From: Thomas Monjalon <thomas@monjalon.net>
To: Bruce Richardson <bruce.richardson@intel.com>,
Dongdong Liu <liudongdong3@huawei.com>,
fengchengwen <fengchengwen@huawei.com>
Cc: dev@dpdk.org, Ferruh Yigit <ferruh.yigit@amd.com>,
andrew.rybchenko@oktetlabs.ru, dev@dpdk.org,
ciara.power@intel.com, kevin.laatz@intel.com,
david.marchand@redhat.com
Subject: Re: [PATCH v5 2/2] ethdev: support xstats reset telemetry command
Date: Mon, 20 Feb 2023 14:05:21 +0100 [thread overview]
Message-ID: <12802674.ZYm5mLc6kN@thomas> (raw)
In-Reply-To: <4ba214e6-6e9c-a527-0027-9f98b1fec537@huawei.com>
17/02/2023 10:44, fengchengwen:
> On 2023/2/16 20:54, Bruce Richardson wrote:
> > On Thu, Feb 16, 2023 at 08:42:34PM +0800, fengchengwen wrote:
> >> On 2023/2/16 20:06, Ferruh Yigit wrote:
> >>> On 2/16/2023 11:53 AM, fengchengwen wrote:
> >>>> On 2023/2/15 11:19, Dongdong Liu wrote:
> >>>>> Hi Chengwen
> >>>>>
> >>>>> On 2023/2/9 10:32, Chengwen Feng wrote:
> >>>>>> The xstats reset is useful for debugging, so add it to the ethdev
> >>>>>> telemetry command lists.
> >>>>>>
> >>>>>> Signed-off-by: Chengwen Feng <fengchengwen@huawei.com>
> >>>>> This patch looks good, so
> >>>>> Reviewed-by: Dongdong Liu <liudongdong3@huawei.com>
> >>>>>
> >>>>> A minior question
> >>>>> Do we need to support stats reset ?
> >>>>
> >>>> Stats is contained by xstats, and future direction I think is xstats.
> >>>> So I think we don't need support stats reset.
> >>>>
> >>>
> >>> I have similar question with Dongdong, readonly values are safe for
> >>> telemetry, but modifying data can be more tricky since we don't have
> >>> locking in ethdev APIs, this can cause concurrency issues.
> >>
> >> Yes, it indeed has concurrency issues.
> >>
> >>>
> >>> Overall do we want telemetry go that way and become something that
> >>> alters ethdev data/config?
> >>
> >> There are at least two part of data: config and status.
> >> For stats (which belong status data) could help for debugging, I think it's acceptable.
> >>
> >> As for concurrency issues. People should know what to do and when to do, just like
> >> the don't invoke config API (e.g. dev_configure/dev_start/...) concurrency.
> >>
> > While this is probably ok for now, I think in next release we should look
> > to add some sort of support for locking for destructive ops in a future
> > release. For example, we could:
> >
> > 1. Add support for marking a callback as "destructive" and only allow it to
> > be called if only one connection is present or
> >
> > 2. Make it possible for callbacks to query the number of connections so
> > that the callback itself is non-destructive in more than one connection is
> > open.
> >
> > [Both of these will require locking support so that new connections aren't
> > openned when the callback is in-flight!]
>
> Except telemetry, the application may have other console could execute DPDK API.
> So I think trying to keep it simple, it's up to the user to invoke.
No, the user should not be responsible for concurrency issues.
We can ask the app developper to take care,
but not to the user who has no control on what happens in the app.
On a more general note, I feel the expansion of telemetry is not controlled enough.
I would like to stop on adding more telemetry until we have a clear guideline
about what is telemetry for and how to use it.
