On Sun, 24 Mar 2019 07:58:34 +0100
Felix Fietkau <n...@nbd.name> wrote:
> Since we're freeing multiple skbs, we might as well use bulk free to save a
> few cycles. Use the same conditions for bulk free as in napi_consume_skb.
>
> Signed-off-by: Felix Fietkau <n...@nbd.name>
Thanks for working on this, it's been on my todo list for a very long
time. I just discussed this with Florian at NetDevconf.
> ---
> net/core/skbuff.c | 35 +++++++++++++++++++++++++++++++----
> 1 file changed, 31 insertions(+), 4 deletions(-)
>
> diff --git a/net/core/skbuff.c b/net/core/skbuff.c
> index 2415d9cb9b89..ec030ab7f1e7 100644
> --- a/net/core/skbuff.c
> +++ b/net/core/skbuff.c
> @@ -666,12 +666,39 @@ EXPORT_SYMBOL(kfree_skb);
>
> void kfree_skb_list(struct sk_buff *segs)
> {
> - while (segs) {
> - struct sk_buff *next = segs->next;
> + struct sk_buff *next = segs;
> + void *skbs[16];
> + int n_skbs = 0;
>
> - kfree_skb(segs);
> - segs = next;
> + while ((segs = next) != NULL) {
> + next = segs->next;
> +
> + if (!skb_unref(segs))
> + continue;
> +
> + if (segs->fclone != SKB_FCLONE_UNAVAILABLE ||
> + n_skbs >= ARRAY_SIZE(skbs)) {
You could call kmem_cache_free_bulk() here and reset n_skbs=0.
> + kfree_skb(segs);
> + continue;
> + }
> +
> + trace_kfree_skb(segs, __builtin_return_address(0));
> +
> + /* drop skb->head and call any destructors for packet */
> + skb_release_all(segs);
> +
> +#ifdef CONFIG_SLUB
> + /* SLUB writes into objects when freeing */
> + prefetchw(segs);
> +#endif
> +
> + skbs[n_skbs++] = segs;
> }
> +
> + if (!n_skbs)
> + return;
> +
> + kmem_cache_free_bulk(skbuff_head_cache, n_skbs, skbs);
> }
> EXPORT_SYMBOL(kfree_skb_list);
>
--
Best regards,
Jesper Dangaard Brouer
MSc.CS, Principal Kernel Engineer at Red Hat
LinkedIn: http://www.linkedin.com/in/brouer
