On Mon, Sep 13, 2021 at 09:28:20AM -0400, Dennis Dalessandro wrote: > Here is a series of perf improvements and debug/trace fixes from Mike, > who has this to say about the patches... > > The AIP SDMA interrupt handling is inefficient: > > - A slab entry is allocated for each sent packet > > This is despite the fact that there is a ring for each possible send slot > that could be occupied by a tx descriptor > > - The interrupt handling/NAPI is lock happy has a mixed up notion of > producer and consumer > > The ring should be a ring of tx descriptors vs. a ring of pointers > > The consumer of descriptors should be the xmit side of the TX > > The producer of the descriptors is the SDMA interrupt handling and NAPI > tx completion > > There is certainly no locking required in the interrupt/TX napi tx queue > > There is no locking required in the xmit side since that is held off by NAPI > code > > Note that these patches are also staged publicly on our GitHub site for easy > browsing in context. > > https://github.com/cornelisnetworks/linux > > --- > > Mike Marciniszyn (6): > IB/hfi1: Remove cache and embed txreq in ring > IB/hfi1: Get rid of hot path divide > IB/hfi1: Get rid of tx priv backpointer > IB/hfi1: Tune netdev xmit cachelines > IB/hfi1: Remove atomic completion count > IB/hfi1: Add ring consumer and producers traces Applied to for-next, thanks Jason
