infiniband/ulp/srpt/ib_srpt.c b/drivers/infiniband/ulp/srpt/ib_srpt.c index 4a4155640d516..9a3b954e862d0 100644 --- a/drivers/infiniband/ulp/srpt/ib_srpt.c +++ b/drivers/infiniband/ulp/srpt/ib_srpt.c @@ -1601,6 +1601,7 @@ static int srpt_create_ch_ib(struct srpt_rdma_ch *ch) struct ib_qp_init_attr *qp_init; struct srpt_port *sport = ch->sport; struct srpt_device *sdev = sport->sdev; + const struct ib_device_attr *attrs = &sdev->device->attrs; u32 srp_sq_size = sport->port_attrib.srp_sq_size; int ret; @@ -1638,7 +1639,7 @@ retry: */ qp_init->cap.max_send_wr = srp_sq_size / 2; qp_init->cap.max_rdma_ctxs = srp_sq_size / 2; - qp_init->cap.max_send_sge = SRPT_DEF_SG_PER_WQE; + qp_init->cap.max_send_sge = min(attrs->max_sge, SRPT_MAX_SG_PER_WQE); qp_init->port_num = ch->sport->port; ch->qp = ib_create_qp(sdev->pd, qp_init); diff --git a/drivers/infiniband/ulp/srpt/ib_srpt.h b/drivers/infiniband/ulp/srpt/ib_srpt.h index 389030487da7e..5818787828543 100644 --- a/drivers/infiniband/ulp/srpt/ib_srpt.h +++ b/drivers/infiniband/ulp/srpt/ib_srpt.h @@ -106,7 +106,11 @@ enum { SRP_LOGIN_RSP_MULTICHAN_MAINTAINED = 0x2, SRPT_DEF_SG_TABLESIZE = 128, - SRPT_DEF_SG_PER_WQE = 16, + /* + * An experimentally determined value that avoids that QP creation + * fails due to "swiotlb buffer is full" on systems using the swiotlb. + */ + SRPT_MAX_SG_PER_WQE = 16, MIN_SRPT_SQ_SIZE = 16, DEF_SRPT_SQ_SIZE = 4096, -- 2.47.2