[Intel-wired-lan] [PATCH v3 2/4] e1000e: Do not read icr in Other interrupt

[Brown, Aaron F]

> From: Intel-wired-lan [intel-wired-lan-bounces at lists.osuosl.org] on behalf of Benjamin Poirier [bpoirier at suse.com]
> Sent: Monday, November 09, 2015 3:50 PM
> To: Kirsher, Jeffrey T
> Cc: Frank Steiner; linux-kernel at vger.kernel.org; intel-wired-lan at lists.osuosl.org; netdev at vger.kernel.org
> Subject: [Intel-wired-lan] [PATCH v3 2/4] e1000e: Do not read icr in Other      interrupt
>
> removes the icr read in the other interrupt handler, uses eiac to
> autoclear the Other bit from icr and ims. This allows us to avoid
> interference with rx and tx interrupts in the Other interrupt handler.
>
> The information read from icr is not needed. IMS is configured such that
> the only interrupt cause that can trigger the Other interrupt is Link
> Status Change.
>
> Signed-off-by: Benjamin Poirier <bpoirier at suse.com>
>
> ---
> I noticed a 8-16% improvement in netperf rr tests after applying this
> patch. This is a little surprising since this patch touches the handling
> of Other interrupts, which do not occur during such a test. Some
> profiling was not very insightful but the improvement seems related to
> writing Other to EIAC.
> ---
>  drivers/net/ethernet/intel/e1000e/netdev.c | 22 +++++++---------------
>  1 file changed, 7 insertions(+), 15 deletions(-)

Tested-by: Aaron Brown <aaron.f.brown at intel.com>