.TH DCB-BUFFER 8 "12 November 2020" "iproute2" "Linux"
.SH NAME
dcb-buffer \- show / manipulate port buffer settings of
the DCB (Data Center Bridging) subsystem
.SH SYNOPSIS
.sp
.ad l
.in +8

.ti -8
.B dcb
.RI "[ " OPTIONS " ] "
.B buffer
.RI "{ " COMMAND " | " help " }"
.sp

.ti -8
.B dcb buffer show dev
.RI DEV
.RB "[ " prio-buffer " ]"
.RB "[ " buffer-size " ]"
.RB "[ " total-size " ]"

.ti -8
.B dcb buffer set dev
.RI DEV
.RB "[ " prio-buffer " " \fIPRIO-MAP " ]"
.RB "[ " buffer-size " " \fISIZE-MAP " ]"

.ti -8
.IR PRIO-MAP " := [ " PRIO-MAP " ] " PRIO-MAPPING

.ti -8
.IR PRIO-MAPPING " := { " PRIO " | " \fBall " }" \fB:\fIBUFFER\fR

.ti -8
.IR SIZE-MAP " := [ " SIZE-MAP " ] " SIZE-MAPPING

.ti -8
.IR SIZE-MAPPING " := { " BUFFER " | " \fBall " }" \fB:\fISIZE\fR

.ti -8
.IR PRIO " := { " \fB0\fR " .. " \fB7\fR " }"

.ti -8
.IR BUFFER " := { " \fB0\fR " .. " \fB7\fR " }"

.ti -8
.IR SIZE " := { " INTEGER " | " INTEGER\fBK\fR " | " INTEGER\fBM\fR " | " ... " }"

.SH DESCRIPTION

.B dcb buffer
is used to configure assignment of traffic to port buffers based on traffic
priority, and sizes of those buffers. It can be also used to inspect the current
configuration, as well as total device memory that the port buffers take.

.SH PARAMETERS

For read-write parameters, the following describes only the write direction,
i.e. as used with the \fBset\fR command. For the \fBshow\fR command, the
parameter name is to be used as a simple keyword without further arguments. This
instructs the tool to show the value of a given parameter. When no parameters
are given, the tool shows the complete buffer configuration.

.TP
.B total-size
A read-only property that shows the total device memory taken up by port
buffers. This might be more than a simple sum of individual buffer sizes if
there are any hidden or internal buffers.

.TP
.B prio-buffer \fIPRIO-MAP
\fIPRIO-MAP\fR uses the array parameter syntax, see
.BR dcb (8)
for details. Keys are priorities, values are buffer indices. For each priority
sets a buffer where traffic with that priority is directed to.

.TP
.B buffer-size \fISIZE-MAP
\fISIZE-MAP\fR uses the array parameter syntax, see
.BR dcb (8)
for details. Keys are buffer indices, values are sizes of that buffer in bytes.
The sizes can use the notation documented in section PARAMETERS at
.BR tc (8).
Note that the size requested by the tool can be rounded or capped by the driver
to satisfy the requirements of the device.

.SH EXAMPLE & USAGE

Configure the priomap in a one-to-one fashion:

.P
# dcb buffer set dev eth0 prio-buffer 0:0 1:1 2:2 3:3 4:4 5:5 6:6 7:7

Set sizes of all buffers to 10KB, except for buffer 6, which will have the size
1MB:

.P
# dcb buffer set dev eth0 buffer-size all:10K 6:1M

Show what was set:

.P
# dcb buffer show dev eth0
.br
prio-buffer 0:0 1:1 2:2 3:3 4:4 5:5 6:6 7:7
.br
buffer-size 0:10Kb 1:10Kb 2:10Kb 3:10Kb 4:10Kb 5:10Kb 6:1Mb 7:10Kb
.br
total-size 1222Kb

.SH EXIT STATUS
Exit status is 0 if command was successful or a positive integer upon failure.

.SH SEE ALSO
.BR dcb (8)

.SH REPORTING BUGS
Report any bugs to the Network Developers mailing list
.B <netdev@vger.kernel.org>
where the development and maintenance is primarily done.
You do not have to be subscribed to the list to send a message there.

.SH AUTHOR
Petr Machata <me@pmachata.org>