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From: peterz@infradead.org
To: Qais Yousef <qais.yousef@arm.com>
Cc: Dietmar Eggemann <dietmar.eggemann@arm.com>,
	vincent.donnefort@arm.com, mingo@redhat.com,
	vincent.guittot@linaro.org, linux-kernel@vger.kernel.org,
	valentin.schneider@arm.com, Phil Auld <pauld@redhat.com>
Subject: Re: [PATCH v2] sched/debug: Add new tracepoint to track cpu_capacity
Date: Mon, 7 Sep 2020 13:13:20 +0200	[thread overview]
Message-ID: <20200907111320.GP2674@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <20200907104845.6rust2lf2o3d5gmq@e107158-lin.cambridge.arm.com>

On Mon, Sep 07, 2020 at 11:48:45AM +0100, Qais Yousef wrote:
> IMHO the above is a hack. Out-of-tree modules should rely on public headers and
> exported functions only. What you propose means that people who want to use
> these tracepoints in meaningful way must have a prebuilt kernel handy. Which is
> maybe true for us who work in the embedded world. But users who run normal
> distro kernels (desktop/servers) will fail to build against

But this isn't really aimed at regular users. We're aiming this at
developers (IIUC) so I dont really see this as a problem.

> FWIW, I did raise this concern with Peter in 2019 OSPM and he was okay with the
> exports as it's still not a contract and they can disappear anytime we want.
> Migrating to using BTF is the right way forward IMO. I don't think what we have
> here is out-of-control yet. Though I agree they're annoying.

Right, we're hiding behind the explicit lack of ABI for modules.

Anyway, CTF/BTF/random other crap that isn't DWARFs should work fine to
replace all this muck. Just no idea what the state of any of that is.

  reply	other threads:[~2020-09-07 17:54 UTC|newest]

Thread overview: 26+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-08-28  9:00 [PATCH v2] sched/debug: Add new tracepoint to track cpu_capacity vincent.donnefort
2020-08-28 10:27 ` Qais Yousef
2020-08-28 17:10   ` Dietmar Eggemann
2020-08-28 17:26     ` Qais Yousef
2020-09-02 10:44       ` Dietmar Eggemann
2020-09-02 13:54         ` Phil Auld
2020-09-07 11:02           ` Qais Yousef
2020-09-08 13:19             ` Phil Auld
2020-09-08 15:22               ` Qais Yousef
2021-01-04 18:26               ` Qais Yousef
2021-01-04 18:59                 ` Alexei Starovoitov
2021-01-05 11:38                   ` Qais Yousef
2021-01-05 16:44                     ` Alexei Starovoitov
2021-01-06 11:27                       ` Qais Yousef
2021-01-06 23:42                         ` Andrii Nakryiko
2021-01-07 11:23                           ` Qais Yousef
2021-01-11 14:04                 ` Peter Zijlstra
2021-01-11 14:08                   ` Qais Yousef
2020-09-07 10:48         ` Qais Yousef
2020-09-07 11:13           ` peterz [this message]
2020-09-07 14:51             ` Qais Yousef
2020-09-08 11:17               ` Dietmar Eggemann
2020-09-08 15:17                 ` Qais Yousef
2020-09-08 16:17                   ` Dietmar Eggemann
2021-01-04 15:18             ` Qais Yousef
2020-10-05  7:43 ` [tip: sched/core] " tip-bot2 for Vincent Donnefort

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