samples: bpf: Refactor XDP kern program maps with BTF-defined map

Most of the samples were converted to use the new BTF-defined MAP as
they moved to libbpf, but some of the samples were missing.

Instead of using the previous BPF MAP definition, this commit refactors
xdp_monitor and xdp_sample_pkts_kern MAP definition with the new
BTF-defined MAP format.

Also, this commit removes the max_entries attribute at PERF_EVENT_ARRAY
map type. The libbpf's bpf_object__create_map() will automatically
set max_entries to the maximum configured number of CPUs on the host.

Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20201010181734.1109-4-danieltimlee@gmail.com
This commit is contained in:
Daniel T. Lee 2020-10-11 03:17:34 +09:00 committed by Alexei Starovoitov
parent 151936bf51
commit 321f632450
3 changed files with 35 additions and 38 deletions

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@ -6,21 +6,21 @@
#include <uapi/linux/bpf.h>
#include <bpf/bpf_helpers.h>
struct bpf_map_def SEC("maps") redirect_err_cnt = {
.type = BPF_MAP_TYPE_PERCPU_ARRAY,
.key_size = sizeof(u32),
.value_size = sizeof(u64),
.max_entries = 2,
struct {
__uint(type, BPF_MAP_TYPE_PERCPU_ARRAY);
__type(key, u32);
__type(value, u64);
__uint(max_entries, 2);
/* TODO: have entries for all possible errno's */
};
} redirect_err_cnt SEC(".maps");
#define XDP_UNKNOWN XDP_REDIRECT + 1
struct bpf_map_def SEC("maps") exception_cnt = {
.type = BPF_MAP_TYPE_PERCPU_ARRAY,
.key_size = sizeof(u32),
.value_size = sizeof(u64),
.max_entries = XDP_UNKNOWN + 1,
};
struct {
__uint(type, BPF_MAP_TYPE_PERCPU_ARRAY);
__type(key, u32);
__type(value, u64);
__uint(max_entries, XDP_UNKNOWN + 1);
} exception_cnt SEC(".maps");
/* Tracepoint format: /sys/kernel/debug/tracing/events/xdp/xdp_redirect/format
* Code in: kernel/include/trace/events/xdp.h
@ -129,19 +129,19 @@ struct datarec {
};
#define MAX_CPUS 64
struct bpf_map_def SEC("maps") cpumap_enqueue_cnt = {
.type = BPF_MAP_TYPE_PERCPU_ARRAY,
.key_size = sizeof(u32),
.value_size = sizeof(struct datarec),
.max_entries = MAX_CPUS,
};
struct {
__uint(type, BPF_MAP_TYPE_PERCPU_ARRAY);
__type(key, u32);
__type(value, struct datarec);
__uint(max_entries, MAX_CPUS);
} cpumap_enqueue_cnt SEC(".maps");
struct bpf_map_def SEC("maps") cpumap_kthread_cnt = {
.type = BPF_MAP_TYPE_PERCPU_ARRAY,
.key_size = sizeof(u32),
.value_size = sizeof(struct datarec),
.max_entries = 1,
};
struct {
__uint(type, BPF_MAP_TYPE_PERCPU_ARRAY);
__type(key, u32);
__type(value, struct datarec);
__uint(max_entries, 1);
} cpumap_kthread_cnt SEC(".maps");
/* Tracepoint: /sys/kernel/debug/tracing/events/xdp/xdp_cpumap_enqueue/format
* Code in: kernel/include/trace/events/xdp.h
@ -210,12 +210,12 @@ 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,
};
struct {
__uint(type, BPF_MAP_TYPE_PERCPU_ARRAY);
__type(key, u32);
__type(value, struct datarec);
__uint(max_entries, 1);
} devmap_xmit_cnt SEC(".maps");
/* Tracepoint: /sys/kernel/debug/tracing/events/xdp/xdp_devmap_xmit/format
* Code in: kernel/include/trace/events/xdp.h

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@ -5,14 +5,12 @@
#include <bpf/bpf_helpers.h>
#define SAMPLE_SIZE 64ul
#define MAX_CPUS 128
struct bpf_map_def SEC("maps") my_map = {
.type = BPF_MAP_TYPE_PERF_EVENT_ARRAY,
.key_size = sizeof(int),
.value_size = sizeof(u32),
.max_entries = MAX_CPUS,
};
struct {
__uint(type, BPF_MAP_TYPE_PERF_EVENT_ARRAY);
__uint(key_size, sizeof(int));
__uint(value_size, sizeof(u32));
} my_map SEC(".maps");
SEC("xdp_sample")
int xdp_sample_prog(struct xdp_md *ctx)

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@ -18,7 +18,6 @@
#include "perf-sys.h"
#define MAX_CPUS 128
static int if_idx;
static char *if_name;
static __u32 xdp_flags = XDP_FLAGS_UPDATE_IF_NOEXIST;