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Subject: Re: [PATCH v3 0/6] RPC/RDMA client fixes
To:     Chuck Lever <chuck.lever@oracle.com>, linux-nfs@vger.kernel.org,
        linux-rdma@vger.kernel.org
References: <161238257595.946943.6571271028482175652.stgit@manet.1015granger.net>
From:   Tom Talpey <tom@talpey.com>
Message-ID: <84c2694b-9c73-0125-4327-098d8e5e9f96@talpey.com>
Date:   Wed, 3 Feb 2021 16:24:37 -0500
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On 2/3/2021 3:06 PM, Chuck Lever wrote:
> Changes since v2:
> - Another minor optimization in rpcrdma_convert_kvec()
> - Some patch description clarifications
> - Add Reviewed-by (thanks Tom!)
> 
> Changes since v1:
> - Respond to review comments
> - Split "Remove FMR support" into three patches for clarity
> - Fix implicit chunk roundup
> - Improve Receive completion tracepoints
> 
> ---
> 
> Chuck Lever (6):
>        xprtrdma: Remove FMR support in rpcrdma_convert_iovs()
>        xprtrdma: Simplify rpcrdma_convert_kvec() and frwr_map()
>        xprtrdma: Refactor invocations of offset_in_page()
>        rpcrdma: Fix comments about reverse-direction operation
>        xprtrdma: Pad optimization, revisited
>        rpcrdma: Capture bytes received in Receive completion tracepoints
> 
> 
>   include/trace/events/rpcrdma.h             | 50 +++++++++++++++++++++-
>   net/sunrpc/xprtrdma/backchannel.c          |  4 +-
>   net/sunrpc/xprtrdma/frwr_ops.c             | 12 ++----
>   net/sunrpc/xprtrdma/rpc_rdma.c             | 17 +++-----

While reviewing the changes in rpc_rdma.c, I noticed a related minor
nit, which might be worth cleaning up for clarity.

Toward the end of rpcrdma_convert_iovs, there is no longer any
need to capture the returned value of rpcrdma_convert_kvec:

	if (xdrbuf->tail[0].iov_len)
		seg = rpcrdma_convert_kvec(&xdrbuf->tail[0], seg, &n);

                 ^^^^^^ --> (void)?
out:
	if (unlikely(n > RPCRDMA_MAX_SEGS))
		return -EIO;
	return n;

The two "goto out" statements just above it are getting kinda ugly
too, but...

Tom.


>   net/sunrpc/xprtrdma/svc_rdma_backchannel.c |  4 +-
>   net/sunrpc/xprtrdma/xprt_rdma.h            | 15 ++++---
>   6 files changed, 68 insertions(+), 34 deletions(-)
> 
> --
> Chuck Lever
> 
>