Details
-
Improvement
-
Resolution: Unresolved
-
Minor
-
None
-
None
-
3
-
9223372036854775807
Description
It would be useful to add a new "{osc,mdc}.*.max_mb_per_rpc" tunable parameter to dissociate the RPC size from the client page size as implied by "{osc,mdc}.*.max_pages_per_rpc". While it is already to specify "max_pages_per_rpc" with a unit like "4M" or "16M" to avoid issues with page sizes, this is still printed as a number of pages, and values without units are assumed to be pages. It would be better to have a dedicated parameter for specifying the RPC size, and (very) slowly deprecate max_pages_per_rpc in the future.
The max_mb_per_rpc parameter should internally convert the specified parameter to pages and still modify the same cl_max_pages_per_rpc variable, in addition to the existing max_pages_per_rpc parameter, but will provide a more consistent userspace interface for doing so.
The parameter should accept units and fractional parameters (e.g. 0.5M and 64k), which is already handled by sysfs_memparse(), so that it is possible to specify RPC sizes smaller than 1MiB in the rare case this is needed.
