Hi Jerin,
> -----Original Message-----
> From: Jerin Jacob <jerinjac...@gmail.com>
>
> On Tue, Jul 7, 2020 at 11:51 AM Ori Kam <or...@mellanox.com> wrote:
> >
> > Hi Jerin,
> > Thanks you for your quick reply.
> >
> > > -----Original Message-----
> > > From: Jerin Jacob <jerinjac...@gmail.com>
> > > Subject: Re: [dpdk-dev] [PATCH] add flow shared action API
> > >
> > > On Mon, Jul 6, 2020 at 7:02 PM Andrey Vesnovaty
> > > <andrey.vesnov...@gmail.com> wrote:
> > > >
> > > > Hi, Jerin.
> > >
> > > Hi Ori and Andrey,
> > >
> > >
> > > >
> > > > Please see below Ori's suggestion below to implement your
> > > rte_flow_action_update() idea
> > > > with some API changes of rte_flow_shared_action_xxx API changes.
> > > >
> > > > On Mon, Jul 6, 2020 at 3:28 PM Ori Kam <or...@mellanox.com> wrote:
> > > >>
> > > >> Hi Jerin,
> > > >>
> > > >> > -----Original Message-----
> > > >> > From: Jerin Jacob <jerinjac...@gmail.com>
> > > >> > Sent: Monday, July 6, 2020 12:00 PM
> > > >> > Subject: Re: [dpdk-dev] [PATCH] add flow shared action API
> > > >> >
> > > >> > On Sun, Jul 5, 2020 at 3:56 PM Ori Kam <or...@mellanox.com> wrote:
> > > >> > >
> > > >> > > Hi Jerin,
> > > >> > > PSB,
> > > >> > >
> > > >> > > Thanks,
> > > >> > > Ori
> > > >> > >
> > > >> > > > -----Original Message-----
> > > >> > > > From: Jerin Jacob <jerinjac...@gmail.com>
> > > >> > > > Sent: Saturday, July 4, 2020 3:33 PM
> > > >> > > > dpdk-dev <dev@dpdk.org>
> > > >> > > > Subject: Re: [dpdk-dev] [PATCH] add flow shared action API
> > > >> > > >
> > > >> > > > On Sat, Jul 4, 2020 at 3:40 PM Andrey Vesnovaty
> > > >> > > > <andrey.vesnov...@gmail.com> wrote:
> > > >> > > > >
> > > >> > > > >
> > > >> > > > > Thanks,
> > > >> > > > >
> > > >> > > > > Andrey Vesnovaty
> > > >> > > > > (+972)526775512 | Skype: andrey775512
> > > >> > > > >
> > > >> > >
> > > >> > >
> > > >> > > [..Nip ..]
> > > >> > >
> > > >> > > > > I need to mention the locking issue once again.
> > > >> > > > > If there is a need to maintain "shared session" in the generic
> > > rte_flow
> > > >> > layer
> > > >> > > > all
> > > >> > > > > calls to flow_create() with shared action & all delete need to
> > > >> > > > > take
> > > >> > > > sharedsession
> > > >> > > > > management locks at least for verification. Lock partitioning
> > > >> > > > > is
> also
> > > bit
> > > >> > > > problematic
> > > >> > > > > since one flow may have more than one shared action.
> > > >> > > >
> > > >> > > > Then, I think better approach would be to introduce
> > > >> > > > rte_flow_action_update() public
> > > >> > > > API which can either take "const struct rte_flow_action []" OR
> shared
> > > >> > > > context ID, to cater to
> > > >> > > > both cases or something on similar lines. This would allow HW's
> > > >> > > > without have the shared context ID
> > > >> > > > to use the action update.
> > > >> > >
> > > >> > > Can you please explain your idea?
> > > >> >
> > > >> > I see two types of HW schemes supporting action updates without
> going
> > > >> > through call `rte_flow_destroy()` and call `rte_flow_create()`
> > > >> > - The shared HW action context feature
> > > >> > - The HW has "pattern" and "action" mapped to different HW objects
> and
> > > >> > action can be updated any time.
> > > >> > Other than above-mentioned RSS use case, another use case would be
> to
> > > >> > a) create rte_flow and set the action as DROP (Kind of reserving the
> HW
> > > object)
> > > >> > b) Update the action only when the rest of the requirements ready.
> > > >> >
> > > >> > Any API schematic that supports both notions of HW is fine with me.
