[lwip-devel] [bug #51663] tcp_out rto: delay re-transmission earlier if link writes are deferred.

[Douglas]

URL:
  <http://savannah.nongnu.org/bugs/?51663>

                 Summary: tcp_out rto: delay re-transmission earlier if link
writes are deferred.
                 Project: lwIP - A Lightweight TCP/IP stack
            Submitted by: ourairquality
            Submitted on: Sat 05 Aug 2017 09:37:33 AM UTC
                Category: TCP
                Severity: 3 - Normal
              Item Group: Change Request
                  Status: None
                 Privacy: Public
             Assigned to: None
             Open/Closed: Open
         Discussion Lock: Any
         Planned Release: None
            lwIP version: git head

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Details:

There is already a guard in tcp_output_segment() for a pbuf still being
referenced by the netif driver due to deferred transmission, however the
callers are modifying state even when this gives up.

It seems cleaner to have the callers guard this case and avoid modifying their
state.

tcp_rexmit_rto() might better avoid re-transmission of any segments if any of
the unacked segments are deferred, to avoid loading the link further if it is
struggling to flush its buffered writes. Link level queues can be limited on
some devices and need spares for link management.




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File Attachments:


-------------------------------------------------------
Date: Sat 05 Aug 2017 09:37:33 AM UTC  Name:
0001-tcp_out-rto-delay-re-transmission-earlier-if-link-wr.patch  Size: 3KiB  
By: ourairquality

<http://savannah.nongnu.org/bugs/download.php?file_id=41421>

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