From: Willem de Bruijn <willemdebruijn.kernel@gmail.com>
To: Xin Zhao <jackzxcui1989@163.com>,
willemdebruijn.kernel@gmail.com, edumazet@google.com,
ferenc@fejes.dev
Cc: davem@davemloft.net, kuba@kernel.org, pabeni@redhat.com,
horms@kernel.org, netdev@vger.kernel.org,
linux-kernel@vger.kernel.org, Xin Zhao <jackzxcui1989@163.com>
Subject: Re: [PATCH net-next v3] net: af_packet: Use hrtimer to do the retire operation
Date: Sat, 16 Aug 2025 05:34:43 -0400 [thread overview]
Message-ID: <willemdebruijn.kernel.1096d5f9f114f@gmail.com> (raw)
In-Reply-To: <20250816024831.1451167-1-jackzxcui1989@163.com>
Xin Zhao wrote:
> In a system with high real-time requirements, the timeout mechanism of
> ordinary timers with jiffies granularity is insufficient to meet the
> demands for real-time performance. Meanwhile, the optimization of CPU
> usage with af_packet is quite significant. Use hrtimer instead of timer
> to help compensate for the shortcomings in real-time performance.
> In HZ=100 or HZ=250 system, the update of TP_STATUS_USER is not real-time
> enough, with fluctuations reaching over 8ms (on a system with HZ=250).
> This is unacceptable in some high real-time systems that require timely
> processing of network packets. By replacing it with hrtimer, if a timeout
> of 2ms is set, the update of TP_STATUS_USER can be stabilized to within
> 3 ms.
>
> Signed-off-by: Xin Zhao <jackzxcui1989@163.com>
Discussion in v2 is still ongoing. This will have to be respun based
on that.
next prev parent reply other threads:[~2025-08-16 9:34 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-08-16 2:48 [PATCH net-next v3] net: af_packet: Use hrtimer to do the retire operation Xin Zhao
2025-08-16 9:34 ` Willem de Bruijn [this message]
2025-08-17 13:28 ` Willem de Bruijn
-- strict thread matches above, loose matches on Subject: below --
2025-08-16 17:01 Xin Zhao
2025-08-17 14:47 Xin Zhao
2025-08-17 15:55 ` Willem de Bruijn
2025-08-18 5:38 Xin Zhao
2025-08-18 7:21 ` Willem de Bruijn
2025-08-18 7:13 Xin Zhao
2025-08-18 9:21 ` Willem de Bruijn
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