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  1. 13 May, 2018 7 commits
  3. 11 May, 2018 23 commits
  5. 09 May, 2018 5 commits
  7. 08 May, 2018 5 commits
    • Chris Wilson's avatar
      drm/i915: Annotate timeline lock nesting · 0adb90d3
      Chris Wilson authored 
      CI noticed

<4>[   23.430701] ============================================
<4>[   23.430706] WARNING: possible recursive locking detected
<4>[   23.430713] 4.17.0-rc4-CI-CI_DRM_4156+ #1 Not tainted
<4>[   23.430720] --------------------------------------------
<4>[   23.430725] systemd-udevd/169 is trying to acquire lock:
<4>[   23.430732]         (ptrval) (&(&timeline->lock)->rlock){....}, at: move_to_timeline+0x48/0x12c [i915]
<4>[   23.430888]
                  but task is already holding lock:
<4>[   23.430894]         (ptrval) (&(&timeline->lock)->rlock){....}, at: i915_request_submit+0x1a/0x40 [i915]
<4>[   23.430995]
                  other info that might help us debug this:
<4>[   23.431002]  Possible unsafe locking scenario:

<4>[   23.431007]        CPU0
<4>[   23.431010]        ----
<4>[   23.431013]   lock(&(&timeline->lock)->rlock);
<4>[   23.431021]   lock(&(&timeline->lock)->rlock);
<4>[   23.431028]
                   *** DEADLOCK ***

<4>[   23.431036]  May be due to missing lock nesting notation

<4>[   23.431044] 5 locks held by systemd-udevd/169:
<4>[   23.431049]  #0:         (ptrval) (&dev->mutex){....}, at: __driver_attach+0x42/0xe0
<4>[   23.431065]  #1:         (ptrval) (&dev->mutex){....}, at: __driver_attach+0x50/0xe0
<4>[   23.431078]  #2:         (ptrval) (&dev->struct_mutex){+.+.}, at: i915_gem_init+0xca/0x630 [i915]
<4>[   23.431174]  #3:         (ptrval) (rcu_read_lock){....}, at: submit_notify+0x35/0x124 [i915]
<4>[   23.431271]  #4:         (ptrval) (&(&timeline->lock)->rlock){....}, at: i915_request_submit+0x1a/0x40 [i915]
<4>[   23.431369]
                  stack backtrace:
<4>[   23.431377] CPU: 0 PID: 169 Comm: systemd-udevd Not tainted 4.17.0-rc4-CI-CI_DRM_4156+ #1
<4>[   23.431385] Hardware name: Dell Inc.                 OptiPlex GX280               /0G8310, BIOS A04 02/09/2005
<4>[   23.431394] Call Trace:
<4>[   23.431403]  dump_stack+0x67/0x9b
<4>[   23.431411]  __lock_acquire+0xc67/0x1b50
<4>[   23.431421]  ? ring_buffer_lock_reserve+0x154/0x3f0
<4>[   23.431429]  ? lock_acquire+0xa6/0x210
<4>[   23.431435]  lock_acquire+0xa6/0x210
<4>[   23.431530]  ? move_to_timeline+0x48/0x12c [i915]
<4>[   23.431540]  _raw_spin_lock+0x2a/0x40
<4>[   23.431634]  ? move_to_timeline+0x48/0x12c [i915]
<4>[   23.431730]  move_to_timeline+0x48/0x12c [i915]
<4>[   23.431826]  __i915_request_submit+0xfa/0x280 [i915]
<4>[   23.431923]  i915_request_submit+0x25/0x40 [i915]
<4>[   23.432024]  i9xx_submit_request+0x11/0x140 [i915]
<4>[   23.432120]  submit_notify+0x8d/0x124 [i915]
<4>[   23.432202]  __i915_sw_fence_complete+0x81/0x250 [i915]
<4>[   23.432300]  __i915_request_add+0x31c/0x7c0 [i915]
<4>[   23.432395]  i915_gem_init+0x621/0x630 [i915]
<4>[   23.432476]  i915_driver_load+0xbee/0x10b0 [i915]
<4>[   23.432485]  ? trace_hardirqs_on_caller+0xe0/0x1b0
<4>[   23.432566]  i915_pci_probe+0x29/0x90 [i915]
<4>[   23.432574]  pci_device_probe+0xa1/0x130
<4>[   23.432582]  driver_probe_device+0x306/0x480
<4>[   23.432589]  __driver_attach+0xb7/0xe0
<4>[   23.432596]  ? driver_probe_device+0x480/0x480
<4>[   23.432602]  ? driver_probe_device+0x480/0x480
<4>[   23.432609]  bus_for_each_dev+0x74/0xc0
<4>[   23.432616]  bus_add_driver+0x15f/0x250
<4>[   23.432623]  ? 0xffffffffa02d7000
<4>[   23.432629]  driver_register+0x52/0xc0
<4>[   23.432635]  ? 0xffffffffa02d7000
<4>[   23.432642]  do_one_initcall+0x58/0x370
<4>[   23.432653]  ? do_init_module+0x1d/0x1ea
<4>[   23.432660]  ? rcu_read_lock_sched_held+0x6f/0x80
<4>[   23.432667]  ? kmem_cache_alloc_trace+0x282/0x2e0
<4>[   23.432675]  do_init_module+0x56/0x1ea
<4>[   23.432682]  load_module+0x2435/0x2b20
<4>[   23.432694]  ? __se_sys_finit_module+0xd3/0xf0
<4>[   23.432701]  __se_sys_finit_module+0xd3/0xf0
<4>[   23.432710]  do_syscall_64+0x55/0x190
<4>[   23.432717]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
<4>[   23.432724] RIP: 0033:0x7fa780782839
<4>[   23.432729] RSP: 002b:00007ffcea73e668 EFLAGS: 00000246 ORIG_RAX: 0000000000000139
<4>[   23.432738] RAX: ffffffffffffffda RBX: 0000561a472a4b30 RCX: 00007fa780782839
<4>[   23.432745] RDX: 0000000000000000 RSI: 00007fa7804610e5 RDI: 000000000000000e
<4>[   23.432752] RBP: 00007fa7804610e5 R08: 0000000000000000 R09: 00007ffcea73e780
<4>[   23.432758] R10: 000000000000000e R11: 0000000000000246 R12: 0000000000000000
<4>[   23.432765] R13: 0000561a47296450 R14: 0000000000020000 R15: 0000561a472a4b30

