[PATCH-v4 0/6] target/vhost/iscsi: Add per-cpu ida tag pre-allocation for v3.12

["Nicholas A. Bellinger" <nab@linux-iscsi.org>]

From: Nicholas Bellinger <nab@linux-iscsi.org>

Hi folks,

This is an updated -v4 series for adding tag pre-allocation support of
target fabric descriptor memory, utilizing Kent's latest per-cpu ida
bits.

The first patch is a standalone version of per-cpu-ida, seperate from
the full idr rewrite from Kent that is still being discussed.  Jens has
also expressed interest in a blk-mq conversion to use these per-cpu-ida
primatives, so getting this piece merged for v3.12 would make life easier
for both of us.  ;)

The second patch includes target-core setup of se_sess->sess_cmd_map +
se_sess->sess_tag_pool resources at session creation time, using
fabric independent code in transport_init_session_tags().

The third patch is the initial conversion of vhost-scsi fabric code
to use per-cpu ida logic for obtaining a new tcm_vhost_cmd descriptor
via vhost_scsi_get_tag() during vhost_work_fn_t->handle_kick() ->
vhost_scsi_handle_vq() callback execution.

The forth patch is a vhost-scsi change that adds pre-allocation of
per tcm_vhost_cmd descriptor scatterlist + user-space page pointer
memory, that allows the last two fast-path allocations to be dropped
from tcm_vhost_submission_work() -> vhost_scsi_map_to_sgl() fast-path
execution.

The fifth patch converts iscsi/iser-target to use allocations based on
iscsit_transport->priv_size within iscsit_allocate_cmd(), instead of
using an embedded isert_cmd->iscsi_cmd.  This makes the conversion to
percpu-ida pre-allocation easier.

And the sixth patch enables iscsi-target to use pre-allocation logic for
per-cpu session tag pooling with internal ida_alloc() + ida_free() calls
based upon the saved iscsi_cmd->se_cmd.map_tag id.

v4 changes:

  - Fix tags.c reference in percpu_ida_init (akpm)
  - Add transport_alloc_session_tags() for fabrics that need early
    transport_init_session()
  - Fix bug with SessionType=Discovery in iscsi_target_locate_portal()

Please review as v3.12 material.

Thank you,

--nab

Kent Overstreet (1):
  idr: Percpu ida

Nicholas Bellinger (5):
  target: Add transport_init_session_tags using per-cpu ida
  vhost/scsi: Convert to per-cpu ida_alloc + ida_free command map
  vhost/scsi: Add pre-allocation for tv_cmd SGL + upages memory
  iscsi/iser-target: Convert to command priv_size usage
  iscsi-target: Convert to per-cpu ida_alloc + ida_free command map

 drivers/infiniband/ulp/isert/ib_isert.c      |  114 ++++------
 drivers/infiniband/ulp/isert/ib_isert.h      |    2 +-
 drivers/target/iscsi/iscsi_target.c          |   16 +--
 drivers/target/iscsi/iscsi_target.h          |    1 -
 drivers/target/iscsi/iscsi_target_configfs.c |    2 +-
 drivers/target/iscsi/iscsi_target_core.h     |    3 +-
 drivers/target/iscsi/iscsi_target_nego.c     |   28 ++-
 drivers/target/iscsi/iscsi_target_util.c     |   41 ++--
 drivers/target/target_core_transport.c       |   48 ++++
 drivers/vhost/scsi.c                         |  132 ++++++++---
 include/linux/idr.h                          |   53 +++++
 include/target/iscsi/iscsi_transport.h       |    8 +-
 include/target/target_core_base.h            |    5 +
 include/target/target_core_fabric.h          |    3 +
 lib/idr.c                                    |  316 +++++++++++++++++++++++++-
 15 files changed, 616 insertions(+), 156 deletions(-)

-- 
1.7.2.5