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From: Willy Tarreau <w@1wt.eu>
To: ??? <jaymaacton@gmail.com>
Cc: netdev@vger.kernel.org
Subject: Re: Question about TCP delayed-ack and PUSH flag behavior
Date: Fri, 14 Feb 2025 18:12:19 +0100	[thread overview]
Message-ID: <20250214171219.GA8209@1wt.eu> (raw)
In-Reply-To: <CAPpvP8+0KftCR7WOFTf2DEOc1q_hszCHHb6pE2R-bhXMOub6Rw@mail.gmail.com>

On Fri, Feb 14, 2025 at 12:03:17PM -0500, ??? wrote:
> Hi netdev,
> 
> When tcp stack receives a segment with PUSH flag set, does the stack
> immediately send out for the corresponding ACK with ignoring delay-ack
> timer?
> Or regardless of the PUSH flag, delay-ack is always enforced?

It depends, it's possible for the application to force a delayed ack
by setting TCP_QUICKACK to zero. This is convenient for web servers
that know they respond quickly and can merge this ack with the
response to save one packet.

Willy

  reply	other threads:[~2025-02-14 17:12 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-02-14 17:03 Question about TCP delayed-ack and PUSH flag behavior 제임스
2025-02-14 17:12 ` Willy Tarreau [this message]
2025-02-14 17:58   ` 제임스
2025-02-15  0:16     ` Jason Xing

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