On Wed, Mar 1, 2023 at 10:31 AM Hou Tao <houtao@xxxxxxxxxxxxxxx> wrote:
>
> From: Hou Tao <houtao1@xxxxxxxxxx>
>
> Hi,
>
> > trie_mem_usage() is introduced to calculate the lpm_trie memory usage.
> > Some small memory allocations are ignored. The inner node is also
> > ignored.
> >
> > The result as follows,
> >
> > - before
> > 10: lpm_trie flags 0x1
> > key 8B value 8B max_entries 65536 memlock 1048576B
> >
> > - after
> > 10: lpm_trie flags 0x1
> > key 8B value 8B max_entries 65536 memlock 2291536B
> >
> > Signed-off-by: Yafang Shao <laoar.shao@xxxxxxxxx>
> > ---
> > kernel/bpf/lpm_trie.c | 11 +++++++++++
> > 1 file changed, 11 insertions(+)
> >
> > diff --git a/kernel/bpf/lpm_trie.c b/kernel/bpf/lpm_trie.c
> > index d833496..e0ca08e 100644
> > --- a/kernel/bpf/lpm_trie.c
> > +++ b/kernel/bpf/lpm_trie.c
> > @@ -720,6 +720,16 @@ static int trie_check_btf(const struct bpf_map *map,
> > -EINVAL : 0;
> > }
> >
> > +static u64 trie_mem_usage(const struct bpf_map *map)
> > +{
> > + struct lpm_trie *trie = container_of(map, struct lpm_trie, map);
> > + u64 elem_size;
> > +
> > + elem_size = sizeof(struct lpm_trie_node) + trie->data_size +
> > + trie->map.value_size;
> > + return elem_size * trie->n_entries;
> Need to use READ_ONCE(trie->n_entries) because all updates of n_entries are protected by trie->lock and here it is a lockless read.
Indeed. Will change it in the next version.
Thanks for your review.
--
Regards
Yafang
