Messages in this thread | | | From | William Tu <> | Date | Fri, 23 Aug 2019 06:19:49 -0700 | Subject | Re: [PATCH net v3] ixgbe: fix double clean of tx descriptors with xdp |
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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
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