[PATCH-v3 0/4] target/vhost-scsi: 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 series for adding tag pre-allocation support of
target fabric descriptor memory, utilizing Kent's latest per-cpu ida
bits here, along with Christoph Lameter's latest comments:

   [PATCH 04/10] idr: Percpu ida
   http://marc.info/?l=linux-kernel&m=137160026006974&w=2

The first patch is a standalone version of per-cpu-ida, seperate from
the full idr rewrite from Kent that is still being discussed.  Given
that I have a number of other target items aside from this series that
depend on this code, I'd like to go ahead and include this standalone
version into target-pending/for-next as a v3.12 item.

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.

And 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.

Please review as v3.12 material.

Thanks!

--nab

Kent Overstreet (1):
  idr: Percpu ida

Nicholas Bellinger (3):
  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

 drivers/target/target_core_transport.c |   33 ++++
 drivers/vhost/scsi.c                   |  132 +++++++++----
 include/linux/idr.h                    |   53 ++++++
 include/target/target_core_base.h      |    5 +
 include/target/target_core_fabric.h    |    1 +
 lib/idr.c                              |  316 +++++++++++++++++++++++++++++++-
 6 files changed, 501 insertions(+), 39 deletions(-)

-- 
1.7.10.4