Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 3059303f authored by Alexei Starovoitov's avatar Alexei Starovoitov Committed by David S. Miller
Browse files

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



Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent df570f57

samples/bpf/tracex2_kern.c

+1 −1
Original line number Diff line number Diff line
@@ -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,

samples/bpf/tracex2_user.c

+6 −1
Original line number Diff line number Diff line
@@ -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)

samples/bpf/tracex3_kern.c

+4 −4
Original line number Diff line number Diff line
@@ -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;

}

samples/bpf/tracex3_user.c

+14 −7
Original line number Diff line number Diff line
@@ -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)