[bpf-next V4 PATCH 4/8] samples/bpf: xdp_monitor use tracepoint xdp:xdp_devmap_xmit

Jesper Dangaard Brouer
2018-05-18T13:34:53Z

The xdp_monitor sample/tool is updated to use the new tracepoint
xdp:xdp_devmap_xmit the previous patch just introduced.

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
---
samples/bpf/xdp_monitor_kern.c | 39 +++++++++++++++++++++++++++++++++++
samples/bpf/xdp_monitor_user.c | 44 +++++++++++++++++++++++++++++++++++++++-
2 files changed, 82 insertions(+), 1 deletion(-)

diff --git a/samples/bpf/xdp_monitor_kern.c b/samples/bpf/xdp_monitor_kern.c
index 211db8ded0de..2854aa0665ea 100644
--- a/samples/bpf/xdp_monitor_kern.c
+++ b/samples/bpf/xdp_monitor_kern.c
@@ -208,3 +208,42 @@ int trace_xdp_cpumap_kthread(struct cpumap_kthread_ctx *ctx)

return 0;
}
+
+struct bpf_map_def SEC("maps") devmap_xmit_cnt = {
+ .type = BPF_MAP_TYPE_PERCPU_ARRAY,
+ .key_size = sizeof(u32),
+ .value_size = sizeof(struct datarec),
+ .max_entries = 1,
+};
+
+/* Tracepoint: /sys/kernel/debug/tracing/events/xdp/xdp_devmap_xmit/format
+ * Code in: kernel/include/trace/events/xdp.h
+ */
+struct devmap_xmit_ctx {
+ u64 __pad; // First 8 bytes are not accessible by bpf code
+ int map_id; // offset:8; size:4; signed:1;
+ u32 act; // offset:12; size:4; signed:0;
+ u32 map_index; // offset:16; size:4; signed:0;
+ int drops; // offset:20; size:4; signed:1;
+ int sent; // offset:24; size:4; signed:1;
+ int from_ifindex; // offset:28; size:4; signed:1;
+ int to_ifindex; // offset:32; size:4; signed:1;
+};
+
+SEC("tracepoint/xdp/xdp_devmap_xmit")
+int trace_xdp_devmap_xmit(struct devmap_xmit_ctx *ctx)
+{
+ struct datarec *rec;
+ u32 key = 0;
+
+ rec = bpf_map_lookup_elem(&devmap_xmit_cnt, &key);
+ if (!rec)
+ return 0;
+ rec->processed += ctx->sent;
+ rec->dropped += ctx->drops;
+
+ /* Record bulk events, then userspace can calc average bulk size */
+ rec->info += 1;
+
+ return 1;
+}
diff --git a/samples/bpf/xdp_monitor_user.c b/samples/bpf/xdp_monitor_user.c
index bf09b5188acd..7e18a454924c 100644
--- a/samples/bpf/xdp_monitor_user.c
+++ b/samples/bpf/xdp_monitor_user.c
@@ -141,6 +141,7 @@ struct stats_record {
struct record_u64 xdp_exception[XDP_ACTION_MAX];
struct record xdp_cpumap_kthread;
struct record xdp_cpumap_enqueue[MAX_CPUS];
+ struct record xdp_devmap_xmit;
};

static bool map_collect_record(int fd, __u32 key, struct record *rec)
@@ -397,7 +398,7 @@ static void stats_print(struct stats_record *stats_rec,
info = calc_info(r, p, t);
if (info > 0)
i_str = "sched";
- if (pps > 0)
+ if (pps > 0 || drop > 0)
printf(fmt1, "cpumap-kthread",
i, pps, drop, info, i_str);
}
@@ -409,6 +410,42 @@ static void stats_print(struct stats_record *stats_rec,
printf(fmt2, "cpumap-kthread", "total", pps, drop, info, i_str);
}

+ /* devmap ndo_xdp_xmit stats */
+ {
+ char *fmt1 = "%-15s %-7d %'-12.0f %'-12.0f %'-10.2f %s\n";
+ char *fmt2 = "%-15s %-7s %'-12.0f %'-12.0f %'-10.2f %s\n";
+ struct record *rec, *prev;
+ double drop, info;
+ char *i_str = "";
+
+ rec = &stats_rec->xdp_devmap_xmit;
+ prev = &stats_prev->xdp_devmap_xmit;
+ t = calc_period(rec, prev);
+ for (i = 0; i < nr_cpus; i++) {
+ struct datarec *r = &rec->cpu[i];
+ struct datarec *p = &prev->cpu[i];
+
+ pps = calc_pps(r, p, t);
+ drop = calc_drop(r, p, t);
+ info = calc_info(r, p, t);
+ if (info > 0) {
+ i_str = "bulk-average";
+ info = (pps+drop) / info; /* calc avg bulk */
+ }
+ if (pps > 0 || drop > 0)
+ printf(fmt1, "devmap-xmit",
+ i, pps, drop, info, i_str);
+ }
+ pps = calc_pps(&rec->total, &prev->total, t);
+ drop = calc_drop(&rec->total, &prev->total, t);
+ info = calc_info(&rec->total, &prev->total, t);
+ if (info > 0) {
+ i_str = "bulk-average";
+ info = (pps+drop) / info; /* calc avg bulk */
+ }
+ printf(fmt2, "devmap-xmit", "total", pps, drop, info, i_str);
+ }
+
printf("\n");
}

@@ -437,6 +474,9 @@ static bool stats_collect(struct stats_record *rec)
fd = map_data[3].fd; /* map3: cpumap_kthread_cnt */
map_collect_record(fd, 0, &rec->xdp_cpumap_kthread);

+ fd = map_data[4].fd; /* map4: devmap_xmit_cnt */
+ map_collect_record(fd, 0, &rec->xdp_devmap_xmit);
+
return true;
}

@@ -480,6 +520,7 @@ static struct stats_record *alloc_stats_record(void)

rec_sz = sizeof(struct datarec);
rec->xdp_cpumap_kthread.cpu = alloc_rec_per_cpu(rec_sz);
+ rec->xdp_devmap_xmit.cpu = alloc_rec_per_cpu(rec_sz);

for (i = 0; i < MAX_CPUS; i++)
rec->xdp_cpumap_enqueue[i].cpu = alloc_rec_per_cpu(rec_sz);
@@ -498,6 +539,7 @@ static void free_stats_record(struct stats_record *r)
free(r->xdp_exception[i].cpu);

free(r->xdp_cpumap_kthread.cpu);
+ free(r->xdp_devmap_xmit.cpu);

for (i = 0; i < MAX_CPUS; i++)
free(r->xdp_cpumap_enqueue[i].cpu);