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From:   Haiyang Zhang <haiyangz@microsoft.com>
To:     Stephen Hemminger <stephen@networkplumber.org>
CC:     Yuchung Cheng <ycheng@google.com>,
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Subject: RE: [PATCH net-next,v2] tcp: Set pingpong threshold via sysctl
Thread-Topic: [PATCH net-next,v2] tcp: Set pingpong threshold via sysctl
Thread-Index: AQHZ+69YvRb6AGIE90C77PuAO4ZvjLBDlskAgAADo4CAAAYaoIAAOcYAgAET4jA=
Date:   Wed, 11 Oct 2023 18:49:22 +0000
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> -----Original Message-----
> From: Stephen Hemminger <stephen@networkplumber.org>
> Sent: Tuesday, October 10, 2023 10:16 PM
> To: Haiyang Zhang <haiyangz@microsoft.com>
> Cc: Yuchung Cheng <ycheng@google.com>; linux-hyperv@vger.kernel.org;
> netdev@vger.kernel.org; KY Srinivasan <kys@microsoft.com>;
> davem@davemloft.net; edumazet@google.com; kuba@kernel.org;
> pabeni@redhat.com; corbet@lwn.net; dsahern@kernel.org;
> ncardwell@google.com; kuniyu@amazon.com; morleyd@google.com;
> mfreemon@cloudflare.com; mubashirq@google.com; linux-
> doc@vger.kernel.org; weiwan@google.com; linux-kernel@vger.kernel.org
> Subject: Re: [PATCH net-next,v2] tcp: Set pingpong threshold via sysctl
>=20
> On Tue, 10 Oct 2023 22:59:49 +0000
> Haiyang Zhang <haiyangz@microsoft.com> wrote:
>=20
> > > > If this an application specific optimization, it should be in a soc=
ket option
> > > > rather than system wide via sysctl.
> > > Initially I had a similar comment but later decided a sysctl could
> > > still be useful if
> > > 1) the entire host (e.g. virtual machine) is dedicated to that applic=
ation
> > > 2) that application is difficult to change
> >
> > Yes, the customer actually wants a global setting. But as suggested by =
Neal,
> > I changed it to be per-namespace to match other TCP tunables.
>=20
> Like congestion control choice, it could be both a sysctl and a socket op=
tion.
> The reason is that delayed ack is already controlled by socket options.

I see. I am updating the doc and variable location for this sysctl tunable =
patch=20
as suggested by the reviewers, and will resubmit it.

I will also work on a separate patch for the setsockopt option.

Thanks,
- Haiyang