but did not report it as an issue as it only occurred during the first
module on boot. This is due to the removal of the distinct global
timeline, and its separate lock class. So instead mark up the expected
nesting. An alternative would be to define a separate lock class for the
engine, but since we only expect to have a single point of nesting, we
can avoid having multiple lock classes for the struct.

Fixes: a89d1f92 ("drm/i915: Split i915_gem_timeline into individual timelines")
Signed-off-by: default avatarChris Wilson <chris@chris-wilson.co.uk>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Tested-by: default avatarMichel Thierry <michel.thierry@intel.com>
Reviewed-by: default avatarTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180508153514.20251-1-chris@chris-wilson.co.uk
      0adb90d3
    • Chris Wilson's avatar
      drm/i915: Remove unused i915_flip tracepoints · a33f084c
      Chris Wilson authored 
      The i915_flip* tracepoints are no longer in use since the removal of CS
flip in commit 8b5d27b9 ("drm/i915: Remove intel_flip_work
infrastructure")

References: 8b5d27b9 ("drm/i915: Remove intel_flip_work infrastructure")
Signed-off-by: default avatarChris Wilson <chris@chris-wilson.co.uk>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Daniel Vetter <daniel.vetter@intel.com>
Reviewed-by: default avatarVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180508151552.31024-1-chris@chris-wilson.co.uk
      a33f084c
    • Chris Wilson's avatar
      drm/i915: Disable tasklet scheduling across initial scheduling · 71ace7ca
      Chris Wilson authored 
      During request submission, we call the engine->schedule() function so
that we may reorder the active requests as required for inheriting the
new request's priority. This may schedule several tasklets to run on the
local CPU, but we will need to schedule the tasklets again for the new
request. Delay all the local tasklets until the end, so that we only
have to process the queue just once.

v2: Beware PREEMPT_RCU, as then local_bh_disable() is then not a
superset of rcu_read_lock().
Signed-off-by: default avatarChris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180507135731.10587-2-chris@chris-wilson.co.ukReviewed-by: default avatarTvrtko Ursulin <tvrtko.ursulin@intel.com>
      71ace7ca
    • Chris Wilson's avatar
      drm/i915: Flush submission tasklet after bumping priority · 4f6d8fcf
      Chris Wilson authored 
      When called from process context tasklet_schedule() defers itself to
ksoftirqd. From experience this may cause unacceptable latencies of over
200ms in executing the submission tasklet, our goal is to reprioritise
the HW execution queue and trigger HW preemption immediately, so disable
bh over the call to schedule and force the tasklet to run afterwards if
scheduled.

v2: Keep rcu_read_lock() around for PREEMPT_RCU
Signed-off-by: default avatarChris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180507135731.10587-1-chris@chris-wilson.co.ukReviewed-by: default avatarTvrtko Ursulin <tvrtko.ursulin@intel.com>
      4f6d8fcf
    • Chris Wilson's avatar
      drm/i915/selftests: Return to kernel context after each test · 4cdf65ce
      Chris Wilson authored 
      As we flush each test and wait for idle before the next, also switch
back to the kernel context. This helps limit the amount of collateral
damage a test may cause by resetting to the default state each time (and
also helps clean up temporaries used by the test).
Signed-off-by: default avatarChris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Reviewed-by: default avatarMika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180508115312.12628-1-chris@chris-wilson.co.uk
      4cdf65ce
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