On May 7, 2024, at 8:44 PM, Jakub Kicinski [off-list ref] wrote:

On Fri,  3 May 2024 16:07:38 +0100 David Howells wrote:

quoted

Here some miscellaneous fixes for AF_RXRPC:

(1) Fix the congestion control algorithm to start cwnd at 4 and to not cut
 ssthresh when the peer cuts its rwind size.

(2) Only transmit a single ACK for all the DATA packets glued together
 into a jumbo packet to reduce the number of ACKs being generated.

(3) Clean up the generation of flags in the protocol header when creating
 a packet for transmission.  This means we don't carry the old
 REQUEST-ACK bit around from previous transmissions, will make it
 easier to fix the MORE-PACKETS flag and make it easier to do jumbo
 packet assembly in future.

(4) Fix how the MORE-PACKETS flag is driven.  We shouldn't be setting it
 in sendmsg() as the packet is then queued and the bit is left in that
 state, no matter how long it takes us to transmit the packet - and
 will still be in that state if the packet is retransmitted.

(5) Request an ACK on an impending transmission stall due to the app layer
 not feeding us new data fast enough.  If we don't request an ACK, we
 may have to hold on to the packet buffers for a significant amount of
 time until the receiver gets bored and sends us an ACK anyway.

Looks like these got marked as Rejected in patchwork.
I think either because lore is confused and attaches an exchange with
DaveM from 2022 to them (?) or because I mentioned to DaveM that I'm
not sure these are fixes. So let me ask - on a scale of 1 to 10, how
convinced are you that these should go to Linus this week rather than
being categorized as general improvements and go during the merge
window (without the Fixes tags)?

Jakub,

In my opinion, the first two patches in the series I believe are important to back port to the stable branches.

Reviewed-by: Jeffrey Altman <jaltman@auristor.com <mailto:jaltman@auristor.com>>

Jeffrey