From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from dpdk.org (dpdk.org [92.243.14.124]) by inbox.dpdk.org (Postfix) with ESMTP id E5FD5A04DD; Wed, 28 Oct 2020 17:47:44 +0100 (CET) Received: from [92.243.14.124] (localhost [127.0.0.1]) by dpdk.org (Postfix) with ESMTP id 7151D5947; Wed, 28 Oct 2020 17:47:43 +0100 (CET) Received: from mga03.intel.com (mga03.intel.com [134.134.136.65]) by dpdk.org (Postfix) with ESMTP id 7D87754AE for ; Wed, 28 Oct 2020 17:47:41 +0100 (CET) IronPort-SDR: de7iVza5NUXiJb5FeoTSBtR9PhR5G6uPB3EdRJkGYP4cQFo6DzQqkZ3rWBx1FW0ApRQpdIsRM9 BSo6lH6cXBSg== X-IronPort-AV: E=McAfee;i="6000,8403,9788"; a="168391465" X-IronPort-AV: E=Sophos;i="5.77,427,1596524400"; d="scan'208";a="168391465" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga006.jf.intel.com ([10.7.209.51]) by orsmga103.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 28 Oct 2020 09:47:40 -0700 IronPort-SDR: vqzplNhYKPmB9rHf2Mr9mnUGT5e70fpSx5HArRx516naWnQc09BUZuqZ8ql/SfPmK75MXB479o wPkmxYJAQVXg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.77,427,1596524400"; d="scan'208";a="323398916" Received: from irvmail001.ir.intel.com ([163.33.26.43]) by orsmga006.jf.intel.com with ESMTP; 28 Oct 2020 09:47:36 -0700 Received: from sivswdev09.ir.intel.com (sivswdev09.ir.intel.com [10.237.217.48]) by irvmail001.ir.intel.com (8.14.3/8.13.6/MailSET/Hub) with ESMTP id 09SGlarH029643; Wed, 28 Oct 2020 16:47:36 GMT Received: from sivswdev09.ir.intel.com (localhost [127.0.0.1]) by sivswdev09.ir.intel.com with ESMTP id 09SGlZAH019279; Wed, 28 Oct 2020 16:47:35 GMT Received: (from lma25@localhost) by sivswdev09.ir.intel.com with LOCAL id 09SGlZaa019264; Wed, 28 Oct 2020 16:47:35 GMT Date: Wed, 28 Oct 2020 16:47:35 +0000 From: "Liang, Ma" To: Jerin Jacob Cc: "Ananyev, Konstantin" , Thomas Monjalon , dpdk-dev , "Ruifeng Wang (Arm Technology China)" , "Wang, Haiyue" , "Richardson, Bruce" , "Hunt, David" , Neil Horman , "McDaniel, Timothy" , "Eads, Gage" , Marcin Wojtas , Guy Tzalik , Ajit Khaparde , Harman Kalra , John Daley , "Wei Hu (Xavier" , Ziyang Xuan , "matan@nvidia.com" , Yong Wang , "david.marchand@redhat.com" Message-ID: <20201028164735.GG29706@sivswdev09.ir.intel.com> References: <1603494392-7181-1-git-send-email-liang.j.ma@intel.com> <20201028133507.GC29706@sivswdev09.ir.intel.com> <2373759.1G5EZAqFcn@thomas> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Subject: Re: [dpdk-dev] [PATCH v10 0/9] Add PMD power mgmt X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" On 28 Oct 21:27, Jerin Jacob wrote: > On Wed, Oct 28, 2020 at 9:19 PM Ananyev, Konstantin > wrote: > > > > > > > 28/10/2020 14:49, Jerin Jacob: > > > > > > > > On Wed, Oct 28, 2020 at 7:05 PM Liang, Ma 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. > > I see. But the current implementation dictates the only queue bound to > a core. Right? Current implementation only support 1:1 queue/core mapping is because of the limitation of umwait/umonitor which can not work with multiple address range. However, for other scheme like PASUE/Freq Scale have no such limitation. The proposed API itself doesn't limit the 1:1 queue/core mapping. > > > > > > > > > > > > > > > > > > > > > > > > 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. > > > > > > > > > > > > > > > > > > > >