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From:   Emil Velikov <emil.l.velikov@gmail.com>
Date:   Tue, 20 Jun 2023 15:48:42 +0100
Message-ID: <CACvgo51DmeM7Tbboozxu3Yn-Pe-eALVTkiq4vZBJJHKfqP_HeA@mail.gmail.com>
Subject: Re: [RFC 02/10] drm: Update file owner during use
To:     Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Cc:     Intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org,
        Rob Clark <robdclark@chromium.org>,
        Brian Welty <brian.welty@intel.com>, Kenny.Ho@amd.com,
        Tvrtko Ursulin <tvrtko.ursulin@intel.com>,
        Daniel Vetter <daniel.vetter@ffwll.ch>,
        Johannes Weiner <hannes@cmpxchg.org>,
        linux-kernel@vger.kernel.org,
        =?UTF-8?Q?St=C3=A9phane_Marchesin?= <marcheu@chromium.org>,
        =?UTF-8?Q?Christian_K=C3=B6nig?= <christian.koenig@amd.com>,
        Zefan Li <lizefan.x@bytedance.com>,
        Dave Airlie <airlied@redhat.com>, Tejun Heo <tj@kernel.org>,
        cgroups@vger.kernel.org, "T . J . Mercier" <tjmercier@google.com>
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Hi Tvrtko

Sorry for the delay, real life and other obligations got in the way.

On Thu, 8 Jun 2023 at 15:26, Tvrtko Ursulin
<tvrtko.ursulin@linux.intel.com> wrote:
> On 21/04/2023 13:13, Emil Velikov wrote:

> Are you okay if I just paste your very fine explanation verbatim, with
> credits?
>

Yes, feel free to use as much of if as you see reasonable.

> > I also had a brief look at 01/10, although I cannot find many
> > references for the pid <> tguid mappings. Be that on the kernel side
> > or userspace - do you have any links that I can educate myself?
>
> TGID or thread group leader. For single threaded userspace TGID equals
> to PID, while for multi-threaded first thread TGID equals PID/TID, while
> additional threads PID/TID does not equal TGID. Clear, as mud? :) My
> POSIX book is misplaced somewhere having not consulted it years... :)
>

Ack. /me looks into actually buying one, perhaps

Thanks
Emil