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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?rZxzD9zQO5yNdHgeR/xDG++OsMHDqEUUAfjcHDPHYohSezIOGqugLtSfveRl?= =?us-ascii?Q?1V7VyK3UBsFhuNdouDToVvzXZwJA38ukZL2q59w6yTDyETYUm9rfh25bveTx?= =?us-ascii?Q?s8joCyR4s47+vCi1+PmvFHZmlAHIfELMJ2sRztW0Zk4S1P3m/ZsEc/3bTucr?= =?us-ascii?Q?PdV4tU8VnS33AIHsUgJbveCfTR66lrVadJzY0GyDFnKJchUZzPze/JBi0uYy?= =?us-ascii?Q?iCHhGbnN0WdWPxfiUnuLHNQnsN+o1YVgkMDsIubj3T+aYHBzmzlEANCbnZeg?= =?us-ascii?Q?Mxq4aB3FLzMBqb3lZND6BLfObFic7SCSvtr4gYatIiWO7F7a9zHSjufrwEtc?= =?us-ascii?Q?sUbtKLFW+95XLzBo2mkWSPNznNI2CQ+jUujVnMXXoNAhUfE5ZJqXFecHPMEX?= =?us-ascii?Q?+TPznAiePzqBeF4LkZOOysbYQ+K6wSCX1krN7gnVwCzl+qO7DdypWVMgW0ZB?= =?us-ascii?Q?H7ZoHiGTB6+4JRfT+AFkfxFmfKS7Ci930g+yVE/06ubn7NFPS9ZuPF6/S+mZ?= =?us-ascii?Q?CH6xwag9dcwg+KtoDpf0KvOTcrauuz2GZDdKGIMU7NActZE2gTyRgUL3Jb9n?= =?us-ascii?Q?o3pdd/jjBerIDYKATbQ8IpYN3H2L2F5DeJ6IUkcSTXX3mbpdLJuQxlYDU7zR?= =?us-ascii?Q?J+Zbcn3fA6MgkH51tQLeaWF6/kXrhwG3vL8WxzNgTC25kS6dcrTdyyW9Lq8V?= =?us-ascii?Q?Am0HUgCYSbzTfRkSzSSo1Ph/hMnELtpvtYV2wyRMRbRnF0nDZBOkVI4J4pUm?= =?us-ascii?Q?K7f2kAhs//Olf6sakFR36ttcsAWfv6h73JCBmRFGJ0xB6J0m0qtaAmqaew+U?= =?us-ascii?Q?miP1SgV8ENrrhuJ76S1Y0DchaieaOURgppBfqSINzIVTcd9npD2yFj3Tc6Ay?= =?us-ascii?Q?qGgK5mAkbrkP18CfsP04XMgxAJCVklTYXwQaw/SigsEQgqD2z4e+RUWlrjyK?= =?us-ascii?Q?DB+zJ+SVuOHBGVMwC2+ERPkYWpcxG86k9SmQlUFGFLavo5Q3pZmcEurw+cD2?= =?us-ascii?Q?In9bw+jJueakEaxdtXJq4FX1BtN1AQibrUKkA4e+BdhggZVhUIgUNF/h8cis?= =?us-ascii?Q?sVnhUESJz9dg8brvrKJ0v17uW+WGZjTMZXbtqk+jfYxY9CbOI7wpMysGm8Sa?= =?us-ascii?Q?WFGdBW2xc9Uq5R70stw2ldh0mkT/uXnKorUWeJe7Ioa/wit4cpqEvW9SVOSY?= =?us-ascii?Q?PiNBI6aZVs8MC7y6K2FXYBK9rt/evHTX4XFGga0sBPX0YtpFxtYqeOpaJt8G?= =?us-ascii?Q?ImPaL0UkBCh5cgwJyUhxcoV9OtRcTVV9dCx9eqf8xDjt0G4m2d6IU+YDfySi?= =?us-ascii?Q?8PxiPMN/GYsMP12/+I4zY2psymUSyKeA2t5d9hlwdkJuV6BVhdTVst5OYbfs?= =?us-ascii?Q?XgHGTqeqjEX6tbHfBh6jVhP42Nz2nhbYh8Wq6bxQjMWZlfoE0vEamBrm5rIv?= =?us-ascii?Q?aXYK2WFJaFWbftXqGAaYairtt5Bh0Va+rf08KSik21fXgGi4I5XfvAfqSIUl?= =?us-ascii?Q?hnAhkpJ9x4pERZvDRWc6fjEtIpYNMuu1AUa1+lwU9vqq/SRbRtetWGfl6MXK?= =?us-ascii?Q?2Ca8YDi2tapRchEeqnXii6W/vqphHxQ7miLwxPChAsB4IMx/8Z7hGRMeMxY3?= =?us-ascii?Q?Fg=3D=3D?= X-OriginatorOrg: nxp.com X-MS-Exchange-CrossTenant-Network-Message-Id: a132e6b5-2244-4968-c202-08db65e573c1 X-MS-Exchange-CrossTenant-AuthSource: AM0PR04MB6452.eurprd04.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 05 Jun 2023 16:53:56.8775 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 686ea1d3-bc2b-4c6f-a92c-d99c5c301635 X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: j87EKMfRCiY8KZ9eqKQBFJY1W6mqR2L/m/b97aYX66PL6alI6Sp46OqyL38isRysvhCsX3X5gbKMZMiqpz++dQ== X-MS-Exchange-Transport-CrossTenantHeadersStamped: DU2PR04MB8981 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Jamal, On Mon, Jun 05, 2023 at 11:44:17AM -0400, Jamal Hadi Salim wrote: > I havent been following - but if you show me sample intended tc > configs for both s/w and hardware offloads i can comment. There is