From: Jakub Kicinski <kuba@kernel.org>
To: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Haiyang Zhang <haiyangz@linux.microsoft.com>,
"linux-hyperv@vger.kernel.org" <linux-hyperv@vger.kernel.org>,
"netdev@vger.kernel.org" <netdev@vger.kernel.org>,
KY Srinivasan <kys@microsoft.com>, Wei Liu <wei.liu@kernel.org>,
Dexuan Cui <DECUI@microsoft.com>, Long Li <longli@microsoft.com>,
Andrew Lunn <andrew+netdev@lunn.ch>,
"David S. Miller" <davem@davemloft.net>,
Eric Dumazet <edumazet@google.com>,
Paolo Abeni <pabeni@redhat.com>,
Konstantin Taranov <kotaranov@microsoft.com>,
Simon Horman <horms@kernel.org>,
Erni Sri Satya Vennela <ernis@linux.microsoft.com>,
Shradha Gupta <shradhagupta@linux.microsoft.com>,
Saurabh Sengar <ssengar@linux.microsoft.com>,
Aditya Garg <gargaditya@linux.microsoft.com>,
Dipayaan Roy <dipayanroy@linux.microsoft.com>,
Shiraz Saleem <shirazsaleem@microsoft.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"linux-rdma@vger.kernel.org" <linux-rdma@vger.kernel.org>,
Paul Rosswurm <paulros@microsoft.com>
Subject: Re: [EXTERNAL] Re: [PATCH V2,net-next, 1/2] net: mana: Add support for coalesced RX packets on CQE
Date: Mon, 12 Jan 2026 17:21:46 -0800 [thread overview]
Message-ID: <20260112172146.04b4a70f@kernel.org> (raw)
In-Reply-To: <SA3PR21MB3867BAD6022A1CAE2AC9E202CA81A@SA3PR21MB3867.namprd21.prod.outlook.com>
On Mon, 12 Jan 2026 21:01:59 +0000 Haiyang Zhang wrote:
> > > Our NIC can have up to 4 RX packets on 1 CQE. To support this feature,
> > > check and process the type CQE_RX_COALESCED_4. The default setting is
> > > disabled, to avoid possible regression on latency.
> > >
> > > And add ethtool handler to switch this feature. To turn it on, run:
> > > ethtool -C <nic> rx-frames 4
> > > To turn it off:
> > > ethtool -C <nic> rx-frames 1
> >
> > Exposing just rx frame count, and only two values is quite unusual.
> > Please explain in more detail the coalescing logic of the device.
> Our NIC device only supports coalescing on RX. And when it's disabled each
> RX CQE indicates 1 RX packet; when enabled each RX CQE indicates up to 4 packets.
I get that. What is the logic for combining 4 packets into a single
completion? How does it work? Your commit message mentions "regression
on latency" - what is the bound on that regression?
next prev parent reply other threads:[~2026-01-13 1:21 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-01-06 20:46 [PATCH V2,net-next, 0/2] net: mana: Add support for coalesced RX packets Haiyang Zhang
2026-01-06 20:46 ` [PATCH V2,net-next, 1/2] net: mana: Add support for coalesced RX packets on CQE Haiyang Zhang
2026-01-06 21:50 ` Long Li
2026-01-10 1:56 ` Jakub Kicinski
2026-01-12 21:01 ` [EXTERNAL] " Haiyang Zhang
2026-01-13 1:21 ` Jakub Kicinski [this message]
2026-01-13 15:09 ` Haiyang Zhang
2026-01-13 15:13 ` Haiyang Zhang
2026-01-14 1:09 ` Jakub Kicinski
2026-01-14 18:27 ` Haiyang Zhang
2026-01-15 2:54 ` Jakub Kicinski
2026-01-15 19:57 ` Haiyang Zhang
2026-01-16 2:14 ` Jakub Kicinski
2026-01-16 16:44 ` Haiyang Zhang
2026-01-17 16:58 ` Jakub Kicinski
2026-01-17 18:01 ` Haiyang Zhang
2026-01-17 22:48 ` Jakub Kicinski
2026-01-18 18:31 ` Haiyang Zhang
2026-02-22 21:32 ` Haiyang Zhang
2026-01-06 20:46 ` [PATCH V2,net-next, 2/2] net: mana: Add ethtool counters for RX CQEs in coalesced type Haiyang Zhang
2026-01-06 22:10 ` Long Li
2026-01-10 1:56 ` Jakub Kicinski
2026-01-12 21:03 ` [EXTERNAL] " Haiyang Zhang
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