Before commit b571ae6e7a ("intel: Make memory heaps consistent
between KMDs"), we had the following policy for reporting Sytem RAM
memory sizes:
- For OpenGL, we reported the total available RAM.
- For Vulkan, we reported the total available RAM as:
- 50% of the total RAM if the total RAM was <= 4GB,
- 75% otherwise
- In addition, the Memory Budget (for VK_EXT_memory_budget) is 90%
of the "free" memory, which can be an extra 10% off of the 50% or
75%.
When xe.ko was added, one key difference was noted: while i915.ko
reported the "real" RAM memory sizes in its ioctls, xe.ko reported
only 50% of the system RAM as available. Because of that (and other
reasons, see this discussion on MR 28513), commit b571ae6e7a decided
to unify the behavior by changing the Anv i915.ko rule to "always 50%"
instead of "50% or 75%". This also changed the Iris rule to 50%
instead of 100%.
In my research, I couldn't find any reason why this restriction should
also apply to Iris, so here we revert back to handling these size
restrictions on Anv only.
Reviewed-by: José Roberto de Souza <jose.souza@intel.com>
Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/28513>
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