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From:   Olga Kornievskaia <olga.kornievskaia@gmail.com>
Date:   Mon, 30 Aug 2021 12:55:52 -0400
Message-ID: <CAN-5tyExcCg7vNN=jweMds03QNgHZ1zH5V9KvCxyong2UEq8Yw@mail.gmail.com>
Subject: Re: [RFC 0/2] revisit RMDA XDR padding management
To:     Trond Myklebust <trond.myklebust@hammerspace.com>,
        Anna Schumaker <anna.schumaker@netapp.com>,
        Chuck Lever <chuck.lever@oracle.com>
Cc:     linux-nfs <linux-nfs@vger.kernel.org>
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On Mon, Aug 30, 2021 at 12:53 PM Olga Kornievskaia
<olga.kornievskaia@gmail.com> wrote:
>
> From: Olga Kornievskaia <kolga@netapp.com>
>
> We have previously revisited how XDR padding management was done
> for the RDMA read chunks.
>
> This patch series attempts to do the same for the RDMA read chunks
> and altogether remove the options of doing an implicit roundup.

Apologies for typos but this is about RDMA write chunks.

> According to the RFC 8166 client "SHOULD NOT" include additional
> space for XDR roundup padding. Furthermore, server MUST NOT write
> XDR padding into the a write chunk. Given those two statement and
> a patch "NFS: Always provide aligned buffers to the RPC read layers",
> there is no reason for the client to look at the tail and assume
> there is any padding data for which it needs to allocate space for.
>
> The only operation that this patch series effects is an NFS read.
> All non-read ops that might use a write chunk are setup to use
> reply chunk if reply is larger than inline threshold, not a write
> chunk.
>
>
>
> *** SUBJECT HERE ***
>
> *** BLURB HERE ***
>
> Olga Kornievskaia (2):
>   xprtrdma: xdr pad optimization revisted again
>   xprtrdma: remove re_implicit_roundup xprt_rdma_pad_optimize
>
>  net/sunrpc/xprtrdma/rpc_rdma.c  | 15 ---------------
>  net/sunrpc/xprtrdma/transport.c |  8 --------
>  net/sunrpc/xprtrdma/verbs.c     |  2 --
>  net/sunrpc/xprtrdma/xprt_rdma.h |  6 ------
>  4 files changed, 31 deletions(-)
>
> --
> 2.27.0
>