Summary: | [CI][SNB,HSW,APL,KBL] igt@prime_mmap@test_userptr - possible circular locking dependency detected | ||
---|---|---|---|
Product: | DRI | Reporter: | Marta Löfstedt <marta.lofstedt> |
Component: | DRM/Intel | Assignee: | Intel GFX Bugs mailing list <intel-gfx-bugs> |
Status: | CLOSED FIXED | QA Contact: | Intel GFX Bugs mailing list <intel-gfx-bugs> |
Severity: | normal | ||
Priority: | high | CC: | intel-gfx-bugs |
Version: | DRI git | ||
Hardware: | Other | ||
OS: | All | ||
Whiteboard: | ReadyForDev | ||
i915 platform: | BXT, HSW, KBL, SNB | i915 features: | GEM/Other |
Description
Marta Löfstedt
2017-09-22 07:08:45 UTC
*** This bug has been marked as a duplicate of bug 102886 *** From https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_3170/shard-snb4/igt@prime_mmap@test_userptr.html the lockdep is no longer reproduced on the igt@prime_mmap@test_userptr. However it is still reproduced by the gem_eio tests in BUG 102886. I was to quick to close this one: The issue has started again on CI_DRM_3172 and forward [ 85.488531] ====================================================== [ 85.488534] WARNING: possible circular locking dependency detected [ 85.488537] 4.14.0-rc3-CI-CI_DRM_3172+ #1 Tainted: G U [ 85.488539] ------------------------------------------------------ [ 85.488542] prime_mmap/1588 is trying to acquire lock: [ 85.488544] (cpu_hotplug_lock.rw_sem){++++}, at: [<ffffffff8109e5a7>] apply_workqueue_attrs+0x17/0x50 [ 85.488552] but task is already holding lock: [ 85.488555] (&dev_priv->mm_lock){+.+.}, at: [<ffffffffa01b2dfa>] i915_gem_userptr_init__mmu_notifier+0x14a/0x270 [i915] [ 85.488589] which lock already depends on the new lock. It is very weird that this lockdep wasn't caught on CI_DRM_3170 CI_DRM_3171. https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_3172/shard-snb5/igt@prime_mmap@test_userptr.html https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_3172/shard-hsw5/igt@prime_mmap@test_userptr.html I suggest we keep BUG 102886 and this one un-duplicated, since this one is flip-flopping on catching the lockdep and the BUG 102886 seem solid. I just realized that lockdeps are warn once. So, if other lockdep:ing tests are scheduled in the same shard we will miss the next one. This explains why we didn't hit this on: CI_DRM_3170 CI_DRM_3171 I will redo the duplicate again. *** This bug has been marked as a duplicate of bug 102886 *** The lockdep splat in igt@prime_mmap@test_userptr needs to be taken out of this bug here in cibuglog, it is a different kind of lockdep splat. That one goes through i915_gem_userptr_init__mmu_notifier as the critical call, but not through i915_gem_set_wedged. Marta, can you pls update cibuglog to create a separate entry and new bugzilla? I need that for my patch :-) It's the same cause. Overzealous lock coupling via /dev/cpu/*/msr. *** This bug has been marked as a duplicate of bug 102886 *** "commit 7741b547b6e000b08e20667bb3bef22e1a362661 Author: Daniel Vetter <daniel.vetter@ffwll.ch> Date: Mon Oct 9 18:44:00 2017 +0200 drm/i915: Preallocate our mmu notifier workequeu to unbreak cpu hotplug deadlock" was integrated in CI_DRM_3202. From then the lockdep in igt@prime_mmap@test_userptr has not been reproduced. Note that this is not due it being hidden by another lockdep, in for example: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_3202/shard-apl3/igt@prime_mmap@test_userptr.html there is no lockdep either in bootlog or runtime dmesg. The same is true for: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_3202/shard-kbl5/igt@gem_userptr_blits@process-exit-gtt.html. From which I draw the conclusion that all the gem_userptr_blits lockdeps are fixed by above commit. However, the gem_eio lockdep is still present, see for example: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_3202/shard-kbl7/igt@gem_eio@throttle.html. Also, this is still present: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_3202/shard-hsw2/igt@kms_frontbuffer_tracking@fbc-1p-primscrn-cur-indfb-draw-render.html From this I (again) draw the conclusion that this is not a duplicate BUG 102886. I consider all igt@gem_userptr_blits lockdeps to be handled by this bug see: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_3201/shard-apl2/igt@gem_userptr_blits@map-fixed-invalidate-overlap.html These have not been reproduced since CI_DRM_3202. |
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