diff options
author | Michał Winiarski <michal.winiarski@intel.com> | 2017-12-13 23:13:47 +0100 |
---|---|---|
committer | Chris Wilson <chris@chris-wilson.co.uk> | 2017-12-14 08:06:54 +0000 |
commit | 3176ff49bc3e56871ec9f338cac759dacd0135e1 (patch) | |
tree | 04fc7e8a743a34aea79249b5cf05d16aa2f3957e /drivers/gpu/drm/i915/intel_guc_submission.h | |
parent | 1bbbca0db722d137ed426368bff42b17808ad11e (diff) | |
download | linux-3176ff49bc3e56871ec9f338cac759dacd0135e1.tar.bz2 |
drm/i915/guc: Move GuC workqueue allocations outside of the mutex
This gets rid of the following lockdep splat:
======================================================
WARNING: possible circular locking dependency detected
4.15.0-rc2-CI-Patchwork_7428+ #1 Not tainted
------------------------------------------------------
debugfs_test/1351 is trying to acquire lock:
(&dev->struct_mutex){+.+.}, at: [<000000009d90d1a3>] i915_mutex_lock_interruptible+0x47/0x130 [i915]
but task is already holding lock:
(&mm->mmap_sem){++++}, at: [<000000005df01c1e>] __do_page_fault+0x106/0x560
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #6 (&mm->mmap_sem){++++}:
__might_fault+0x63/0x90
_copy_to_user+0x1e/0x70
filldir+0x8c/0xf0
dcache_readdir+0xeb/0x160
iterate_dir+0xe6/0x150
SyS_getdents+0xa0/0x130
entry_SYSCALL_64_fastpath+0x1c/0x89
-> #5 (&sb->s_type->i_mutex_key#5){++++}:
lockref_get+0x9/0x20
-> #4 ((completion)&req.done){+.+.}:
wait_for_common+0x54/0x210
devtmpfs_create_node+0x130/0x150
device_add+0x5ad/0x5e0
device_create_groups_vargs+0xd4/0xe0
device_create+0x35/0x40
msr_device_create+0x22/0x40
cpuhp_invoke_callback+0xc5/0xbf0
cpuhp_thread_fun+0x167/0x210
smpboot_thread_fn+0x17f/0x270
kthread+0x173/0x1b0
ret_from_fork+0x24/0x30
-> #3 (cpuhp_state-up){+.+.}:
cpuhp_issue_call+0x132/0x1c0
__cpuhp_setup_state_cpuslocked+0x12f/0x2a0
__cpuhp_setup_state+0x3a/0x50
page_writeback_init+0x3a/0x5c
start_kernel+0x393/0x3e2
secondary_startup_64+0xa5/0xb0
-> #2 (cpuhp_state_mutex){+.+.}:
__mutex_lock+0x81/0x9b0
__cpuhp_setup_state_cpuslocked+0x4b/0x2a0
__cpuhp_setup_state+0x3a/0x50
page_alloc_init+0x1f/0x26
start_kernel+0x139/0x3e2
secondary_startup_64+0xa5/0xb0
-> #1 (cpu_hotplug_lock.rw_sem){++++}:
cpus_read_lock+0x34/0xa0
apply_workqueue_attrs+0xd/0x40
__alloc_workqueue_key+0x2c7/0x4e1
intel_guc_submission_init+0x10c/0x650 [i915]
intel_uc_init_hw+0x29e/0x460 [i915]
i915_gem_init_hw+0xca/0x290 [i915]
i915_gem_init+0x115/0x3a0 [i915]
i915_driver_load+0x9a8/0x16c0 [i915]
i915_pci_probe+0x2e/0x90 [i915]
pci_device_probe+0x9c/0x120
driver_probe_device+0x2a3/0x480
__driver_attach+0xd9/0xe0
bus_for_each_dev+0x57/0x90
bus_add_driver+0x168/0x260
driver_register+0x52/0xc0
do_one_initcall+0x39/0x150
do_init_module+0x56/0x1ef
load_module+0x231c/0x2d70
SyS_finit_module+0xa5/0xe0
entry_SYSCALL_64_fastpath+0x1c/0x89
-> #0 (&dev->struct_mutex){+.+.}:
lock_acquire+0xaf/0x200
__mutex_lock+0x81/0x9b0
i915_mutex_lock_interruptible+0x47/0x130 [i915]
i915_gem_fault+0x201/0x760 [i915]
