Netdev Archive on lore.kernel.org
help / color / mirror / Atom feed
* [PATCH bpf-next v3] bpf: increase supported cgroup storage value size
@ 2021-07-26 23:00 Stanislav Fomichev
2021-07-27 0:33 ` Martin KaFai Lau
2021-07-27 19:32 ` Andrii Nakryiko
0 siblings, 2 replies; 6+ messages in thread
From: Stanislav Fomichev @ 2021-07-26 23:00 UTC (permalink / raw)
To: netdev, bpf
Cc: ast, daniel, andrii, Stanislav Fomichev, Martin KaFai Lau, Yonghong Song
Current max cgroup storage value size is 4k (PAGE_SIZE). The other local
storages accept up to 64k (BPF_LOCAL_STORAGE_MAX_VALUE_SIZE). Let's align
max cgroup value size with the other storages.
For percpu, the max is 32k (PCPU_MIN_UNIT_SIZE) because percpu
allocator is not happy about larger values.
netcnt test is extended to exercise those maximum values
(non-percpu max size is close to, but not real max).
v3:
* refine SIZEOF_BPF_LOCAL_STORAGE_ELEM comment (Yonghong Song)
* anonymous struct in percpu_net_cnt & net_cnt (Yonghong Song)
* reorder free (Yonghong Song)
v2:
* cap max_value_size instead of BUILD_BUG_ON (Martin KaFai Lau)
Cc: Martin KaFai Lau <kafai@fb.com>
Cc: Yonghong Song <yhs@fb.com>
Signed-off-by: Stanislav Fomichev <sdf@google.com>
---
kernel/bpf/local_storage.c | 11 +++++-
tools/testing/selftests/bpf/netcnt_common.h | 38 +++++++++++++++++----
tools/testing/selftests/bpf/test_netcnt.c | 17 ++++++---
3 files changed, 53 insertions(+), 13 deletions(-)
diff --git a/kernel/bpf/local_storage.c b/kernel/bpf/local_storage.c
index 7ed2a14dc0de..035e9e3a7132 100644
--- a/kernel/bpf/local_storage.c
+++ b/kernel/bpf/local_storage.c
@@ -1,6 +1,7 @@
//SPDX-License-Identifier: GPL-2.0
#include <linux/bpf-cgroup.h>
#include <linux/bpf.h>
+#include <linux/bpf_local_storage.h>
#include <linux/btf.h>
#include <linux/bug.h>
#include <linux/filter.h>
@@ -283,9 +284,17 @@ static int cgroup_storage_get_next_key(struct bpf_map *_map, void *key,
static struct bpf_map *cgroup_storage_map_alloc(union bpf_attr *attr)
{
+ __u32 max_value_size = BPF_LOCAL_STORAGE_MAX_VALUE_SIZE;
int numa_node = bpf_map_attr_numa_node(attr);
struct bpf_cgroup_storage_map *map;
+ /* percpu is bound by PCPU_MIN_UNIT_SIZE, non-percu
+ * is the same as other local storages.
+ */
+ if (attr->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE)
+ max_value_size = min_t(__u32, max_value_size,
+ PCPU_MIN_UNIT_SIZE);
+
if (attr->key_size != sizeof(struct bpf_cgroup_storage_key) &&
attr->key_size != sizeof(__u64))
return ERR_PTR(-EINVAL);
@@ -293,7 +302,7 @@ static struct bpf_map *cgroup_storage_map_alloc(union bpf_attr *attr)
if (attr->value_size == 0)
return ERR_PTR(-EINVAL);
- if (attr->value_size > PAGE_SIZE)
+ if (attr->value_size > max_value_size)
return ERR_PTR(-E2BIG);
if (attr->map_flags & ~LOCAL_STORAGE_CREATE_FLAG_MASK ||
diff --git a/tools/testing/selftests/bpf/netcnt_common.h b/tools/testing/selftests/bpf/netcnt_common.h
index 81084c1c2c23..87f5b97e1932 100644
--- a/tools/testing/selftests/bpf/netcnt_common.h
+++ b/tools/testing/selftests/bpf/netcnt_common.h
@@ -6,19 +6,43 @@
#define MAX_PERCPU_PACKETS 32
+/* sizeof(struct bpf_local_storage_elem):
+ *
+ * It really is about 128 bytes on x86_64, but allocate more to account for
+ * possible layout changes, different architectures, etc.
+ * The kernel will wrap up to PAGE_SIZE internally anyway.
