From: Eric Dumazet <eric.dumazet@gmail•com>
To: Ben Greear <greearb@candelatech•com>, netdev <netdev@vger•kernel.org>
Subject: Re: TCP many-connection regression between 4.7 and 4.13 kernels.
Date: Mon, 22 Jan 2018 10:16:06 -0800 [thread overview]
Message-ID: <1516644966.3478.10.camel@gmail.com> (raw)
In-Reply-To: <e44000ce-1b94-f014-59c5-07305714ffcc@candelatech.com>
On Mon, 2018-01-22 at 09:28 -0800, Ben Greear wrote:
> My test case is to have 6 processes each create 5000 TCP IPv4 connections to each other
> on a system with 16GB RAM and send slow-speed data. This works fine on a 4.7 kernel, but
> will not work at all on a 4.13. The 4.13 first complains about running out of tcp memory,
> but even after forcing those values higher, the max connections we can get is around 15k.
>
> Both kernels have my out-of-tree patches applied, so it is possible it is my fault
> at this point.
>
> Any suggestions as to what this might be caused by, or if it is fixed in more recent kernels?
>
> I will start bisecting in the meantime...
>
Hi Ben
Unfortunately I have no idea.
Are you using loopback flows, or have I misunderstood you ?
How loopback connections can be slow-speed ?
next prev parent reply other threads:[~2018-01-22 18:16 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-01-22 17:28 TCP many-connection regression between 4.7 and 4.13 kernels Ben Greear
2018-01-22 18:16 ` Eric Dumazet [this message]
2018-01-22 18:27 ` Willy Tarreau
2018-01-22 18:30 ` Ben Greear
2018-01-22 18:44 ` Ben Greear
2018-01-22 18:46 ` Josh Hunt
2018-01-23 22:06 ` Ben Greear
2018-01-23 21:49 ` TCP many-connection regression (bisected to 4.5.0-rc2+) Ben Greear
2018-01-23 22:07 ` Eric Dumazet
2018-01-23 22:09 ` Ben Greear
2018-01-23 22:29 ` Eric Dumazet
2018-01-23 23:10 ` Ben Greear
2018-01-23 23:21 ` Eric Dumazet
2018-01-23 23:27 ` Ben Greear
2018-01-24 0:05 ` Ben Greear
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