Hi Saeed,
On Wed, Oct 16, 2019 at 03:50:22PM -0700, Jonathan Lemon wrote:
> From: Saeed Mahameed <sae...@mellanox.com>
>
> Add page_pool_update_nid() to be called from drivers when they detect
> numa node changes.
>
> It will do:
> 1) Flush the pool's page cache and ptr_ring.
> 2) Update page pool nid value to start allocating from the new numa
> node.
>
> Signed-off-by: Saeed Mahameed <sae...@mellanox.com>
> Signed-off-by: Jonathan Lemon <jonathan.le...@gmail.com>
> ---
> include/net/page_pool.h | 10 ++++++++++
> net/core/page_pool.c | 16 +++++++++++-----
> 2 files changed, 21 insertions(+), 5 deletions(-)
>
> diff --git a/include/net/page_pool.h b/include/net/page_pool.h
> index 2cbcdbdec254..fb13cf6055ff 100644
> --- a/include/net/page_pool.h
> +++ b/include/net/page_pool.h
> @@ -226,4 +226,14 @@ static inline bool page_pool_put(struct page_pool *pool)
> return refcount_dec_and_test(&pool->user_cnt);
> }
>
> +/* Only safe from napi context or when user guarantees it is thread safe */
> +void __page_pool_flush(struct page_pool *pool);
This should be called per packet right? Any noticeable impact on performance?
> +static inline void page_pool_update_nid(struct page_pool *pool, int new_nid)
> +{
> + if (unlikely(pool->p.nid != new_nid)) {
> + /* TODO: Add statistics/trace */
> + __page_pool_flush(pool);
> + pool->p.nid = new_nid;
> + }
> +}
> #endif /* _NET_PAGE_POOL_H */
> diff --git a/net/core/page_pool.c b/net/core/page_pool.c
> index 5bc65587f1c4..678cf85f273a 100644
> --- a/net/core/page_pool.c
> +++ b/net/core/page_pool.c
> @@ -373,16 +373,13 @@ void __page_pool_free(struct page_pool *pool)
> }
> EXPORT_SYMBOL(__page_pool_free);
>
> -/* Request to shutdown: release pages cached by page_pool, and check
> - * for in-flight pages
> - */
> -bool __page_pool_request_shutdown(struct page_pool *pool)
> +void __page_pool_flush(struct page_pool *pool)
> {
> struct page *page;
>
> /* Empty alloc cache, assume caller made sure this is
> * no-longer in use, and page_pool_alloc_pages() cannot be
> - * call concurrently.
> + * called concurrently.
> */
> while (pool->alloc.count) {
> page = pool->alloc.cache[--pool->alloc.count];
> @@ -393,6 +390,15 @@ bool __page_pool_request_shutdown(struct page_pool *pool)
> * be in-flight.
> */
> __page_pool_empty_ring(pool);
> +}
> +EXPORT_SYMBOL(__page_pool_flush);
A later patch removes this, do we actually need it here?
> +
> +/* Request to shutdown: release pages cached by page_pool, and check
> + * for in-flight pages
> + */
> +bool __page_pool_request_shutdown(struct page_pool *pool)
> +{
> + __page_pool_flush(pool);
>
> return __page_pool_safe_to_destroy(pool);
> }
> --
> 2.17.1
>
Thanks
/Ilias
