[RFC PATCH v2 11/21] core/skbuff: add page recycling logic for netgpu pages
From: Jonathan Lemon <hidden>
Date: 2020-07-27 22:45:01
Subsystem:
networking [general], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
From: Jonathan Lemon <redacted> netgpu pages will always have a refcount of at least one (held by the netgpu module). If the skb is marked as containing netgpu ZC pages, recycle them back to netgpu. Signed-off-by: Jonathan Lemon <redacted> --- net/core/skbuff.c | 32 ++++++++++++++++++++++++++++++-- 1 file changed, 30 insertions(+), 2 deletions(-)
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 1422b99b7090..50dbb7ce1965 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c@@ -591,6 +591,27 @@ static void skb_free_head(struct sk_buff *skb) kfree(head); } +#if IS_ENABLED(CONFIG_NETGPU) +static void skb_netgpu_unref(struct skb_shared_info *shinfo) +{ + struct netgpu_ifq *ifq = shinfo->destructor_arg; + struct page *page; + int i; + + /* pages attached for skbs for TX shouldn't come here, since + * the skb is not marked as "zc_netgpu". (only RX skbs have this). + * dummy page does come here, but always has elevated refc. + * + * Undelivered zc skb's will arrive at this point. + */ + for (i = 0; i < shinfo->nr_frags; i++) { + page = skb_frag_page(&shinfo->frags[i]); + if (page && page_ref_dec_return(page) <= 2) + netgpu_put_page(ifq, page, false); + } +} +#endif + static void skb_release_data(struct sk_buff *skb) { struct skb_shared_info *shinfo = skb_shinfo(skb);
@@ -601,8 +622,15 @@ static void skb_release_data(struct sk_buff *skb) &shinfo->dataref)) return; - for (i = 0; i < shinfo->nr_frags; i++) - __skb_frag_unref(&shinfo->frags[i]); +#if IS_ENABLED(CONFIG_NETGPU) + if (skb->zc_netgpu && shinfo->nr_frags) { + skb_netgpu_unref(shinfo); + } else +#endif + { + for (i = 0; i < shinfo->nr_frags; i++) + __skb_frag_unref(&shinfo->frags[i]); + } if (shinfo->frag_list) kfree_skb_list(shinfo->frag_list);
--
2.24.1