OCF-CHANGELOG.txt

There are a few changes in the bdev_ocf_create API compared to SPDK 21.04 and earlier releases:

1. OCF will no longer attempt to automatically load based on found OCF metadata. Restarting SPDK application will now require OCF entry in configuration file (e.g. taken from './scripts/rpc.py save_config' during runtime).

2. Two new parameters were added to bdev_ocf_create: '--create' and '--force', with the following effects:
 '--create' will attempt to create a new OCF bdev instance, if no previous OCF metadata is found on the supplied cache device; if metadata is detected, the bdev won't be created/surfaced
 '--create --force' will always create an OCF bdev instance, overwriting any previous OCF metadata
 '--force' is by itself an illegal parameter, it needs to be used in conjunction with '--create'
 When neither of the above parameters is used, loading of previous metadata is attempted (as mentioned in point 1). If no metadata is found, no OCF bdev will be created.

3. Additional new (optional) parameter has been added to bdev_ocf_create: '--cpu_mask <x>'.
When used, OCF will pin background processes (like cleaning) to the given CPU core(s). See 'CPU mask' section in https://spdk.io/doc/app_overview.html for allowed mask formats.
If the parameter isn't supplied, the background tasks will be ran on an arbitrary CPU core.
It may be necessary to also supply a CPU mask to the overall SPDK application (e.g. './build/bin/spdk_tgt -m ff') for this parameter to take effect.