Wed, Mar 02, 2016 at 05:22:48PM CET, john.fastab...@gmail.com wrote: >On 16-03-02 05:22 AM, Jiri Pirko wrote: >> Wed, Mar 02, 2016 at 12:14:39PM CET, gerlitz...@gmail.com wrote: >>> On Tue, Mar 1, 2016 at 7:01 PM, Jiri Pirko <j...@resnulli.us> wrote: >>>> Tue, Mar 01, 2016 at 05:49:27PM CET, a...@vadai.me wrote: >>>>> On Tue, Mar 01, 2016 at 03:47:19PM +0100, Jiri Pirko wrote: >>>>>> Tue, Mar 01, 2016 at 03:24:43PM CET, a...@vadai.me wrote: >>>>>>> This patch is based on a patch made by John Fastabend. >>> >>>>>>> It adds support for offloading cls_flower. >>>>>>> A filter that is offloaded successfully by hardware, will not be added >>>>>>> to >>>>>>> the hashtable and won't be processed by software. >>> >>>>>> That is wrong. User should explicitly specify to not include rule into sw >>>>>> by SKIP_KERNEL flag (does not exist now, with John's recent patch we'll >>>>>> have only SKIP_HW). Please add that in this patchset. >>> >>>>> Why? If a rule is offloaded, why would the user want to reprocess it by >>>>> software? >>> >>>>> If the user use SKIP_HW, it will be processed by SW. Else, the user >>>>> would want it to be processed by HW or fallback to SW. I don't >>>>> understand in which case the user would like to have it done twice. >>> >>>> For example if you turn on the offloading by unsetting NETIF_F_HW_TC. >>>> Or if someone inserts skbs into rx path directly, for example pktgen. >>>> We need SKIP_KERNEL to be set by user, not implicit. >>> >>> As discussed in netdev, we want to have three modes for TC offloads >>> >>> 1. SW only >>> 2. HW only (and err if can't) >>> 3. HW and if not supported fallback to SW >>> >>> Now, from your reply, I understand we want a fourth mode >>> >>> 4. Both (HW and SW) >> >> I would perhaps do it a litte bit differently: >> NO FLAG (default)- insert into kernel and HW now: >> if NETIF_F_HW_TC is off (default) >> -> push to kernel only (current behaviour) >> if NETIF_F_HW_TC is on AND push to HW fails >> -> return error >> SKIP_HW - flag to tell kernel not to insert into HW >> SKIP_SW - flag to tell kernel not to insert into kernel >> >> to achieve hw only, user has to turn on the NETIF_F_HW_TC and >> pass SKIP_SW flag. >> > >The modes Jiri describes here is exactly how I planned to build >this. And at the moment the only one we are missing is SKIP_HW >which I'm reworking now and should have in a few days. > >To resolve the error handling if the rule is SKIP_HW or NO_FLAG >an error will be thrown if it can not be applied to software. >Notice if an error happens on the software insert with NO_FLAG then >the hardware insert is not attempted either. With SKIP_SW I will >throw an error if the hardware insert fails because there is >no software fallback in this mode. > >The only mode I haven't looked at doing is > > 3. HW and if not supported fallback to SW > >I'm not sure I have a use case for it at the moment. It is sufficient >for me to just do a SKIP_SW command followed by a SKIP_HW command >if needed. I guess someone else could implement it if they really need >it.
I'd let user to resolve this as you described.
