On Tue, 2007-07-03 at 09:09 -0400, jamal wrote: > On Mon, 2007-02-07 at 14:20 -0700, Matt Carlson wrote: > > > > > > Hi Jamal. I'll be testing your patch soon, > > much thanks. Please let me know if you need help while doing this. > What tools are you planning to test with? I have tested this patch > with pktgen on a dual opteron/tg3-buggy. > There is an outstanding issue in regards to clocksource - however the > batch does well regardless of the clock source.
I had planned on using netperf, but pktgen sounds like a more controlled environment. Thanks for the tip. > > but I wanted to point out a > > bug in the patch. The patch defines TG3_SKB_CB() as follows : > > > > #define TG3_SKB_CB(__skb) ((struct tg3_tx_cbdata *)&((__skb)->cb[0])) > > > > This definition will collide with the VLAN macros if TG3_VLAN_TAG_USED > > is set. vlan_tx_tag_get() is defined as : > > > > #define vlan_tx_tag_get(__skb) (VLAN_TX_SKB_CB(__skb)->vlan_tag) > > > > VLAN_TX_SKB_CB is defined as : > > > > #define VLAN_TX_SKB_CB(__skb) \ > > ((struct vlan_skb_tx_cookie *)&((__skb)->cb[0])) > > > > yikes. Thanks for catching that - I thought i had this pretty much > covered after scanning the source. So that bug exists on the e1000 as > well. > [It sounds very dangerous to me the way skb->cb is being used by the > vlan code (i.e requires human intervention/knowledge to catch it as an > issue). I had no freaking idea the vlan code was using it. Maybe a huge > comment somewhere on how these cbs are being used by drivers would help > or even a registration on startup to just make sure there is no conflict > at a layer (i have been meaning to do the later for years now). In any > case this is is a digression]. > > In the meantime, changing it to use byte 8 and above should do it? i.e. > #define TG3_SKB_CB(__skb) ((struct tg3_tx_cbdata *)&((__skb)->cb[8])) > > There are 48 bytes there on the skb-cb, so there should be plenty. Do you see any reason why we couldn't just add the VLAN code to the prep stage and simply overwrite that portion of the skb-cb? Our driver would just store its value in the base_flags member of tg3_tx_cbdata. > > Also, I think the count, max_per_txd, and nr_frags fields of the > > tg3_tx_cbdata struct are not needed. > > Yes, you are right. That was a result of the LinuxWay(tm) (aka cutnpaste > from the e1000 which needs them), Can you send me a patch for that and > TG3_SKB_CB? Once we iron out the skb-cb issue, sure. > > cheers, > jamal > > - To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
