linux/drivers/gpu/drm
Chris Wilson 11abf0c5a0 drm/i915: Limit the backpressure for i915_request allocation
If we try and fail to allocate a i915_request, we apply some
backpressure on the clients to throttle the memory allocations coming
from i915.ko. Currently, we wait until completely idle, but this is far
too heavy and leads to some situations where the only escape is to
declare a client hung and reset the GPU. The intent is to only ratelimit
the allocation requests and to allow ourselves to recycle requests and
memory from any long queues built up by a client hog.

Although the system memory is inherently a global resources, we don't
want to overly penalize an unlucky client to pay the price of reaping a
hog. To reduce the influence of one client on another, we can instead of
waiting for the entire GPU to idle, impose a barrier on the local client.
(One end goal for request allocation is for scalability to many
concurrent allocators; simultaneous execbufs.)

To prevent ourselves from getting caught out by long running requests
(requests that may never finish without userspace intervention, whom we
are blocking) we need to impose a finite timeout, ideally shorter than
hangcheck. A long time ago Paul McKenney suggested that RCU users should
ratelimit themselves using judicious use of cond_synchronize_rcu(). This
gives us the opportunity to reduce our indefinite wait for the GPU to
idle to a wait for the RCU grace period of the previous allocation along
this timeline to expire, satisfying both the local and finite properties
we desire for our ratelimiting.

There are still a few global steps (reclaim not least amongst those!)
when we exhaust the immediate slab pool, at least now the wait is itself
decoupled from struct_mutex for our glorious highly parallel future!

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=106680
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180914080017.30308-1-chris@chris-wilson.co.uk
2018-09-14 11:54:59 +01:00
..
amd Merge branch 'drm-next-4.19' of git://people.freedesktop.org/~agd5f/linux into drm-next 2018-07-20 14:54:31 +10:00
arc drm: drop _mode_ from drm_mode_connector_attach_encoder 2018-07-13 18:40:27 +02:00
arm Merge commit 'refs/for-upstream/mali-dp' of git://linux-arm.org/linux-ld into drm-next 2018-07-06 10:02:13 +10:00
armada dma-buf: remove kmap_atomic interface 2018-06-20 15:59:34 +02:00
ast drm: drop _mode_ from drm_mode_connector_attach_encoder 2018-07-13 18:40:27 +02:00
atmel-hlcdc Merge v4.18-rc3 into drm-next 2018-07-04 10:27:12 +10:00
bochs drm: drop _mode_ from drm_mode_connector_attach_encoder 2018-07-13 18:40:27 +02:00
bridge drm: drop _mode_ from drm_mode_connector_attach_encoder 2018-07-13 18:40:27 +02:00
cirrus drm: drop _mode_ from drm_mode_connector_attach_encoder 2018-07-13 18:40:27 +02:00
etnaviv drm/scheduler: modify args of drm_sched_entity_init 2018-07-13 14:46:05 -05:00
exynos drm: drop _mode_ from drm_mode_connector_attach_encoder 2018-07-13 18:40:27 +02:00
fsl-dcu drm: drop _mode_ from drm_mode_connector_attach_encoder 2018-07-13 18:40:27 +02:00
gma500 drm: drop _mode_ from drm_mode_connector_attach_encoder 2018-07-13 18:40:27 +02:00
hisilicon drm: drop _mode_ from drm_mode_connector_attach_encoder 2018-07-13 18:40:27 +02:00
i2c drm: drop _mode_ from drm_mode_connector_attach_encoder 2018-07-13 18:40:27 +02:00
i810 drm/i810: off by one in i810_dma_vertex() 2018-07-03 15:00:42 +02:00
i915 drm/i915: Limit the backpressure for i915_request allocation 2018-09-14 11:54:59 +01:00
imx drm: drop _mode_ from drm_mode_connector_attach_encoder 2018-07-13 18:40:27 +02:00
lib
mediatek drm-misc-next for 4.19: 2018-07-20 10:46:49 +10:00
meson drm/meson: Make DMT timings parameters and pixel clock generic 2018-07-16 11:14:59 +02:00
