Message-ID: <c82660f4-e2d0-35ca-304a-57d1abcf814d@asahilina.net>
Date:   Thu, 9 Mar 2023 02:44:42 +0900
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Subject: Re: [PATCH RFC 11/18] drm/scheduler: Clean up jobs when the scheduler
 is torn down
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To:     alyssa@rosenzweig.io,
        =?UTF-8?Q?Christian_K=c3=b6nig?= <christian.koenig@amd.com>,
        Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
        Maxime Ripard <mripard@kernel.org>,
        Thomas Zimmermann <tzimmermann@suse.de>,
        David Airlie <airlied@gmail.com>,
        Daniel Vetter <daniel@ffwll.ch>,
        Miguel Ojeda <ojeda@kernel.org>,
        Alex Gaynor <alex.gaynor@gmail.com>,
        Wedson Almeida Filho <wedsonaf@gmail.com>,
        Boqun Feng <boqun.feng@gmail.com>, Gary Guo <gary@garyguo.net>,
        =?UTF-8?Q?Bj=c3=b6rn_Roy_Baron?= <bjorn3_gh@protonmail.com>,
        Sumit Semwal <sumit.semwal@linaro.org>,
        Luben Tuikov <luben.tuikov@amd.com>,
        Jarkko Sakkinen <jarkko@kernel.org>,
        Dave Hansen <dave.hansen@linux.intel.com>
Cc:     Karol Herbst <kherbst@redhat.com>,
        Ella Stanforth <ella@iglunix.org>,
        Faith Ekstrand <faith.ekstrand@collabora.com>,
        Mary <mary@mary.zone>, linux-kernel@vger.kernel.org,
        dri-devel@lists.freedesktop.org, rust-for-linux@vger.kernel.org,
        linux-media@vger.kernel.org, linaro-mm-sig@lists.linaro.org,
        linux-sgx@vger.kernel.org, asahi@lists.linux.dev
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 <20230307-rust-drm-v1-11-917ff5bc80a8@asahilina.net>
 <bbd7c5ee-c2f0-3e19-757d-a9aff1a26d3d@linux.intel.com>
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 <3320e497-09c0-6eb6-84c5-bab2e63f28ec@asahilina.net>
 <7b39ef96-3ec5-c492-6e1b-bf065b7c90a2@amd.com>
 <8e93126cfaf47ebad0dc70e038ccc92f@rosenzweig.io>
From:   Asahi Lina <lina@asahilina.net>
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On 09/03/2023 02.39, alyssa@rosenzweig.io wrote:
>> You can't ask me for a list
>> of pending jobs (the scheduler knows this, it doesn't make any sense to
>> duplicate that outside)
> 
> Silly question: could you add a new exported function to drm_sched to get the list of pending jobs, to be used by the Rust abstraction internally? IDK if that makes any sense.

The drm_sched struct is public, we could just go in there and do it
anyway... but then I need to figure out how to do
`list_for_each_entry_safe` in Rust and this all makes very little sense
when it's clearly the scheduler's job to provide some form of cleanup
function users can use to do it...

I mean, I guess I can do that if Christian is adamantly against
providing a safe C API, but it's clearly not the right solution and I
hope this is not the approach maintainers take with Rust abstractions,
because that's going to make our lives a lot harder for no good reason,
and it also means C users don't get any of the benefits of Rust
abstraction work if the APIs can't be improved at all along with it.

~~ Lina