On Wed, Apr 22, 2015 at 10:52 AM, Jesse Gross <je...@nicira.com> wrote: > On Wed, Apr 22, 2015 at 10:03 AM, Pravin Shelar <pshe...@nicira.com> wrote: >> On Mon, Apr 20, 2015 at 9:54 PM, Jesse Gross <je...@nicira.com> wrote: >>> On Mon, Apr 20, 2015 at 7:33 PM, Pravin Shelar <pshe...@nicira.com> wrote: >>>> On Mon, Apr 20, 2015 at 5:56 PM, Jesse Gross <je...@nicira.com> wrote: >>>>> On Mon, Apr 20, 2015 at 3:54 PM, Pravin Shelar <pshe...@nicira.com> wrote: >>>>>> On Mon, Apr 20, 2015 at 3:36 PM, Jesse Gross <je...@nicira.com> wrote: >>>>>>> On Mon, Apr 20, 2015 at 1:29 PM, Pravin B Shelar <pshe...@nicira.com> >>>>>>> wrote: >>>>>>>> diff --git a/datapath/linux/compat/stt.c b/datapath/linux/compat/stt.c >>>>>>>> new file mode 100644 >>>>>>>> index 0000000..209bf1a >>>>>>>> --- /dev/null >>>>>>>> +++ b/datapath/linux/compat/stt.c >>>>>>>> +static void update_headers(struct sk_buff *skb, bool head, >>>>>>>> + unsigned int l4_offset, unsigned int >>>>>>>> hdr_len, >>>>>>>> + bool ipv4, u32 tcp_seq) >>>>>>> [...] >>>>>>>> + skb->truesize = SKB_TRUESIZE(skb_end_offset(skb)) + >>>>>>>> skb->data_len; >>>>>>>> +} >>>>>>> >>>>>>> I wonder if there are any possible edge cases with resetting truesize >>>>>>> where the packet is still in someone's transmit queue (such as if we >>>>>>> are looping back packet). Do we need to orphan it first? >>>>>>> >>>>>> ok, I will orphan it in update_headers. >>>>> >>>>> Just to clarify - I was mostly just thinking aloud on orphaning it. >>>>> I'm not totally sure if that is the right thing to do or if this is >>>>> the right place to do it. I'm not sure what the conceptual >>>>> justification would be for it and it could potentially result in the >>>>> sender's buffers not being properly limited. Perhaps not resetting the >>>>> truesize is the right thing too... >>>>> >>>> I have seen warning msg if we do no keep truesize update along with >>>> changes to skb. >>> >>> Hmm, interesting, what is the warning? I don't think that I have seen >>> that before. >> >> Actually skb_try_coalesce() is updating it correctly. so there no need >> to change truesize anymore. I will update patch accordingly. > > That's much nicer. I also checked and other receive side code (like > TCP input) doesn't worry about the case where a local sender may still > be accounting for the packet since any type of loopback device does > call skb_orphan() in some form. > > I hate to bring this up but what about on transmit? In cases where we > merge or split skbs (skb_try_coalesce() and normalize_frag_list() > respectively) we do track the truesize for correctly for the result > but the individual pieces might not have the right destructors or > might not have their truesize updated for the destructor they do have.
How about about we update merged skb stats (len, data_len, truesize) according to *delta_truesize we get from skb_try_coalesce() and then free the skb? _______________________________________________ dev mailing list dev@openvswitch.org http://openvswitch.org/mailman/listinfo/dev
