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 b32367c..09c1adc 100644
--- a/samples/bpf/tracex2_kern.c
+++ b/samples/bpf/tracex2_kern.c
@@ -70,7 +70,7 @@
};
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 cd0241c..ab5b19e 100644
--- a/samples/bpf/tracex2_user.c
+++ b/samples/bpf/tracex2_user.c
@@ -37,6 +37,8 @@
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 @@
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 bf337fb..9974c3d 100644
--- a/samples/bpf/tracex3_kern.c
+++ b/samples/bpf/tracex3_kern.c
@@ -20,7 +20,7 @@
/* 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 @@
#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 @@
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 0aaa933..48716f7 100644
--- 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_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)