+ */
+#define SIZEOF_BPF_LOCAL_STORAGE_ELEM 256
+
+/* Try to estimate kernel's BPF_LOCAL_STORAGE_MAX_VALUE_SIZE: */
+#define BPF_LOCAL_STORAGE_MAX_VALUE_SIZE (0xFFFF - \
+ SIZEOF_BPF_LOCAL_STORAGE_ELEM)
+
+#define PCPU_MIN_UNIT_SIZE 32768
+
struct percpu_net_cnt {
- __u64 packets;
- __u64 bytes;
+ union {
+ struct {
+ __u64 packets;
+ __u64 bytes;
- __u64 prev_ts;
+ __u64 prev_ts;
- __u64 prev_packets;
- __u64 prev_bytes;
+ __u64 prev_packets;
+ __u64 prev_bytes;
+ };
+ __u8 data[PCPU_MIN_UNIT_SIZE];
+ };
};
struct net_cnt {
- __u64 packets;
- __u64 bytes;
+ union {
+ struct {
+ __u64 packets;
+ __u64 bytes;
+ };
+ __u8 data[BPF_LOCAL_STORAGE_MAX_VALUE_SIZE];
+ };
};
#endif
diff --git a/tools/testing/selftests/bpf/test_netcnt.c b/tools/testing/selftests/bpf/test_netcnt.c
index a7b9a69f4fd5..372afccf2d17 100644
--- a/tools/testing/selftests/bpf/test_netcnt.c
+++ b/tools/testing/selftests/bpf/test_netcnt.c
@@ -33,11 +33,11 @@ static int bpf_find_map(const char *test, struct bpf_object *obj,
int main(int argc, char **argv)
{
- struct percpu_net_cnt *percpu_netcnt;
+ struct percpu_net_cnt *percpu_netcnt = NULL;
struct bpf_cgroup_storage_key key;
+ struct net_cnt *netcnt = NULL;
int map_fd, percpu_map_fd;
int error = EXIT_FAILURE;
- struct net_cnt netcnt;
struct bpf_object *obj;
int prog_fd, cgroup_fd;
unsigned long packets;
@@ -52,6 +52,12 @@ int main(int argc, char **argv)
goto err;
}
+ netcnt = malloc(sizeof(*netcnt));
+ if (!netcnt) {
+ printf("Not enough memory for non-per-cpu area\n");
+ goto err;
+ }
+
if (bpf_prog_load(BPF_PROG, BPF_PROG_TYPE_CGROUP_SKB,
&obj, &prog_fd)) {
printf("Failed to load bpf program\n");
@@ -96,7 +102,7 @@ int main(int argc, char **argv)
goto err;
}
- if (bpf_map_lookup_elem(map_fd, &key, &netcnt)) {
+ if (bpf_map_lookup_elem(map_fd, &key, netcnt)) {
printf("Failed to lookup cgroup storage\n");
goto err;
}
@@ -109,8 +115,8 @@ int main(int argc, char **argv)
/* Some packets can be still in per-cpu cache, but not more than
* MAX_PERCPU_PACKETS.
*/
- packets = netcnt.packets;
- bytes = netcnt.bytes;
+ packets = netcnt->packets;
+ bytes = netcnt->bytes;
for (cpu = 0; cpu < nproc; cpu++) {
if (percpu_netcnt[cpu].packets > MAX_PERCPU_PACKETS) {
printf("Unexpected percpu value: %llu\n",
@@ -141,6 +147,7 @@ int main(int argc, char **argv)
err:
cleanup_cgroup_environment();
+ free(netcnt);
free(percpu_netcnt);
out:
--
2.32.0.432.gabb21c7263-goog
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH bpf-next v3] bpf: increase supported cgroup storage value size
2021-07-26 23:00 [PATCH bpf-next v3] bpf: increase supported cgroup storage value size Stanislav Fomichev
@ 2021-07-27 0:33 ` Martin KaFai Lau
2021-07-27 19:32 ` Andrii Nakryiko
1 sibling, 0 replies; 6+ messages in thread
From: Martin KaFai Lau @ 2021-07-27 0:33 UTC (permalink / raw)
To: Stanislav Fomichev; +Cc: netdev, bpf, ast, daniel, andrii, Yonghong Song
On Mon, Jul 26, 2021 at 04:00:32PM -0700, Stanislav Fomichev wrote:
> Current max cgroup storage value size is 4k (PAGE_SIZE). The other local
> storages accept up to 64k (BPF_LOCAL_STORAGE_MAX_VALUE_SIZE). Let's align
> max cgroup value size with the other storages.
>
> For percpu, the max is 32k (PCPU_MIN_UNIT_SIZE) because percpu
> allocator is not happy about larger values.
>
> netcnt test is extended to exercise those maximum values
> (non-percpu max size is close to, but not real max).
>
> v3:
> * refine SIZEOF_BPF_LOCAL_STORAGE_ELEM comment (Yonghong Song)
> * anonymous struct in percpu_net_cnt & net_cnt (Yonghong Song)
> * reorder free (Yonghong Song)
>
> v2:
> * cap max_value_size instead of BUILD_BUG_ON (Martin KaFai Lau)
Acked-by: Martin KaFai Lau <kafai@fb.com>
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH bpf-next v3] bpf: increase supported cgroup storage value size
2021-07-26 23:00 [PATCH bpf-next v3] bpf: increase supported cgroup storage value size Stanislav Fomichev
2021-07-27 0:33 ` Martin KaFai Lau
@ 2021-07-27 19:32 ` Andrii Nakryiko
2021-07-27 20:47 ` sdf
1 sibling, 1 reply; 6+ messages in thread
From: Andrii Nakryiko @ 2021-07-27 19:32 UTC (permalink / raw)
To: Stanislav Fomichev
Cc: Networking, bpf, Alexei Starovoitov, Daniel Borkmann,
Andrii Nakryiko, Martin KaFai Lau, Yonghong Song
On Mon, Jul 26, 2021 at 4:00 PM Stanislav Fomichev <sdf@google.com> wrote:
>
> Current max cgroup storage value size is 4k (PAGE_SIZE). The other local
> storages accept up to 64k (BPF_LOCAL_STORAGE_MAX_VALUE_SIZE). Let's align
> max cgroup value size with the other storages.
>
> For percpu, the max is 32k (PCPU_MIN_UNIT_SIZE) because percpu
> allocator is not happy about larger values.
>
> netcnt test is extended to exercise those maximum values
> (non-percpu max size is close to, but not real max).