next prev parent reply other threads:[~2023-02-20 13:05 UTC|newest]
Thread overview: 61+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-12-19 9:07 [PATCH v5 0/5] support dmadev/ethdev stats reset Chengwen Feng
2022-12-19 9:07 ` [PATCH v5 1/5] dmadev: support stats reset telemetry command Chengwen Feng
2022-12-19 9:07 ` [PATCH v5 2/5] telemetry: fix repeated display when callback don't set dict Chengwen Feng
2022-12-19 9:33 ` Bruce Richardson
2022-12-26 4:53 ` fengchengwen
2023-01-06 16:07 ` Bruce Richardson
2023-01-06 17:33 ` Bruce Richardson
2023-01-11 12:38 ` fengchengwen
2022-12-19 9:07 ` [PATCH v5 3/5] ethdev: support xstats reset telemetry command Chengwen Feng
2022-12-19 9:07 ` [PATCH v5 4/5] ethdev: telemetry xstats support hide zero Chengwen Feng
2022-12-19 9:07 ` [PATCH v5 5/5] ethdev: add newline to telemetry log string Chengwen Feng
2022-12-26 4:55 ` [PATCH v5 0/5] support dmadev/ethdev stats reset fengchengwen
2023-01-11 12:02 ` [PATCH v2 " Chengwen Feng
2023-01-11 12:02 ` [PATCH v2 1/5] dmadev: support stats reset telemetry command Chengwen Feng
2023-01-11 12:02 ` [PATCH v2 2/5] telemetry: fix repeat display when callback don't set dict Chengwen Feng
2023-01-11 12:02 ` [PATCH v2 3/5] ethdev: add newline to telemetry log string Chengwen Feng
2023-01-11 12:02 ` [PATCH v2 4/5] ethdev: support xstats reset telemetry command Chengwen Feng
2023-01-11 12:02 ` [PATCH v2 5/5] ethdev: telemetry xstats support hide zero Chengwen Feng
2023-01-11 12:06 ` [PATCH v2 0/5] support dmadev/ethdev stats reset Chengwen Feng
2023-01-11 12:06 ` [PATCH v2 1/5] dmadev: support stats reset telemetry command Chengwen Feng
2023-01-11 13:58 ` Bruce Richardson
2023-01-11 12:06 ` [PATCH v2 2/5] telemetry: fix repeat display when callback don't set dict Chengwen Feng
2023-01-11 14:01 ` Bruce Richardson
2023-01-11 12:06 ` [PATCH v2 3/5] ethdev: add newline to telemetry log string Chengwen Feng
2023-01-11 12:06 ` [PATCH v2 4/5] ethdev: support xstats reset telemetry command Chengwen Feng
2023-01-11 12:06 ` [PATCH v2 5/5] ethdev: telemetry xstats support hide zero Chengwen Feng
2023-01-11 14:08 ` Bruce Richardson
2023-01-20 3:51 ` fengchengwen
2023-01-11 12:36 ` [PATCH v2 0/5] support dmadev/ethdev stats reset fengchengwen
2023-01-20 3:25 ` [PATCH v3 " Chengwen Feng
2023-01-20 3:25 ` [PATCH v3 1/5] dmadev: support stats reset telemetry command Chengwen Feng
2023-01-20 3:25 ` [PATCH v3 2/5] telemetry: fix repeat display when callback don't init dict Chengwen Feng
2023-01-20 3:25 ` [PATCH v3 3/5] ethdev: add newline to telemetry log string Chengwen Feng
2023-01-20 3:25 ` [PATCH v3 4/5] ethdev: support xstats reset telemetry command Chengwen Feng
2023-01-20 3:25 ` [PATCH v3 5/5] ethdev: telemetry xstats support hide zero Chengwen Feng
2023-01-20 3:34 ` [PATCH v4 0/5] support dmadev/ethdev stats reset Chengwen Feng
2023-01-20 3:34 ` [PATCH v4 1/5] dmadev: support stats reset telemetry command Chengwen Feng
2023-01-20 3:34 ` [PATCH v4 2/5] telemetry: fix repeat display when callback don't init dict Chengwen Feng
2023-02-08 14:15 ` Bruce Richardson
2023-02-09 1:33 ` fengchengwen
2023-01-20 3:34 ` [PATCH v4 3/5] ethdev: add newline to telemetry log string Chengwen Feng
2023-01-20 3:34 ` [PATCH v4 4/5] ethdev: support xstats reset telemetry command Chengwen Feng
2023-01-20 3:34 ` [PATCH v4 5/5] ethdev: telemetry xstats support hide zero Chengwen Feng
2023-02-06 8:39 ` [PATCH v4 0/5] support dmadev/ethdev stats reset Thomas Monjalon
2023-02-08 14:17 ` Bruce Richardson
2023-02-09 1:45 ` fengchengwen
2023-02-09 2:32 ` [PATCH v5 0/2] " Chengwen Feng
2023-02-09 2:32 ` [PATCH v5 1/2] dmadev: support stats reset telemetry command Chengwen Feng
2023-02-09 2:32 ` [PATCH v5 2/2] ethdev: support xstats " Chengwen Feng
2023-02-15 3:19 ` Dongdong Liu
2023-02-16 11:53 ` fengchengwen
2023-02-16 12:06 ` Ferruh Yigit
2023-02-16 12:42 ` fengchengwen
2023-02-16 12:54 ` Bruce Richardson
2023-02-16 12:55 ` Bruce Richardson
2023-02-17 9:44 ` fengchengwen
2023-02-20 13:05 ` Thomas Monjalon [this message]
2023-07-03 3:58 ` fengchengwen
2023-07-03 7:20 ` Thomas Monjalon
2023-07-03 13:44 ` Morten Brørup
2023-07-04 6:41 ` fengchengwen
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