linux/drivers/gpu/drm
Chris Wilson 2d6692e642 drm/i915: Start writeback from the shrinker
When we are called to relieve mempressue via the shrinker, the only way
we can make progress is either by discarding unwanted pages (those
objects that userspace has marked MADV_DONTNEED) or by reclaiming the
dirty objects via swap. As we know that is the only way to make further
progress, we can initiate the writeback as we invalidate the objects.
This means the objects we put onto the inactive anon lru list are
already marked for reclaim+writeback and so will trigger a wait upon the
writeback inside direct reclaim, greatly improving the success rate of
direct reclaim on i915 objects.

The corollary is that we may start a slow swap on opportunistic
mempressure from the likes of the compaction + migration kthreads. This
is limited by those threads only being allowed to shrink idle pages, but
also that if we reactivate the page before it is swapped out by gpu
activity, we only page the cost of repinning the page. The cost is most
felt when an object is reused after mempressure, which hopefully
excludes the latency sensitive tasks (as we are just extending the
impact of swap thrashing to them).

Apparently this is not the first time we've had this idea. Back in
commit 5537252b6b ("drm/i915: Invalidate our pages under memory
pressure") we wanted to start writeback but settled on invalidate after
Hugh Dickins warned us about a possibility of a deadlock within shmemfs
if we started writeback from shrink_slab. Looking at the callchain,
using writeback from i915_gem_shrink should be equivalent to the pageout
also employed by shrink_slab, i.e. it should not be any riskier afaict.

v2: Leave mmapings intact. At this point, the only mmapings of our
objects will be via CPU mmaps on the shmemfs filp, which are
out-of-scope for our LRU tracking. Instead leave those pages to the
inactive anon LRU page list for aging and pageout as normal.

v3: Be selective on which paths trigger writeback, in particular
excluding paths shrinking just to reclaim vm space (e.g. mmap, vmap
reapers) and avoid starting writeback on the entire process space from
within the pm freezer.

