On 2019-08-22 19:32, William Tu wrote:
On Thu, Aug 22, 2019 at 10:21 AM Alexander Duyck
<alexander.duyck@xxxxxxxxx> wrote:
On Thu, Aug 22, 2019 at 10:12 AM Ilya Maximets <i.maximets@xxxxxxxxxxx> wrote:
Tx code doesn't clear the descriptors' status after cleaning.
So, if the budget is larger than number of used elems in a ring, some
descriptors will be accounted twice and xsk_umem_complete_tx will move
prod_tail far beyond the prod_head breaking the completion queue ring.
Fix that by limiting the number of descriptors to clean by the number
of used descriptors in the tx ring.
'ixgbe_clean_xdp_tx_irq()' function refactored to look more like
'ixgbe_xsk_clean_tx_ring()' since we're allowed to directly use
'next_to_clean' and 'next_to_use' indexes.
Fixes: 8221c5eba8c1 ("ixgbe: add AF_XDP zero-copy Tx support")
Signed-off-by: Ilya Maximets <i.maximets@xxxxxxxxxxx>
---
Version 3:
* Reverted some refactoring made for v2.
* Eliminated 'budget' for tx clean.
* prefetch returned.
Version 2:
* 'ixgbe_clean_xdp_tx_irq()' refactored to look more like
'ixgbe_xsk_clean_tx_ring()'.
drivers/net/ethernet/intel/ixgbe/ixgbe_xsk.c | 29 ++++++++------------
1 file changed, 11 insertions(+), 18 deletions(-)
Thanks for addressing my concerns.
Acked-by: Alexander Duyck <alexander.h.duyck@xxxxxxxxxxxxxxx>
Thanks.
Tested-by: William Tu <u9012063@xxxxxxxxx>
Will, thanks for testing! For this patch, did you notice any performance
degradation?
Cheers,
Björn
