diff mbox series

[bpf-next,2/5] libbpf: Allow the number of hashes in bloom filter maps to be configurable

Message ID 20210831225005.2762202-3-joannekoong@fb.com (mailing list archive)
State Superseded
Delegated to: BPF
Headers show
Series Implement bloom filter map | expand

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Commit Message

Joanne Koong Aug. 31, 2021, 10:50 p.m. UTC 
This patch adds the libbpf infrastructure that will allow the user to
specify the number of hash functions to use for the bloom filter map.

Signed-off-by: Joanne Koong <joannekoong@fb.com>
---
 tools/lib/bpf/bpf.c             |  2 ++
 tools/lib/bpf/bpf.h             |  1 +
 tools/lib/bpf/libbpf.c          | 32 +++++++++++++++++++++++++++++++-
 tools/lib/bpf/libbpf.h          |  3 +++
 tools/lib/bpf/libbpf.map        |  2 ++
 tools/lib/bpf/libbpf_internal.h |  4 +++-
 6 files changed, 42 insertions(+), 2 deletions(-)

Comments

Andrii Nakryiko Sept. 2, 2021, 3:30 a.m. UTC | #1 
On Tue, Aug 31, 2021 at 3:51 PM Joanne Koong <joannekoong@fb.com> wrote:
>
> This patch adds the libbpf infrastructure that will allow the user to
> specify the number of hash functions to use for the bloom filter map.
>
> Signed-off-by: Joanne Koong <joannekoong@fb.com>
> ---
>  tools/lib/bpf/bpf.c             |  2 ++
>  tools/lib/bpf/bpf.h             |  1 +
>  tools/lib/bpf/libbpf.c          | 32 +++++++++++++++++++++++++++++++-
>  tools/lib/bpf/libbpf.h          |  3 +++
>  tools/lib/bpf/libbpf.map        |  2 ++
>  tools/lib/bpf/libbpf_internal.h |  4 +++-
>  6 files changed, 42 insertions(+), 2 deletions(-)
>

[...]

>  __u32 bpf_map__key_size(const struct bpf_map *map)
>  {
>         return map->def.key_size;
> diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
> index f177d897c5f7..497b84772be8 100644
> --- a/tools/lib/bpf/libbpf.h
> +++ b/tools/lib/bpf/libbpf.h
> @@ -538,6 +538,9 @@ LIBBPF_API __u32 bpf_map__btf_value_type_id(const struct bpf_map *map);
>  /* get/set map if_index */
>  LIBBPF_API __u32 bpf_map__ifindex(const struct bpf_map *map);
>  LIBBPF_API int bpf_map__set_ifindex(struct bpf_map *map, __u32 ifindex);
> +/* get/set nr_hashes. used for bloom filter maps */
> +LIBBPF_API __u32 bpf_map__nr_hashes(const struct bpf_map *map);
> +LIBBPF_API int bpf_map__set_nr_hashes(struct bpf_map *map, __u32 nr_hashes);
>
>  typedef void (*bpf_map_clear_priv_t)(struct bpf_map *, void *);
>  LIBBPF_API int bpf_map__set_priv(struct bpf_map *map, void *priv,
> diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map
> index bbc53bb25f68..372c2478274f 100644
> --- a/tools/lib/bpf/libbpf.map
> +++ b/tools/lib/bpf/libbpf.map
> @@ -385,4 +385,6 @@ LIBBPF_0.5.0 {
>                 btf__load_vmlinux_btf;
>                 btf_dump__dump_type_data;
>                 libbpf_set_strict_mode;
> +               bpf_map__nr_hashes;
> +               bpf_map__set_nr_hashes;

I'd really like to avoid this very niche and specific set of APIs. As
I mentioned on first patch, I think nr_hash can be easily passed
through map_flags property.

>  } LIBBPF_0.4.0;
> diff --git a/tools/lib/bpf/libbpf_internal.h b/tools/lib/bpf/libbpf_internal.h
> index 533b0211f40a..501ae042980d 100644
> --- a/tools/lib/bpf/libbpf_internal.h
> +++ b/tools/lib/bpf/libbpf_internal.h
> @@ -171,8 +171,9 @@ enum map_def_parts {
>         MAP_DEF_NUMA_NODE       = 0x080,
>         MAP_DEF_PINNING         = 0x100,
>         MAP_DEF_INNER_MAP       = 0x200,
> +       MAP_DEF_NR_HASHES       = 0x400,
>
> -       MAP_DEF_ALL             = 0x3ff, /* combination of all above */
> +       MAP_DEF_ALL             = 0x7ff, /* combination of all above */
>  };
>
>  struct btf_map_def {
> @@ -186,6 +187,7 @@ struct btf_map_def {
>         __u32 map_flags;
>         __u32 numa_node;
>         __u32 pinning;
> +       __u32 nr_hashes; /* used for bloom filter maps */

we can't extend btf_map_def, it's fixed indefinitely

>  };
>
>  int parse_btf_map_def(const char *map_name, struct btf *btf,
> --
> 2.30.2
>
diff mbox series

