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Groups > linux.kernel > #1445532
| From | kan.liang@intel.com |
|---|---|
| Newsgroups | linux.kernel |
| Subject | [RFC PATCH 30/30] Documentation/networking: Document net policy |
| Date | 2016-07-18 16:30 +0200 |
| Message-ID | <rWhIv-7l8-41@gated-at.bofh.it> (permalink) |
| References | <rWhIu-7l8-7@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
From: Kan Liang <kan.liang@intel.com> Signed-off-by: Kan Liang <kan.liang@intel.com> --- Documentation/networking/netpolicy.txt | 158 +++++++++++++++++++++++++++++++++ 1 file changed, 158 insertions(+) create mode 100644 Documentation/networking/netpolicy.txt diff --git a/Documentation/networking/netpolicy.txt b/Documentation/networking/netpolicy.txt new file mode 100644 index 0000000..2ce938e --- /dev/null +++ b/Documentation/networking/netpolicy.txt @@ -0,0 +1,158 @@ +What is Linux Net Policy? + +It is a big challenge to get good network performance. First, the network +performance is not good with default system settings. Second, it is too +difficult to do automatic tuning for all possible workloads, since workloads +have different requirements. Some workloads may want high throughput. Some may +need low latency. Last but not least, there are lots of manual configurations. +Fine grained configuration is too difficult for users. + +"NET policy" intends to simplify the network configuration and get a +good network performance according to the hints(policy) which is applied by +user. It provides some typical "policies" for user which can be set +per-socket, per-task or per-device. The kernel will automatically figures out +how to merge different requests to get good network performance. + +"Net policy" is designed for multiqueue network devices. This document +describes the concepts and APIs of "net policy" support. + +NET POLICY CONCEPTS + +Scope of Net Policies + + Device net policy: this policy applies to the whole device. Once the + device net policy is set, it automatically configures the system + according to the applied policy. The configuration usually includes irq + affinity, irq balance disable, interrupt moderation, and so on. But the + device net policy does not change the packet direction. + + Task net policy: this is a per-task policy. When it is applied to specific + task, all packets transmissions of the task will be redirect to the + assigned queues accordingly. If a task does not define a task policy, + it "falls back" to the system default way to direct the packets. The + per-task policy must be compatible with device net policy. + + Socket net policy: this is a per-socket policy. When it is applied to + specific socket, all packets transmissions of the socket will be redirect + to the assigned queues accordingly. If a socket does not define a socket + policy, it "falls back" to the system default way to direct the packets. + The per-socket policy must be compatible with both device net policy and + per-task policy. + +Components of Net Policies + + Net policy object: it is a combination of cpu and queue. The queue irq has + to set affinity with the cpu. It can be shared between sockets and tasks. + A reference counter is used to track the sharing number. + + Net policy object list: each device policy has an object list. Once the + device policy is determined, the net policy object will be inserted into + the net policy object list. The net policy object list does not change + unless the cpu/queue number is changed, the netpolicy is disabled or + the device policy is changed. + The network performance for objects could be different because of the + queue/cpu topology and dev location. The objects which can bring high + performance are in the front of the list. + + RCU hash table: a RCU hash table to maintain the relationship between + the task/socket and the assigned object. The task/socket can get the + assigned object by searching the table. + If it is the first time, there is no assigned object in the table. It will + go through the object list to find the available object based on position + and reference number. + If the net policy object list changes, all the assigned object will become + invalid. + +NET POLICY APIs + +Interfaces between net policy