not much difference in usage between the 2 modes. IMO the software data path logic is only a simulation for demonstrative purposes of what the shaper is intended to do. If hardware offload is available, it is always preferable. Otherwise, I'm not sure if anyone uses the pure software scheduling mode (also without txtime assist) for a real life use case. I was working with something like this for testing the code paths affected by these changes: #!/bin/bash add_taprio() { local offload=$1 local extra_flags case $offload in true) extra_flags="flags 0x2" ;; false) extra_flags="clockid CLOCK_TAI" ;; esac tc qdisc replace dev eno0 handle 8001: parent root stab overhead 24 taprio \ num_tc 8 \ map 0 1 2 3 4 5 6 7 \ queues 1@0 1@1 1@2 1@3 1@4 1@5 1@6 1@7 \ max-sdu 0 0 0 0 0 200 0 0 \ base-time 200 \ sched-entry S 80 20000 \ sched-entry S a0 20000 \ sched-entry S 5f 60000 \ $extra_flags } add_cbs() { local offload=$1 local extra_flags case $offload in true) extra_flags="offload 1" ;; false) extra_flags="" ;; esac max_frame_size=1500 data_rate_kbps=20000 port_transmit_rate_kbps=1000000 idleslope=$data_rate_kbps sendslope=$(($idleslope - $port_transmit_rate_kbps)) locredit=$(($max_frame_size * $sendslope / $port_transmit_rate_kbps)) hicredit=$(($max_frame_size * $idleslope / $port_transmit_rate_kbps)) tc qdisc replace dev eno0 parent 8001:8 cbs \ idleslope $idleslope \ sendslope $sendslope \ hicredit $hicredit \ locredit $locredit \ $extra_flags } # this should always fail add_second_taprio() { tc qdisc replace dev eno0 parent 8001:7 taprio \ num_tc 8 \ map 0 1 2 3 4 5 6 7 \ queues 1@0 1@1 1@2 1@3 1@4 1@5 1@6 1@7 \ max-sdu 0 0 0 0 0 200 0 0 \ base-time 200 \ sched-entry S 80 20000 \ sched-entry S a0 20000 \ sched-entry S 5f 60000 \ clockid CLOCK_TAI } ip link set eno0 up echo "Offload:" add_taprio true add_cbs true add_second_taprio mausezahn eno0 -t ip -b 00:04:9f:05:f6:27 -c 100 -p 60 sleep 5 tc -s class show dev eno0 tc qdisc del dev eno0 root echo "Software:" add_taprio false add_cbs false add_second_taprio mausezahn eno0 -t ip -b 00:04:9f:05:f6:27 -c 100 -p 60 sleep 5 tc -s class show dev eno0 tc qdisc del dev eno0 root > In my cursory look i assumed you wanted to go along the path of mqprio > where nothing much happens in the s/w datapath other than requeues > when the tx hardware path is busy (notice it is missing an > enqueue/deque ops). In that case the hardware selection is essentially > of a DMA ring based on skb tags. It seems you took it up a notch by > infact having a choice of whether to have pure s/w or offload path. Yes. Actually the original taprio design always had the enqueue()/dequeue() ops involved in the data path, then commit 13511704f8d7 ("net: taprio offload: enforce qdisc to netdev queue mapping") retrofitted the mqprio model when using the "flags 0x2" argument. If you have time to read, the discussion behind that redesign was here: https://lore.kernel.org/netdev/20210511171829.17181-1-yannick.vignon@oss.nxp.com/