__do_fault+0x15/0x70
__handle_mm_fault+0x85b/0xe40
handle_mm_fault+0x14f/0x2f0
__do_page_fault+0x2d1/0x560
page_fault+0x22/0x30
other info that might help us debug this:
Chain exists of:
&dev->struct_mutex --> &sb->s_type->i_mutex_key#5 --> &mm->mmap_sem
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&mm->mmap_sem);
lock(&sb->s_type->i_mutex_key#5);
lock(&mm->mmap_sem);
lock(&dev->struct_mutex);
*** DEADLOCK ***
1 lock held by debugfs_test/1351:
#0: (&mm->mmap_sem){++++}, at: [<000000005df01c1e>] __do_page_fault+0x106/0x560
stack backtrace:
CPU: 2 PID: 1351 Comm: debugfs_test Not tainted 4.15.0-rc2-CI-Patchwork_7428+ #1
Hardware name: /NUC6i5SYB, BIOS SYSKLi35.86A.0057.2017.0119.1758 01/19/2017
Call Trace:
dump_stack+0x5f/0x86
print_circular_bug+0x230/0x3b0
check_prev_add+0x439/0x7b0
? lockdep_init_map_crosslock+0x20/0x20
? unwind_get_return_address+0x16/0x30
? __lock_acquire+0x1385/0x15a0
__lock_acquire+0x1385/0x15a0
lock_acquire+0xaf/0x200
? i915_mutex_lock_interruptible+0x47/0x130 [i915]
__mutex_lock+0x81/0x9b0
? i915_mutex_lock_interruptible+0x47/0x130 [i915]
? i915_mutex_lock_interruptible+0x47/0x130 [i915]
? i915_mutex_lock_interruptible+0x47/0x130 [i915]
i915_mutex_lock_interruptible+0x47/0x130 [i915]
? __pm_runtime_resume+0x4f/0x80
i915_gem_fault+0x201/0x760 [i915]
__do_fault+0x15/0x70
__handle_mm_fault+0x85b/0xe40
handle_mm_fault+0x14f/0x2f0
__do_page_fault+0x2d1/0x560
page_fault+0x22/0x30
RIP: 0033:0x7f98d6f49116
RSP: 002b:00007ffd6ffc3278 EFLAGS: 00010283
RAX: 00007f98d39a2bc0 RBX: 0000000000000000 RCX: 0000000000001680
RDX: 0000000000001680 RSI: 00007ffd6ffc3400 RDI: 00007f98d39a2bc0
RBP: 00007ffd6ffc33a0 R08: 0000000000000000 R09: 00000000000005a0
R10: 000055e847c2a830 R11: 0000000000000002 R12: 0000000000000001
R13: 000055e847c1d040 R14: 00007ffd6ffc3400 R15: 00007f98d6752ba0
v2: Init preempt_work unconditionally (Chris)
v3: Mention that we need the enable_guc=1 for lockdep splat (Chris)
Testcase: igt/debugfs_test/read_all_entries # with i915.enable_guc=1
Signed-off-by: Michał Winiarski <michal.winiarski@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Michal Wajdeczko <michal.wajdeczko@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20171213221352.7173-2-michal.winiarski@intel.com
Diffstat (limited to 'drivers/gpu/drm/i915/intel_guc_submission.h')
-rw-r--r-- | drivers/gpu/drm/i915/intel_guc_submission.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/intel_guc_submission.h b/drivers/gpu/drm/i915/intel_guc_submission.h index 021fe85c8f71..fb081cefef93 100644 --- a/drivers/gpu/drm/i915/intel_guc_submission.h +++ b/drivers/gpu/drm/i915/intel_guc_submission.h @@ -77,5 +77,7 @@ int intel_guc_submission_init(struct intel_guc *guc); int intel_guc_submission_enable(struct intel_guc *guc); void intel_guc_submission_disable(struct intel_guc *guc); void intel_guc_submission_fini(struct intel_guc *guc); +int intel_guc_preempt_work_create(struct intel_guc *guc); +void intel_guc_preempt_work_destroy(struct intel_guc *guc); #endif |