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Message-ID: <1452206155-1492617-5-git-send-email-kafai@fb.com>
Date: Thu, 7 Jan 2016 14:35:55 -0800
From: Martin KaFai Lau <kafai@...com>
To: <netdev@...r.kernel.org>, <linux-kernel@...r.kernel.org>
CC: FB Kernel Team <kernel-team@...com>,
Alexei Starovoitov <alexei.starovoitov@...il.com>
Subject: [PATCH net-next 4/4] bpf: bpf_htab: Test for BPF_MAP_TYPE_PERCPU_HASH
A sanity test for BPF_MAP_TYPE_PERCPU_HASH.
Signed-off-by: Martin KaFai Lau <kafai@...com>
---
samples/bpf/libbpf.c | 13 ++++++
samples/bpf/libbpf.h | 1 +
samples/bpf/test_maps.c | 112 ++++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 126 insertions(+)
diff --git a/samples/bpf/libbpf.c b/samples/bpf/libbpf.c
index 65a8d48..a9c5e61 100644
--- a/samples/bpf/libbpf.c
+++ b/samples/bpf/libbpf.c
@@ -54,6 +54,19 @@ int bpf_lookup_elem(int fd, void *key, void *value)
return syscall(__NR_bpf, BPF_MAP_LOOKUP_ELEM, &attr, sizeof(attr));
}
+int bpf_lookup_percpu_elem(int fd, void *key, void *value, unsigned int cpu)
+{
+ union bpf_attr attr = {
+ .map_fd = fd,
+ .key = ptr_to_u64(key),
+ .value = ptr_to_u64(value),
+ .cpu = cpu,
+ };
+
+ return syscall(__NR_bpf, BPF_MAP_LOOKUP_PERCPU_ELEM, &attr,
+ sizeof(attr));
+}
+
int bpf_delete_elem(int fd, void *key)
{
union bpf_attr attr = {
diff --git a/samples/bpf/libbpf.h b/samples/bpf/libbpf.h
index 014aacf..7759517 100644
--- a/samples/bpf/libbpf.h
+++ b/samples/bpf/libbpf.h
@@ -8,6 +8,7 @@ int bpf_create_map(enum bpf_map_type map_type, int key_size, int value_size,
int max_entries);
int bpf_update_elem(int fd, void *key, void *value, unsigned long long flags);
int bpf_lookup_elem(int fd, void *key, void *value);
+int bpf_lookup_percpu_elem(int fd, void *key, void *value, unsigned int cpu);
int bpf_delete_elem(int fd, void *key);
int bpf_get_next_key(int fd, void *key, void *next_key);
diff --git a/samples/bpf/test_maps.c b/samples/bpf/test_maps.c
index 6299ee9..d0638aa 100644
--- a/samples/bpf/test_maps.c
+++ b/samples/bpf/test_maps.c
@@ -89,6 +89,117 @@ static void test_hashmap_sanity(int i, void *data)
close(map_fd);
}
+/* sanity tests for percpu map API */
+static void test_percpu_hashmap_sanity(int i, void *data)
+{
+ long long key, next_key, value;
+ int expected_key_mask = 0;
+ unsigned int nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
+ int map_fd;
+
+ map_fd = bpf_create_map(BPF_MAP_TYPE_PERCPU_HASH, sizeof(key),
+ sizeof(value), 2);
+ if (map_fd < 0) {
+ printf("failed to create hashmap '%s'\n", strerror(errno));
+ exit(1);
+ }
+
+ key = 1;
+ value = 1234;
+ /* insert key=1 element */
+ assert(!(expected_key_mask & key));
+ assert(bpf_update_elem(map_fd, &key, &value, BPF_ANY) == 0);
+ expected_key_mask |= key;
+
+ /* BPF_NOEXIST means: add new element if it doesn't exist */
+ assert(bpf_update_elem(map_fd, &key, &value, BPF_NOEXIST) == -1 &&
+ /* key=1 already exists */
+ errno == EEXIST);
+
+ /* -1 is an invalid flag */
+ assert(bpf_update_elem(map_fd, &key, &value, -1) == -1
+ && errno == EINVAL);
+
+ /* check that key=1 can be found. value could be 0 if the lookup
+ * was run from a different cpu.
+ */
+ assert(bpf_lookup_elem(map_fd, &key, &value) == 0 &&
+ (value == 0 || value == 1234));
+
+ key = 2;
+ /* check that key=2 is not found */
+ assert(bpf_lookup_elem(map_fd, &key, &value) == -1 && errno == ENOENT);
+
+ /* BPF_EXIST means: update existing element */
+ assert(bpf_update_elem(map_fd, &key, &value, BPF_EXIST) == -1 &&
+ /* key=2 is not there */
+ errno == ENOENT);
+
+ /* insert key=2 element */
+ assert(!(expected_key_mask & key));
+ assert(bpf_update_elem(map_fd, &key, &value, BPF_NOEXIST) == 0);
+ expected_key_mask |= key;
+
+ /* key=1 and key=2 were inserted, check that key=0 cannot be inserted
+ * due to max_entries limit
+ */
+ key = 0;
+ assert(bpf_update_elem(map_fd, &key, &value, BPF_NOEXIST) == -1
+ && errno == E2BIG);
+
+ /* check that key = 0 doesn't exist */
+ assert(bpf_delete_elem(map_fd, &key) == -1 && errno == ENOENT);
+
+ /* iterate over two elements */
+ while (!bpf_get_next_key(map_fd, &key, &next_key)) {
+ unsigned int cpu;
+ int found;
+
+ assert((expected_key_mask & next_key) == next_key);
+ expected_key_mask &= ~next_key;
+
+ found = 0;
+ for (cpu = 0; cpu < nr_cpus; cpu++) {
+ if (!bpf_lookup_percpu_elem(map_fd, &next_key,
+ &value, cpu)) {
+ if (value == 1234) {
+ assert(!found);
+ found = 1;
+ } else {
+ assert(value == 0);
+ }
+ } else {
+ assert(errno == ENXIO);
+ }
+ }
+ assert(found);
+
+ key = next_key;
+ }
+ assert(errno == ENOENT);
+
+ /* Look up the value with an invalid CPU */
+ key = 1;
+ assert(bpf_lookup_percpu_elem(map_fd, &key, &value, nr_cpus) == -1 && errno == EINVAL);
+
+ /* Update with BPF_EXIST */
+ key = 1;
+ assert(bpf_update_elem(map_fd, &key, &value, BPF_EXIST) == 0);
+
+ /* delete both elements */
+ key = 1;
+ assert(bpf_delete_elem(map_fd, &key) == 0);
+ key = 2;
+ assert(bpf_delete_elem(map_fd, &key) == 0);
+ assert(bpf_delete_elem(map_fd, &key) == -1 && errno == ENOENT);
+
+ key = 0;
+ /* check that map is empty */
+ assert(bpf_get_next_key(map_fd, &key, &next_key) == -1 &&
+ errno == ENOENT);
+ close(map_fd);
+}
+
static void test_arraymap_sanity(int i, void *data)
{
int key, next_key, map_fd;
@@ -282,6 +393,7 @@ static void test_map_parallel(void)
int main(void)
{
test_hashmap_sanity(0, NULL);
+ test_percpu_hashmap_sanity(0, NULL);
test_arraymap_sanity(0, NULL);
test_map_large();
test_map_parallel();
--
2.5.1
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