>
> v3:
> * refine SIZEOF_BPF_LOCAL_STORAGE_ELEM comment (Yonghong Song)
> * anonymous struct in percpu_net_cnt & net_cnt (Yonghong Song)
> * reorder free (Yonghong Song)
>
> v2:
> * cap max_value_size instead of BUILD_BUG_ON (Martin KaFai Lau)
>
> Cc: Martin KaFai Lau <kafai@fb.com>
> Cc: Yonghong Song <yhs@fb.com>
> Signed-off-by: Stanislav Fomichev <sdf@google.com>
> ---
> kernel/bpf/local_storage.c | 11 +++++-
> tools/testing/selftests/bpf/netcnt_common.h | 38 +++++++++++++++++----
> tools/testing/selftests/bpf/test_netcnt.c | 17 ++++++---
> 3 files changed, 53 insertions(+), 13 deletions(-)
>
> diff --git a/kernel/bpf/local_storage.c b/kernel/bpf/local_storage.c
> index 7ed2a14dc0de..035e9e3a7132 100644
> --- a/kernel/bpf/local_storage.c
> +++ b/kernel/bpf/local_storage.c
> @@ -1,6 +1,7 @@
> //SPDX-License-Identifier: GPL-2.0
> #include <linux/bpf-cgroup.h>
> #include <linux/bpf.h>
> +#include <linux/bpf_local_storage.h>
> #include <linux/btf.h>
> #include <linux/bug.h>
> #include <linux/filter.h>
> @@ -283,9 +284,17 @@ static int cgroup_storage_get_next_key(struct bpf_map *_map, void *key,
>
> static struct bpf_map *cgroup_storage_map_alloc(union bpf_attr *attr)
> {
> + __u32 max_value_size = BPF_LOCAL_STORAGE_MAX_VALUE_SIZE;
> int numa_node = bpf_map_attr_numa_node(attr);
> struct bpf_cgroup_storage_map *map;
>
> + /* percpu is bound by PCPU_MIN_UNIT_SIZE, non-percu
> + * is the same as other local storages.
> + */
> + if (attr->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE)
> + max_value_size = min_t(__u32, max_value_size,
> + PCPU_MIN_UNIT_SIZE);
> +
> if (attr->key_size != sizeof(struct bpf_cgroup_storage_key) &&
> attr->key_size != sizeof(__u64))
> return ERR_PTR(-EINVAL);
> @@ -293,7 +302,7 @@ static struct bpf_map *cgroup_storage_map_alloc(union bpf_attr *attr)
> if (attr->value_size == 0)
> return ERR_PTR(-EINVAL);
>
> - if (attr->value_size > PAGE_SIZE)
> + if (attr->value_size > max_value_size)
> return ERR_PTR(-E2BIG);
>
> if (attr->map_flags & ~LOCAL_STORAGE_CREATE_FLAG_MASK ||
> diff --git a/tools/testing/selftests/bpf/netcnt_common.h b/tools/testing/selftests/bpf/netcnt_common.h
> index 81084c1c2c23..87f5b97e1932 100644
> --- a/tools/testing/selftests/bpf/netcnt_common.h
> +++ b/tools/testing/selftests/bpf/netcnt_common.h
> @@ -6,19 +6,43 @@
>
> #define MAX_PERCPU_PACKETS 32
>
> +/* sizeof(struct bpf_local_storage_elem):
> + *
> + * It really is about 128 bytes on x86_64, but allocate more to account for
> + * possible layout changes, different architectures, etc.
> + * The kernel will wrap up to PAGE_SIZE internally anyway.
> + */
> +#define SIZEOF_BPF_LOCAL_STORAGE_ELEM 256
> +
> +/* Try to estimate kernel's BPF_LOCAL_STORAGE_MAX_VALUE_SIZE: */
> +#define BPF_LOCAL_STORAGE_MAX_VALUE_SIZE (0xFFFF - \
> + SIZEOF_BPF_LOCAL_STORAGE_ELEM)
> +
> +#define PCPU_MIN_UNIT_SIZE 32768
> +
> struct percpu_net_cnt {
> - __u64 packets;
> - __u64 bytes;
> + union {
so you have a struct with a single anonymous union inside, isn't that
right? Any problems with just making struct percpu_net_cnt into union
percpu_net_cnt?
> + struct {
> + __u64 packets;
> + __u64 bytes;
>
> - __u64 prev_ts;
> + __u64 prev_ts;
>
> - __u64 prev_packets;
> - __u64 prev_bytes;
> + __u64 prev_packets;
> + __u64 prev_bytes;
> + };
> + __u8 data[PCPU_MIN_UNIT_SIZE];
> + };
> };
>
> struct net_cnt {
> - __u64 packets;
> - __u64 bytes;
> + union {
similarly here
> + struct {
> + __u64 packets;
> + __u64 bytes;
> + };
> + __u8 data[BPF_LOCAL_STORAGE_MAX_VALUE_SIZE];
> + };
> };
>
> #endif
> diff --git a/tools/testing/selftests/bpf/test_netcnt.c b/tools/testing/selftests/bpf/test_netcnt.c
> index a7b9a69f4fd5..372afccf2d17 100644
> --- a/tools/testing/selftests/bpf/test_netcnt.c
> +++ b/tools/testing/selftests/bpf/test_netcnt.c
> @@ -33,11 +33,11 @@ static int bpf_find_map(const char *test, struct bpf_object *obj,
>
> int main(int argc, char **argv)
> {
> - struct percpu_net_cnt *percpu_netcnt;
> + struct percpu_net_cnt *percpu_netcnt = NULL;
> struct bpf_cgroup_storage_key key;
> + struct net_cnt *netcnt = NULL;
> int map_fd, percpu_map_fd;
> int error = EXIT_FAILURE;
> - struct net_cnt netcnt;
> struct bpf_object *obj;
> int prog_fd, cgroup_fd;
> unsigned long packets;
> @@ -52,6 +52,12 @@ int main(int argc, char **argv)
> goto err;
> }
>
> + netcnt = malloc(sizeof(*netcnt));
curious, was it too big to be just allocated on the stack? Isn't the
thread stack size much bigger than 64KB (at least by default)?