Patch

diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c
index 2401fad090c5..cc928c5b92a4 100644
--- a/tools/lib/bpf/bpf.c
+++ b/tools/lib/bpf/bpf.c
@@ -100,6 +100,8 @@  int bpf_create_map_xattr(const struct bpf_create_map_attr *create_attr)
 	if (attr.map_type == BPF_MAP_TYPE_STRUCT_OPS)
 		attr.btf_vmlinux_value_type_id =
 			create_attr->btf_vmlinux_value_type_id;
+	else if (attr.map_type == BPF_MAP_TYPE_BLOOM_FILTER)
+		attr.nr_hashes = create_attr->nr_hashes;
 	else
 		attr.inner_map_fd = create_attr->inner_map_fd;
 
diff --git a/tools/lib/bpf/bpf.h b/tools/lib/bpf/bpf.h
index 6fffb3cdf39b..ea29d6647e20 100644
--- a/tools/lib/bpf/bpf.h
+++ b/tools/lib/bpf/bpf.h
@@ -49,6 +49,7 @@  struct bpf_create_map_attr {
 	union {
 		__u32 inner_map_fd;
 		__u32 btf_vmlinux_value_type_id;
+		__u32 nr_hashes; /* used for bloom filter maps */
 	};
 };
 
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 88d8825fc6f6..ac03404aeb57 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -377,6 +377,7 @@  struct bpf_map {
 	char *pin_path;
 	bool pinned;
 	bool reused;
+	__u32 nr_hashes; /* used for bloom filter maps */
 };
 
 enum extern_type {
@@ -1290,6 +1291,11 @@  static bool bpf_map_type__is_map_in_map(enum bpf_map_type type)
 	return false;
 }
 
+static bool bpf_map_type__is_bloom_filter(enum bpf_map_type type)
+{
+	return type == BPF_MAP_TYPE_BLOOM_FILTER;
+}
+
 int bpf_object__section_size(const struct bpf_object *obj, const char *name,
 			     __u32 *size)
 {
@@ -2080,6 +2086,10 @@  int parse_btf_map_def(const char *map_name, struct btf *btf,
 			if (!get_map_field_int(map_name, btf, m, &map_def->map_flags))
 				return -EINVAL;
 			map_def->parts |= MAP_DEF_MAP_FLAGS;
+		} else if (strcmp(name, "nr_hashes") == 0) {
+			if (!get_map_field_int(map_name, btf, m, &map_def->nr_hashes))
+				return -EINVAL;
+			map_def->parts |= MAP_DEF_NR_HASHES;
 		} else if (strcmp(name, "numa_node") == 0) {
 			if (!get_map_field_int(map_name, btf, m, &map_def->numa_node))
 				return -EINVAL;
@@ -2264,6 +2274,7 @@  static void fill_map_from_def(struct bpf_map *map, const struct btf_map_def *def
 	map->numa_node = def->numa_node;
 	map->btf_key_type_id = def->key_type_id;
 	map->btf_value_type_id = def->value_type_id;
+	map->nr_hashes = def->nr_hashes;
 
 	if (def->parts & MAP_DEF_MAP_TYPE)
 		pr_debug("map '%s': found type = %u.\n", map->name, def->map_type);
@@ -2288,6 +2299,8 @@  static void fill_map_from_def(struct bpf_map *map, const struct btf_map_def *def
 		pr_debug("map '%s': found pinning = %u.\n", map->name, def->pinning);
 	if (def->parts & MAP_DEF_NUMA_NODE)
 		pr_debug("map '%s': found numa_node = %u.\n", map->name, def->numa_node);
+	if (def->parts & MAP_DEF_NR_HASHES)
+		pr_debug("map '%s': found nr_hashes = %u.\n", map->name, def->nr_hashes);
 
 	if (def->parts & MAP_DEF_INNER_MAP)
 		pr_debug("map '%s': found inner map definition.\n", map->name);
@@ -3979,6 +3992,7 @@  int bpf_map__reuse_fd(struct bpf_map *map, int fd)
 	map->btf_key_type_id = info.btf_key_type_id;
 	map->btf_value_type_id = info.btf_value_type_id;
 	map->reused = true;
+	map->nr_hashes = info.nr_hashes;
 
 	return 0;
 
