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Date:   Tue, 21 Nov 2023 15:48:41 -0800
From:   Jakub Kicinski <kuba@kernel.org>
To:     Souradeep Chakrabarti <schakrabarti@linux.microsoft.com>
Cc:     kys@microsoft.com, haiyangz@microsoft.com, wei.liu@kernel.org,
        decui@microsoft.com, davem@davemloft.net, edumazet@google.com,
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        leon@kernel.org, cai.huoqing@linux.dev,
        ssengar@linux.microsoft.com, vkuznets@redhat.com,
        tglx@linutronix.de, linux-hyperv@vger.kernel.org,
        netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-rdma@vger.kernel.org, schakrabarti@microsoft.com,
        paulros@microsoft.com
Subject: Re: [PATCH V2 net-next] net: mana: Assigning IRQ affinity on HT
 cores
Message-ID: <20231121154841.7fc019c8@kernel.org>
In-Reply-To: <1700574877-6037-1-git-send-email-schakrabarti@linux.microsoft.com>
References: <1700574877-6037-1-git-send-email-schakrabarti@linux.microsoft.com>
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On Tue, 21 Nov 2023 05:54:37 -0800 Souradeep Chakrabarti wrote:
> Existing MANA design assigns IRQ to every CPUs, including sibling hyper-threads
> in a core. This causes multiple IRQs to work on same CPU and may reduce the network
> performance with RSS.
> 
> Improve the performance by adhering the configuration for RSS, which assigns IRQ
> on HT cores.

Drivers should not have to carry 120 LoC for something as basic as
spreading IRQs. Please take a look at include/linux/topology.h and
if there's nothing that fits your needs there - add it. That way
other drivers can reuse it.