> + if (!netcnt) {
> + printf("Not enough memory for non-per-cpu area\n");
> + goto err;
> + }
> +
> if (bpf_prog_load(BPF_PROG, BPF_PROG_TYPE_CGROUP_SKB,
> &obj, &prog_fd)) {
> printf("Failed to load bpf program\n");
> @@ -96,7 +102,7 @@ int main(int argc, char **argv)
> goto err;
> }
>
> - if (bpf_map_lookup_elem(map_fd, &key, &netcnt)) {
> + if (bpf_map_lookup_elem(map_fd, &key, netcnt)) {
> printf("Failed to lookup cgroup storage\n");
> goto err;
> }
> @@ -109,8 +115,8 @@ int main(int argc, char **argv)
> /* Some packets can be still in per-cpu cache, but not more than
> * MAX_PERCPU_PACKETS.
> */
> - packets = netcnt.packets;
> - bytes = netcnt.bytes;
> + packets = netcnt->packets;
> + bytes = netcnt->bytes;
> for (cpu = 0; cpu < nproc; cpu++) {
> if (percpu_netcnt[cpu].packets > MAX_PERCPU_PACKETS) {
> printf("Unexpected percpu value: %llu\n",
> @@ -141,6 +147,7 @@ int main(int argc, char **argv)
>
> err:
> cleanup_cgroup_environment();
> + free(netcnt);
> free(percpu_netcnt);
>
> out:
> --
> 2.32.0.432.gabb21c7263-goog
>
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH bpf-next v3] bpf: increase supported cgroup storage value size
2021-07-27 19:32 ` Andrii Nakryiko
@ 2021-07-27 20:47 ` sdf
2021-07-27 21:30 ` Andrii Nakryiko
0 siblings, 1 reply; 6+ messages in thread
From: sdf @ 2021-07-27 20:47 UTC (permalink / raw)
To: Andrii Nakryiko
Cc: Networking, bpf, Alexei Starovoitov, Daniel Borkmann,
Andrii Nakryiko, Martin KaFai Lau, Yonghong Song
On 07/27, Andrii Nakryiko wrote:
> On Mon, Jul 26, 2021 at 4:00 PM Stanislav Fomichev <sdf@google.com> wrote:
> >
> > Current max cgroup storage value size is 4k (PAGE_SIZE). The other local
> > storages accept up to 64k (BPF_LOCAL_STORAGE_MAX_VALUE_SIZE). Let's
> align
> > max cgroup value size with the other storages.
> >
> > For percpu, the max is 32k (PCPU_MIN_UNIT_SIZE) because percpu
> > allocator is not happy about larger values.
> >
> > netcnt test is extended to exercise those maximum values
> > (non-percpu max size is close to, but not real max).
> >
> > v3:
> > * refine SIZEOF_BPF_LOCAL_STORAGE_ELEM comment (Yonghong Song)
> > * anonymous struct in percpu_net_cnt & net_cnt (Yonghong Song)
> > * reorder free (Yonghong Song)
> >
> > v2:
> > * cap max_value_size instead of BUILD_BUG_ON (Martin KaFai Lau)
> >
> > Cc: Martin KaFai Lau <kafai@fb.com>
> > Cc: Yonghong Song <yhs@fb.com>
> > Signed-off-by: Stanislav Fomichev <sdf@google.com>
> > ---
> > kernel/bpf/local_storage.c | 11 +++++-
> > tools/testing/selftests/bpf/netcnt_common.h | 38 +++++++++++++++++----
> > tools/testing/selftests/bpf/test_netcnt.c | 17 ++++++---
> > 3 files changed, 53 insertions(+), 13 deletions(-)
> >
> > diff --git a/kernel/bpf/local_storage.c b/kernel/bpf/local_storage.c
> > index 7ed2a14dc0de..035e9e3a7132 100644
> > --- a/kernel/bpf/local_storage.c
> > +++ b/kernel/bpf/local_storage.c
> > @@ -1,6 +1,7 @@
> > //SPDX-License-Identifier: GPL-2.0
> > #include <linux/bpf-cgroup.h>
> > #include <linux/bpf.h>
> > +#include <linux/bpf_local_storage.h>
> > #include <linux/btf.h>
> > #include <linux/bug.h>
> > #include <linux/filter.h>
> > @@ -283,9 +284,17 @@ static int cgroup_storage_get_next_key(struct
> bpf_map *_map, void *key,
> >
> > static struct bpf_map *cgroup_storage_map_alloc(union bpf_attr *attr)
> > {
> > + __u32 max_value_size = BPF_LOCAL_STORAGE_MAX_VALUE_SIZE;
> > int numa_node = bpf_map_attr_numa_node(attr);
> > struct bpf_cgroup_storage_map *map;
> >
> > + /* percpu is bound by PCPU_MIN_UNIT_SIZE, non-percu
> > + * is the same as other local storages.
> > + */
> > + if (attr->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE)
> > + max_value_size = min_t(__u32, max_value_size,
> > + PCPU_MIN_UNIT_SIZE);
> > +
> > if (attr->key_size != sizeof(struct bpf_cgroup_storage_key) &&
> > attr->key_size != sizeof(__u64))
> > return ERR_PTR(-EINVAL);
> > @@ -293,7 +302,7 @@ static struct bpf_map
> *cgroup_storage_map_alloc(union bpf_attr *attr)
> > if (attr->value_size == 0)
> > return ERR_PTR(-EINVAL);
> >
> > - if (attr->value_size > PAGE_SIZE)
> > + if (attr->value_size > max_value_size)
> > return ERR_PTR(-E2BIG);
> >
> > if (attr->map_flags & ~LOCAL_STORAGE_CREATE_FLAG_MASK ||
> > diff --git a/tools/testing/selftests/bpf/netcnt_common.h
> b/tools/testing/selftests/bpf/netcnt_common.h
> > index 81084c1c2c23..87f5b97e1932 100644
> > --- a/tools/testing/selftests/bpf/netcnt_common.h
> > +++ b/tools/testing/selftests/bpf/netcnt_common.h
> > @@ -6,19 +6,43 @@
> >
> > #define MAX_PERCPU_PACKETS 32
> >
> > +/* sizeof(struct bpf_local_storage_elem):
> > + *
> > + * It really is about 128 bytes on x86_64, but allocate more to
> account for
> > + * possible layout changes, different architectures, etc.
