On Tue, 2025-10-07 at 11:51 +0200, Hannes Reinecke wrote:

On 10/7/25 11:24, Wilfred Mallawa wrote:

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On Tue, 2025-10-07 at 07:19 +0200, Hannes Reinecke wrote:

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On 10/7/25 02:46, Wilfred Mallawa wrote:

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From: Wilfred Mallawa <redacted>

[...]

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I wonder: Do we really need to check for a partially assembled
record,
or wouldn't it be easier to call queue->write_space() every time
here?
We sure would end up with executing the callback more often, but
if
no
data is present it shouldn't do any harm.

IE just use

if (nvme_tcp_queue_tls(queue)
      queue->write_space(sk);

Hey Hannes,

This was my initial approach, but I figured using
tls_is_partially_sent_record() might be slightly more efficient.
But if
we think that's negligible, happy to go with this approach
(omitting
the partial record check).

Please do.
Performance testing on NVMe-TCP is notoriously tricky, so for now we
really should not assume anything here.
And it's making the patch _vastly_ simpler, _and_ we don't have to
involve the networking folks here.

Okay, will send a V2 with this approach.

We have a similar patch for the data_ready() function in nvmet_tcp(),
and that seemed to work, too.
Nit: we don't unset the 'NOSPACE' flag there. Can you check if that's
really required? 
And, if it is, fixup nvmet_tcp() to unset it?
Or, if not, modify your patch to not clear it?

I don't see why we would need to clear the NOSPACE flag in
data_ready()? My understanding is that this flag is used when the send
buffer is full.

I would think the clear_bit() is necessary in write_space() since it
would typically get done in something like sk_stream_write_space()? 
However, running some quick FIOs with the clear_bit() removed, things
seem to work. Not sure if removing it has any further implications
though...

Regards,
Wilfred

Cheers,

Hannes