Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]
Groups > linux.kernel > #1307986
| From | Eric Dumazet <eric.dumazet@gmail.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [PATCH v2 net-next 3/4] bpf: bpf_htab: Add syscall to iterate percpu value of a key |
| Date | 2016-01-13 03:30 +0100 |
| Message-ID | <qQjma-1rE-1@gated-at.bofh.it> (permalink) |
| References | <qQ2v0-6Gt-3@gated-at.bofh.it> <qQ2v0-6Gt-15@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
On Tue, 2016-01-12 at 00:20 -0800, Martin KaFai Lau wrote:
> Add map_lookup_percpu_elem() syscall to lookup value
> of a particular CPU.
...
> +static int map_lookup_percpu_elem(union bpf_attr *attr)
> +{
> + void __user *ukey = u64_to_ptr(attr->key);
> + void __user *uvalue = u64_to_ptr(attr->value);
> + u32 __user ucpu = attr->cpu;
> + int ufd = attr->map_fd;
> + struct percpu_map_value_info value_info;
> + struct bpf_map *map;
> + void *key, *value;
> + struct fd f;
> + int err;
> +
> + if (CHECK_ATTR(BPF_MAP_LOOKUP_PERCPU_ELEM) ||
> + ucpu >= num_possible_cpus())
> + return -EINVAL;
Arg, a num_possible_cpus() wrong call.
You probably want to use (ucpu >= nr_cpu_ids)
hint : You can have hosts with 2 possibles cpus, CPU0 and CPU2
So the userland loop in your changelog is wrong.
Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread
[PATCH v2 net-next 3/4] bpf: bpf_htab: Add syscall to iterate percpu value of a key Martin KaFai Lau <kafai@fb.com> - 2016-01-12 09:30 +0100
Re: [PATCH v2 net-next 3/4] bpf: bpf_htab: Add syscall to iterate percpu value of a key Eric Dumazet <eric.dumazet@gmail.com> - 2016-01-13 03:30 +0100
Re: [PATCH v2 net-next 3/4] bpf: bpf_htab: Add syscall to iterate percpu value of a key Ming Lei <tom.leiming@gmail.com> - 2016-01-13 03:50 +0100
Re: [PATCH v2 net-next 3/4] bpf: bpf_htab: Add syscall to iterate percpu value of a key Alexei Starovoitov <alexei.starovoitov@gmail.com> - 2016-01-13 06:30 +0100
Re: [PATCH v2 net-next 3/4] bpf: bpf_htab: Add syscall to iterate percpu value of a key Ming Lei <tom.leiming@gmail.com> - 2016-01-13 16:50 +0100
Re: [PATCH v2 net-next 3/4] bpf: bpf_htab: Add syscall to iterate percpu value of a key Alexei Starovoitov <alexei.starovoitov@gmail.com> - 2016-01-14 02:30 +0100
Re: [PATCH v2 net-next 3/4] bpf: bpf_htab: Add syscall to iterate percpu value of a key Ming Lei <tom.leiming@gmail.com> - 2016-01-14 04:30 +0100
csiph-web