Re: [RFC PATCH 0/3] net: ethernet: ti: cpsw: Add XDP support

[Ivan Khoronzhuk]

On Thu, Apr 18, 2019 at 08:12:06AM +0200, Björn Töpel wrote:
> On Wed, 17 Apr 2019 at 19:51, Ivan Khoronzhuk
> <ivan.khoronzhuk@xxxxxxxxxx> wrote:
> > This patchset is RFC adding XDP support for TI cpsw driver that is
> > based on page_pool allocator. It was verified with af_xdp sockets
> > and on xdp drop. For XDP redirect to another interface it's under
> > verification, still not sure about all cases that should be verified.
> > Also regular tests with iperf2 were done in order to verify impact on
> > regular netstack performance, compared with base commit from
> > net-next/master: 432bc230700f86801cffa5e159e05dea6229f722
> >
> > It was verified with following configs enabled:
> > CONFIG_JIT=y
> > CONFIG_BPFILTER=y
> > CONFIG_BPF_SYSCALL=y
> > CONFIG_XDP_SOCKETS=y
> > CONFIG_BPF_EVENTS=y
> > CONFIG_HAVE_EBPF_JIT=y
> > CONFIG_BPF_JIT=y
> > CONFIG_CGROUP_BPF=y
> >
> > iperf2 UDP RX summary (packet size / Mbps):
> > +--------------------------------------------------------------+
> > | pkt_size/rate | 1024 | 1500 | 1470 |  64  | 128  | 512 | 256 |
> > |---------------+------+------+------+------+------+-----+-----|
> > | base commit   | 561  | 470  | 796  |  35  | 70.1 | 281 | 140 |
> > |---------------+------+------+------+------+------+-----+-----|
> > | XDP patched   | 563  | 455  | 808  |  35  | 70.2 | 282 | 141 |
> > +--------------------------------------------------------------+
> >
> > iperf2 UDP TX summary (packet size / Mbps):
> > +--------------------------------------------------------------+
> > | pkt_size/rate | 1024 | 1500 | 1470 |  64  | 128  | 512 | 256 |
> > |---------------+------+------+------+------+------+-----+-----|
> > | base commit   | 555  | 666  | 736  | 34.5 | 70.3 | 281 | 140 |
> > |---------------+------+------+------+------+------+-----+-----|
> > | XDP patched   | 558  | 696  | 759  | 35.2 | 69.2 | 279 | 140 |
> > +--------------------------------------------------------------+
> >
> > iperf2 TCP summary (window size / Mbps):
> > +------------------------------------------------------------+
> > | window size/rate |  16  |  32  |  64  |  128 |  8   | 256  |
> > |------------------+------+------+------+------+------+------|
> > | base commit      | 753  | 887  | 931  | 932  | 676  | 932  |
> > |------------------+------+------+------+------+------+------|
> > | XDP patched      | 823  | 888  | 932  | 933  | 669  | 933  |
> > +------------------------------------------------------------+
> >
> > For af_xdp socket type verification several generic changes should be added
> > that can be seen here (rough fixes, for samples related seems like last version
> > of samples is more integrated with libbpf api, so should be rebased,
> > witch I will send as RFC separately):
> > https://github.com/ikhorn/af_xdp_stuff/tree/af_xdp_armv7
>
> More XDP support, yay!
>
> As for mmap/AF_XDP on 32-bit systems; Instead of hacking the if_xdp.h,
> mmap2 should be used. Have a look at the libbpf code here [1]
I more bothering about this fast fix (not investigated deep enough):
https://github.com/ikhorn/af_xdp_stuff/commit/f77cd4faf95ad744bbf37d0ba81d0ec79c1b0d29

That's about when page_address(umem->pgs[i]) returns nothing.

> Björn
>
> [1] https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git/tree/tools/lib/bpf/xsk.c#n81
>
>
> > Ivan Khoronzhuk (3):
> >   net: ethernet: ti: davinci_cpdma: add dma mapped submit
> >   net: ethernet: ti: davinci_cpdma: return handler status
> >   net: ethernet: ti: cpsw: add XDP support
> >
> >  drivers/net/ethernet/ti/Kconfig         |   1 +
> >  drivers/net/ethernet/ti/cpsw.c          | 552 +++++++++++++++++++++---
> >  drivers/net/ethernet/ti/davinci_cpdma.c | 117 +++--
> >  drivers/net/ethernet/ti/davinci_cpdma.h |   6 +-
> >  drivers/net/ethernet/ti/davinci_emac.c  |  18 +-
> >  5 files changed, 591 insertions(+), 103 deletions(-)
> >
> > --
> > 2.17.1

--
Regards,
Ivan Khoronzhuk