Chris Wilson
f6168e3304
drm/i915: Convert breadcrumbs spinlock to be irqsafe ...
The breadcrumbs are about to be used from within IRQ context sections
(e.g. nouveau signals a fence from an interrupt handler causing us to
submit a new request) and/or from bottom-half tasklets (i.e.
intel_lrc_irq_handler), therefore we need to employ the irqsafe spinlock
variants.
For example, deferring the request submission to the
intel_lrc_irq_handler generates this trace:
[ 66.388639] =================================
[ 66.388650] [ INFO: inconsistent lock state ]
[ 66.388663] 4.9.0-rc2+ #56 Not tainted
[ 66.388672] ---------------------------------
[ 66.388682] inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage.
[ 66.388695] swapper/1/0 [HC0[0]:SC1[1]:HE0:SE0] takes:
[ 66.388706] (&(&b->lock)->rlock){+.?...} , at: [<ffffffff81401c88>] intel_engine_enable_signaling+0x78/0x150
[ 66.388761] {SOFTIRQ-ON-W} state was registered at:
[ 66.388772] [ 66.388783] [<ffffffff810bd842>] __lock_acquire+0x682/0x1870
[ 66.388795] [ 66.388803] [<ffffffff810bedbc>] lock_acquire+0x6c/0xb0
[ 66.388814] [ 66.388824] [<ffffffff8161753a>] _raw_spin_lock+0x2a/0x40
[ 66.388835] [ 66.388845] [<ffffffff81401e41>] intel_engine_reset_breadcrumbs+0x21/0xb0
[ 66.388857] [ 66.388866] [<ffffffff81403ae7>] gen8_init_common_ring+0x67/0x100
[ 66.388878] [ 66.388887] [<ffffffff81403b92>] gen8_init_render_ring+0x12/0x60
[ 66.388903] [ 66.388912] [<ffffffff813f8707>] i915_gem_init_hw+0xf7/0x2a0
[ 66.388927] [ 66.388936] [<ffffffff813f899b>] i915_gem_init+0xbb/0xf0
[ 66.388950] [ 66.388959] [<ffffffff813b4980>] i915_driver_load+0x7e0/0x1330
[ 66.388978] [ 66.388988] [<ffffffff813c09d8>] i915_pci_probe+0x28/0x40
[ 66.389003] [ 66.389013] [<ffffffff812fa0db>] pci_device_probe+0x8b/0xf0
[ 66.389028] [ 66.389037] [<ffffffff8147737e>] driver_probe_device+0x21e/0x430
[ 66.389056] [ 66.389065] [<ffffffff8147766e>] __driver_attach+0xde/0xe0
[ 66.389080] [ 66.389090] [<ffffffff814751ad>] bus_for_each_dev+0x5d/0x90
[ 66.389105] [ 66.389113] [<ffffffff81477799>] driver_attach+0x19/0x20
[ 66.389134] [ 66.389144] [<ffffffff81475ced>] bus_add_driver+0x15d/0x260
[ 66.389159] [ 66.389168] [<ffffffff81477e3b>] driver_register+0x5b/0xd0
[ 66.389183] [ 66.389281] [<ffffffff812fa19b>] __pci_register_driver+0x5b/0x60
[ 66.389301] [ 66.389312] [<ffffffff81aed333>] i915_init+0x3e/0x45
[ 66.389326] [ 66.389336] [<ffffffff81ac2ffa>] do_one_initcall+0x8b/0x118
[ 66.389350] [ 66.389359] [<ffffffff81ac323a>] kernel_init_freeable+0x1b3/0x23b
[ 66.389378] [ 66.389387] [<ffffffff8160fc39>] kernel_init+0x9/0x100
[ 66.389402] [ 66.389411] [<ffffffff816180e7>] ret_from_fork+0x27/0x40
[ 66.389426] irq event stamp: 315865
[ 66.389438] hardirqs last enabled at (315864): [<ffffffff816178f1>] _raw_spin_unlock_irqrestore+0x31/0x50
[ 66.389469] hardirqs last disabled at (315865): [<ffffffff816176b3>] _raw_spin_lock_irqsave+0x13/0x50
[ 66.389499] softirqs last enabled at (315818): [<ffffffff8107a04c>] _local_bh_enable+0x1c/0x50
