net: add IFLA_MAX_PACING_OFFLOAD_HORIZON device attribute

Some network devices have the ability to offload EDT (Earliest
Departure Time) which is the model used for TCP pacing and FQ
packet scheduler.

Some of them implement the timing wheel mechanism described in
https://saeed.github.io/files/carousel-sigcomm17.pdf
with an associated 'timing wheel horizon'.

This patch adds dev->max_pacing_offload_horizon expressing
this timing wheel horizon in nsec units.

This is a read-only attribute.

Unless a driver sets it, dev->max_pacing_offload_horizon
is zero.

v2: addressed Jakub feedback ( https://lore.kernel.org/netdev/20240930152304.472767-2-edumazet@google.com/T/#mf6294d714c41cc459962154cc2580ce3c9693663 )
v3: added yaml doc (also per Jakub feedback)

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20241003121219.2396589-2-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

This commit is contained in:

Eric Dumazet

2024-10-04 15:37:53 -07:00

committed by

Jakub Kicinski

parent 3d07b691ee

commit f858cc9eed

6 changed files with 15 additions and 0 deletions

									
										include/uapi/linux/if_link.h
									
		+1
		
												View File
												
				@@ -377,6 +377,7 @@ enum {

					IFLA_GSO_IPV4_MAX_SIZE,

					IFLA_GRO_IPV4_MAX_SIZE,

					IFLA_DPLL_PIN,

					IFLA_MAX_PACING_OFFLOAD_HORIZON,

					__IFLA_MAX

				};