Many open source projects have moved to using SPDX identifiers to specify license information, reducing the amount of boilerplate code in every source file. This patch replaces the bulk of SPDK .c, .cpp and Makefiles with the BSD-3-Clause identifier. Almost all of these files share the exact same license text, and this patch only modifies the files that contain the most common license text. There can be slight variations because the third clause contains company names - most say "Intel Corporation", but there are instances for Nvidia, Samsung, Eideticom and even "the copyright holder". Used a bash script to automate replacement of the license text with SPDX identifier which is checked into scripts/spdx.sh. Signed-off-by: Jim Harris <james.r.harris@intel.com> Change-Id: Iaa88ab5e92ea471691dc298cfe41ebfb5d169780 Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/12904 Community-CI: Broadcom CI <spdk-ci.pdl@broadcom.com> Community-CI: Mellanox Build Bot Tested-by: SPDK CI Jenkins <sys_sgci@intel.com> Reviewed-by: Aleksey Marchuk <alexeymar@nvidia.com> Reviewed-by: Changpeng Liu <changpeng.liu@intel.com> Reviewed-by: Dong Yi <dongx.yi@intel.com> Reviewed-by: Konrad Sztyber <konrad.sztyber@intel.com> Reviewed-by: Paul Luse <paul.e.luse@intel.com> Reviewed-by: <qun.wan@intel.com> |
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overhead.c | ||
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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.