mirror of
https://github.com/torvalds/linux.git
synced 2024-12-28 22:02:28 +00:00
fad3917e36
This sample program show how to use cpumap and the associated tracepoints. It provides command line stats, which shows how the XDP-RX process, cpumap-enqueue and cpumap kthread dequeue is cooperating on a per CPU basis. It also utilize the xdp_exception and xdp_redirect_err transpoints to allow users quickly to identify setup issues. One issue with ixgbe driver is that the driver reset the link when loading XDP. This reset the procfs smp_affinity settings. Thus, after loading the program, these must be reconfigured. The easiest workaround it to reduce the RX-queue to e.g. two via: # ethtool --set-channels ixgbe1 combined 2 And then add CPUs above 0 and 1, like: # xdp_redirect_cpu --dev ixgbe1 --prog 2 --cpu 2 --cpu 3 --cpu 4 Another issue with ixgbe is that the page recycle mechanism is tied to the RX-ring size. And the default setting of 512 elements is too small. This is the same issue with regular devmap XDP_REDIRECT. To overcome this I've been using 1024 rx-ring size: # ethtool -G ixgbe1 rx 1024 tx 1024 V3: - whitespace cleanups - bpf tracepoint cannot access top part of struct V4: - report on kthread sched events, according to tracepoint change - report average bulk enqueue size V5: - bpf_map_lookup_elem on cpumap not allowed from bpf_prog use separate map to mark CPUs not available V6: - correct kthread sched summary output V7: - Added a --stress-mode for concurrently changing underlying cpumap Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> |
||
|---|---|---|
| .. | ||
| auxdisplay | ||
| blackfin | ||
| bpf | ||
| configfs | ||
| connector | ||
| hidraw | ||
| hw_breakpoint | ||
| kdb | ||
| kfifo | ||
| kobject | ||
| kprobes | ||
| livepatch | ||
| mei | ||
| mic/mpssd | ||
| pktgen | ||
| rpmsg | ||
| seccomp | ||
| sockmap | ||
| statx | ||
| timers | ||
| trace_events | ||
| trace_printk | ||
| uhid | ||
| v4l | ||
| vfio-mdev | ||
| watchdog | ||
| Kconfig | ||
| Makefile | ||