mirror/xdp-project-bpf-examples
1
0
Fork 0
mirror of https://github.com/xdp-project/bpf-examples.git synced 2024-05-06 15:54:53 +00:00
Code Issues Projects Releases Wiki Activity

tc-policy: Monitor TXQ usage with bpftrace script

Browse Source 
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
This commit is contained in:
Jesper Dangaard Brouer
2022-02-01 11:56:32 +01:00
parent 520d2e6109
commit e72d309789
2 changed files with 44 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files

18
tc-policy/README.org
View File

@@ -54,3 +54,21 @@ You can now use it in all perf tools, such as:
#+end_src
Afterwards run =perf script= and see results.
** bpftrace
It is also possible to monitor TXQ usage via a =bpftrace= script.
* see [[file:monitor_txq_usage.bt]].
The main part of the script is:
#+begin_src sh
tracepoint:net:net_dev_start_xmit {
$qm = args->queue_mapping;
$dev = str(args->name, 15);
@stat_txq_usage[$dev] = lhist($qm, 0,32,1);
}
#+end_src
Or as oneliner:
* =bpftrace -e 't:net:net_dev_start_xmit {@txq[str(args->name, 15)]=lhist(args->queue_mapping, 0,32,1)}'=

26
tc-policy/monitor_txq_usage.bt Executable file
View File

@@ -0,0 +1,26 @@
#!/usr/bin/bpftrace
//BEGIN {
// printf("Monitor TXQ usage\n");
// printf(" - Remember: BPF set queue_mapping is one-less here (zero-indexed)\n");
//}
tracepoint:net:net_dev_start_xmit {
$qm = args->queue_mapping;
$dev = str(args->name, 15);
@stat_txq_usage[$dev] = lhist($qm, 0,32,1);
}
/* Periodically print stats */
interval:s:3
{
printf("\nPeriodic show stats - time: ");
time();
print(@stat_txq_usage);
}
/* Default bpftrace will print all remaining maps at END */
//END {
// printf("END stats:\n");
//}