> > + * The kernel will wrap up to PAGE_SIZE internally anyway.
> > + */
> > +#define SIZEOF_BPF_LOCAL_STORAGE_ELEM 256
> > +
> > +/* Try to estimate kernel's BPF_LOCAL_STORAGE_MAX_VALUE_SIZE: */
> > +#define BPF_LOCAL_STORAGE_MAX_VALUE_SIZE (0xFFFF - \
> > +
> SIZEOF_BPF_LOCAL_STORAGE_ELEM)
> > +
> > +#define PCPU_MIN_UNIT_SIZE 32768
> > +
> > struct percpu_net_cnt {
> > - __u64 packets;
> > - __u64 bytes;
> > + union {
> so you have a struct with a single anonymous union inside, isn't that
> right? Any problems with just making struct percpu_net_cnt into union
> percpu_net_cnt?
We'd have to s/struct/union/ everywhere in this case, not sure
we want to add more churn? Seemed easier to do anonymous union+struct.
> > + struct {
> > + __u64 packets;
> > + __u64 bytes;
> >
> > - __u64 prev_ts;
> > + __u64 prev_ts;
> >
> > - __u64 prev_packets;
> > - __u64 prev_bytes;
> > + __u64 prev_packets;
> > + __u64 prev_bytes;
> > + };
> > + __u8 data[PCPU_MIN_UNIT_SIZE];
> > + };
> > };
> >
> > struct net_cnt {
> > - __u64 packets;
> > - __u64 bytes;
> > + union {
> similarly here
> > + struct {
> > + __u64 packets;
> > + __u64 bytes;
> > + };
> > + __u8 data[BPF_LOCAL_STORAGE_MAX_VALUE_SIZE];
> > + };
> > };
> >
> > #endif
> > diff --git a/tools/testing/selftests/bpf/test_netcnt.c
> b/tools/testing/selftests/bpf/test_netcnt.c
> > index a7b9a69f4fd5..372afccf2d17 100644
> > --- a/tools/testing/selftests/bpf/test_netcnt.c
> > +++ b/tools/testing/selftests/bpf/test_netcnt.c
> > @@ -33,11 +33,11 @@ static int bpf_find_map(const char *test, struct
> bpf_object *obj,
> >
> > int main(int argc, char **argv)
> > {
> > - struct percpu_net_cnt *percpu_netcnt;
> > + struct percpu_net_cnt *percpu_netcnt = NULL;
> > struct bpf_cgroup_storage_key key;
> > + struct net_cnt *netcnt = NULL;
> > int map_fd, percpu_map_fd;
> > int error = EXIT_FAILURE;
> > - struct net_cnt netcnt;
> > struct bpf_object *obj;
> > int prog_fd, cgroup_fd;
> > unsigned long packets;
> > @@ -52,6 +52,12 @@ int main(int argc, char **argv)
> > goto err;
> > }
> >
> > + netcnt = malloc(sizeof(*netcnt));
> curious, was it too big to be just allocated on the stack? Isn't the
> thread stack size much bigger than 64KB (at least by default)?
I haven't tried really, I just moved it to malloc because it crossed
some unconscious boundary for the 'stuff I allocate on the stack'.
I can try it out if you prefer to keep it on the stack, let me know.
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH bpf-next v3] bpf: increase supported cgroup storage value size
2021-07-27 20:47 ` sdf
@ 2021-07-27 21:30 ` Andrii Nakryiko
2021-07-27 22:17 ` sdf
0 siblings, 1 reply; 6+ messages in thread
From: Andrii Nakryiko @ 2021-07-27 21:30 UTC (permalink / raw)
To: Stanislav Fomichev
Cc: Networking, bpf, Alexei Starovoitov, Daniel Borkmann,
Andrii Nakryiko, Martin KaFai Lau, Yonghong Song
On Tue, Jul 27, 2021 at 1:47 PM <sdf@google.com> wrote:
>
> On 07/27, Andrii Nakryiko wrote:
> > On Mon, Jul 26, 2021 at 4:00 PM Stanislav Fomichev <sdf@google.com> wrote:
> > >
> > > Current max cgroup storage value size is 4k (PAGE_SIZE). The other local
> > > storages accept up to 64k (BPF_LOCAL_STORAGE_MAX_VALUE_SIZE). Let's
> > align
> > > max cgroup value size with the other storages.
> > >
> > > For percpu, the max is 32k (PCPU_MIN_UNIT_SIZE) because percpu
> > > allocator is not happy about larger values.
> > >
> > > netcnt test is extended to exercise those maximum values
> > > (non-percpu max size is close to, but not real max).
