_x_b_s_t_a_t monitors the traffic from and to each of the active slots of the
Crossbow (Xbow) i/o interconnect. It reports the total number of
micropackets sent from and received at each link. It also reports the
LLP retries at each link.
The ----dddd _d_e_v_n_a_m_e option specifies which Crossbow to monitor in a multi-
Crossbow system. _d_e_v_n_a_m_e should be a valid Xtalk monitor point under the
/hw graph. If the _d_e_v_n_a_m_e is not explicitly specified, xbstat monitors
/dev/xbmon by default.
The ----tttt _s_e_c option determines the duration of time in units of seconds
that the Xbow traffic will be monitored. If this option is not is
selected, the monitoring continues until the user terminates it with a
CTRL-C (or intr).
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_x_b_s_t_a_t gets its information from the two hardware performance counters
and the Link Auxiliary Status Registers in the Xbow. It uses a
multiplexing technique to sample and report the SRC and DST link traffic
at each XBow slot. Cumulative counts since the beginning of the
monitoring period are reported in units of micropackets.
_x_b_s_t_a_t is capable of monitoring any selected Xbow in a multi-Xbow system.
Use ffffiiiinnnndddd ////hhhhwwww ----nnnnaaaammmmeeee mmmmoooonnnn ----pppprrrriiiinnnntttt |||| ggggrrrreeeepppp xxxxttttaaaallllkkkk to find all possible Xbow
monitor points. A specific Xbow can be selected in two ways: explicitly,
as a _d_e_v_n_a_m_e with the ----dddd option, or implicitly, as a soft link to
/dev/xbmon.
When specifying the Xbow implicitly, first create a symbolic link between
the selected Xbow monitor point and /dev/xbmon before invoking this
command. See examples below.
Multiple instances of the command selecting different Xbows can be
executed at a time. However, one Xbow can be specified at a time with
each instance of the command.
The monitor data is statistical since the traffic over many links and
slots is sampled or scanned during any given monitoring period. All live
links are monitored for the same amount of time during any monitoring