[ 66.389530] softirqs last disabled at (315819): [<ffffffff8107a50e>] irq_exit+0xbe/0xd0
[ 66.389559]
[ 66.389559] other info that might help us debug this:
[ 66.389580] Possible unsafe locking scenario:
[ 66.389580]
[ 66.389598] CPU0
[ 66.389609] ----
[ 66.389620] lock(&(&b->lock)->rlock);
[ 66.389650] <Interrupt>
[ 66.389661] lock(&(&b->lock)->rlock);
[ 66.389690]
[ 66.389690] *** DEADLOCK ***
[ 66.389690]
[ 66.389715] 2 locks held by swapper/1/0:
[ 66.389728] #0 : (&(&tl->lock)->rlock){..-...}, at: [<ffffffff81403e01>] intel_lrc_irq_handler+0x201/0x3c0
[ 66.389785] #1 : (&(&req->lock)->rlock/1){..-...}, at: [<ffffffff813fc0af>] __i915_gem_request_submit+0x8f/0x170
[ 66.389854]
[ 66.389854] stack backtrace:
[ 66.389959] CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.9.0-rc2+ #56
[ 66.389976] Hardware name: / , BIOS PYBSWCEL.86A.0027.2015.0507.1758 05/07/2015
[ 66.389999] ffff88027fd03c58 ffffffff812beae5 ffff88027696e680 ffffffff822afe20
[ 66.390036] ffff88027fd03ca8 ffffffff810bb420 0000000000000001 0000000000000000
[ 66.390070] 0000000000000000 0000000000000006 0000000000000004 ffff88027696ee10
[ 66.390104] Call Trace:
[ 66.390117] <IRQ>
[ 66.390128] [<ffffffff812beae5>] dump_stack+0x68/0x93
[ 66.390147] [<ffffffff810bb420>] print_usage_bug+0x1d0/0x1e0
[ 66.390164] [<ffffffff810bb8a0>] mark_lock+0x470/0x4f0
[ 66.390181] [<ffffffff810ba9d0>] ? print_shortest_lock_dependencies+0x1b0/0x1b0
[ 66.390203] [<ffffffff810bd75d>] __lock_acquire+0x59d/0x1870
[ 66.390221] [<ffffffff810bedbc>] lock_acquire+0x6c/0xb0
[ 66.390237] [<ffffffff810bedbc>] ? lock_acquire+0x6c/0xb0
[ 66.390255] [<ffffffff81401c88>] ? intel_engine_enable_signaling+0x78/0x150
[ 66.390273] [<ffffffff8161753a>] _raw_spin_lock+0x2a/0x40
[ 66.390291] [<ffffffff81401c88>] ? intel_engine_enable_signaling+0x78/0x150
[ 66.390309] [<ffffffff81401c88>] intel_engine_enable_signaling+0x78/0x150
[ 66.390327] [<ffffffff813fc170>] __i915_gem_request_submit+0x150/0x170
[ 66.390345] [<ffffffff81403e8b>] intel_lrc_irq_handler+0x28b/0x3c0
[ 66.390363] [<ffffffff81079d97>] tasklet_action+0x57/0xc0
[ 66.390380] [<ffffffff8107a249>] __do_softirq+0x119/0x240
[ 66.390396] [<ffffffff8107a50e>] irq_exit+0xbe/0xd0
[ 66.390414] [<ffffffff8101afd5>] do_IRQ+0x65/0x110
[ 66.390431] [<ffffffff81618806>] common_interrupt+0x86/0x86
[ 66.390446] <EOI>
[ 66.390457] [<ffffffff814ec6d1>] ? cpuidle_enter_state+0x151/0x200
[ 66.390480] [<ffffffff814ec7a2>] cpuidle_enter+0x12/0x20
[ 66.390498] [<ffffffff810b639e>] call_cpuidle+0x1e/0x40
[ 66.390516] [<ffffffff810b65ae>] cpu_startup_entry+0x10e/0x1f0
[ 66.390534] [<ffffffff81036133>] start_secondary+0x103/0x130
(This is split out of the defer global seqno allocation patch due to
realisation that we need a more complete conversion if we want to defer
request submission even further.)
v2: lockdep was warning about mixed SOFTIRQ contexts not HARDIRQ
contexts so we only need to use spin_lock_bh and not disable interrupts.
v3: We need full irq protection as we may be called from a third party
interrupt handler (via fences).
