Hi Stefan,
wt., 13 kwi 2021 o 11:56 Stefan Chulski <[email protected]> napisał(a):
>
> > > -----Original Message-----
> > > From: Russell King - ARM Linux admin <[email protected]>
> > > Sent: Tuesday, April 13, 2021 12:18 PM
> > > To: Stefan Chulski <[email protected]>
> > > Cc: [email protected]; [email protected];
> > > [email protected]; Nadav Haklai <[email protected]>; Yan
> > Markman
> > > <[email protected]>; [email protected];
> > [email protected];
> > > [email protected]; [email protected]; [email protected]; Liron Himi
> > > <[email protected]>; Dana Vardi <[email protected]>
> > > Subject: [EXT] Re: [PATCH net-next] net: mvpp2: Add parsing support
> > > for different IPv4 IHL values
> > >
> > > External Email
> > >
> > > ----------------------------------------------------------------------
> > > On Tue, Apr 13, 2021 at 11:45:31AM +0300, [email protected] wrote:
> > > > From: Stefan Chulski <[email protected]>
> > > >
> > > > Add parser entries for different IPv4 IHL values.
> > > > Each entry will set the L4 header offset according to the IPv4 IHL field.
> > > > L3 header offset will set during the parsing of the IPv4 protocol.
> > >
> > > What is the impact of this commit? Is something broken at the moment,
> > > if so what? Does this need to be backported to stable kernels?
> > >
> > > These are key questions, of which the former two should be covered in
> > > every commit message so that the reason for the change can be known.
> > > It's no good just describing what is being changed in the commit
> > > without also describing why the change is being made.
> > >
> > > Thanks.
> >
> > Due to missed parser support for IP header length > 20, RX IPv4 checksum
> > offload fail.
> >
> > Regards.
>
> Currently driver set skb->ip_summed = CHECKSUM_NONE and checksum done by software.
> So this just improve performance for packets with IP header length > 20.
> IMO we can keep it in net-next.
>
> Stefan.
Please update the commit message in v2 with the explanation.
Also - is there an easy way to test it? L3 forwarding with forced header length?
Thanks,
Marcin
> -----Original Message-----
> From: Marcin Wojtas <[email protected]>
> Sent: Tuesday, April 13, 2021 12:59 PM
> To: Stefan Chulski <[email protected]>
> Cc: Russell King - ARM Linux admin <[email protected]>;
> [email protected]; [email protected];
> [email protected]; Nadav Haklai <[email protected]>; Yan
> Markman <[email protected]>; [email protected];
> [email protected]; [email protected]; [email protected]; Liron Himi
> <[email protected]>; Dana Vardi <[email protected]>
> Subject: Re: [EXT] Re: [PATCH net-next] net: mvpp2: Add parsing support for
> different IPv4 IHL values
>
> Hi Stefan,
>
> wt., 13 kwi 2021 o 11:56 Stefan Chulski <[email protected]> napisał(a):
> >
> > > > -----Original Message-----
> > > > From: Russell King - ARM Linux admin <[email protected]>
> > > > Sent: Tuesday, April 13, 2021 12:18 PM
> > > > To: Stefan Chulski <[email protected]>
> > > > Cc: [email protected]; [email protected];
> > > > [email protected]; Nadav Haklai <[email protected]>; Yan
> > > Markman
> > > > <[email protected]>; [email protected];
> > > [email protected];
> > > > [email protected]; [email protected]; [email protected]; Liron Himi
> > > > <[email protected]>; Dana Vardi <[email protected]>
> > > > Subject: [EXT] Re: [PATCH net-next] net: mvpp2: Add parsing
> > > > support for different IPv4 IHL values
> > > >
> > > > External Email
> > > >
> > > > ------------------------------------------------------------------
> > > > ---- On Tue, Apr 13, 2021 at 11:45:31AM +0300, [email protected]
> > > > wrote:
> > > > > From: Stefan Chulski <[email protected]>
> > > > >
> > > > > Add parser entries for different IPv4 IHL values.
> > > > > Each entry will set the L4 header offset according to the IPv4 IHL field.
> > > > > L3 header offset will set during the parsing of the IPv4 protocol.
> > > >
> > > > What is the impact of this commit? Is something broken at the
> > > > moment, if so what? Does this need to be backported to stable
> kernels?
> > > >
> > > > These are key questions, of which the former two should be covered
> > > > in every commit message so that the reason for the change can be
> known.
> > > > It's no good just describing what is being changed in the commit
> > > > without also describing why the change is being made.
> > > >
> > > > Thanks.
> > >
> > > Due to missed parser support for IP header length > 20, RX IPv4
> > > checksum offload fail.
> > >
> > > Regards.
> >
> > Currently driver set skb->ip_summed = CHECKSUM_NONE and checksum
> done by software.
> > So this just improve performance for packets with IP header length > 20.
> > IMO we can keep it in net-next.
> >
> > Stefan.
>
> Please update the commit message in v2 with the explanation.
>
> Also - is there an easy way to test it? L3 forwarding with forced header
> length?
>
> Thanks,
> Marcin
I will wait for additional comments and resend it tomorrow.
We probably should see this in "perf top" in L3 forwarding. Less cycles consumed by Network stack checksum callback.
Regards.