> From: netdev-ow...@vger.kernel.org [mailto:netdev-ow...@vger.kernel.org] > On Behalf Of Shota Suzuki > Sent: Tuesday, June 30, 2015 5:26 PM > To: Kirsher, Jeffrey T; Brandeburg, Jesse; Nelson, Shannon; Wyborny, > Carolyn; Skidmore, Donald C; Vick, Matthew; Ronciak, John; Williams, Mitch > A; intel-wired-...@lists.osuosl.org; net...@vger.kernel.org; linux- > ker...@vger.kernel.org > Cc: Shota Suzuki > Subject: [PATCH net] igb: Fix oops caused by missing queue pairing > > When initializing igb driver (e.g. 82576, I350), IGB_FLAG_QUEUE_PAIRS is > set if adapter->rss_queues exceeds half of max_rss_queues in > igb_init_queue_configuration(). > On the other hand, IGB_FLAG_QUEUE_PAIRS is not set even if the number of > queues exceeds half of max_combined in igb_set_channels() when changing > the number of queues by "ethtool -L". > In this case, if numvecs is larger than MAX_MSIX_ENTRIES (10), the size > of adapter->msix_entries[], an overflow can occur in > igb_set_interrupt_capability(), which in turn leads to an oops. > > Fix this problem as follows: > - When changing the number of queues by "ethtool -L", set > IGB_FLAG_QUEUE_PAIRS in the same way as initializing igb driver. > - When increasing the size of q_vector, reallocate it appropriately. > (With IGB_FLAG_QUEUE_PAIRS set, the size of q_vector gets larger.) > > Another possible way to fix this problem is to cap the queues at its > initial number, which is the number of the initial online cpus. But this > is not the optimal way because we cannnot increase queues when another > cpu becomes online. > > Note that before commit cd14ef54d25b ("igb: Change to use statically > allocated array for MSIx entries"), this problem did not cause oops > but just made the number of queues become 1 because of entering msi_only > mode in igb_set_interrupt_capability(). > > Fixes: 907b7835799f ("igb: Add ethtool support to configure number of > channels") > Signed-off-by: Shota Suzuki <suzuki_shota...@lab.ntt.co.jp> > --- > Although we might be able to additionally unset IGB_FLAG_QUEUE_PAIRS > when it is not needed, this patch doesn't change existing behaviour > because such a change is not a bug fix. > > drivers/net/ethernet/intel/igb/igb.h | 1 + > drivers/net/ethernet/intel/igb/igb_ethtool.c | 5 ++++- > drivers/net/ethernet/intel/igb/igb_main.c | 16 ++++++++++++++-- > 3 files changed, 19 insertions(+), 3 deletions(-)
Tested-by: Aaron Brown <aaron.f.br...@intel.com> -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
