Re: [PATCH RFC 1/6] skbuff: support per-page destructors in copy_ubufs
From: Ian Campbell <hidden>
Date: 2012-05-11 09:00:04
Subsystem:
networking [general], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
On Thu, 2012-05-10 at 19:42 +0100, Michael S. Tsirkin wrote:
On Thu, May 10, 2012 at 06:46:17PM +0100, Ian Campbell wrote:quoted
On Mon, 2012-05-07 at 14:54 +0100, Michael S. Tsirkin wrote:So the below on top then. I pushed these on top of my zerocopy branch - can you confirm pls?
I added these to my test branch: 93772fea6cd66616912101b9e0144dfed645d8fe fix per page destructors in copy ubufs d72b7ab15f944c5df5f28cce7b5c9a0bca61ff6d clear destructor arg when set zerocopy I think you also need, as part of the second one:
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index af2d10e..40ca43e 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h@@ -1744,6 +1744,7 @@ static inline void skb_copy_frag_destructor(struct sk_buff *to, { skb_shinfo(to)->tx_flags |= skb_shinfo(from)->tx_flags & SKBTX_DEV_ZEROCOPY; + skb_shinfo(to)->destructor_arg = NULL; } /**
I'm seeing copy_ubufs called in my remote NFS test, which I don't think I expected -- I'll investigate why this is happening today. Ian.
quoted hunk ↗ jump to hunk
---diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 930a50e..e52bc8d 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h@@ -1270,8 +1270,10 @@ static inline void skb_frag_set_destructor(struct sk_buff *skb, int i, { skb_frag_t *frag = &skb_shinfo(skb)->frags[i]; frag->page.destructor = destroy; - if (destroy) + if (destroy) { skb_shinfo(skb)->tx_flags |= SKBTX_DEV_ZEROCOPY; + skb_shinfo(skb)->destructor_arg = NULL; + } } /**diff --git a/net/core/skbuff.c b/net/core/skbuff.c index b7fc47e..453f621 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c@@ -753,12 +753,11 @@ int skb_copy_ubufs(struct sk_buff *skb, gfp_t gfp_mask) uarg->callback(uarg); /* skb frags point to kernel buffers */ - for (i = skb_shinfo(skb)->nr_frags; i > 0; i--) { + for (i = skb_shinfo(skb)->nr_frags - 1; i >= 0; i--) { skb_frag_t *f = &skb_shinfo(skb)->frags[i]; if (unlikely((!uarg && !f->page.destructor))) continue; - __skb_fill_page_desc(skb, i-1, head, 0, - skb_shinfo(skb)->frags[i - 1].size); + __skb_fill_page_desc(skb, i, head, 0, f->size); head = (struct page *)head->private; }