References: https://bugs.freedesktop.org/show_bug.cgi?id=108686
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Michal Hocko <mhocko@suse.com>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> #v1
Link: https://patchwork.freedesktop.org/patch/msgid/20190420115539.29081-1-chris@chris-wilson.co.uk
2019-04-20 15:06:31 +01:00
..
amd drm-misc-next for 5.2: 2019-03-25 11:05:12 +01:00
arc
arm drm-misc-next for 5.2: 2019-03-25 11:05:12 +01:00
armada
ast
atmel-hlcdc
bochs Merge drm/drm-next into drm-misc-next 2019-03-06 09:22:18 -05:00
bridge drm/bridge: ti-tfp410: Report input bus config through bridge timings 2019-03-18 11:42:13 +02:00
cirrus
etnaviv drm-misc-next for 5.2: 2019-03-25 11:05:12 +01:00
exynos drm/exynos/mixer: fix MIXER shadow registry synchronisation code 2019-03-21 09:47:29 +09:00
fsl-dcu drm: Use new DRM_BUS_FLAG_*_(DRIVE|SAMPLE)_(POS|NEG)EDGE flags 2019-03-18 11:42:13 +02:00
gma500
hisilicon
i2c
i810
i915 drm/i915: Start writeback from the shrinker 2019-04-20 15:06:31 +01:00
imx drm-misc-next for 5.2: 2019-03-25 11:05:12 +01:00
lib
mediatek
meson drm/meson: exclusively use the canvas provider module 2019-03-20 09:28:39 +01:00
mga
mgag200
msm drm-misc-next for 5.2: 2019-03-25 11:05:12 +01:00
mxsfb drm: Use new DRM_BUS_FLAG_*_(DRIVE|SAMPLE)_(POS|NEG)EDGE flags 2019-03-18 11:42:13 +02:00
nouveau Merge branch 'linux-5.1' of git://github.com/skeggsb/linux into drm-fixes 2019-03-22 10:39:35 +10:00
omapdrm drm/omap: panel-tpo-td028ttec1: add backlight support 2019-03-18 11:42:14 +02:00
panel drm-misc-next for 5.2: 2019-03-25 11:05:12 +01:00
pl111 drm: Use new DRM_BUS_FLAG_*_(DRIVE|SAMPLE)_(POS|NEG)EDGE flags 2019-03-18 11:42:13 +02:00
qxl drm-misc-next for 5.2: 2019-03-25 11:05:12 +01:00
r128
radeon Merge drm/drm-next into drm-misc-next 2019-03-06 09:22:18 -05:00
rcar-du drm: rcar-du: Add writeback support for R-Car Gen3 2019-03-18 17:24:51 +02:00
rockchip Linux 5.0-rc7 2019-02-18 13:27:15 +10:00
savage
scheduler Merge branch 'drm-next-5.1' of git://people.freedesktop.org/~agd5f/linux into drm-next 2019-02-22 15:56:42 +10:00
selftests drm/selftests/mm: Switch to bitmap_zalloc() 2019-03-20 17:36:06 +00:00
shmobile
sis
sti
stm drm/stm: fix CONFIG_FB dependency 2019-03-11 15:40:29 +01:00
sun4i drm-misc-next for 5.2: 2019-03-25 11:05:12 +01:00
tdfx
tegra
tilcdc
tinydrm tinydrm/mipi-dbi: Use dma-safe buffers for all SPI transfers 2019-03-20 12:02:41 +01:00
ttm
tve200 drm: Use new DRM_BUS_FLAG_*_(DRIVE|SAMPLE)_(POS|NEG)EDGE flags 2019-03-18 11:42:13 +02:00
udl drm-misc-next for 5.2: 2019-03-25 11:05:12 +01:00
v3d drm/v3d: Use the new shmem helpers to reduce driver boilerplate. 2019-03-14 12:06:44 -07:00
vboxvideo drm/vboxvideo: Remove unused including <linux/version.h> 2019-03-20 10:16:40 +01:00
vc4 drm-misc-next for 5.2: 2019-03-25 11:05:12 +01:00
vgem
via
virtio drm/virtio: implement prime export 2019-02-28 09:09:02 +01:00
vkms Linux 5.0-rc7 2019-02-18 13:27:15 +10:00
vmwgfx Merge branch 'vmwgfx-fixes-5.1' of git://people.freedesktop.org/~thomash/linux into drm-fixes 2019-03-22 11:53:36 +10:00
xen drm/drv: drm_dev_unplug(): Move out drm_dev_put() call 2019-02-21 12:11:58 +01:00
zte
ati_pcigart.c
drm_agpsupport.c
drm_atomic.c
drm_atomic_helper.c drm-misc-next for 5.2: 2019-03-25 11:05:12 +01:00
drm_atomic_state_helper.c drm: writeback: Fix leak of writeback job 2019-03-18 17:24:32 +02:00
drm_atomic_uapi.c drm-misc-next for 5.2: 2019-03-25 11:05:12 +01:00
drm_auth.c
drm_blend.c
drm_bridge.c
drm_bufs.c
drm_cache.c
drm_client.c
drm_color_mgmt.c
drm_connector.c drm/dp: Set the connector's TILE property even for DP SST connectors 2019-03-14 11:33:17 -07:00
drm_context.c
drm_crtc.c
drm_crtc_helper.c
drm_crtc_helper_internal.h
drm_crtc_internal.h
drm_damage_helper.c
drm_debugfs.c
drm_debugfs_crc.c
drm_dma.c
drm_dp_aux_dev.c
drm_dp_cec.c
drm_dp_dual_mode_helper.c
drm_dp_helper.c
drm_dp_mst_topology.c drm/dp: Set the connector's TILE property even for DP SST connectors 2019-03-14 11:33:17 -07:00
drm_drv.c drm/drv: DOC: Add driver example code 2019-03-04 15:23:34 +01:00
drm_dsc.c drm/dsc: Split DSC PPS and SDP header initialisations 2019-03-05 13:24:34 -05:00
drm_dumb_buffers.c
drm_edid.c drm: add non-desktop quirks to Sensics and OSVR headsets. 2019-03-15 10:46:53 +00:00
drm_edid_load.c
drm_encoder.c
drm_encoder_slave.c
drm_fb_cma_helper.c
drm_fb_helper.c drm/fb-helper: generic: Don't take module ref for fbcon 2019-02-21 12:24:28 +01:00
drm_file.c Merge drm/drm-next into drm-misc-next 2019-03-06 09:22:18 -05:00
drm_flip_work.c
drm_fourcc.c drm/fourcc: Fix conflicting Y41x definitions 2019-03-21 09:49:04 +01:00
drm_framebuffer.c
drm_gem.c drm: Add helpers for locking an array of BO reservations. 2019-03-14 09:22:57 -07:00
drm_gem_cma_helper.c
drm_gem_framebuffer_helper.c
drm_gem_shmem_helper.c drm: Add library for shmem backed GEM objects 2019-03-14 12:06:44 -07:00
drm_hashtab.c
drm_internal.h
drm_ioc32.c drm: add __user attribute to ptr_to_compat() 2019-03-04 09:55:31 -05:00
drm_ioctl.c
drm_irq.c
drm_kms_helper_common.c drm: fix spelling mistake "intead" -> "instead" 2019-03-04 11:18:50 -05:00
drm_lease.c Linux 5.0-rc7 2019-02-18 13:27:15 +10:00
drm_legacy.h
drm_lock.c
drm_memory.c drm: change func to better detect wether swiotlb is needed 2019-02-20 13:29:29 +01:00
drm_mipi_dsi.c
drm_mm.c
drm_mode_config.c
drm_mode_object.c
drm_modes.c drm: Use new DRM_BUS_FLAG_*_(DRIVE|SAMPLE)_(POS|NEG)EDGE flags 2019-03-18 11:42:13 +02:00
drm_modeset_helper.c
drm_modeset_lock.c
drm_of.c
drm_panel.c
drm_panel_orientation_quirks.c drm: panel-orientation-quirks: Add quirk for Lenovo Ideapad D330 2019-03-01 09:15:55 +02:00
drm_pci.c
drm_plane.c
drm_plane_helper.c
drm_prime.c drm: Add reservation_object to drm_gem_object 2019-02-19 11:08:40 +01:00
drm_print.c
drm_probe_helper.c
drm_property.c
drm_rect.c
drm_scatter.c
drm_scdc_helper.c
drm_simple_kms_helper.c
drm_syncobj.c drm: export drm_timeout_abs_to_jiffies 2019-03-07 12:00:30 -06:00
drm_sysfs.c
drm_trace.h
drm_trace_points.c
drm_vblank.c
drm_vm.c drm/drm_vm: Mark expected switch fall-throughs 2019-02-19 12:20:41 +01:00
drm_vma_manager.c
drm_writeback.c drm: writeback: Add job prepare and cleanup operations 2019-03-18 17:24:38 +02:00
Kconfig drm: Add library for shmem backed GEM objects 2019-03-14 12:06:44 -07:00
Makefile drm: Add library for shmem backed GEM objects 2019-03-14 12:06:44 -07:00