>On 06.05.2026 10:13, javen wrote:
>> From: Javen Xu <javen_xu@realsil.com.cn>
>>
>> This patch series adds RSS (Receive Side Scaling) support for the
>> r8169 ethernet driver, specifically for RTL8127 (RTL_GIGA_MAC_VER_80).
>
>Series adds RSS support for RTL8127 only. Is this generic enough to retrofit RSS
>support for other chip versions like RTL8126 w/o bigger refactoring?
>
Yes. The current implementation is generic enough. Almost all the registers are shared and can be reused. If we want to enable rss for 8125/8126 later, the only necessary change would be setting tp->init_rx_desc_type to a new value. And add a new struct rx_desc for 8125 or 8126. For example, this is a desc type for 8125.
struct RxDescV3 {
        union {
                struct {
                        u32 rsv1;
                        u32 rsv2;
                } RxDescDDWord1;
        };
        union {
                struct {
                        u32 RSSResult;
                        u16 HeaderBufferLen;
                        u16 HeaderInfo;
                } RxDescNormalDDWord2;

                struct {
                        u32 rsv5;
                        u32 rsv6;
                } RxDescDDWord2;
        };
        union {
                u64   addr;

                struct {
                        u32 TimeStampLow;
                        u32 TimeStampHigh;
                } RxDescTimeStamp;

                struct {
                        u32 rsv8;
                        u32 rsv9;
                } RxDescDDWord3;
        };
        union {
                struct {
                        u32 opts2;
                        u32 opts1;
                } RxDescNormalDDWord4;

                struct {
                        u16 TimeStampHHigh;
                        u16 rsv11;
                        u32 opts1;
                } RxDescPTPDDWord4;
        };
};
This is complex because it reserves some words for PTP.

Thanks,
BRs,
Javen

>>
>> RSS enables packet distribution across multiple receive queues, which
>> can significantly improve network throughput on multi-core systems by
>> allowing parallel processing of incoming packets.
>>
>> Key features:
>> - Multi-queue RX support (up to 8 queues)
>> - MSI-X interrupt with vector mapping
>> - Dynamic queue configuration via ethtool (-L)
>> - RSS hash computation for flow classification
>>
>> Experiments:
>> Platform: AMD Ryzen Embedded R2514 with Radeon Graphics(4 Cores/8
>> Threads)
>> Arch: x86_64
>> Test command:
>>   Server: iperf3 -s
>>   Client: iperf3 -c 192.168.2.1 -P 20 -t 3600
>> Monitor: mpstat -P ALL 1
>>
>> Before this patch (Without RSS):
>>   Throughput: Unstable, fluctuating between 3.76 Gbits/sec and
>>   8.2 Gbits/sec.
>>   CPU Usage: A single CPU core is fully occupied with softirq reaching
>>   up to 96%.
>>
>> After this patch (With RSS enabled):
>>   Throughput: Stable at 9.42 Gbits/sec.
>>   CPU Usage: The traffic load is evenly distributed across multiple CPU
>>   cores. The maximum softirq on a single core dropped to 63%.
>>
>> Other Experiments:
>> Link:
>> https://lore.kernel.org/netdev/0A5279953D81BB9C+f50c9b49-3e5d-467f-
>b69
>> a-7e49ed223383@radxa.com/
>>
>> Javen Xu (7):
>>   r8169: add support for multi irqs
>>   r8169: add support for multi rx queues
>>   r8169: add support for new interrupt mapping
>>   r8169: enable new interrupt mapping
>>   r8169: add support and enable rss
>>   r8169: move struct ethtool_ops
>>   r8169: add support for ethtool
>>
>>  drivers/net/ethernet/realtek/r8169_main.c | 1202
>> ++++++++++++++++++---
>>  1 file changed, 1080 insertions(+), 122 deletions(-)
>>