Messages in this thread | | | From | William Tu <> | Date | Thu, 22 Aug 2019 09:23:46 -0700 | Subject | Re: [PATCH net v2] ixgbe: fix double clean of tx descriptors with xdp |
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On Thu, Aug 22, 2019 at 5:30 AM Ilya Maximets <i.maximets@samsung.com> 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 comletion queue ring.
s/comletion/completion/
> > 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 don't need most of the > complications implemented in the regular 'ixgbe_clean_tx_irq()' > and 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@samsung.com> > ---
Tested-by: William Tu <u9012063@gmail.com>
Instead of measuring tx performance at the tx machine, I measured the TX performance at the other side (the traffic generating machine). This time it is more consistent and showing not much difference with (5.9Mpps) and without this patch (6.1Mpps).
> > 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 | 34 ++++++++------------ > 1 file changed, 13 insertions(+), 21 deletions(-) >
<snip>
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