• Jason Gunthorpe's avatar
    Merge tag 'blk-dim-v2' into rdma.git for-next · 2ef38e38
    Jason Gunthorpe authored
    Generic DIM
    
    From: Tal Gilboa and Yamin Fridman
    
    Implement net DIM over a generic DIM library, add RDMA DIM
    
    dim.h lib exposes an implementation of the DIM algorithm for
    dynamically-tuned interrupt moderation for networking interfaces.
    
    We want a similar functionality for other protocols, which might need to
    optimize interrupts differently. Main motivation here is DIM for NVMf
    storage protocol.
    
    Current DIM implementation prioritizes reducing interrupt overhead over
    latency. Also, in order to reduce DIM's own overhead, the algorithm might
    take some time to identify it needs to change profiles. While this is
    acceptable for networking, it might not work well on other scenarios.
    
    Here we propose a new structure to DIM. The idea is to allow a slightly
    modified functionality without the risk of breaking Net DIM behavior for
    netdev. We verified there are no degradations in current DIM behavior with
    the modified solution.
    
    Suggested solution:
    - Common logic is implemented in lib/dim/dim.c
    - Net DIM (existing) logic is implemented in lib/dim/net_dim.c, which uses
      the common logic in dim.c
    - Any new DIM logic will be implemented in "lib/dim/new_dim.c".
      This new implementation will expose modified versions of profiles,
      dim_step() and dim_decision().
    - DIM API is declared in include/linux/dim.h for all implementations.
    
    Pros for this solution are:
    - Zero impact on existing net_dim implementation and usage
    - Relatively more code reuse (compared to two separate solutions)
    - Increased extensibility
    
    Required for dependencies in the next series.
    Signed-off-by: default avatarJason Gunthorpe <jgg@mellanox.com>
    2ef38e38
bcmsysport.h 23 KB