Hi, On Wed, Mar 30, 2011 at 9:09 PM, swathi suresh <swathi.suresh07@xxxxxxxxx> wrote: > > On Wed, Mar 30, 2011 at 10:42 PM, sk.syed2 <sk.syed2@xxxxxxxxx> wrote: >> >> > struct page *page = virt_to_page(skb->data); >> > int offset = (unsigned long) skb->data - (unsigned long) >> > page_address(page); >> > skb_add_rx_frag(master_skb, skb_shinfo(master_skb)->nr_frags, page, >> > offset, >> > skb->len) >> > . >> > . >> > is this the right way to do ? >> This will work if skb->len < PAGE_SIZE, otherwise it means it spans >> more than a page and you need to do skb_add_rx_frag for each PAGE_SIZE >> data present. Refer to Understanding Linux network internals By >> Christian Benvenuti p 488/489. > > Thanks Syed, skb->len is always smaller then PAGE_SIZE because i have set > the mtu size as 1500 from my network driver. > But am facing kernel panic, if i just the moment the driver call > dev_queue_xmit, so i guess this may not be right way to get > the page. It isn't sufficient for skb->len to just be less than PAGE_SIZE. offset + skb->len also has to be less than PAGE_SIZE, otherwise your data will cross into a different page. -- Dave Hylands Shuswap, BC, Canada http://www.davehylands.com _______________________________________________ Kernelnewbies mailing list Kernelnewbies@xxxxxxxxxxxxxxxxx http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
