From: Tom Talpey <tom@talpey.com>
To: David Howells <dhowells@redhat.com>
Cc: Steve French <smfrench@gmail.com>,
Steve French <sfrench@samba.org>,
Stefan Metzmacher <metze@samba.org>,
Paulo Alcantara <pc@manguebit.com>,
Matthew Wilcox <willy@infradead.org>,
CIFS <linux-cifs@vger.kernel.org>
Subject: Re: cifs RDMA restrictions
Date: Wed, 2 Apr 2025 15:36:15 -0400 [thread overview]
Message-ID: <49b8b758-2d72-4de9-b0f1-dbf9a7124cdf@talpey.com> (raw)
In-Reply-To: <843601.1743622017@warthog.procyon.org.uk>
On 4/2/2025 3:26 PM, David Howells wrote:
> Hi Tom,
>
> Btw, in smb_recv_buf(), am I reading it right that it doesn't actually pass
> buf off to the RDMA layer, but rather just copies into it from a response
> popped off of the reassembly queue?
>
> If that's the case, it should be possible to collapse smbd_recv_buf() and
> smbd_recv_page() into smbd_recv() and just replace the memcpy() with
> copy_to_iter().
I guess so. That code has been there all long and I haven't
looked into changing it. The comment at the top certainly says
it's something to consider.
The SMB Direct reassembly stuff is the non-RDMA path, where a
message payload is too large for a single ~1KB datagram, but
was not registered for direct placement. This would mainly be
fsctl's and small reads. I wouldn't get too worked up about
highly optimizing those.
Tom.
next prev parent reply other threads:[~2025-04-02 19:36 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-04-01 16:55 cifs RDMA restrictions David Howells
2025-04-01 18:02 ` Tom Talpey
2025-04-01 19:34 ` David Howells
2025-04-02 17:02 ` Tom Talpey
2025-04-02 17:09 ` David Howells
[not found] ` <CAH2r5ms2J06tJr4VEVDgmcj_1uqOnhYzbC1ybrMWDm=f8wVDoA@mail.gmail.com>
2025-04-02 18:04 ` Tom Talpey
2025-04-02 19:26 ` David Howells
2025-04-02 19:36 ` Tom Talpey [this message]
2025-04-02 19:54 ` [RFC PATCH] cifs: Collapse smbd_recv_*() into smbd_recv() and just use copy_to_iter() David Howells
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