and device driver + + int (*ndo_netpolicy_init)(struct net_device *dev, + struct netpolicy_info *info); + + The device driver who has NET policy support must implement this interface. + In this interface, the device driver do necessory initialization, and fill + the info for net policy module. The information could inlcude supported + policy, MIX policy support, queue pair support and so on. + + int (*ndo_get_irq_info)(struct net_device *dev, + struct netpolicy_dev_info *info); + + This interface is used to get more accurate device irq information. + + int (*ndo_set_net_policy)(struct net_device *dev, + enum netpolicy_name name); + + This interface is used to set device net policy by name + +Interfaces between net policy and kernel + + int netpolicy_register(struct netpolicy_reg *reg); + void netpolicy_unregister(struct netpolicy_reg *reg); + + This interface is used to register per task/socket net policy. + If it's the first time to register, an record will be created and inserted + into RCU hash table. The record includes ptr, policy and object + information. There is only one user for each record. The record cannot be + share. + + + int netpolicy_pick_queue(struct netpolicy_reg *reg, bool is_rx); + + This interface is used to find the proper queue(object) for packet + receiving and transmitting. The proper queue is picked from object list + according to policy, reference, location and so on. + + + int netpolicy_set_rules(struct netpolicy_reg *reg, + u32 queue_index, + struct netpolicy_flow_spec *flow); + + This interface is used to add device specific rules. Once the rule is + applied, the packet from specific IP and port will be redirect to the + given queue. This interface usually be used in receive side. + +NET POLICY INTERFACE + +Device net policy setting + + /proc/net/netpolicy/$DEV/policy + + Concatenating(cat) the "policy" file can show the available device + policies, if there is no device policy applied. Otherwise, the device + policy name will be print out. If it is MIX policy, the policy for each + queue will also be print out. + User can set device net policy by writing policy name. + +Task policy setting + + /proc/$PID/net_policy + + Concatenating(cat) the "net_policy" file can show the applied per task + policy. + User can set per task net policy by writing policy name. + + OR + + prctl(PR_SET_NETPOLICY, POLICY_NAME, NULL, NULL, NULL) + + "prctl" is an alternative way to set/get per task policy. + +Socket policy setting + + setsockopt(sockfd,SOL_SOCKET,SO_NETPOLICY,&policy,sizeof(int)) + + The socket net policy can be set by option SO_NETPOLICY of setsockopt + +AVAILABLE NET POLICIES + + The available net policies are defined as below: + - CPU: intends to get higher throughput and lower CPU%. This policy can be + applied as either device net policy or task/socket net policy. + - BULK: intends to get highest throughput. This policy can be applied as + either device net policy or task/socket net policy. + - LATENCY: intends to get lowest latency. This policy can be applied as + either device net policy or task/socket net policy. + - MIX: combination of other policies, which allows each queue has + different policy. This policy can only be set as device net policy. + -- 2.5.5
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[RFC PATCH 00/30] Kernel NET policy kan.liang@intel.com - 2016-07-18 16:30 +0200
[RFC PATCH 10/30] net/netpolicy: introduce netpolicy object kan.liang@intel.com - 2016-07-18 16:30 +0200
[RFC PATCH 20/30] net/netpolicy: introduce per socket netpolicy kan.liang@intel.com - 2016-07-18 16:30 +0200
[RFC PATCH 28/30] net/netpolicy: optimize for queue pair kan.liang@intel.com - 2016-07-18 16:30 +0200
[RFC PATCH 29/30] net/netpolicy: limit the total record number kan.liang@intel.com - 2016-07-18 16:30 +0200
[RFC PATCH 30/30] Documentation/networking: Document net policy kan.liang@intel.com - 2016-07-18 16:30 +0200
Re: [RFC PATCH 30/30] Documentation/networking: Document net policy Randy Dunlap <rdunlap@infradead.org> - 2016-07-18 19:10 +0200
[RFC PATCH 24/30] net/netpolicy: set rx queues according to policy kan.liang@intel.com - 2016-07-18 16:30 +0200
[RFC PATCH 23/30] i40e/ethtool: support RX_CLS_LOC_ANY kan.liang@intel.com - 2016-07-18 16:30 +0200
