From: Bart Van Assche Date: Thu, 21 Jul 2016 20:03:47 +0000 (-0700) Subject: IB/srpt: Limit the number of SG elements per work request X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=30c6d8773de06878f920666d8c945f81cb2081b3;p=linux-beck.git IB/srpt: Limit the number of SG elements per work request 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 Cc: #v4.7+ Reviewed-by: Christoph Hellwig Signed-off-by: Doug Ledford --- diff --git a/drivers/infiniband/ulp/srpt/ib_srpt.c b/drivers/infiniband/ulp/srpt/ib_srpt.c index 4a4155640d51..9a3b954e862d 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 389030487da7..581878782854 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,