<html> <head> <base href="https://bugs.freedesktop.org/"> </head> <body> <div> <a class="bz_bug_link bz_status_NEW " title="NEW - [CI] igt@* - dmesg-warn - WARNING: possible circular locking dependency detected" href="https://bugs.freedesktop.org/show_bug.cgi?id=103950#c1">Comment # 1</a> on <a class="bz_bug_link bz_status_NEW " title="NEW - [CI] igt@* - dmesg-warn - WARNING: possible circular locking dependency detected" href="https://bugs.freedesktop.org/show_bug.cgi?id=103950">bug 103950</a> from <a class="email" href="mailto:marta.lofstedt@intel.com" title="Marta Löfstedt <marta.lofstedt@intel.com>"> Marta Löfstedt</a> <pre><a href="https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_3397/shard-hsw3/igt@kms_cursor_crc@cursor-256x256-suspend.html">https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_3397/shard-hsw3/igt@kms_cursor_crc@cursor-256x256-suspend.html</a> [ 282.801181] Suspending console(s) (use no_console_suspend to debug) [ 282.809347] sd 4:0:0:0: [sda] Synchronizing SCSI cache [ 282.809672] sd 4:0:0:0: [sda] Stopping disk [ 282.921866] ====================================================== [ 282.921867] WARNING: possible circular locking dependency detected [ 282.921868] 4.15.0-rc1-CI-CI_DRM_3397+ #1 Tainted: G U [ 282.921869] ------------------------------------------------------ [ 282.921870] watchdog/1/15 is trying to acquire lock: [ 282.921870] (&cpuctx_mutex){+.+.}, at: [<ffffffff8116071c>] perf_event_ctx_lock_nested+0xbc/0x1d0 [ 282.921875] but now in release context of a crosslock acquired at the following: [ 282.921876] ((completion)&self->parked){+.+.}, at: [<ffffffff8109d69d>] kthread_park+0x3d/0x50 [ 282.921879] which lock already depends on the new lock. [ 282.921879] the existing dependency chain (in reverse order) is: [ 282.921879] -> #3 ((completion)&self->parked){+.+.}: [ 282.921883] wait_for_common+0x54/0x210 [ 282.921884] kthread_park+0x3d/0x50 [ 282.921917] i915_gem_reset_prepare_engine+0x1d/0x90 [i915] [ 282.921940] i915_gem_reset_prepare+0x2c/0x60 [i915] [ 282.921957] i915_reset+0x66/0x230 [i915] [ 282.921974] i915_reset_device+0x1cb/0x230 [i915] [ 282.921991] i915_handle_error+0x2d3/0x430 [i915] [ 282.922011] i915_wedged_set+0x79/0xc0 [i915] [ 282.922013] simple_attr_write+0xab/0xc0 [ 282.922016] full_proxy_write+0x4b/0x70 [ 282.922017] __vfs_write+0x1e/0x130 [ 282.922017] vfs_write+0xc0/0x1b0 [ 282.922018] SyS_write+0x40/0xa0 [ 282.922020] entry_SYSCALL_64_fastpath+0x1c/0x89 [ 282.922020] -> #2 (&dev->struct_mutex){+.+.}: [ 282.922023] __mutex_lock+0x81/0x9b0 [ 282.922044] i915_mutex_lock_interruptible+0x47/0x130 [i915] [ 282.922065] i915_gem_fault+0x201/0x760 [i915] [ 282.922067] __do_fault+0x15/0x70 [ 282.922069] __handle_mm_fault+0x7bf/0xda0 [ 282.922071] handle_mm_fault+0x14f/0x2f0 [ 282.922072] __do_page_fault+0x2d1/0x560 [ 282.922073] page_fault+0x22/0x30 [ 282.922073] -> #1 (&mm->mmap_sem){++++}: [ 282.922076] __might_fault+0x63/0x90 [ 282.922078] _copy_to_user+0x1e/0x70 [ 282.922079] perf_read+0x1aa/0x290 [ 282.922080] __vfs_read+0x1e/0x120 [ 282.922081] vfs_read+0xa1/0x150 [ 282.922082] SyS_read+0x40/0xa0 [ 282.922083] entry_SYSCALL_64_fastpath+0x1c/0x89 [ 282.922083] -> #0 (&cpuctx_mutex){+.+.}: [ 282.922085] perf_event_ctx_lock_nested+0xbc/0x1d0 [ 282.922086] other info that might help us debug this: [ 282.922086] Chain exists of: &cpuctx_mutex --> &dev->struct_mutex --> (completion)&self->parked [ 282.922088] Possible unsafe locking scenario by crosslock: [ 282.922089] CPU0 CPU1 [ 282.922089] ---- ---- [ 282.922089] lock(&dev->struct_mutex); [ 282.922090] lock((completion)&self->parked); [ 282.922091] lock(&cpuctx_mutex); [ 282.922092] unlock((completion)&self->parked); [ 282.922093] *** DEADLOCK *** [ 282.922094] 1 lock held by watchdog/1/15: [ 282.922094] #0: (&x->wait){....}, at: [<ffffffff810c7b03>] complete+0x13/0x50 [ 282.922098] stack backtrace: [ 282.922100] CPU: 1 PID: 15 Comm: watchdog/1 Tainted: G U 4.15.0-rc1-CI-CI_DRM_3397+ #1 [ 282.922100] Hardware name: MSI MS-7924/Z97M-G43(MS-7924), BIOS V1.12 02/15/2016 [ 282.922101] Call Trace: [ 282.922105] dump_stack+0x5f/0x86 [ 282.922108] print_circular_bug+0x230/0x3b0 [ 282.922110] check_prev_add+0x439/0x7b0 [ 282.922112] ? HARDIRQ_verbose+0x10/0x10 [ 282.922115] ? lock_commit_crosslock+0x3e8/0x640 [ 282.922116] lock_commit_crosslock+0x3e8/0x640 [ 282.922118] ? __kthread_parkme+0x39/0x90 [ 282.922120] ? smpboot_thread_fn+0x184/0x270 [ 282.922122] complete+0x1f/0x50 [ 282.922123] ? __kthread_parkme+0x39/0x90 [ 282.922124] __kthread_parkme+0x63/0x90 [ 282.922126] ? smpboot_thread_fn+0x2c/0x270 [ 282.922127] smpboot_thread_fn+0xaa/0x270 [ 282.922128] kthread+0x139/0x170 [ 282.922130] ? sort_range+0x20/0x20 [ 282.922131] ? kthread_create_on_node+0x40/0x40 [ 282.922133] ret_from_fork+0x24/0x30</pre> </div> <hr> You are receiving this mail because: <ul> <li>You are on the CC list for the bug.</li> <li>You are the assignee for the bug.</li> <li>You are the QA Contact for the bug.</li> </ul> </body> </html>