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per Intel policy to include file commit date using git cmd below. The policy does not apply to non-Intel (C) notices. git log --follow -C90% --format=%ad --date default <file> | tail -1 and then pull just the 4 digit year from the result. Intel copyrights were not added to files where Intel either had no contribution ot the contribution lacked substance (ie license header updates, formatting changes, etc). Contribution date used "--follow -C95%" to get the most accurate date. Note that several files in this patch didn't end the license/(c) block with a blank comment line so these were added as the vast majority of files do have this last blank line. Simply there for consistency. Signed-off-by: paul luse <paul.e.luse@intel.com> Change-Id: Id5b7ce4f658fe87132f14139ead58d6e285c04d4 Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/15192 Tested-by: SPDK CI Jenkins <sys_sgci@intel.com> Reviewed-by: Jim Harris <james.r.harris@intel.com> Reviewed-by: Ben Walker <benjamin.walker@intel.com> Community-CI: Mellanox Build Bot |
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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.