From cf9610f9116d55c5a66ef9f1faecacabd93a9322 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Mon, 24 Aug 2026 08:46:03 -0700 Subject: Merge tag 'pinctrl-v7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl Pull pin control updates from Linus Walleij: "Core changes: - Use the non-blocking mux_state_try_select() in the generic MUX pin control back-end - Free pin maps on pinctrl_generic_to_map() failure in the core helpers New hardware pin control: - Qualcomm Maili TLMM SoC, PMG1110 PMIC, and Eliza LPASS LPI TLMM SoC (this is for the low power audio, LPASS = Low Power Audio SubSystem portions) - Upboard support on top of the Intel pin controller - Apple T6030 and T6031 support (just compatible strings) - Samsung Exynos 8855 SoC - Mediatek MT6858 SoC - Rockchip RK3308B and RV1106 SoCs - Airoha EN7523 and AN7563 SoCs Improvements: - Qualcomm TLMM GPIOs are unconditionally marked as wakeup capable - Qualcomm improvements on top of the Qualcomm PDC (power domain controller) irqchip improvements from tglx:s tree - Qualcomm IPQ806x and IPQ9650 non-urgent pin grop fixups - The NPCM8xx driver has been put into shape fixing many pin and group definitions - Some non-urgent Tegra 264 pin assignments are fixed up - Some non-urgent fixups to Airoha AN7581 and AN7583 registers and pin assignments, missing features etc" * tag 'pinctrl-v7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl: (130 commits) dt-bindings: pinctrl: Convert TI DA850 pupd to DT schema pinctrl: meson: sync some modify from A4 pinctrl: meson: a4: Add input enable pin configuration pinctrl: realtek: rtd1625: remove unused group name spdif_sel pinctrl: realtek: rtd1625: fix base_bit for VE4 GPIO 13 dt-bindings: pinctrl: microchip,pic32mzda-pinctrl: Convert to DT schema Revert "Merge branch 'ib-rsk7204' into devel" pinctrl: rockchip: Add RV1106 pinctrl support dt-bindings: pinctrl: rockchip: Add RV1106 compatible pinctrl: rockchip: Decode drive strength in the get function pinctrl: fix PINCTRL_GENERIC_MUX not always being selectable pinctrl: airoha: add support of an7563 SoC dt-bindings: pinctrl: airoha: add support of an7563 pin controller pinctrl: airoha: try to find chip scu node by phandle first pinctrl: airoha: add support of en7523 SoC dt-bindings: pinctrl: airoha: add support of en7523 pin controller pinctrl: airoha: an7583: add support for olt pinmux pinctrl: airoha: an7583: add support for pon_alt pinmux pinctrl: airoha: an7583: add support for npu_uart pinmux dt-bindings: pinctrl: airoha: an7583: add missed features ... --- Documentation/gpu/drm-compute.rst | 54 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 54 insertions(+) create mode 100644 Documentation/gpu/drm-compute.rst (limited to 'Documentation/gpu/drm-compute.rst') diff --git a/Documentation/gpu/drm-compute.rst b/Documentation/gpu/drm-compute.rst new file mode 100644 index 000000000..f90c3e63a --- /dev/null +++ b/Documentation/gpu/drm-compute.rst @@ -0,0 +1,54 @@ +================================== +Long running workloads and compute +================================== + +Long running workloads (compute) are workloads that will not complete in 10 +seconds. (The time let the user wait before he reaches for the power button). +This means that other techniques need to be used to manage those workloads, +that cannot use fences. + +Some hardware may schedule compute jobs, and have no way to pre-empt them, or +have their memory swapped out from them. Or they simply want their workload +not to be preempted or swapped out at all. + +This means that it differs from what is described in driver-api/dma-buf.rst. + +As with normal compute jobs, dma-fence may not be used at all. In this case, +not even to force preemption. The driver with is simply forced to unmap a BO +from the long compute job's address space on unbind immediately, not even +waiting for the workload to complete. Effectively this terminates the workload +when there is no hardware support to recover. + +Since this is undesirable, there need to be mitigations to prevent a workload +from being terminated. There are several possible approach, all with their +advantages and drawbacks. + +The first approach you will likely try is to pin all buffers used by compute. +This guarantees that the job will run uninterrupted, but also allows a very +denial of service attack by pinning as much memory as possible, hogging the +all GPU memory, and possibly a huge chunk of CPU memory. + +A second approach that will work slightly better on its own is adding an option +not to evict when creating a new job (any kind). If all of userspace opts in +to this flag, it would prevent cooperating userspace from forced terminating +older compute jobs to start a new one. + +If job preemption and recoverable pagefaults are not available, those are the +only approaches possible. So even with those, you want a separate way of +controlling resources. The standard kernel way of doing so is cgroups. + +This creates a third option, using cgroups to prevent eviction. Both GPU and +driver-allocated CPU memory would be accounted to the correct cgroup, and +eviction would be made cgroup aware. This allows the GPU to be partitioned +into cgroups, that will allow jobs to run next to each other without +interference. + +The interface to the cgroup would be similar to the current CPU memory +interface, with similar semantics for min/low/high/max, if eviction can +be made cgroup aware. + +What should be noted is that each memory region (tiled memory for example) +should have its own accounting. + +The key is set to the regionid set by the driver, for example "tile0". +For the value of $card, we use drmGetUnique(). -- cgit v1.3.1