Message ID | 4A2925B7.6050800@gmail.com |
---|---|
State | Accepted, archived |
Delegated to: | David Miller |
Headers | show |
From: Eric Dumazet <eric.dumazet@gmail.com> Date: Fri, 05 Jun 2009 16:03:35 +0200 > Get rid of num_dma_maps in struct skb_shared_info, as it seems unused. > > Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> It's going to be used when architectures implement optimized versions of skb_dma_map(), which can thus virtually map page vectors via IOMMU's and thus the resulting number of DMA address/length pairs will be smaller than (num_frags + 1) Similarly to how dma_map_sg() works. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
From: David Miller <davem@davemloft.net> Date: Fri, 05 Jun 2009 18:09:49 -0700 (PDT) > From: Eric Dumazet <eric.dumazet@gmail.com> > Date: Fri, 05 Jun 2009 16:03:35 +0200 > >> Get rid of num_dma_maps in struct skb_shared_info, as it seems unused. >> >> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> > > It's going to be used when architectures implement optimized > versions of skb_dma_map(), which can thus virtually map > page vectors via IOMMU's and thus the resulting number of > DMA address/length pairs will be smaller than (num_frags + 1) > > Similarly to how dma_map_sg() works. But we aren't doing that yet and I have no idea when I'll get to it, so I've applied your patch for now, thanks! -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 7305da9..7485058 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -194,9 +194,6 @@ struct skb_shared_info { unsigned short gso_type; __be32 ip6_frag_id; union skb_shared_tx tx_flags; -#ifdef CONFIG_HAS_DMA - unsigned int num_dma_maps; -#endif struct sk_buff *frag_list; struct skb_shared_hwtstamps hwtstamps; skb_frag_t frags[MAX_SKB_FRAGS]; diff --git a/net/core/skb_dma_map.c b/net/core/skb_dma_map.c index 8623492..7adb623 100644 --- a/net/core/skb_dma_map.c +++ b/net/core/skb_dma_map.c @@ -30,7 +30,6 @@ int skb_dma_map(struct device *dev, struct sk_buff *skb, goto unwind; sp->dma_maps[i + 1] = map; } - sp->num_dma_maps = i + 1; return 0;
Get rid of num_dma_maps in struct skb_shared_info, as it seems unused. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> --- include/linux/skbuff.h | 3 --- net/core/skb_dma_map.c | 1 - 2 files changed, 4 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html