RE: [Intel-wired-lan] [PATCH v7] ixgbe: let the xdpdrv work with more than 64 cpus

[Penigalapati, Sandeep]

>-----Original Message-----
>From: Intel-wired-lan <intel-wired-lan-bounces@xxxxxxxxxx> On Behalf Of
>kerneljasonxing@xxxxxxxxx
>Sent: Wednesday, September 1, 2021 3:42 PM
>To: Brandeburg, Jesse <jesse.brandeburg@xxxxxxxxx>; Nguyen, Anthony L
><anthony.l.nguyen@xxxxxxxxx>; davem@xxxxxxxxxxxxx; kuba@xxxxxxxxxx;
>ast@xxxxxxxxxx; daniel@xxxxxxxxxxxxx; hawk@xxxxxxxxxx;
>john.fastabend@xxxxxxxxx; andrii@xxxxxxxxxx; kafai@xxxxxx;
>songliubraving@xxxxxx; yhs@xxxxxx; kpsingh@xxxxxxxxxx
>Cc: Shujin Li <lishujin@xxxxxxxxxxxx>; Jason Xing
><xingwanli@xxxxxxxxxxxx>; kerneljasonxing@xxxxxxxxx;
>netdev@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; intel-wired-
>lan@xxxxxxxxxxxxxxxx; bpf@xxxxxxxxxxxxxxx
>Subject: [Intel-wired-lan] [PATCH v7] ixgbe: let the xdpdrv work with more
>than 64 cpus
>
>From: Jason Xing <xingwanli@xxxxxxxxxxxx>
>
>Originally, ixgbe driver doesn't allow the mounting of xdpdrv if the server is
>equipped with more than 64 cpus online. So it turns out that the loading of
>xdpdrv causes the "NOMEM" failure.
>
>Actually, we can adjust the algorithm and then make it work through mapping
>the current cpu to some xdp ring with the protect of @tx_lock.
>
>Here're some numbers before/after applying this patch with xdp-example
>loaded on the eth0X:
>
>As client (tx path):
>                     Before    After
>TCP_STREAM send-64   734.14    714.20
>TCP_STREAM send-128  1401.91   1395.05
>TCP_STREAM send-512  5311.67   5292.84
>TCP_STREAM send-1k   9277.40   9356.22 (not stable)
>TCP_RR     send-1    22559.75  21844.22
>TCP_RR     send-128  23169.54  22725.13
>TCP_RR     send-512  21670.91  21412.56
>
>As server (rx path):
>                     Before    After
>TCP_STREAM send-64   1416.49   1383.12
>TCP_STREAM send-128  3141.49   3055.50
>TCP_STREAM send-512  9488.73   9487.44
>TCP_STREAM send-1k   9491.17   9356.22 (not stable)
>TCP_RR     send-1    23617.74  23601.60
>...
>
>Notice: the TCP_RR mode is unstable as the official document explaines.
>
>I tested many times with different parameters combined through netperf.
>Though the result is not that accurate, I cannot see much influence on this
>patch. The static key is places on the hot path, but it actually shouldn't cause a
>huge regression theoretically.
>
>Fixes: 33fdc82f08 ("ixgbe: add support for XDP_TX action")
>Reported-by: kernel test robot <lkp@xxxxxxxxx>
>Co-developed-by: Shujin Li <lishujin@xxxxxxxxxxxx>
>Signed-off-by: Shujin Li <lishujin@xxxxxxxxxxxx>
>Signed-off-by: Jason Xing <xingwanli@xxxxxxxxxxxx>
>---
>v7:
>- Factorized to a single spin_lock/unlock in ixgbe_xdp_xmit() (Eric)
>- Handle other parts of lock/unlock in ixgbe_run_xdp()/_zc() (Jason)
>
>v6:
>- Move the declaration of static-key to the proper position (Test Robot)
>- Add reported-by tag (Jason)
>- Add more detailed performance test results (Jason)
>
>v5:
>- Change back to nr_cpu_ids (Eric)
>
>v4:
>- Update the wrong commit messages. (Jason)
>
>v3:
>- Change nr_cpu_ids to num_online_cpus() (Maciej)
>- Rename MAX_XDP_QUEUES to IXGBE_MAX_XDP_QS (Maciej)
>- Rename ixgbe_determine_xdp_cpu() to ixgbe_determine_xdp_q_idx()
>(Maciej)
>- Wrap ixgbe_xdp_ring_update_tail() with lock into one function (Maciej)
>
>v2:
>- Adjust cpu id in ixgbe_xdp_xmit(). (Jesper)
>- Add a fallback path. (Maciej)
>- Adjust other parts related to xdp ring.
>---
> drivers/net/ethernet/intel/ixgbe/ixgbe.h           | 23 +++++++++-
> drivers/net/ethernet/intel/ixgbe/ixgbe_lib.c       |  9 +++-
> drivers/net/ethernet/intel/ixgbe/ixgbe_main.c      | 50 ++++++++++++++++-----
>-
> .../net/ethernet/intel/ixgbe/ixgbe_txrx_common.h   |  3 +-
> drivers/net/ethernet/intel/ixgbe/ixgbe_xsk.c       | 16 ++++---
> 5 files changed, 77 insertions(+), 24 deletions(-)
>
Tested-by: Sandeep Penigalapati <sandeep.penigalapati@xxxxxxxxx>