From 3059303f59cf90a84e7fdef154ff0b215bcfaa97 Mon Sep 17 00:00:00 2001 From: Alexei Starovoitov Date: Mon, 1 Feb 2016 22:39:58 -0800 Subject: samples/bpf: update tracex[23] examples to use per-cpu maps Signed-off-by: Alexei Starovoitov Signed-off-by: David S. Miller --- samples/bpf/tracex2_kern.c | 2 +- samples/bpf/tracex2_user.c | 7 ++++++- samples/bpf/tracex3_kern.c | 8 ++++---- samples/bpf/tracex3_user.c | 21 ++++++++++++++------- 4 files changed, 25 insertions(+), 13 deletions(-) (limited to 'samples/bpf') diff --git a/samples/bpf/tracex2_kern.c b/samples/bpf/tracex2_kern.c index b32367cfbff4..09c1adc27d42 100644 --- 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 cd0241c1447a..ab5b19e68acf 100644 --- 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 bf337fbb0947..9974c3d7c18b 100644 --- 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 0aaa933ab938..48716f7f0d8b 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_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) -- cgit