From: Enke Chen <enkechen2020@gmail.com>
To: Neal Cardwell <ncardwell@google.com>
Cc: Jakub Kicinski <kuba@kernel.org>,
Eric Dumazet <edumazet@google.com>,
"David S. Miller" <davem@davemloft.net>,
Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>,
Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>,
Netdev <netdev@vger.kernel.org>,
LKML <linux-kernel@vger.kernel.org>,
enkechen2020@gmail.com
Subject: Re: [PATCH net] tcp: make TCP_USER_TIMEOUT accurate for zero window probes
Date: Sat, 23 Jan 2021 16:56:43 -0800 [thread overview]
Message-ID: <20210124005643.GH129261@localhost.localdomain> (raw)
In-Reply-To: <CADVnQy=zzrFf=sF+oMwjm+Pp-VJ-veC93poVp0XUPFKRoiGRUQ@mail.gmail.com>
Hi, Neal:
What you described is more accurate, and is correct.
Thanks. -- Enke
On Sat, Jan 23, 2021 at 07:19:13PM -0500, Neal Cardwell wrote:
> On Fri, Jan 22, 2021 at 9:45 PM Enke Chen <enkechen2020@gmail.com> wrote:
> >
> > Hi, Jakub:
> >
> > On Fri, Jan 22, 2021 at 06:34:24PM -0800, Jakub Kicinski wrote:
> > > On Fri, 22 Jan 2021 18:28:23 -0800 Enke Chen wrote:
> > > > Hi, Jakub:
> > > >
> > > > In terms of backporting, this patch should go together with:
> > > >
> > > > 9d9b1ee0b2d1 tcp: fix TCP_USER_TIMEOUT with zero window
> > >
> > > As in it:
> > >
> > > Fixes: 9d9b1ee0b2d1 tcp: fix TCP_USER_TIMEOUT with zero window
> > >
> > > or does it further fix the same issue, so:
> > >
> > > Fixes: 9721e709fa68 ("tcp: simplify window probe aborting on USER_TIMEOUT")
> > >
> > > ?
> >
> > Let me clarify:
> >
> > 1) 9d9b1ee0b2d1 tcp: fix TCP_USER_TIMEOUT with zero window
> >
> > fixes the bug and makes it work.
> >
> > 2) The current patch makes the TCP_USER_TIMEOUT accurate for 0-window probes.
> > It's independent.
>
> Patch (2) ("tcp: make TCP_USER_TIMEOUT accurate for zero window
> probes") is indeed conceptually independent of (1) but its
> implementation depends on the icsk_probes_tstamp field defined in (1),
> so AFAICT (2) cannot be backported further back than (1).
>
> Patch (1) fixes a bug in 5.1:
> Fixes: 9721e709fa68 ("tcp: simplify window probe aborting on USER_TIMEOUT")
>
> So probably (1) and (2) should be backported as a pair, and only back
> as far as 5.1. (That covers 2 LTS kernels, 5.4 and 5.10, so hopefully
> that is good enough.)
>
> neal
next prev parent reply other threads:[~2021-01-24 0:57 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-22 19:13 [PATCH net] tcp: make TCP_USER_TIMEOUT accurate for zero window probes Enke Chen
2021-01-22 20:41 ` Eric Dumazet
2021-01-23 1:43 ` Jakub Kicinski
2021-01-23 2:28 ` Enke Chen
2021-01-23 2:34 ` Jakub Kicinski
2021-01-23 2:45 ` Enke Chen
2021-01-24 0:19 ` Neal Cardwell
2021-01-24 0:56 ` Enke Chen [this message]
2021-01-24 3:36 ` Jakub Kicinski
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