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doc: Really minor updates to NVMe-oF programmers guide

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You can take it or leave it. I read through looking for substantive
updates I could make and didn't find much. This guide appears to have
stayed pretty true to form.

Change-Id: I6f0e53d9bef4c7e6cea40ff6d6605127d0640a63
Signed-off-by: Seth Howell <seth.howell@intel.com>
Reviewed-on: https://review.gerrithub.io/426404
Chandler-Test-Pool: SPDK Automated Test System <sys_sgsw@intel.com>
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: Paul Luse <paul.e.luse@intel.com>
Reviewed-by: Shuhei Matsumoto <shuhei.matsumoto.xt@hitachi.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>
This commit is contained in:
Seth Howell 2018-09-21 10:04:40 -07:00 committed by Jim Harris
parent 0ee7ebcc70
commit 74d4e7e645
1 changed files with 7 additions and 7 deletions
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14
doc/nvmf_tgt_pg.md
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@ -67,9 +67,9 @@ system. This is used for access control.
## The Basics
A user of the NVMe-oF target library begins by creating a target using
spdk_nvmf_tgt_create(), setting up a set of addresses to accept connections on
by calling spdk_nvmf_tgt_listen(), then creating a subsystem using
spdk_nvmf_subsystem_create().
spdk_nvmf_tgt_create(), setting up a set of addresses on which to accept
connections by calling spdk_nvmf_tgt_listen(), then creating a subsystem
using spdk_nvmf_subsystem_create().
Subsystems begin in an inactive state and must be activated by calling
spdk_nvmf_subsystem_start(). Subsystems may be modified at run time, but only
@ -89,13 +89,13 @@ All I/O to a subsystem is driven by a poll group, which polls for incoming
network I/O. Poll groups may be created by calling
spdk_nvmf_poll_group_create(). They automatically request to begin polling
upon creation on the thread from which they were created. Most importantly, *a
poll group may only be accessed from the thread it was created on.*
poll group may only be accessed from the thread on which it was created.*
When spdk_nvmf_tgt_accept() detects a new connection, it will construct a new
struct spdk_nvmf_qpair object and call the user provided `new_qpair_fn`
callback for each new qpair. In response to this callback, the user must
assign the qpair to a poll group by calling spdk_nvmf_poll_group_add().
Remember, a poll group may only be accessed from the thread it was created on,
Remember, a poll group may only be accessed from the thread on which it was created,
so making a call to spdk_nvmf_poll_group_add() may require passing a message
to the appropriate thread.
@ -136,7 +136,7 @@ per thread used in the application. New qpairs created in response to
spdk_nvmf_tgt_accept() can be handed out round-robin to the poll groups. This
is how the SPDK NVMe-oF target application currently functions.
More advanced algorithms for distributing qpairs to poll groups is possible.
More advanced algorithms for distributing qpairs to poll groups are possible.
For instance, a NUMA-aware algorithm would be an improvement over basic
round-robin, where NUMA-aware means assigning qpairs to poll groups running on
CPU cores that are on the same NUMA node as the network adapter and storage
@ -166,7 +166,7 @@ the I/O path.
## Zero Copy Support
For the RDMA transport, data is transferred from the RDMA NIC to host memory
and then host memory to the SSD (or vis. versa), without any intermediate
and then host memory to the SSD (or vice versa), without any intermediate
copies. Data is never moved from one location in host memory to another. Other
transports in the future may require data copies.