> > >
> > > v3:
> > > * refine SIZEOF_BPF_LOCAL_STORAGE_ELEM comment (Yonghong Song)
> > > * anonymous struct in percpu_net_cnt & net_cnt (Yonghong Song)
> > > * reorder free (Yonghong Song)
> > >
> > > v2:
> > > * cap max_value_size instead of BUILD_BUG_ON (Martin KaFai Lau)
> > >
> > > Cc: Martin KaFai Lau <kafai@fb.com>
> > > Cc: Yonghong Song <yhs@fb.com>
> > > Signed-off-by: Stanislav Fomichev <sdf@google.com>
> > > ---
> > > kernel/bpf/local_storage.c | 11 +++++-
> > > tools/testing/selftests/bpf/netcnt_common.h | 38 +++++++++++++++++----
> > > tools/testing/selftests/bpf/test_netcnt.c | 17 ++++++---
> > > 3 files changed, 53 insertions(+), 13 deletions(-)
> > >
> > > diff --git a/kernel/bpf/local_storage.c b/kernel/bpf/local_storage.c
> > > index 7ed2a14dc0de..035e9e3a7132 100644
> > > --- a/kernel/bpf/local_storage.c
> > > +++ b/kernel/bpf/local_storage.c
> > > @@ -1,6 +1,7 @@
> > > //SPDX-License-Identifier: GPL-2.0
> > > #include <linux/bpf-cgroup.h>
> > > #include <linux/bpf.h>
> > > +#include <linux/bpf_local_storage.h>
> > > #include <linux/btf.h>
> > > #include <linux/bug.h>
> > > #include <linux/filter.h>
> > > @@ -283,9 +284,17 @@ static int cgroup_storage_get_next_key(struct
> > bpf_map *_map, void *key,
> > >
> > > static struct bpf_map *cgroup_storage_map_alloc(union bpf_attr *attr)
> > > {
> > > + __u32 max_value_size = BPF_LOCAL_STORAGE_MAX_VALUE_SIZE;
> > > int numa_node = bpf_map_attr_numa_node(attr);
> > > struct bpf_cgroup_storage_map *map;
> > >
> > > + /* percpu is bound by PCPU_MIN_UNIT_SIZE, non-percu
> > > + * is the same as other local storages.
> > > + */
> > > + if (attr->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE)
> > > + max_value_size = min_t(__u32, max_value_size,
> > > + PCPU_MIN_UNIT_SIZE);
> > > +
> > > if (attr->key_size != sizeof(struct bpf_cgroup_storage_key) &&
> > > attr->key_size != sizeof(__u64))
> > > return ERR_PTR(-EINVAL);
> > > @@ -293,7 +302,7 @@ static struct bpf_map
> > *cgroup_storage_map_alloc(union bpf_attr *attr)
> > > if (attr->value_size == 0)
> > > return ERR_PTR(-EINVAL);
> > >
> > > - if (attr->value_size > PAGE_SIZE)
> > > + if (attr->value_size > max_value_size)
> > > return ERR_PTR(-E2BIG);
> > >
> > > if (attr->map_flags & ~LOCAL_STORAGE_CREATE_FLAG_MASK ||
> > > diff --git a/tools/testing/selftests/bpf/netcnt_common.h
> > b/tools/testing/selftests/bpf/netcnt_common.h
> > > index 81084c1c2c23..87f5b97e1932 100644
> > > --- a/tools/testing/selftests/bpf/netcnt_common.h
> > > +++ b/tools/testing/selftests/bpf/netcnt_common.h
> > > @@ -6,19 +6,43 @@
> > >
> > > #define MAX_PERCPU_PACKETS 32
> > >
> > > +/* sizeof(struct bpf_local_storage_elem):
> > > + *
> > > + * It really is about 128 bytes on x86_64, but allocate more to
> > account for
> > > + * possible layout changes, different architectures, etc.
> > > + * The kernel will wrap up to PAGE_SIZE internally anyway.
> > > + */
> > > +#define SIZEOF_BPF_LOCAL_STORAGE_ELEM 256
> > > +
> > > +/* Try to estimate kernel's BPF_LOCAL_STORAGE_MAX_VALUE_SIZE: */
> > > +#define BPF_LOCAL_STORAGE_MAX_VALUE_SIZE (0xFFFF - \
> > > +
> > SIZEOF_BPF_LOCAL_STORAGE_ELEM)
> > > +
> > > +#define PCPU_MIN_UNIT_SIZE 32768
> > > +
> > > struct percpu_net_cnt {
> > > - __u64 packets;
> > > - __u64 bytes;
> > > + union {
>
> > so you have a struct with a single anonymous union inside, isn't that
> > right? Any problems with just making struct percpu_net_cnt into union
> > percpu_net_cnt?
> We'd have to s/struct/union/ everywhere in this case, not sure
> we want to add more churn? Seemed easier to do anonymous union+struct.
4 occurrences for net_cnt and another 4 for percpu_net_cnt, not much
churn (and all pretty localized). But I honestly don't care, just
wanted to note that you don't need this extra nesting.
