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When Dave originally added SLM, he did so with a preamble pushbuf which sets up the SLM area prior to executing any actual command buffers. This has the advantage that the SLM BO is never directly referenced in any command buffer and we can swap it out even after command buffers have been built. When I added image/sampler tables, I sort-of went along with it but then did something different for 3D. Thanks to buffer reference counting, we can employ a fairly simple locking scheme. Each of the globals: images, samplers, and TSL has a lock which gets taken whenever the table is modified. When we go to do a submit, we take each lock and take a queue-local reference to the BO and grab a copy of its size parameter under the lock. If anything has changed, we update the queue-local preamble pushbuf. Because the queue also holds a reference, we can safely proceed to submit command buffers which reference those global BOs without the individual global locks taken. If SLM or one of the descriptor tables resizes while we're mid-submit, our reference to the BO will remain valid until either the destruction of the queue or the next submit. The one small bit of threaded cleverness (one always has to be careful with that) is that the SLM size can be checked without taking the lock because the SLM size only ever increases. Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/24326>
`Mesa <https://mesa3d.org>`_ - The 3D Graphics Library ====================================================== Source ------ This repository lives at https://gitlab.freedesktop.org/mesa/mesa. Other repositories are likely forks, and code found there is not supported. Build & install --------------- You can find more information in our documentation (`docs/install.rst <https://mesa3d.org/install.html>`_), but the recommended way is to use Meson (`docs/meson.rst <https://mesa3d.org/meson.html>`_): .. code-block:: sh $ mkdir build $ cd build $ meson .. $ sudo ninja install Support ------- Many Mesa devs hang on IRC; if you're not sure which channel is appropriate, you should ask your question on `OFTC's #dri-devel <irc://irc.oftc.net/dri-devel>`_, someone will redirect you if necessary. Remember that not everyone is in the same timezone as you, so it might take a while before someone qualified sees your question. To figure out who you're talking to, or which nick to ping for your question, check out `Who's Who on IRC <https://dri.freedesktop.org/wiki/WhosWho/>`_. The next best option is to ask your question in an email to the mailing lists: `mesa-dev\@lists.freedesktop.org <https://lists.freedesktop.org/mailman/listinfo/mesa-dev>`_ Bug reports ----------- If you think something isn't working properly, please file a bug report (`docs/bugs.rst <https://mesa3d.org/bugs.html>`_). Contributing ------------ Contributions are welcome, and step-by-step instructions can be found in our documentation (`docs/submittingpatches.rst <https://mesa3d.org/submittingpatches.html>`_). Note that Mesa uses gitlab for patches submission, review and discussions.