lkml.org 
[lkml]   [2019]   [Aug]   [23]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Date
SubjectRe: [PATCH net v3] ixgbe: fix double clean of tx descriptors with xdp
On Thu, Aug 22, 2019 at 11:10 PM Björn Töpel <bjorn.topel@intel.com> wrote:
>
> On 2019-08-22 19:32, William Tu wrote:
> > On Thu, Aug 22, 2019 at 10:21 AM Alexander Duyck
> > <alexander.duyck@gmail.com> wrote:
> >>
> >> On Thu, Aug 22, 2019 at 10:12 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 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@samsung.com>
> >>> ---
> >>>
> >>> 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@linux.intel.com>
> >
> > Thanks.
> >
> > Tested-by: William Tu <u9012063@gmail.com>
> >
>
> Will, thanks for testing! For this patch, did you notice any performance
> degradation?
>

No noticeable performance degradation seen this time.
Thanks,
William

\
 
 \ /
  Last update: 2019-08-23 15:21    [W:0.154 / U:0.036 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site