>
> > > + struct {
> > > + __u64 packets;
> > > + __u64 bytes;
> > >
> > > - __u64 prev_ts;
> > > + __u64 prev_ts;
> > >
> > > - __u64 prev_packets;
> > > - __u64 prev_bytes;
> > > + __u64 prev_packets;
> > > + __u64 prev_bytes;
> > > + };
> > > + __u8 data[PCPU_MIN_UNIT_SIZE];
> > > + };
> > > };
> > >
> > > struct net_cnt {
> > > - __u64 packets;
> > > - __u64 bytes;
> > > + union {
>
> > similarly here
>
> > > + struct {
> > > + __u64 packets;
> > > + __u64 bytes;
> > > + };
> > > + __u8 data[BPF_LOCAL_STORAGE_MAX_VALUE_SIZE];
> > > + };
> > > };
> > >
> > > #endif
> > > diff --git a/tools/testing/selftests/bpf/test_netcnt.c
> > b/tools/testing/selftests/bpf/test_netcnt.c
> > > index a7b9a69f4fd5..372afccf2d17 100644
> > > --- a/tools/testing/selftests/bpf/test_netcnt.c
> > > +++ b/tools/testing/selftests/bpf/test_netcnt.c
> > > @@ -33,11 +33,11 @@ static int bpf_find_map(const char *test, struct
> > bpf_object *obj,
> > >
> > > int main(int argc, char **argv)
> > > {
> > > - struct percpu_net_cnt *percpu_netcnt;
> > > + struct percpu_net_cnt *percpu_netcnt = NULL;
> > > struct bpf_cgroup_storage_key key;
> > > + struct net_cnt *netcnt = NULL;
> > > int map_fd, percpu_map_fd;
> > > int error = EXIT_FAILURE;
> > > - struct net_cnt netcnt;
> > > struct bpf_object *obj;
> > > int prog_fd, cgroup_fd;
> > > unsigned long packets;
> > > @@ -52,6 +52,12 @@ int main(int argc, char **argv)
> > > goto err;
> > > }
> > >
> > > + netcnt = malloc(sizeof(*netcnt));
>
> > curious, was it too big to be just allocated on the stack? Isn't the
> > thread stack size much bigger than 64KB (at least by default)?
> I haven't tried really, I just moved it to malloc because it crossed
> some unconscious boundary for the 'stuff I allocate on the stack'.
> I can try it out if you prefer to keep it on the stack, let me know.
Yeah, if it can stay on the stack. Less thinking about freeing memory.
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH bpf-next v3] bpf: increase supported cgroup storage value size
2021-07-27 21:30 ` Andrii Nakryiko
@ 2021-07-27 22:17 ` sdf
0 siblings, 0 replies; 6+ messages in thread
From: sdf @ 2021-07-27 22:17 UTC (permalink / raw)
To: Andrii Nakryiko
Cc: Networking, bpf, Alexei Starovoitov, Daniel Borkmann,
Andrii Nakryiko, Martin KaFai Lau, Yonghong Song
On 07/27, Andrii Nakryiko wrote:
> On Tue, Jul 27, 2021 at 1:47 PM <sdf@google.com> wrote:
> >
> > On 07/27, Andrii Nakryiko wrote:
> > > On Mon, Jul 26, 2021 at 4:00 PM Stanislav Fomichev <sdf@google.com>
> wrote:
> > > >
> > > > Current max cgroup storage value size is 4k (PAGE_SIZE). The other
> local
> > > > storages accept up to 64k (BPF_LOCAL_STORAGE_MAX_VALUE_SIZE). Let's
> > > align
> > > > max cgroup value size with the other storages.
> > > >
> > > > For percpu, the max is 32k (PCPU_MIN_UNIT_SIZE) because percpu
> > > > allocator is not happy about larger values.
> > > >
> > > > netcnt test is extended to exercise those maximum values
> > > > (non-percpu max size is close to, but not real max).
> > > >
> > > > v3:
> > > > * refine SIZEOF_BPF_LOCAL_STORAGE_ELEM comment (Yonghong Song)
> > > > * anonymous struct in percpu_net_cnt & net_cnt (Yonghong Song)
> > > > * reorder free (Yonghong Song)
> > > >
> > > > v2:
> > > > * cap max_value_size instead of BUILD_BUG_ON (Martin KaFai Lau)
> > > >
> > > > Cc: Martin KaFai Lau <kafai@fb.com>
> > > > Cc: Yonghong Song <yhs@fb.com>
> > > > Signed-off-by: Stanislav Fomichev <sdf@google.com>
> > > > ---
> > > > kernel/bpf/local_storage.c | 11 +++++-
> > > > tools/testing/selftests/bpf/netcnt_common.h | 38
> +++++++++++++++++----
> > > > tools/testing/selftests/bpf/test_netcnt.c | 17 ++++++---
> > > > 3 files changed, 53 insertions(+), 13 deletions(-)
> > > >
> > > > diff --git a/kernel/bpf/local_storage.c b/kernel/bpf/local_storage.c
> > > > index 7ed2a14dc0de..035e9e3a7132 100644
> > > > --- a/kernel/bpf/local_storage.c
> > > > +++ b/kernel/bpf/local_storage.c
> > > > @@ -1,6 +1,7 @@
> > > > //SPDX-License-Identifier: GPL-2.0
> > > > #include <linux/bpf-cgroup.h>
> > > > #include <linux/bpf.h>
> > > > +#include <linux/bpf_local_storage.h>
> > > > #include <linux/btf.h>
> > > > #include <linux/bug.h>
> > > > #include <linux/filter.h>
> > > > @@ -283,9 +284,17 @@ static int cgroup_storage_get_next_key(struct
> > > bpf_map *_map, void *key,
> > > >
> > > > static struct bpf_map *cgroup_storage_map_alloc(union bpf_attr
> *attr)
> > > > {
> > > > + __u32 max_value_size = BPF_LOCAL_STORAGE_MAX_VALUE_SIZE;
> > > > int numa_node = bpf_map_attr_numa_node(attr);
> > > > struct bpf_cgroup_storage_map *map;
> > > >
> > > > + /* percpu is bound by PCPU_MIN_UNIT_SIZE, non-percu
> > > > + * is the same as other local storages.
