[Xen-devel] "tcp: refine TSO autosizing" causes performance regression on Xen

[George Dunlap]

On Thu, Apr 16, 2015 at 1:42 PM, Eric Dumazet <eric.dumazet at gmail.com> wrote:
> On Thu, 2015-04-16 at 11:01 +0100, George Dunlap wrote:
>
>> He suggested that after he'd been prodded by 4 more e-mails in which two
>> of us guessed what he was trying to get at.  That's what I was
>> complaining about.
>
> My big complain is that I suggested to test to double the sysctl, which
> gave good results.
>
> Then you provided a patch using a 8x factor. How does that sound ?
>
> Next time I ask a raise, I should try a 8x factor as well, who knows,
> it might be accepted.

I see.  I chose the value that Stefano had determined had completely
eliminated the overhead.  Doubling the value reduces the overhead to
8%, which should be fine for a short-term fix while we git a proper
mid/long-term fix.

 -George