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PRR: Avoid accounting left-edge twice in partial ACK.
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Authored by rscheff on Feb 20 2021, 6:39 PM.

Details

Summary

After D18624, accounting the advance of the left edge
in a partial ack is already included in
sackhint.delivered_data.

Therefore this is a cumulative error of the
prr_delivered bytes, over the course of multiple
partial acks while lost packets get acknowledged in
sequence.

Test Plan

Corrected behavior, maximum of 2 segments per ACK:

Incorrect behavior due to double-accounting (counterintutively, being more agressive pushing data out - 3 segments per ACK):

Diff Detail

Repository
rG FreeBSD src repository
Lint
Automatic diff as part of commit; lint not applicable.
Unit
Automatic diff as part of commit; unit tests not applicable.

Event Timeline

rscheff retitled this revision from PRR: avoid accounting left-edge twice in parital ack to PRR: Avoid accounting left-edge twice in partial ACK..Feb 20 2021, 7:42 PM
This revision is now accepted and ready to land.Feb 21 2021, 12:01 AM