Maarten Lankhorst 12235da8c8 kernel/locking: Add context to ww_mutex_trylock() ... i915 will soon gain an eviction path that trylock a whole lot of locks for eviction, getting dmesg failures like below: BUG: MAX_LOCK_DEPTH too low! turning off the locking correctness validator. depth: 48 max: 48! 48 locks held by i915_selftest/5776: #0: ffff888101a79240 (&dev->mutex){....}-{3:3}, at: __driver_attach+0x88/0x160 #1: ffffc900009778c0 (reservation_ww_class_acquire){+.+.}-{0:0}, at: i915_vma_pin.constprop.63+0x39/0x1b0 [i915] #2: ffff88800cf74de8 (reservation_ww_class_mutex){+.+.}-{3:3}, at: i915_vma_pin.constprop.63+0x5f/0x1b0 [i915] #3: ffff88810c7f9e38 (&vm->mutex/1){+.+.}-{3:3}, at: i915_vma_pin_ww+0x1c4/0x9d0 [i915] #4: ffff88810bad5768 (reservation_ww_class_mutex){+.+.}-{3:3}, at: i915_gem_evict_something+0x110/0x860 [i915] #5: ffff88810bad60e8 (reservation_ww_class_mutex){+.+.}-{3:3}, at: i915_gem_evict_something+0x110/0x860 [i915] ... #46: ffff88811964d768 (reservation_ww_class_mutex){+.+.}-{3:3}, at: i915_gem_evict_something+0x110/0x860 [i915] #47: ffff88811964e0e8 (reservation_ww_class_mutex){+.+.}-{3:3}, at: i915_gem_evict_something+0x110/0x860 [i915] INFO: lockdep is turned off. Fixing eviction to nest into ww_class_acquire is a high priority, but it requires a rework of the entire driver, which can only be done one step at a time. As an intermediate solution, add an acquire context to ww_mutex_trylock, which allows us to do proper nesting annotations on the trylocks, making the above lockdep splat disappear. This is also useful in regulator_lock_nested, which may avoid dropping regulator_nesting_mutex in the uncontended path, so use it there. TTM may be another user for this, where we could lock a buffer in a fastpath with list locks held, without dropping all locks we hold. [peterz: rework actual ww_mutex_trylock() implementations] Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/YUBGPdDDjKlxAuXJ@hirez.programming.kicks-ass.net		2021-09-17 15:08:41 +02:00
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amd
arm
armada
aspeed
ast
atmel-hlcdc
bridge
etnaviv
exynos
fsl-dcu
gma500
gud
hisilicon
hyperv
i2c
i810
i915
imx
ingenic
kmb
lib
lima
mcde
mediatek
meson
mga
mgag200
msm
mxsfb
nouveau
omapdrm
panel
panfrost
pl111
qxl
r128
radeon
rcar-du
rockchip
savage
scheduler
selftests
shmobile
sis
sti
stm
sun4i
tdfx
tegra
tidss
tilcdc
tiny
ttm
tve200
udl
v3d
vboxvideo
vc4
vgem
via
virtio
vkms
vmwgfx
xen
xlnx
zte
drm_agpsupport.c
drm_aperture.c
drm_atomic.c
drm_atomic_helper.c
drm_atomic_state_helper.c
drm_atomic_uapi.c
drm_auth.c
drm_blend.c
drm_bridge.c
drm_bridge_connector.c
drm_bufs.c
drm_cache.c
drm_client.c
drm_client_modeset.c
drm_color_mgmt.c
drm_connector.c
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_displayid.c
drm_dma.c
drm_dp_aux_bus.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_mst_topology_internal.h
drm_drv.c
drm_dsc.c
drm_dumb_buffers.c
drm_edid.c
drm_edid_load.c
drm_encoder.c
drm_encoder_slave.c
drm_fb_cma_helper.c
drm_fb_helper.c
drm_file.c
drm_flip_work.c
drm_format_helper.c
drm_fourcc.c
drm_framebuffer.c
drm_gem.c
drm_gem_atomic_helper.c
drm_gem_cma_helper.c
drm_gem_framebuffer_helper.c
drm_gem_shmem_helper.c
drm_gem_ttm_helper.c
drm_gem_vram_helper.c
drm_hashtab.c
drm_hdcp.c
drm_internal.h
drm_ioc32.c
drm_ioctl.c
drm_irq.c
drm_kms_helper_common.c
drm_lease.c
drm_legacy.h
drm_legacy_misc.c
drm_lock.c
drm_managed.c
drm_memory.c
drm_mipi_dbi.c
drm_mipi_dsi.c
drm_mm.c
drm_mode_config.c
drm_mode_object.c
drm_modes.c
drm_modeset_helper.c
drm_modeset_lock.c
drm_of.c
drm_panel.c
drm_panel_orientation_quirks.c
drm_pci.c
drm_plane.c
drm_plane_helper.c
drm_prime.c
drm_print.c
drm_probe_helper.c
drm_property.c
drm_rect.c
drm_scatter.c
drm_scdc_helper.c
drm_self_refresh_helper.c
drm_simple_kms_helper.c
drm_syncobj.c
drm_sysfs.c
drm_trace.h
drm_trace_points.c
drm_vblank.c
drm_vblank_work.c
drm_vm.c
drm_vma_manager.c
drm_writeback.c
Kconfig
Makefile