> > > >> >
> > > >> I have an idea if the API will be changed to something like this,
> > > >> Rte_flow_shared_action_update(uint16_port port, rte_shared_ctx *ctx,
> > > rte_flow_action *action, error)
> > > >> This will enable the application to send a different action than the
> original
> > > one to be switched.
> > > >> Assuming the PMD supports this.
> > > >> Does it answer your concerns?
> > > >
> > > >
> > > > This allows both:
> > > > 1. Update action configuration
> > > > 2. Replace action by some other action
> > > > For 2 pure software implementation may carate shred action (that can be
> > > shared
> > > > with one flow only, depends on PMD) and later on
> > > rte_flow_shared_action_update may replace this
> > > > action with some other action by handle returned from
> > > rte_flow_shared_action_create
> > > > Doesign between 1 and 2 is per PMD.
> > >
> > > struct rte_flow * object holds the driver representation of the
> > > pattern + action.
> > > So in order to update the action, we would need struct rte_flow * in API.
> > >
> > Why is that? The idea is to change the action, the action itself is
> > connected to
> flows.
> > The PMD can save in the shared_ctx all flows that are connected to this
> action.
> >
> > > I think, simple API change would be to accommodate "rte_shared_ctx
> > > *ctx, rte_flow_action *action" modes
> > > without introducing the emulation for one or other mode, will be.
> > >
> > > enum rte_flow_action_update_type {
> > > RTE_FLOW_ACTION_UPDATE_TYPE_SHARED_ACTION,
> > > RTE_FLOW_ACTION_UPDATE_TYPE_ACTION,
> > > };
> > >
> > > struct rte_flow_action_update_type_param {
> > > enum rte_flow_action_update_type type;
> > > union {
> > > struct
> > > rte_flow_action_update_type_shared_action_param {
> > > rte_shared_ctx *ctx;
> > > } shared_action;
> > > struct
> > > rte_flow_action_update_type_shared_action_param {
> > > rte_flow *flow,
> > > rte_flow_action *action;
> > > } action;
> > > }
> > > }
> > >
> > Thank you for the idea but I fall to see how your suggested API is simpler
> > than
> the one suggested by me?
>
> My thought process with the below-proposed API[1] is that It is
> dictates "_shared_action_" in API name as
> well as arguments. I just thought of expressing it as either-or case
> hence I thought [2] is better. i.e The PMD does not support
> shared_action, not even need to create one to use
> rte_flow_action_update() to avoid the confusion. Thoughts?
>
> [1]
> rte_flow_shared_action_update(uint16_port port, rte_shared_ctx *ctx,
> rte_flow_action *action, error)
>
> [2]
> rte_flow_action_update(uint16_port port, struct
> rte_flow_action_update_type_param *param, error)
>
Let me see if I understand you correctly, your suggestion is to allow
the application to change one action in one flow, but instead of creating
the context the application will just supply the rte_flow and the new actions
do I understand correctly?
If so this it is a nice idea, but there are some issues with it,
1. The PMD must save the flow which will result in memory consumption.
2. Assume that two flows are using the same RSS action for example, so the PMD
reuse the RSS object he created for the first flow also for the second. Now
changing
this RSS flow may result in also changing the second flow. (this can be solved
by always
creating new action)
3. It doesn't handle the main use case that the application wants to change
number of
flows at the same time, which is the idea of this feature.
I also think that all PMD that support option 2 can support option 1 since
they can save in the ctx a list of flows and simply apply them again. So by
definition if PMD supports [2] it also support [1] while the other
way is not correct since it forces the PMD to save flows which like I said
waste memory.
I suggest that we will go with option [1], and if needed in the future we will
update the code.
using option [2] will result in dead code since at least for the current time
no PMD will implement this
API.
I can suggest one more thing maybe to change the name from shared_ctx to just
ctx
which implicitly mean it can be shared but not a must. What do you think? (but
again
I think by definition if a PMD can implement number [2] it can also implement
it to number
of flows using API [2].
> > In my suggestion the PMD simply needs to check if the new action and
> change the
> > context and to that action, or just change parameters in the action, if it
> > is the
> same action.
> >
> > Let's go with the original patch API modified to support like you requested
> also changing the action,
> > based on my comments.
> >
> > > rte_flow_action_update(uint16_port port, struct
> > > rte_flow_action_update_type_param *param, error)
> > >
> > > >
[..nip..]
Best,
Ori
