From: Stephen Hemminger <stephen@networkplumber.org>
To: Haiyang Zhang <haiyangz@microsoft.com>
Cc: linux-hyperv@vger.kernel.org, netdev@vger.kernel.org,
kys@microsoft.com, davem@davemloft.net, edumazet@google.com,
kuba@kernel.org, pabeni@redhat.com, corbet@lwn.net,
dsahern@kernel.org, ncardwell@google.com, ycheng@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
Date: Tue, 10 Oct 2023 15:14:04 -0700 [thread overview]
Message-ID: <20231010151404.3f7faa87@hermes.local> (raw)
In-Reply-To: <1696965810-8315-1-git-send-email-haiyangz@microsoft.com>
On Tue, 10 Oct 2023 12:23:30 -0700
Haiyang Zhang <haiyangz@microsoft.com> wrote:
> TCP pingpong threshold is 1 by default. But some applications, like SQL DB
> may prefer a higher pingpong threshold to activate delayed acks in quick
> ack mode for better performance.
>
> The pingpong threshold and related code were changed to 3 in the year
> 2019 in:
> commit 4a41f453bedf ("tcp: change pingpong threshold to 3")
> And reverted to 1 in the year 2022 in:
> commit 4d8f24eeedc5 ("Revert "tcp: change pingpong threshold to 3"")
>
> There is no single value that fits all applications.
> Add net.ipv4.tcp_pingpong_thresh sysctl tunable, so it can be tuned for
> optimal performance based on the application needs.
>
> Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
If this an application specific optimization, it should be in a socket option
rather than system wide via sysctl.
next prev parent reply other threads:[~2023-10-10 22:14 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-10-10 19:23 [PATCH net-next,v2] tcp: Set pingpong threshold via sysctl Haiyang Zhang
2023-10-10 20:06 ` Neal Cardwell
2023-10-10 21:05 ` Haiyang Zhang
2023-10-10 20:11 ` Kuniyuki Iwashima
2023-10-10 21:09 ` Haiyang Zhang
2023-10-10 22:14 ` Stephen Hemminger [this message]
2023-10-10 22:27 ` Yuchung Cheng
2023-10-10 22:59 ` Haiyang Zhang
2023-10-11 2:15 ` Stephen Hemminger
2023-10-11 18:49 ` Haiyang Zhang
2023-10-11 18:57 ` Eric Dumazet
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