> > > > + */
> > > > + if (attr->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE)
> > > > + max_value_size = min_t(__u32, max_value_size,
> > > > + PCPU_MIN_UNIT_SIZE);
> > > > +
> > > > if (attr->key_size != sizeof(struct bpf_cgroup_storage_key)
> &&
> > > > attr->key_size != sizeof(__u64))
> > > > return ERR_PTR(-EINVAL);
> > > > @@ -293,7 +302,7 @@ static struct bpf_map
> > > *cgroup_storage_map_alloc(union bpf_attr *attr)
> > > > if (attr->value_size == 0)
> > > > return ERR_PTR(-EINVAL);
> > > >
> > > > - if (attr->value_size > PAGE_SIZE)
> > > > + if (attr->value_size > max_value_size)
> > > > return ERR_PTR(-E2BIG);
> > > >
> > > > if (attr->map_flags & ~LOCAL_STORAGE_CREATE_FLAG_MASK ||
> > > > diff --git a/tools/testing/selftests/bpf/netcnt_common.h
> > > b/tools/testing/selftests/bpf/netcnt_common.h
> > > > index 81084c1c2c23..87f5b97e1932 100644
> > > > --- a/tools/testing/selftests/bpf/netcnt_common.h
> > > > +++ b/tools/testing/selftests/bpf/netcnt_common.h
> > > > @@ -6,19 +6,43 @@
> > > >
> > > > #define MAX_PERCPU_PACKETS 32
> > > >
> > > > +/* sizeof(struct bpf_local_storage_elem):
> > > > + *
> > > > + * It really is about 128 bytes on x86_64, but allocate more to
> > > account for
> > > > + * possible layout changes, different architectures, etc.
> > > > + * The kernel will wrap up to PAGE_SIZE internally anyway.
> > > > + */
> > > > +#define SIZEOF_BPF_LOCAL_STORAGE_ELEM 256
> > > > +
> > > > +/* Try to estimate kernel's BPF_LOCAL_STORAGE_MAX_VALUE_SIZE: */
> > > > +#define BPF_LOCAL_STORAGE_MAX_VALUE_SIZE (0xFFFF - \
> > > > +
> > > SIZEOF_BPF_LOCAL_STORAGE_ELEM)
> > > > +
> > > > +#define PCPU_MIN_UNIT_SIZE 32768
> > > > +
> > > > struct percpu_net_cnt {
> > > > - __u64 packets;
> > > > - __u64 bytes;
> > > > + union {
> >
> > > so you have a struct with a single anonymous union inside, isn't that
> > > right? Any problems with just making struct percpu_net_cnt into union
> > > percpu_net_cnt?
> > We'd have to s/struct/union/ everywhere in this case, not sure
> > we want to add more churn? Seemed easier to do anonymous union+struct.
> 4 occurrences for net_cnt and another 4 for percpu_net_cnt, not much
> churn (and all pretty localized). But I honestly don't care, just
> wanted to note that you don't need this extra nesting.
I might do it since I'm doing another respin anyway.
> > > > + struct {
> > > > + __u64 packets;
> > > > + __u64 bytes;
> > > >
> > > > - __u64 prev_ts;
> > > > + __u64 prev_ts;
> > > >
> > > > - __u64 prev_packets;
> > > > - __u64 prev_bytes;
> > > > + __u64 prev_packets;
> > > > + __u64 prev_bytes;
> > > > + };
> > > > + __u8 data[PCPU_MIN_UNIT_SIZE];
> > > > + };
> > > > };
> > > >
> > > > struct net_cnt {
> > > > - __u64 packets;
> > > > - __u64 bytes;
> > > > + union {
> >
> > > similarly here
> >
> > > > + struct {
> > > > + __u64 packets;
> > > > + __u64 bytes;
> > > > + };
> > > > + __u8 data[BPF_LOCAL_STORAGE_MAX_VALUE_SIZE];
> > > > + };
> > > > };
> > > >
> > > > #endif
> > > > diff --git a/tools/testing/selftests/bpf/test_netcnt.c
> > > b/tools/testing/selftests/bpf/test_netcnt.c
> > > > index a7b9a69f4fd5..372afccf2d17 100644
> > > > --- a/tools/testing/selftests/bpf/test_netcnt.c
> > > > +++ b/tools/testing/selftests/bpf/test_netcnt.c
> > > > @@ -33,11 +33,11 @@ static int bpf_find_map(const char *test, struct
> > > bpf_object *obj,
> > > >
> > > > int main(int argc, char **argv)
> > > > {
> > > > - struct percpu_net_cnt *percpu_netcnt;
> > > > + struct percpu_net_cnt *percpu_netcnt = NULL;
> > > > struct bpf_cgroup_storage_key key;
> > > > + struct net_cnt *netcnt = NULL;
> > > > int map_fd, percpu_map_fd;
> > > > int error = EXIT_FAILURE;
> > > > - struct net_cnt netcnt;
> > > > struct bpf_object *obj;
> > > > int prog_fd, cgroup_fd;
> > > > unsigned long packets;
> > > > @@ -52,6 +52,12 @@ int main(int argc, char **argv)
> > > > goto err;
> > > > }
> > > >
> > > > + netcnt = malloc(sizeof(*netcnt));
> >
> > > curious, was it too big to be just allocated on the stack? Isn't the
> > > thread stack size much bigger than 64KB (at least by default)?
> > I haven't tried really, I just moved it to malloc because it crossed
> > some unconscious boundary for the 'stuff I allocate on the stack'.
> > I can try it out if you prefer to keep it on the stack, let me know.
> Yeah, if it can stay on the stack. Less thinking about freeing memory.
Ack, seems to be working, will resend shortly..
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2021-07-27 22:17 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-07-26 23:00 [PATCH bpf-next v3] bpf: increase supported cgroup storage value size Stanislav Fomichev
2021-07-27 0:33 ` Martin KaFai Lau
2021-07-27 19:32 ` Andrii Nakryiko
2021-07-27 20:47 ` sdf
2021-07-27 21:30 ` Andrii Nakryiko
2021-07-27 22:17 ` sdf
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).