mga
mgag200 drm: drop _mode_ from drm_mode_connector_attach_encoder 2018-07-13 18:40:27 +02:00
msm drm: drop _mode_ from remaining connector functions 2018-07-13 18:40:27 +02:00
mxsfb
nouveau drm-misc-next for 4.19: 2018-07-20 10:46:49 +10:00
omapdrm drm: drop _mode_ from drm_mode_connector_attach_encoder 2018-07-13 18:40:27 +02:00
panel drm: drop _mode_ from update_edit_property() 2018-07-13 18:40:27 +02:00
pl111 drm/pl111: Use 64-bit arithmetic instead of 32-bit 2018-07-17 11:25:18 -07:00
qxl drm: drop _mode_ from drm_mode_connector_attach_encoder 2018-07-13 18:40:27 +02:00
r128
radeon drm-misc-next for 4.19: 2018-07-20 10:46:49 +10:00
rcar-du drm: drop _mode_ from drm_mode_connector_attach_encoder 2018-07-13 18:40:27 +02:00
rockchip drm/rockchip: Substitute is_yuv_support() with format->is_yuv 2018-07-18 16:59:27 +01:00
savage drm/savage: off by one in savage_bci_cmdbuf() 2018-07-04 14:27:01 +02:00
scheduler drm/scheduler: add NULL pointer check for run queue (v2) 2018-07-16 16:11:48 -05:00
selftests drm-misc-next for 4.19: 2018-06-22 12:58:08 +10:00
shmobile drm: drop _mode_ from drm_mode_connector_attach_encoder 2018-07-13 18:40:27 +02:00
sis
sti drm: drop _mode_ from drm_mode_connector_attach_encoder 2018-07-13 18:40:27 +02:00
stm drm/stm: Replace drm_dev_unref with drm_dev_put 2018-07-13 10:11:02 +02:00
sun4i drm/sun4i: Substitute sun4i_backend_format_is_yuv() with format->is_yuv 2018-07-18 17:00:29 +01:00
tdfx
tegra drm: drop _mode_ from drm_mode_connector_attach_encoder 2018-07-13 18:40:27 +02:00
tilcdc drm-misc-next for 4.19: 2018-07-20 10:46:49 +10:00
tinydrm drm/tinydrm: add backlight dependency for ili9341 2018-07-12 12:10:07 -05:00
ttm drm/ttm: Replace ttm_bo_unref() with ttm_bo_put() 2018-07-10 14:18:28 -05:00
tve200
udl drm: drop _mode_ from drm_mode_connector_attach_encoder 2018-07-13 18:40:27 +02:00
v3d Merge branch 'drm-next-4.19' of git://people.freedesktop.org/~agd5f/linux into drm-next 2018-07-20 14:54:31 +10:00
vc4 drm/vc4: Replace drm_dev_unref with drm_dev_put 2018-07-17 11:24:33 -07:00
vgem drm/vgem: off by one in vgem_gem_fault() 2018-07-03 15:06:15 +02:00
via treewide: Use array_size() in vzalloc() 2018-06-12 16:19:22 -07:00
virtio drm: drop _mode_ from drm_mode_connector_attach_encoder 2018-07-13 18:40:27 +02:00
vkms drm: drop _mode_ from drm_mode_connector_attach_encoder 2018-07-13 18:40:27 +02:00
vmwgfx drm-misc-next for 4.19: 2018-07-20 10:46:49 +10:00
xen drm-misc-next for 4.19: 2018-06-22 12:58:08 +10:00
zte drm: drop _mode_ from drm_mode_connector_attach_encoder 2018-07-13 18:40:27 +02:00
ati_pcigart.c
drm_agpsupport.c
drm_atomic_helper.c drm: drop _mode_ from remaining connector functions 2018-07-13 18:40:27 +02:00
drm_atomic.c drm/atomic: Avoid connector to writeback_connector casts 2018-07-07 07:51:19 +02:00
drm_auth.c
drm_blend.c
drm_bridge.c
drm_bufs.c
drm_cache.c
drm_client.c drm/client: Fix double free in error path 2018-07-13 12:07:46 +02:00
drm_color_mgmt.c
drm_connector.c drm/connector: Fix typo in drm_connector_list_iter_next() 2018-07-16 13:18:09 -04:00
drm_context.c
drm_crtc_helper_internal.h
drm_crtc_helper.c
drm_crtc_internal.h drm: drop _mode_ from remaining connector functions 2018-07-13 18:40:27 +02:00
drm_crtc.c drm: Skip __drm_mode_set_config_internal() on atomic drivers 2018-07-13 17:58:19 +03:00
drm_debugfs_crc.c drm/crc: Only report a single overflow when a CRC fd is opened 2018-07-06 14:57:03 +02:00
drm_debugfs.c drm: drop _mode_ from update_edit_property() 2018-07-13 18:40:27 +02:00
drm_dma.c
drm_dp_aux_dev.c
drm_dp_cec.c drm: add support for DisplayPort CEC-Tunneling-over-AUX 2018-07-13 17:58:19 +03:00
drm_dp_dual_mode_helper.c
drm_dp_helper.c drm/dp_helper: Add DP aux channel tracing 2018-07-16 11:47:53 -04:00
