samples/bpf: update tracex[23] examples to use per-cpu maps

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/samples/bpf/tracex2_kern.c b/samples/bpf/tracex2_kern.c
index b32367cfbff4aff3020bb9c36c8faf6c981dd0f8..09c1adc27d426ed4adec7408a6fbae9193c39bb0 100644 (file)
--- a/samples/bpf/tracex2_kern.c
+++ b/samples/bpf/tracex2_kern.c
@@ -70,7 +70,7 @@ struct hist_key {
 };
 
 struct bpf_map_def SEC("maps") my_hist_map = {
-       .type = BPF_MAP_TYPE_HASH,
+       .type = BPF_MAP_TYPE_PERCPU_HASH,
        .key_size = sizeof(struct hist_key),
        .value_size = sizeof(long),
        .max_entries = 1024,

diff --git a/samples/bpf/tracex2_user.c b/samples/bpf/tracex2_user.c
index cd0241c1447a5fb37d0e9e1633f4a47a457f344f..ab5b19e68acf0c3d53916ce6324f57777cf3acbd 100644 (file)
--- a/samples/bpf/tracex2_user.c
+++ b/samples/bpf/tracex2_user.c
@@ -37,6 +37,8 @@ struct hist_key {
 static void print_hist_for_pid(int fd, void *task)
 {
        struct hist_key key = {}, next_key;
+       unsigned int nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
+       long values[nr_cpus];
        char starstr[MAX_STARS];
        long value;
        long data[MAX_INDEX] = {};
@@ -49,7 +51,10 @@ static void print_hist_for_pid(int fd, void *task)
                        key = next_key;
                        continue;
                }
-               bpf_lookup_elem(fd, &next_key, &value);
+               bpf_lookup_elem(fd, &next_key, values);
+               value = 0;
+               for (i = 0; i < nr_cpus; i++)
+                       value += values[i];
                ind = next_key.index;
                data[ind] = value;
                if (value && ind > max_ind)

diff --git a/samples/bpf/tracex3_kern.c b/samples/bpf/tracex3_kern.c
index bf337fbb09472cbe32bfbaff2d4313b7cafb58c6..9974c3d7c18b90f5850e87822a158c90e2645b8d 100644 (file)
--- a/samples/bpf/tracex3_kern.c
+++ b/samples/bpf/tracex3_kern.c
@@ -20,7 +20,7 @@ struct bpf_map_def SEC("maps") my_map = {
 /* kprobe is NOT a stable ABI. If kernel internals change this bpf+kprobe
  * example will no longer be meaningful
  */
-SEC("kprobe/blk_mq_start_request")
+SEC("kprobe/blk_start_request")
 int bpf_prog1(struct pt_regs *ctx)
 {
        long rq = PT_REGS_PARM1(ctx);
@@ -42,13 +42,13 @@ static unsigned int log2l(unsigned long long n)
 #define SLOTS 100
 
 struct bpf_map_def SEC("maps") lat_map = {
-       .type = BPF_MAP_TYPE_ARRAY,
+       .type = BPF_MAP_TYPE_PERCPU_ARRAY,
        .key_size = sizeof(u32),
        .value_size = sizeof(u64),
        .max_entries = SLOTS,
 };
 
-SEC("kprobe/blk_update_request")
+SEC("kprobe/blk_account_io_completion")
 int bpf_prog2(struct pt_regs *ctx)
 {
        long rq = PT_REGS_PARM1(ctx);
@@ -81,7 +81,7 @@ int bpf_prog2(struct pt_regs *ctx)
 
        value = bpf_map_lookup_elem(&lat_map, &index);
        if (value)
-               __sync_fetch_and_add((long *)value, 1);
+               *value += 1;
 
        return 0;
 }

diff --git a/samples/bpf/tracex3_user.c b/samples/bpf/tracex3_user.c
index 0aaa933ab93818df1634ba170e125e65dc6031d5..48716f7f0d8b9eae647a76ba93b07fe76a79f7bd 100644 (file)
--- a/samples/bpf/tracex3_user.c
+++ b/samples/bpf/tracex3_user.c
@@ -20,11 +20,13 @@
 
 static void clear_stats(int fd)
 {
+       unsigned int nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
+       __u64 values[nr_cpus];
        __u32 key;
-       __u64 value = 0;
 
+       memset(values, 0, sizeof(values));
        for (key = 0; key < SLOTS; key++)
-               bpf_update_elem(fd, &key, &value, BPF_ANY);
+               bpf_update_elem(fd, &key, values, BPF_ANY);
 }
 
 const char *color[] = {
@@ -75,15 +77,20 @@ static void print_banner(void)
 
 static void print_hist(int fd)
 {
-       __u32 key;
-       __u64 value;
-       __u64 cnt[SLOTS];
-       __u64 max_cnt = 0;
+       unsigned int nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
        __u64 total_events = 0;
+       long values[nr_cpus];
+       __u64 max_cnt = 0;
+       __u64 cnt[SLOTS];
+       __u64 value;
+       __u32 key;
+       int i;
 
        for (key = 0; key < SLOTS; key++) {
+               bpf_lookup_elem(fd, &key, values);
                value = 0;
-               bpf_lookup_elem(fd, &key, &value);
+               for (i = 0; i < nr_cpus; i++)
+                       value += values[i];
                cnt[key] = value;
                total_events += value;
                if (value > max_cnt)