Toke Høiland-Jørgensen wrote:
> To make the system page pool usable as a source for allocating XDP
> frames, we need to register it with xdp_reg_mem_model(), so that page
> return works correctly. This is done in preparation for using the system
> page pool for the XDP live frame mode in BPF_TEST_RUN; for the same
> reason, make the per-cpu variable non-static so we can access it from
> the test_run code as well.
>
> Reviewed-by: Alexander Lobakin <aleksander.lobakin@xxxxxxxxx>
> Tested-by: Alexander Lobakin <aleksander.lobakin@xxxxxxxxx>
> Signed-off-by: Toke Høiland-Jørgensen <toke@xxxxxxxxxx>
> ---
> include/linux/netdevice.h | 1 +
> net/core/dev.c | 13 ++++++++++++-
> 2 files changed, 13 insertions(+), 1 deletion(-)
>
> diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
> index c541550b0e6e..e1dfdf0c4075 100644
> --- a/include/linux/netdevice.h
> +++ b/include/linux/netdevice.h
> @@ -3345,6 +3345,7 @@ static inline void input_queue_tail_incr_save(struct softnet_data *sd,
> }
>
> DECLARE_PER_CPU_ALIGNED(struct softnet_data, softnet_data);
> +DECLARE_PER_CPU_ALIGNED(struct page_pool *, system_page_pool);
>
> static inline int dev_recursion_level(void)
> {
> diff --git a/net/core/dev.c b/net/core/dev.c
> index d8dd293a7a27..cdb916a647e7 100644
> --- a/net/core/dev.c
> +++ b/net/core/dev.c
> @@ -428,7 +428,7 @@ EXPORT_PER_CPU_SYMBOL(softnet_data);
> * PP consumers must pay attention to run APIs in the appropriate context
> * (e.g. NAPI context).
> */
> -static DEFINE_PER_CPU_ALIGNED(struct page_pool *, system_page_pool);
> +DEFINE_PER_CPU_ALIGNED(struct page_pool *, system_page_pool);
>
> #ifdef CONFIG_LOCKDEP
> /*
> @@ -11739,12 +11739,20 @@ static int net_page_pool_create(int cpuid)
> .pool_size = SYSTEM_PERCPU_PAGE_POOL_SIZE,
> .nid = NUMA_NO_NODE,
> };
> + struct xdp_mem_info info;
> struct page_pool *pp_ptr;
> + int err;
>
> pp_ptr = page_pool_create_percpu(&page_pool_params, cpuid);
> if (IS_ERR(pp_ptr))
> return -ENOMEM;
>
> + err = xdp_reg_mem_model(&info, MEM_TYPE_PAGE_POOL, pp_ptr);
> + if (err) {
> + page_pool_destroy(pp_ptr);
> + return err;
> + }
> +
> per_cpu(system_page_pool, cpuid) = pp_ptr;
> #endif
> return 0;
> @@ -11834,12 +11842,15 @@ static int __init net_dev_init(void)
> out:
> if (rc < 0) {
> for_each_possible_cpu(i) {
> + struct xdp_mem_info mem = { .type = MEM_TYPE_PAGE_POOL };
> struct page_pool *pp_ptr;
>
> pp_ptr = per_cpu(system_page_pool, i);
> if (!pp_ptr)
> continue;
>
> + mem.id = pp_ptr->xdp_mem_id;
> + xdp_unreg_mem_model(&mem);
Take it or leave it, a net_page_pool_destroy(int cpuid) would be
symmetric here.
> page_pool_destroy(pp_ptr);
> per_cpu(system_page_pool, i) = NULL;
> }
Acked-by: John Fastabend <john.fastabend@xxxxxxxxx>