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20161028125858.23563-32-chris@chris-wilson.co.uk
2016-10-28 20:53:55 +01:00
2016-10-28 20:53:43 +01:00
2016-10-28 20:53:46 +01:00
2016-10-28 20:53:55 +01:00
2016-10-28 20:53:51 +01:00
2016-10-28 20:53:55 +01:00
2016-10-28 20:53:50 +01:00
2016-08-04 20:19:50 +01:00
2016-10-28 20:53:55 +01:00
2016-10-28 20:53:50 +01:00
2016-10-28 20:53:45 +01:00
2016-10-28 20:53:50 +01:00
2016-10-28 20:53:47 +01:00
2016-10-28 20:53:50 +01:00
2016-10-28 20:53:50 +01:00
2016-10-28 20:53:47 +01:00
2016-10-28 20:53:46 +01:00
2016-10-28 20:53:44 +01:00
2016-10-28 20:53:54 +01:00
2016-10-28 20:53:53 +01:00
2016-10-28 20:53:49 +01:00
2016-10-28 20:53:47 +01:00
2016-10-28 20:53:50 +01:00
2016-10-28 20:53:51 +01:00
2016-10-28 20:53:54 +01:00
2016-10-28 20:53:50 +01:00
2016-10-28 20:53:53 +01:00
2016-10-28 20:53:51 +01:00
2016-10-28 20:53:55 +01:00
2016-09-15 10:56:02 +01:00
2016-10-28 20:53:53 +01:00
2016-10-28 20:53:51 +01:00
2016-08-17 12:36:07 +01:00
2016-08-19 17:13:36 +01:00
2016-10-12 12:00:32 +01:00
2016-10-12 12:00:32 +01:00
2016-09-22 14:53:29 +03:00
2016-06-17 19:44:25 +01:00
2016-10-28 12:25:24 +03:00
2016-10-14 12:23:22 +01:00
2016-10-28 20:53:42 +01:00
2016-10-28 20:53:42 +01:00
2016-10-12 12:00:32 +01:00
2016-10-28 20:53:53 +01:00
2016-09-20 06:23:22 +10:00
2016-06-17 19:44:29 +01:00
2016-10-28 20:53:50 +01:00
2016-06-02 17:20:25 +02:00
2016-10-26 12:36:30 +03:00
2016-10-21 15:43:40 +03:00
2016-10-28 20:53:55 +01:00
2016-10-14 12:23:19 +01:00
2016-10-14 12:23:22 +01:00
2016-10-26 14:20:53 -07:00
2016-10-28 12:24:45 +03:00
2016-10-05 15:24:54 +03:00
2016-10-28 20:53:51 +01:00
2016-09-26 12:08:22 +03:00
2016-09-29 11:02:41 +03:00
2016-10-28 15:06:31 +03:00
2016-10-28 12:25:24 +03:00
2016-10-28 12:25:24 +03:00
2016-09-09 14:53:18 -07:00
2016-10-28 20:53:51 +01:00
2016-07-04 12:54:07 +01:00
2016-09-19 18:38:11 +03:00
2016-10-14 12:23:19 +01:00
2016-10-14 12:23:19 +01:00
2016-05-17 16:12:39 +03:00
2016-09-21 09:32:00 -07:00
2016-10-28 20:53:54 +01:00
2016-10-25 08:57:53 +02:00
2016-08-22 12:19:52 +01:00
2016-10-14 12:23:22 +01:00
2016-08-04 20:20:03 +01:00
2016-08-04 20:20:03 +01:00
2016-10-25 09:34:23 +01:00
2016-10-25 09:34:06 +01:00
2016-10-25 09:34:23 +01:00
2016-10-20 17:18:39 +08:00
2016-10-20 17:18:30 +08:00
2016-10-21 15:43:40 +03:00
2016-08-17 12:36:15 +01:00
2016-10-17 14:26:42 +03:00
2016-10-28 20:53:54 +01:00
2016-09-09 14:23:05 +01:00
2016-10-26 12:41:01 +03:00
2016-10-14 12:23:22 +01:00
2016-08-02 22:58:16 +01:00
2016-07-21 09:59:41 +01:00
2016-08-12 10:41:39 +02:00
2016-09-14 11:25:05 +03:00
2016-10-28 20:53:50 +01:00
2016-10-10 16:05:52 +03:00
2016-10-28 20:53:50 +01:00
2016-10-14 12:23:19 +01:00
2016-08-02 22:58:30 +01:00
2016-10-28 20:53:54 +01:00
2016-10-28 20:53:55 +01:00
2016-10-28 12:25:03 +03:00
2016-10-14 12:23:19 +01:00
2016-06-30 15:42:33 +01:00
2016-10-25 16:39:43 +10:00
2016-10-14 12:23:19 +01:00
2016-10-10 16:06:41 +03:00
2016-06-10 10:41:15 +03:00
2016-10-27 10:33:17 +02:00
2016-07-10 13:22:39 +01:00
2016-10-28 20:53:51 +01:00
f6168e3304