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| author |   Kumar Kartikeya Dwivedi <memxor@gmail.com> | 2021-08-21 05:49:56 +0530 |
|---|---|---|
| committer |   Alexei Starovoitov <ast@kernel.org> | 2021-08-24 14:48:41 -0700 |
| commit | 0cf3c2fc4b1afbd8d9c376754af34c1d2bd56de7 (patch) | |
| tree | d67677135ba59e0b9cf4614f11704f075d52e815 /samples | |
| parent | samples: bpf: Add xdp_exception tracepoint statistics support (diff) | |
| download | linux-dev-0cf3c2fc4b1afbd8d9c376754af34c1d2bd56de7.tar.xz linux-dev-0cf3c2fc4b1afbd8d9c376754af34c1d2bd56de7.zip | |
samples: bpf: Add BPF support for cpumap tracepoints
These are invoked in two places, when the XDP frame or SKB (for generic
XDP) enqueued to the ptr_ring (cpumap_enqueue) and when kthread processes
the frame after invoking the CPUMAP program for it (returning stats for
the batch).
We use cpumap_map_id to filter on the map_id as a way to avoid printing
incorrect stats for parallel sessions of xdp_redirect_cpu.
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210821002010.845777-9-memxor@gmail.com
Diffstat (limited to 'samples')
| -rw-r--r-- | samples/bpf/xdp_sample.bpf.c | 58 |
1 files changed, 57 insertions, 1 deletions
diff --git a/samples/bpf/xdp_sample.bpf.c b/samples/bpf/xdp_sample.bpf.c index 53ab5a972405..f01a5529751c 100644 --- a/samples/bpf/xdp_sample.bpf.c +++ b/samples/bpf/xdp_sample.bpf.c @@ -8,6 +8,8 @@ array_map rx_cnt SEC(".maps"); array_map redir_err_cnt SEC(".maps"); +array_map cpumap_enqueue_cnt SEC(".maps"); +array_map cpumap_kthread_cnt SEC(".maps"); array_map exception_cnt SEC(".maps"); const volatile int nr_cpus = 0; @@ -19,6 +21,8 @@ const volatile int nr_cpus = 0; const volatile int from_match[32] = {}; const volatile int to_match[32] = {}; +int cpumap_map_id = 0; + /* Find if b is part of set a, but if a is empty set then evaluate to true */ #define IN_SET(a, b) \ ({ \ @@ -112,6 +116,59 @@ int BPF_PROG(tp_xdp_redirect_map, const struct net_device *dev, return xdp_redirect_collect_stat(dev->ifindex, err); } +SEC("tp_btf/xdp_cpumap_enqueue") +int BPF_PROG(tp_xdp_cpumap_enqueue, int map_id, unsigned int processed, + unsigned int drops, int to_cpu) +{ + u32 cpu = bpf_get_smp_processor_id(); + struct datarec *rec; + u32 idx; + + if (cpumap_map_id && cpumap_map_id != map_id) + return 0; + + idx = to_cpu * nr_cpus + cpu; + rec = bpf_map_lookup_elem(&cpumap_enqueue_cnt, &idx); + if (!rec) + return 0; + NO_TEAR_ADD(rec->processed, processed); + NO_TEAR_ADD(rec->dropped, drops); + /* Record bulk events, then userspace can calc average bulk size */ + if (processed > 0) + NO_TEAR_INC(rec->issue); + /* Inception: It's possible to detect overload situations, via + * this tracepoint. This can be used for creating a feedback + * loop to XDP, which can take appropriate actions to mitigate + * this overload situation. + */ + return 0; +} + +SEC("tp_btf/xdp_cpumap_kthread") +int BPF_PROG(tp_xdp_cpumap_kthread, int map_id, unsigned int processed, + unsigned int drops, int sched, struct xdp_cpumap_stats *xdp_stats) +{ + struct datarec *rec; + u32 cpu; + + if (cpumap_map_id && cpumap_map_id != map_id) + return 0; + + cpu = bpf_get_smp_processor_id(); + rec = bpf_map_lookup_elem(&cpumap_kthread_cnt, &cpu); + if (!rec) + return 0; + NO_TEAR_ADD(rec->processed, processed); + NO_TEAR_ADD(rec->dropped, drops); + NO_TEAR_ADD(rec->xdp_pass, xdp_stats->pass); + NO_TEAR_ADD(rec->xdp_drop, xdp_stats->drop); + NO_TEAR_ADD(rec->xdp_redirect, xdp_stats->redirect); + /* Count times kthread yielded CPU via schedule call */ + if (sched) + NO_TEAR_INC(rec->issue); + return 0; +} + SEC("tp_btf/xdp_exception") int BPF_PROG(tp_xdp_exception, const struct net_device *dev, const struct bpf_prog *xdp, u32 act) @@ -136,4 +193,3 @@ int BPF_PROG(tp_xdp_exception, const struct net_device *dev, return 0; } - |