From: Jakub Kicinski <kuba@kernel.org>
To: Edward Cree <ecree.xilinx@gmail.com>
Cc: Haifeng Xu <haifeng.xu@shopee.com>,
Eric Dumazet <edumazet@google.com>,
Tony Nguyen <anthony.l.nguyen@intel.com>,
Przemek Kitszel <przemyslaw.kitszel@intel.com>,
"David S. Miller" <davem@davemloft.net>,
Paolo Abeni <pabeni@redhat.com>,
linux-kernel@vger.kernel.org, netdev@vger.kernel.org,
intel-wired-lan@lists.osuosl.org
Subject: Re: [Question] ixgbe：Mechanism of RSS
Date: Thu, 2 Jan 2025 08:39:15 -0800 [thread overview]
Message-ID: <20250102083915.6e5375a1@kernel.org> (raw)
In-Reply-To: <87e945f6-2811-0ddb-1666-06accd126efb@gmail.com>
On Thu, 2 Jan 2025 16:01:18 +0000 Edward Cree wrote:
> On 02/01/2025 11:23, Haifeng Xu wrote:
> > We want to make full use of cpu resources to receive packets. So
> > we enable 63 rx queues. But we found the rate of interrupt growth
> > on cpu 0~15 is faster than other cpus(almost twice).
> ...
> > I am confused that why ixgbe NIC can dispatch the packets
> > to the rx queues that not specified in RSS configuration.
>
> Hypothesis: it isn't doing so, RX is only happening on cpus (and
> queues) 0-15, but the other CPUs are still sending traffic and
> thus getting TX completion interrupts from their TX queues.
> `ethtool -S` output has per-queue traffic stats which should
> confirm this.
>
> (But Eric is right that if you _want_ RX to use every CPU you
> should just change the indirection table.)
IIRC Niantic had 4 bit entries in the RSS table or some such.
It wasn't possible to RSS across more than 16 queues at a time.
It's a great NIC but a bit dated at this point.
next prev parent reply other threads:[~2025-01-02 16:39 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-01-02 3:53 [Question] ixgbe：Mechanism of RSS Haifeng Xu
2025-01-02 8:13 ` Eric Dumazet
2025-01-02 8:43 ` Haifeng Xu
2025-01-02 10:34 ` Eric Dumazet
2025-01-02 11:23 ` Haifeng Xu
2025-01-02 11:46 ` Eric Dumazet
2025-01-03 2:36 ` Haifeng Xu
2025-01-02 16:01 ` Edward Cree
2025-01-02 16:39 ` Jakub Kicinski [this message]
2025-01-03 2:37 ` Haifeng Xu
2025-01-03 3:05 ` Haifeng Xu
2025-01-07 17:16 ` Tony Nguyen
2025-01-08 3:36 ` Haifeng Xu
2025-01-08 21:06 ` Tony Nguyen
2025-01-09 3:26 ` Haifeng Xu
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