Re: [PATCH 0/2] igb: drop stats due to OS cannot keep up

[Jeff Kirsher <jeffrey.t.kirsher@intel.com>]

On Thu, May 7, 2009 at 6:35 AM, Jesper Dangaard Brouer <hawk@comx.dk> wrote:
>
> The following patchset address "drop" stats counters in the igb
> driver (chips 82576 and 82575).  The drop stats addressed here
> are due to the OS cannot keep up.
>
> I have only tested it for the 82576 chip, as my (12 port) 82575
> chip based NIC from Hotlava Systems recently died in my testlab :-(((
>
> [First patch]
> Implements reading of the per queue drop stats.
> These stats only gets incremented if the DROP_EN bit it set (in
> the SRRCTL register for that queue, or QDE reg is set).
>
> [Second patch]
> Address the case where the DROP_EN it NOT set.  In
> this case a global register records the equivalent drop type. And
> aggregation of these two types of drops into the device net_stats.
>
> I strongly believe that these drops counters should be made
> available to sysadm's through the normal device stats.  These
> stats are essential when diagnosing server performance issues, as
> these stats are due to the OS cannot keep up. I strongly believe
> that it should be stored in the net_stats rx_fifo_errors counter,
> to indicate performance issues.
>
> --
> Med venlig hilsen / Best regards
>  Jesper Brouer
>  ComX Networks A/S
>  Linux Network developer
>  Cand. Scient Datalog / MSc.
>  Author of http://adsl-optimizer.dk
>  LinkedIn: http://www.linkedin.com/in/brouer
>

Jesper - I have pulled in your patches, and made the necessary
modifications based on Mitch's comments.  Right now, they are in
testing and I should be pushing them to Dave in the next couple of
days.

-- 
Cheers,
Jeff

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