From mboxrd@z Thu Jan  1 00:00:00 1970
From: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Subject: Re: [net-next 12/15] i40evf: Drop i40evf_fire_sw_int as it is prone
 to races
Date: Thu, 4 Jan 2018 12:31:41 +0300
Message-ID: <2d470a24-a79e-b0f4-3a91-5f2dd0be5da0@cogentembedded.com>
References: <20180103212222.17378-1-jeffrey.t.kirsher@intel.com>
 <20180103212222.17378-13-jeffrey.t.kirsher@intel.com>
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Cc: Alexander Duyck <alexander.h.duyck@intel.com>,
        netdev@vger.kernel.org, nhorman@redhat.com, sassmann@redhat.com,
        jogreene@redhat.com
To: Jeff Kirsher <jeffrey.t.kirsher@intel.com>, davem@davemloft.net
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Hello!

On 1/4/2018 12:22 AM, Jeff Kirsher wrote:

> From: Alexander Duyck <alexander.h.duyck@intel.com>
> 
> Having the interrupts firing while we are polling causes extra overhead and
> isn't needed for most systems out there. If an interrupt is lost us
> experiencing a 2s latency spike before recovering is still not acceptable
> and masks the issue. We are better off just identifying systems that lose
> interrupts and instead enable workarounds for those systems.
> 
> To that end I am dropping the code that was strobing the interrupts as
> there is a narrow window where having them enabled can actually cause
> race issues anyway where a few stray packets might get misses if the
> interrupt is re-enabled and fires before we call napi_complete.
> 
> Also replace one line where we were using bit 31 instead of the define
> for the bit to represent masking the interrupt enable bit.

    I'm not seeing this change...

> Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
> Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
> Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
[...]

MBR, Sergei