> -----Original Message----- > From: Jerin Jacob <jerinjac...@gmail.com> > Sent: Wednesday, October 28, 2020 3:40 PM > To: Ananyev, Konstantin <konstantin.anan...@intel.com> > Cc: Thomas Monjalon <tho...@monjalon.net>; Ma, Liang J > <liang.j...@intel.com>; dpdk-dev <dev@dpdk.org>; Ruifeng Wang (Arm > Technology China) <ruifeng.w...@arm.com>; Wang, Haiyue > <haiyue.w...@intel.com>; Richardson, Bruce > <bruce.richard...@intel.com>; Hunt, David <david.h...@intel.com>; Neil Horman > <nhor...@tuxdriver.com>; McDaniel, Timothy > <timothy.mcdan...@intel.com>; Eads, Gage <gage.e...@intel.com>; Marcin Wojtas > <m...@semihalf.com>; Guy Tzalik > <gtza...@amazon.com>; Ajit Khaparde <ajit.khapa...@broadcom.com>; Harman > Kalra <hka...@marvell.com>; John Daley > <johnd...@cisco.com>; Wei Hu (Xavier <xavier.hu...@huawei.com>; Ziyang Xuan > <xuanziya...@huawei.com>; ma...@nvidia.com; Yong > Wang <yongw...@vmware.com>; david.march...@redhat.com > Subject: Re: [PATCH v10 0/9] Add PMD power mgmt > > On Wed, Oct 28, 2020 at 9:04 PM Ananyev, Konstantin > <konstantin.anan...@intel.com> wrote: > > > > > > > > > > > 28/10/2020 14:49, Jerin Jacob: > > > > > > On Wed, Oct 28, 2020 at 7:05 PM Liang, Ma <liang.j...@intel.com> > > > > > > wrote: > > > > > > > > > > > > > > Hi Thomas, > > > > > > > I think I addressed all of the questions in relation to V9. I > > > > > > > don't think I can solve the issue of a generic API on my own. > > > > > > > From the > > > > > Community Call last week Jerin also said that a generic was > > > > > investigated but that a single solution wasn't feasible. > > > > > > > > > > > > I think, From the architecture point of view, the specific > > > > > > functionally of UMONITOR may not be abstracted. > > > > > > But from the ethdev callback point of view, Can it be abstracted in > > > > > > such a way that packet notification available through > > > > > > checking interrupt status register or ring descriptor location, etc > > > > > > by > > > > > > the driver. Use that callback as a notification mechanism rather > > > > > > than defining a memory-based scheme that UMONITOR expects? or > > > > > > similar > > > > > > thoughts on abstraction. > > > > > > > > I think there is probably some sort of misunderstanding. > > > > This API is not about providing acync notification when next packet > > > > arrives. > > > > This is about to putting core to sleep till some event (or timeout) > > > > happens. > > > > From my perspective the closest analogy: cond_timedwait(). > > > > So we need PMD to tell us what will be the address of the condition > > > > variable > > > > we should sleep on. > > > > > > > > > I agree with Jerin. > > > > > The ethdev API is the blocking problem. > > > > > First problem: it is not well explained in doxygen. > > > > > Second problem: it is probably not generic enough (if we understand > > > > > it well) > > > > > > > > It is an address to sleep(/wakeup) on, plus expected value. > > > > Honestly, I can't think-up of anything even more generic then that. > > > > If you guys have something particular in mind - please share. > > > > > > Current PMD callback: > > > typedef int (*eth_get_wake_addr_t)(void *rxq, volatile void > > > **tail_desc_addr, + uint64_t *expected, uint64_t *mask, uint8_t > > > *data_sz); > > > > > > Can we make it as > > > typedef void (*core_sleep_t)(void *rxq) > > > > > > if we do such abstraction and "move the polling on memory by HW/CPU" > > > to the driver using a helper function then > > > I can think of abstracting in some way in all PMDs. > > > > Ok I see, thanks for explanation. > > From my perspective main disadvantage of such approach - > > it can't be extended easily. > > If/when will have an ability for core to sleep/wake-up on multiple events > > (multiple addresses) will have to either rework that API again. > > I think, we can enumerate the policies and pass the associated > structures as input to the driver.
What I am trying to say: with that API we will not be able to wait for events from multiple devices (HW queues). I.E. something like that: get_wake_addr(port=X, ..., &addr[0], ...); get_wake_addr(port=Y,..., &addr[1],...); wait_on_multi(addr, 2); wouldn't be possible. > > > > > > > > > > Note: core_sleep_t can take some more arguments such as enumerated > > > policy if something more needs to be pushed to the driver. > > > > > > Thoughts? > > > > > > > > > > > > > > > > > > > This API is experimental and other vendor support can be added as > > > > > > > needed. If there are any other open issue let me know? > > > > > > > > > > Being experimental is not an excuse to throw something > > > > > which is not satisfying. > > > > > > > > > > > > > >
