Either prefer "normal" or "realtime", via an enum, instead of a boolean.
Also make it configurable with an env var
`MUTTER_DEBUG_KMS_SCHEDULING_PRIORITY`, which can be set to either
`normal` or `realtime`.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/4124>
We're already inhibiting real time scheduling when reading new KMS state
after hot plugs, as well as when during mode sets, due to the kernel not
being able to reliably handle these within the 250 ms limit. However, we
didn't do this during initial probing, which meant that occasionally
we'd run into these kind of issues during startup.
Handle this by always inhibiting real time scheduling up front, and
don't uninhibit until all initially discovered device have finished
processing their initial mode set.
Closes: https://gitlab.gnome.org/GNOME/mutter/-/issues/3628
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3960>
At the moment if a thread is made real-time there's no going back,
it stays real-time for the duration of its life.
That's suboptimal because real-time threads are expected by RTKit to
have an rlimit on their CPU time and certain GPU drivers in the kernel
can exceed that CPU time during certain operations like DPMS off.
This commit adds two new ref counted functions:
meta_thread_{un,}inhibit_realtime_in_impl
that allow turning a thread real-time or normally scheduled. At the same
time, this commit stores the RTKit proxy as private data on the thread
so that it can be reused by the above apis.
A subsequent commit will use the new APIs.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3324>
Most of the code writes "real-time" as "realtime" not "real_time".
The only exception is one function `request_real_time_scheduling`.
This commit changes that function for consistency.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3324>
Dropped obsolete Free Software Foundation address pointing
to the FSF website instead as suggested by
https://www.gnu.org/licenses/gpl-howto.html
keeping intact the important part of the historical notice
as requested by the license.
Resolving rpmlint reported issue E: incorrect-fsf-address.
Signed-off-by: Sandro Bonazzola <sbonazzo@redhat.com>
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3155>
This signal is emitted before terminating the thread, but also when
resetting the thread type. This is to allow thread implementations to
make sure they have no stale pending callbacks to any old main contexts.
This commit "terminates" the impl thread even if there is no actual
thread; this is to trigger the "reset" signal, also when switching from
a user thread to a kernel thread.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/2777>
This means we can add COGL_TRACE*() instrumentation that is grouped
correctly in sysprof. If kernel threading is enabled, they will end up
in a "Compositor (KMS thread)" group (ignoring translations).
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/2777>
Real time scheduling is needed for better control of when we commit
updates to the kernel, so add a property to MetaThread that, if the
thread implementation uses a kernel thread and not a user thread, RTKit
is asked to make the thread real time scheduled using the maximum
priority allowed.
Currently RTKit doesn't support the GetAll() D-Bus properties method, so
some fall back code is added, as GDBusProxy depends on GetAll() working
to make the cached properties up to date. Once
https://github.com/heftig/rtkit/pull/30 lands and becomes widely
available in distributions, the work around can be dropped.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/2777>
This will be necessary in order to default to 'kernel' and then switch
to 'user' if the thread instance can no longer be properly multi
threaded.
To avoid having the same thread impl creating and destroying
GMainContext's, this also means always creating a GMainContext for the
thread-impl. When running in user-thread mode, the GMainContext is
wrapped in a wrapper source and dispatched as part of the real main
thread GMainContext, and when in kernel-thread mode, it runs
independently in the dedicated thread.
This has the consequence that the wrapper source will always have the
priority of the highest impl context GSource, but only after it has
dispatched once. Would we need it earlier than that, we either need a
way to introspect existing sources in a GMainContext and their
priorities, or manually track known sources in MetaThreadImpl.
The wrapper source will never be below 0, as that'd mean it could reach
INT_MAX priority if it had no more sources attached to it, meaning it'd
never be dispatched again.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/2777>
Callbacks could be queued to be invoked either on the impl side or the
main thread side of the thread; change this to take a GMainContext,
which effectively means a callback can be queued to be invoked on any
thread that has a GMainLoop running on its own GMainContext.
Flushing is made to handle flushing callbacks synchronously on all
threads. This works by keeping a hash table of queued callbacks per
thread (GMainContext); when flushing (from the main thread), callbacks
on the main thread context is flushed, followed by synchronization with
all the other threads.
meta_thread_flush_callbacks() is changed to no longer return the number
of dispatched callbacks; it becomes much harder when there are N queues
spread across multiple threads. Since it wasn't used for anything, just
drop the counting, making life slightly easier.
Feedback to thread tasks are however always queued on the callers
thread.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/2777>
This uses the queue that was introduced when migrating impl task
management from MetaThread to MetaThreadImpl, with the exception that
it's now fully used as an actual queue. It now has a GSource that sits
on the right GMainContext that is dispatched whenever there are tasks to
execute.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/2777>
It's the impl side that wants to add impl side idle sources, or fd
sources, etc, so make it part of MetaThreadImpl.
This changes things to be GAsyncQueue based. While things are still
technically single threaded, the GAsyncQueue type is used as later we'll
introduce queuing tasks asynchronously, then eventually queuing across
thread barriers.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/2777>
It currently does exactly what MetaKms and MetaKmsImpl did regarding the
context separation, which is to isolate what may eventually run on a KMS
thread into a separate unit. It works somewhat like a "user thread",
i.e. not a real thread, but will eventually learn how to spawn a
"kernel thread", but provide the same API from the outside.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/2777>
