On Tue, May 11, 2021 at 08:27:52PM -0700, Bart Van Assche wrote:
> Define .init_cmd_priv and .exit_cmd_priv callback functions in struct
> scsi_host_template. Set .cmd_size such that the SCSI core allocates
> per-command private data. Use scsi_cmd_priv() to access that private
> data. Remove the req_ring pointer from struct srp_rdma_ch since it is
> no longer necessary. Convert srp_alloc_req_data() and srp_free_req_data()
> into functions that initialize one instance of the SRP-private command
> data. This is a micro-optimization since this patch removes several
> pointer dereferences from the hot path.
>
> Note: due to commit e73a5e8e8003 ("scsi: core: Only return started requests
> from scsi_host_find_tag()"), it is no longer necessary to protect the
> completion path against duplicate responses.
>
> Cc: Nicolas Morey-Chaisemartin <nmoreychaisemartin@xxxxxxxx>
> Signed-off-by: Bart Van Assche <bvanassche@xxxxxxx>
> ---
> drivers/infiniband/ulp/srp/ib_srp.c | 156 ++++++++++++----------------
> drivers/infiniband/ulp/srp/ib_srp.h | 2 -
> 2 files changed, 65 insertions(+), 93 deletions(-)
>
> diff --git a/drivers/infiniband/ulp/srp/ib_srp.c b/drivers/infiniband/ulp/srp/ib_srp.c
> index 52db42af421b..773ac5929082 100644
> --- a/drivers/infiniband/ulp/srp/ib_srp.c
> +++ b/drivers/infiniband/ulp/srp/ib_srp.c
> @@ -965,69 +965,55 @@ static void srp_disconnect_target(struct srp_target_port *target)
> }
> }
>
> -static void srp_free_req_data(struct srp_target_port *target,
> - struct srp_rdma_ch *ch)
> +static int srp_exit_cmd_priv(struct Scsi_Host *shost, struct scsi_cmnd *cmd)
> {
> + struct srp_target_port *target = host_to_target(shost);
> struct srp_device *dev = target->srp_host->srp_dev;
> struct ib_device *ibdev = dev->dev;
> - struct srp_request *req;
> - int i;
> + struct srp_request *req = scsi_cmd_priv(cmd);
>
> - if (!ch->req_ring)
> - return;
> -
> - for (i = 0; i < target->req_ring_size; ++i) {
> - req = &ch->req_ring[i];
> - if (dev->use_fast_reg)
> - kfree(req->fr_list);
> - if (req->indirect_dma_addr) {
> - ib_dma_unmap_single(ibdev, req->indirect_dma_addr,
> - target->indirect_size,
> - DMA_TO_DEVICE);
> - }
> - kfree(req->indirect_desc);
> + if (dev->use_fast_reg)
> + kfree(req->fr_list);
Isn't cleaner will be to ensure that fr_list is NULL for !dev->use_fast_reg path?
In patch #4 https://lore.kernel.org/linux-rdma/20210512032752.16611-5-bvanassche@xxxxxxx
Thanks
