Spdk/test/lib/nvme/overhead
Daniel Verkamp ce4fcbce71 nvme: add I/O qpair creation options
Add a new struct spdk_nvme_io_qpair_opts to allow the user to override
controller options on a per-I/O qpair basis.

Existing callers with qprio == 0 can be updated to:

  ... = spdk_nvme_ctrlr_alloc_io_qpair(ctrlr, NULL, 0);

Callers that need to specify a non-default qprio should be updated to:

  struct spdk_nvme_io_qpair_opts opts;
  spdk_nvme_ctrlr_get_default_io_qpair_opts(ctrlr, &opts, sizeof(opts));
  opts.qprio = SPDK_NVME_QPRIO_...;
  ... = spdk_nvme_ctrlr_alloc_io_qpair(ctrlr, &opts, sizeof(opts));

Change-Id: I8ac3ea369535cfde759abbe75e1d974b6450a800
Signed-off-by: Daniel Verkamp <daniel.verkamp@intel.com>
Reviewed-on: https://review.gerrithub.io/369676
Tested-by: SPDK Automated Test System <sys_sgsw@intel.com>
Reviewed-by: Ben Walker <benjamin.walker@intel.com>
2017-07-18 18:33:20 -04:00
..
.gitignore nvme: add gitignore to overhead directory 2016-08-02 14:33:21 -07:00
Makefile build: create a common mk file for nvme library tests and examples 2016-11-22 11:45:47 -07:00
overhead.c nvme: add I/O qpair creation options 2017-07-18 18:33:20 -04:00
README nvme: add new test application to measure SW overhead 2016-08-01 12:58:30 -07:00

This application measures the software overhead of I/O submission
and completion for both the SPDK NVMe driver and an AIO file handle.
It runs a random read, queue depth = 1 workload to a single device,
and captures TSC as follows:

* Submission: capture TSC before and after the I/O submission
  call (SPDK or AIO).
* Completion: capture TSC before and after the I/O completion
  check.  Only record the TSC delta if the I/O completion check
  resulted in a completed I/O.  Also use heuristics in the AIO
  case to account for time spent in interrupt handling outside
  of the actual I/O completion check.

Usage:

To test software overhead for a 4KB I/O over a 10 second period:

SPDK:  overhead -s 4096 -t 10
AIO:   overhead -s 4096 -t 10 /dev/nvme0n1

Note that for the SPDK case, it will only use the first namespace
on the first controller found by SPDK.  If a different namespace is
desired, attach controllers individually to the kernel NVMe driver
to ensure they will not be enumerated by SPDK.