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Diffstat (limited to 'src/spdk/test/nvme/overhead/README')
| -rw-r--r-- | src/spdk/test/nvme/overhead/README | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/src/spdk/test/nvme/overhead/README b/src/spdk/test/nvme/overhead/README new file mode 100644 index 000000000..b88c42176 --- /dev/null +++ b/src/spdk/test/nvme/overhead/README @@ -0,0 +1,24 @@ +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. |