netdev - Re: [PATCH net-next] tcp: get rid of sysctl_tcp_adv_win

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Message-ID: <79ad8d95-1fbf-4d86-b391-d7af727dfce7@kernel.org>
Date: Fri, 3 Nov 2023 12:07:21 +0100
From: Jiri Slaby <jirislaby@...nel.org>
To: Eric Dumazet <edumazet@...gle.com>
Cc: "David S . Miller" <davem@...emloft.net>, Jakub Kicinski
 <kuba@...nel.org>, Paolo Abeni <pabeni@...hat.com>, netdev@...r.kernel.org,
 Soheil Hassas Yeganeh <soheil@...gle.com>,
 Neal Cardwell <ncardwell@...gle.com>, Yuchung Cheng <ycheng@...gle.com>,
 eric.dumazet@...il.com
Subject: Re: [PATCH net-next] tcp: get rid of sysctl_tcp_adv_win_scale

On 03. 11. 23, 11:27, Eric Dumazet wrote:
> On Fri, Nov 3, 2023 at 11:14 AM Jiri Slaby <jirislaby@...nel.org> wrote:
>>
>> On 03. 11. 23, 9:17, Eric Dumazet wrote:
>>> What happens if you double /proc/sys/net/ipv4/tcp_wmem  and/or
>>> /proc/sys/net/ipv4/tcp_rmem first value ?
>>> (4096 -> 8192)
>>
>> No change:
>> # cat /proc/sys/net/ipv4/tcp_wmem
>> 8192    16384   4194304
>>
>>
>> But this:
>> # cat /proc/sys/net/ipv4/tcp_rmem
>> 8192    16384   4194304
>>
>> results in test to run 4.7 s, so even 3 more times slower!
> 
> 
> You might try setting tcp_shrink_window sysctl to one, with some side
> effects for normal TCP flows.

That results in 3 seconds.

In anyway, it looks like they need to fix the test, right? Created:
https://github.com/eventlet/eventlet/issues/821

thanks,
-- 
js
suse labs