@@ -4473,7 +4487,8 @@  static bool map_is_reuse_compat(const struct bpf_map *map, int map_fd)
 		map_info.key_size == map->def.key_size &&
 		map_info.value_size == map->def.value_size &&
 		map_info.max_entries == map->def.max_entries &&
-		map_info.map_flags == map->def.map_flags);
+		map_info.map_flags == map->def.map_flags &&
+		map_info.nr_hashes == map->nr_hashes);
 }
 
 static int
@@ -4611,6 +4626,8 @@  static int bpf_object__create_map(struct bpf_object *obj, struct bpf_map *map, b
 		}
 		if (map->inner_map_fd >= 0)
 			create_attr.inner_map_fd = map->inner_map_fd;
+	} else if (bpf_map_type__is_bloom_filter(def->type)) {
+		create_attr.nr_hashes = map->nr_hashes;
 	}
 
 	if (obj->gen_loader) {
@@ -8560,6 +8577,19 @@  int bpf_map__set_numa_node(struct bpf_map *map, __u32 numa_node)
 	return 0;
 }
 
+__u32 bpf_map__nr_hashes(const struct bpf_map *map)
+{
+	return map->nr_hashes;
+}
+
+int bpf_map__set_nr_hashes(struct bpf_map *map, __u32 nr_hashes)
+{
+	if (map->fd >= 0)
+		return libbpf_err(-EBUSY);
+	map->nr_hashes = nr_hashes;
+	return 0;
+}
+
 __u32 bpf_map__key_size(const struct bpf_map *map)
 {
 	return map->def.key_size;
diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
index f177d897c5f7..497b84772be8 100644
--- a/tools/lib/bpf/libbpf.h
+++ b/tools/lib/bpf/libbpf.h
@@ -538,6 +538,9 @@  LIBBPF_API __u32 bpf_map__btf_value_type_id(const struct bpf_map *map);
 /* get/set map if_index */
 LIBBPF_API __u32 bpf_map__ifindex(const struct bpf_map *map);
 LIBBPF_API int bpf_map__set_ifindex(struct bpf_map *map, __u32 ifindex);
+/* get/set nr_hashes. used for bloom filter maps */
+LIBBPF_API __u32 bpf_map__nr_hashes(const struct bpf_map *map);
+LIBBPF_API int bpf_map__set_nr_hashes(struct bpf_map *map, __u32 nr_hashes);
 
 typedef void (*bpf_map_clear_priv_t)(struct bpf_map *, void *);
 LIBBPF_API int bpf_map__set_priv(struct bpf_map *map, void *priv,
diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map
index bbc53bb25f68..372c2478274f 100644
--- a/tools/lib/bpf/libbpf.map
+++ b/tools/lib/bpf/libbpf.map
@@ -385,4 +385,6 @@  LIBBPF_0.5.0 {
 		btf__load_vmlinux_btf;
 		btf_dump__dump_type_data;
 		libbpf_set_strict_mode;
+		bpf_map__nr_hashes;
+		bpf_map__set_nr_hashes;
 } LIBBPF_0.4.0;
diff --git a/tools/lib/bpf/libbpf_internal.h b/tools/lib/bpf/libbpf_internal.h
index 533b0211f40a..501ae042980d 100644
--- a/tools/lib/bpf/libbpf_internal.h
+++ b/tools/lib/bpf/libbpf_internal.h
@@ -171,8 +171,9 @@  enum map_def_parts {
 	MAP_DEF_NUMA_NODE	= 0x080,
 	MAP_DEF_PINNING		= 0x100,
 	MAP_DEF_INNER_MAP	= 0x200,
+	MAP_DEF_NR_HASHES	= 0x400,
 
-	MAP_DEF_ALL		= 0x3ff, /* combination of all above */
+	MAP_DEF_ALL		= 0x7ff, /* combination of all above */
 };
 
 struct btf_map_def {
@@ -186,6 +187,7 @@  struct btf_map_def {
 	__u32 map_flags;
 	__u32 numa_node;
 	__u32 pinning;
+	__u32 nr_hashes; /* used for bloom filter maps */
 };
 
 int parse_btf_map_def(const char *map_name, struct btf *btf,