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After applying wait-boost we often find ourselves stuck at higher clocks than required. The current threshold value requires the GPU to be continuously and completely idle for 313ms before it is dropped by one bin. Conversely, we require the GPU to be busy for an average of 90% over a 84ms period before we upclock. So the current thresholds almost never downclock the GPU, and respond very slowly to sudden demands for more power. It is easy to observe that we currently lock into the wrong bin and both underperform in benchmarks and consume more power than optimal (just by repeating the task and measuring the different results). An alternative approach, as discussed in the bspec, is to use a continuous threshold for upclocking, and an average value for downclocking. This is good for quickly detecting and reacting to state changes within a frame, however it fails with the common throttling method of waiting upon the outstanding frame - at least it is difficult to choose a threshold that works well at 15,000fps and at 60fps. So continue to use average busy/idle loads to determine frequency change. v2: Use 3 power zones to keep frequencies low in steady-state mostly idle (e.g. scrolling, interactive 2D drawing), and frequencies high for demanding games. In between those end-states, we use a fast-reclocking algorithm to converge more quickly on the desired bin. v3: Bug fixes - make sure we reset adj after switching power zones. v4: Tune - drop the continuous busy thresholds as it prevents us from choosing the right frequency for glxgears style swap benchmarks. Instead the goal is to be able to find the right clocks irrespective of the wait-boost. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Kenneth Graunke <kenneth@whitecape.org> Cc: Stéphane Marchesin <stephane.marchesin@gmail.com> Cc: Owen Taylor <otaylor@redhat.com> Cc: "Meng, Mengmeng" <mengmeng.meng@intel.com> Cc: "Zhuang, Lena" <lena.zhuang@intel.com> Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> |
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| .. | ||
| ast | ||
| cirrus | ||
| exynos | ||
| gma500 | ||
| i2c | ||
| i810 | ||
| i915 | ||
| mga | ||
| mgag200 | ||
| msm | ||
| nouveau | ||
| omapdrm | ||
| qxl | ||
| r128 | ||
| radeon | ||
| rcar-du | ||
| savage | ||
| shmobile | ||
| sis | ||
| tdfx | ||
| tilcdc | ||
| ttm | ||
| udl | ||
| via | ||
| vmwgfx | ||
| ati_pcigart.c | ||
| drm_agpsupport.c | ||
| drm_auth.c | ||
| drm_buffer.c | ||
| drm_bufs.c | ||
| drm_cache.c | ||
| drm_context.c | ||
| drm_crtc_helper.c | ||
| drm_crtc.c | ||
| drm_debugfs.c | ||
| drm_dma.c | ||
| drm_dp_helper.c | ||
| drm_drv.c | ||
| drm_edid_load.c | ||
| drm_edid.c | ||
| drm_encoder_slave.c | ||
| drm_fb_cma_helper.c | ||
| drm_fb_helper.c | ||
| drm_flip_work.c | ||
| drm_fops.c | ||
| drm_gem_cma_helper.c | ||
| drm_gem.c | ||
| drm_global.c | ||
| drm_hashtab.c | ||
| drm_info.c | ||
| drm_ioc32.c | ||
| drm_ioctl.c | ||
| drm_irq.c | ||
| drm_lock.c | ||
| drm_memory.c | ||
| drm_mm.c | ||
| drm_modes.c | ||
| drm_pci.c | ||
| drm_platform.c | ||
| drm_prime.c | ||
| drm_rect.c | ||
| drm_scatter.c | ||
| drm_stub.c | ||
| drm_sysfs.c | ||
| drm_trace_points.c | ||
| drm_trace.h | ||
| drm_usb.c | ||
| drm_vm.c | ||
| drm_vma_manager.c | ||
| Kconfig | ||
| Makefile | ||
| README.drm | ||
************************************************************
* For the very latest on DRI development, please see: *
* http://dri.freedesktop.org/ *
************************************************************
The Direct Rendering Manager (drm) is a device-independent kernel-level
device driver that provides support for the XFree86 Direct Rendering
Infrastructure (DRI).
The DRM supports the Direct Rendering Infrastructure (DRI) in four major
ways:
1. The DRM provides synchronized access to the graphics hardware via
the use of an optimized two-tiered lock.
2. The DRM enforces the DRI security policy for access to the graphics
hardware by only allowing authenticated X11 clients access to
restricted regions of memory.
3. The DRM provides a generic DMA engine, complete with multiple
queues and the ability to detect the need for an OpenGL context
switch.
4. The DRM is extensible via the use of small device-specific modules
that rely extensively on the API exported by the DRM module.
Documentation on the DRI is available from:
http://dri.freedesktop.org/wiki/Documentation
http://sourceforge.net/project/showfiles.php?group_id=387
http://dri.sourceforge.net/doc/
For specific information about kernel-level support, see:
The Direct Rendering Manager, Kernel Support for the Direct Rendering
Infrastructure
http://dri.sourceforge.net/doc/drm_low_level.html
Hardware Locking for the Direct Rendering Infrastructure
http://dri.sourceforge.net/doc/hardware_locking_low_level.html
A Security Analysis of the Direct Rendering Infrastructure
http://dri.sourceforge.net/doc/security_low_level.html