Re: [PATCHv2] ixgbe: Re-enable relaxed ordering as part of init/restart sequence for non-DCA config

From: Jeff Kirsher
Date: Fri Jan 16 2015 - 09:46:04 EST


On Wed, 2015-01-14 at 20:03 -0500, Sowmini Varadhan wrote:
> Relaxed ordering is disabled by default at driver initialization
> and re-enabled when DCA is used. The reason it is disabled was
> due to an issue on some chipsets (see comments in
> ixgbe_update_tx_dca()).
> But when DCA is not used, RO needs to be re-enabled, else we have
> a serialization bottleneck on platforms like SPARC.
>
> This patch eliminates the bottleneck for ixgbe when DCA is not
> configured.
>
> Signed-off-by: Sowmini Varadhan <sowmini.varadhan@xxxxxxxxxx>
> Cc: Emil Tantilov <emil.s.tantilov@xxxxxxxxx>
>
> ---
> v2: incoroporate comments from Emil Tantilov
>
> drivers/net/ethernet/intel/ixgbe/ixgbe_82598.c | 23
> +++++++++++++++++++++++
> drivers/net/ethernet/intel/ixgbe/ixgbe_common.c | 20
> ++++++++++++++++++++
> drivers/net/ethernet/intel/ixgbe/ixgbe_common.h | 1 +
> drivers/net/ethernet/intel/ixgbe/ixgbe_main.c | 11 +++++++++++
> drivers/net/ethernet/intel/ixgbe/ixgbe_type.h | 1 +
> drivers/net/ethernet/intel/ixgbe/ixgbe_x540.c | 1 +
> 6 files changed, 57 insertions(+), 0 deletions(-)

Thanks Sowmini, I have added your patch to my queue.

I know that Emil and others are looking into whether we can do this for
all ixgbe silicon, so we may have a follow-on patch to the work you have
done already to enable this for all devices.

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