* [dpdk-dev] Transmit and Receive Queue: Prefetch, Host, Writeback
@ 2013-07-03 6:02 Peter Chen
0 siblings, 0 replies; only message in thread
From: Peter Chen @ 2013-07-03 6:02 UTC (permalink / raw)
To: dev
[-- Attachment #1: Type: text/plain, Size: 1068 bytes --]
I looked at the description for transmit and receive queue configurations
in the Programmar's Guide, but was confused by how the configuration
worked. I am assuming that one descriptor in the queue refers to one
pktmbuf?
I am not sure what prefetch, host and writeback of queue descriptors mean
for the receive and transmission queues. Can anyone explain to me what they
mean?
Also tx_free_threshold is described as the number of descriptors used to
transmit packets before they are freed and written back to the host memory,
so in that sense what does rx_free_threshold stand for? Does that mean the
NIC has to receive x number of descriptors to receive packets before moving
them up to user space?
Another point of confusion is this sentence about tx_rs_threshold: "The RS
bit is
set on the last descriptor used to transmit a packet if the number of
descriptors
used since the last RS bit setting, up to the first descriptor used to
transmit the
packet, exceeds the transmit RS bit threshold (tx_rs_thresh)"..
If anyone know what these means, it would be great!
[-- Attachment #2: Type: text/html, Size: 1199 bytes --]
^ permalink raw reply [flat|nested] only message in thread
only message in thread, other threads:[~2013-07-03 6:02 UTC | newest]
Thread overview: (only message) (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2013-07-03 6:02 [dpdk-dev] Transmit and Receive Queue: Prefetch, Host, Writeback Peter Chen
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).