Re: [RFC PATCH 23/30] i40e/ethtool: support RX_CLS_LOC_ANY Alexander Duyck <alexander.duyck@gmail.com> - 2016-07-18 18:30 +0200
[RFC PATCH 14/30] net/netpolicy: add MIX policy kan.liang@intel.com - 2016-07-18 16:30 +0200
[RFC PATCH 19/30] net/netpolicy: implement netpolicy register kan.liang@intel.com - 2016-07-18 16:30 +0200
[RFC PATCH 27/30] net/netpolicy: fast path for finding the queues kan.liang@intel.com - 2016-07-18 16:30 +0200
[RFC PATCH 09/30] net/netpolicy: enable and disable net policy kan.liang@intel.com - 2016-07-18 16:40 +0200
[RFC PATCH 18/30] net/netpolicy: handle channel changes kan.liang@intel.com - 2016-07-18 16:40 +0200
[RFC PATCH 08/30] net/netpolicy: set and remove irq affinity kan.liang@intel.com - 2016-07-18 16:40 +0200
[RFC PATCH 16/30] net/netpolicy: net device hotplug kan.liang@intel.com - 2016-07-18 16:40 +0200
[RFC PATCH 04/30] net/netpolicy: get driver information kan.liang@intel.com - 2016-07-18 16:40 +0200
[RFC PATCH 15/30] i40e/netpolicy: add MIX policy support kan.liang@intel.com - 2016-07-18 16:40 +0200
[RFC PATCH 05/30] i40e/netpolicy: implement ndo_get_irq_info kan.liang@intel.com - 2016-07-18 16:40 +0200
[RFC PATCH 11/30] net/netpolicy: set net policy by policy name kan.liang@intel.com - 2016-07-18 16:40 +0200
[RFC PATCH 01/30] net: introduce NET policy kan.liang@intel.com - 2016-07-18 16:40 +0200
[RFC PATCH 03/30] i40e/netpolicy: Implement ndo_netpolicy_init kan.liang@intel.com - 2016-07-18 16:40 +0200
[RFC PATCH 17/30] net/netpolicy: support CPU hotplug kan.liang@intel.com - 2016-07-18 16:40 +0200
[RFC PATCH 02/30] net/netpolicy: init NET policy kan.liang@intel.com - 2016-07-18 16:40 +0200
[RFC PATCH 06/30] net/netpolicy: get CPU information kan.liang@intel.com - 2016-07-18 16:40 +0200
[RFC PATCH 07/30] net/netpolicy: create CPU and queue mapping kan.liang@intel.com - 2016-07-18 16:40 +0200
Re: [RFC PATCH 00/30] Kernel NET policy Florian Westphal <fw@strlen.de> - 2016-07-18 17:20 +0200
Re: [RFC PATCH 00/30] Kernel NET policy Andi Kleen <andi@firstfloor.org> - 2016-07-18 17:50 +0200
Re: [RFC PATCH 00/30] Kernel NET policy Cong Wang <xiyou.wangcong@gmail.com> - 2016-07-18 20:00 +0200
Re: [RFC PATCH 00/30] Kernel NET policy Cong Wang <xiyou.wangcong@gmail.com> - 2016-07-18 22:20 +0200
RE: [RFC PATCH 00/30] Kernel NET policy "Liang, Kan" <kan.liang@intel.com> - 2016-07-18 22:30 +0200
RE: [RFC PATCH 00/30] Kernel NET policy "Liang, Kan" <kan.liang@intel.com> - 2016-07-18 22:20 +0200
Re: [RFC PATCH 00/30] Kernel NET policy Hannes Frederic Sowa <hannes@stressinduktion.org> - 2016-07-18 21:10 +0200
Re: [RFC PATCH 00/30] Kernel NET policy Andi Kleen <andi@firstfloor.org> - 2016-07-18 21:50 +0200
Re: [RFC PATCH 00/30] Kernel NET policy Hannes Frederic Sowa <hannes@stressinduktion.org> - 2016-07-19 00:00 +0200
RE: [RFC PATCH 00/30] Kernel NET policy "Liang, Kan" <kan.liang@intel.com> - 2016-07-19 03:50 +0200
Re: [RFC PATCH 00/30] Kernel NET policy David Miller <davem@davemloft.net> - 2016-07-19 07:10 +0200
RE: [RFC PATCH 00/30] Kernel NET policy "Liang, Kan" <kan.liang@intel.com> - 2016-07-19 15:50 +0200
RE: [RFC PATCH 00/30] Kernel NET policy "Liang, Kan" <kan.liang@intel.com> - 2016-07-18 18:00 +0200
Re: [RFC PATCH 00/30] Kernel NET policy Florian Westphal <fw@strlen.de> - 2016-07-18 18:20 +0200
RE: [RFC PATCH 00/30] Kernel NET policy "Liang, Kan" <kan.liang@intel.com> - 2016-07-18 19:50 +0200
Re: [RFC PATCH 00/30] Kernel NET policy Tom Herbert <tom@herbertland.com> - 2016-07-18 18:40 +0200
RE: [RFC PATCH 00/30] Kernel NET policy "Liang, Kan" <kan.liang@intel.com> - 2016-07-18 20:00 +0200
Re: [RFC PATCH 00/30] Kernel NET policy Daniel Borkmann <daniel@iogearbox.net> - 2016-07-18 18:30 +0200
RE: [RFC PATCH 00/30] Kernel NET policy "Liang, Kan" <kan.liang@intel.com> - 2016-07-18 20:40 +0200
Re: [RFC PATCH 00/30] Kernel NET policy Daniel Borkmann <daniel@iogearbox.net> - 2016-07-18 23:00 +0200
Re: [RFC PATCH 00/30] Kernel NET policy Alexander Duyck <alexander.duyck@gmail.com> - 2016-07-18 19:10 +0200
RE: [RFC PATCH 00/30] Kernel NET policy "Liang, Kan" <kan.liang@intel.com> - 2016-07-18 21:50 +0200
Re: [RFC PATCH 00/30] Kernel NET policy Andi Kleen <andi@firstfloor.org> - 2016-07-18 22:00 +0200
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