drm_dp_mst_topology.c drm: drop _mode_ from remaining connector functions 2018-07-13 18:40:27 +02:00
drm_drv.c drm/dp_helper: Add DP aux channel tracing 2018-07-16 11:47:53 -04:00
drm_dumb_buffers.c drm-misc-next for 4.19: 2018-06-28 13:29:07 +10:00
drm_edid_load.c
drm_edid.c drm-misc-next for 4.19: 2018-06-22 12:58:08 +10:00
drm_encoder_slave.c
drm_encoder.c
drm_fb_cma_helper.c drm/cma-helper: Remove drm_fb_cma_fbdev_init_with_funcs() 2018-07-10 14:54:50 +02:00
drm_fb_helper.c drm/fb-helper: Finish the generic fbdev emulation 2018-07-10 14:54:09 +02:00
drm_file.c drm: Begin an API for in-kernel clients 2018-07-10 14:51:37 +02:00
drm_flip_work.c
drm_fourcc.c drm/fourcc: Add is_yuv field to drm_format_info to denote if the format is yuv 2018-07-18 16:56:45 +01:00
drm_framebuffer.c drm: Add drm_plane_mask() 2018-07-02 18:45:55 +03:00
drm_gem_cma_helper.c
drm_gem_framebuffer_helper.c drm/gem-fb-helper: Always do implicit sync 2018-06-20 14:43:13 +02:00
drm_gem.c drm/i915: Prevent writing into a read-only object via a GGTT mmap 2018-07-13 16:14:04 +01:00
drm_global.c drm: add SPDX identifier and clarify license 2018-06-29 15:28:47 -05:00
drm_hashtab.c treewide: Use array_size() in vzalloc() 2018-06-12 16:19:22 -07:00
drm_info.c
drm_internal.h drm: provide management functions for drm_file 2018-06-25 16:17:03 +02:00
drm_ioc32.c
drm_ioctl.c drm: drop _mode_ from remaining connector functions 2018-07-13 18:40:27 +02:00
drm_irq.c
drm_kms_helper_common.c
drm_lease.c
drm_legacy.h
drm_lock.c
drm_memory.c treewide: Use array_size() in vmalloc() 2018-06-12 16:19:22 -07:00
drm_mipi_dsi.c
drm_mm.c drm/mm: Add a search-by-address variant to only inspect a single hole 2018-05-24 15:04:30 +01:00
drm_mode_config.c drm: writeback: Add client capability for exposing writeback connectors 2018-06-20 15:30:20 +01:00
drm_mode_object.c drm: drop _mode_ from remaining connector functions 2018-07-13 18:40:27 +02:00
drm_modes.c drm: drop _mode_ from remaining connector functions 2018-07-13 18:40:27 +02:00
drm_modeset_helper.c
drm_modeset_lock.c drm: Change deadlock-avoidance algorithm for the modeset locks. 2018-07-03 09:46:05 +02:00
drm_of.c drm/doc: Include drm_of.c helpers 2018-07-13 18:40:28 +02:00
drm_panel_orientation_quirks.c drm: panel-orientation-quirks: Convert to use match_string() helper 2018-05-10 11:36:25 -04:00
drm_panel.c drm/panel: Let of_drm_find_panel() return -ENODEV when the panel is disabled 2018-07-10 17:59:05 +02:00
drm_pci.c drm: drop drm_pcie_get_speed_cap_mask and drm_pcie_get_max_link_width 2018-07-05 16:40:00 -05:00
drm_plane_helper.c drm: add missing ctx argument to plane transitional helpers 2018-07-03 09:30:19 +02:00
drm_plane.c drm: Introduce __setplane_atomic() 2018-07-13 17:58:19 +03:00
drm_prime.c dma-buf: remove kmap_atomic interface 2018-06-20 15:59:34 +02:00
drm_print.c
drm_probe_helper.c drm: drop _mode_ from remaining connector functions 2018-07-13 18:40:27 +02:00
drm_property.c
drm_rect.c
drm_scatter.c
drm_scdc_helper.c
drm_simple_kms_helper.c drm: drop _mode_ from drm_mode_connector_attach_encoder 2018-07-13 18:40:27 +02:00
drm_syncobj.c drm: Remove unecessary dma_fence_ops 2018-07-03 13:13:22 +02:00
drm_sysfs.c
drm_trace_points.c
drm_trace.h
drm_vblank.c
drm_vm.c gpu: drm: drm_vm: Adding new typedef vm_fault_t 2018-05-29 08:58:46 +02:00
drm_vma_manager.c drm: add SPDX idenitifier and clarify license 2018-06-29 15:28:47 -05:00
drm_writeback.c drm: writeback: Fix doc that says connector should be disconnected 2018-07-16 16:35:27 +01:00
Kconfig drm: add support for DisplayPort CEC-Tunneling-over-AUX 2018-07-13 17:58:19 +03:00
Makefile drm: add support for DisplayPort CEC-Tunneling-over-AUX 2018-07-13 17:58:19 +03:00