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From: Jason Gunthorpe <jgg@nvidia.com>
To: Dennis Dalessandro <dennis.dalessandro@cornelisnetworks.com>
Cc: dledford@redhat.com, linux-rdma@vger.kernel.org
Subject: Re: [PATCH for-next 0/6] Perf and debug fixes for hfi
Date: Mon, 27 Sep 2021 20:15:37 -0300	[thread overview]
Message-ID: <20210927231537.GA1621884@nvidia.com> (raw)
In-Reply-To: <20210913132317.131370.54825.stgit@awfm-01.cornelisnetworks.com>

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

      parent reply	other threads:[~2021-09-27 23:15 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-09-13 13:28 Dennis Dalessandro
2021-09-13 13:28 ` [PATCH for-next 1/6] IB/hfi1: Remove cache and embed txreq in ring Dennis Dalessandro
2021-09-13 13:28 ` [PATCH for-next 2/6] IB/hfi1: Get rid of hot path divide Dennis Dalessandro
2021-09-13 13:28 ` [PATCH for-next 3/6] IB/hfi1: Get rid of tx priv backpointer Dennis Dalessandro
2021-09-13 13:28 ` [PATCH for-next 4/6] IB/hfi1: Tune netdev xmit cachelines Dennis Dalessandro
2021-09-13 13:28 ` [PATCH for-next 5/6] IB/hfi1: Remove atomic completion count Dennis Dalessandro
2021-09-13 13:28 ` [PATCH for-next 6/6] IB/hfi1: Add ring consumer and producers traces Dennis Dalessandro
2021-09-27 23:15 ` Jason Gunthorpe [this message]

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