From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ben Widawsky Subject: [PATCH] drm/i915: Make vm eviction uninterruptible Date: Sat, 5 Apr 2014 13:08:02 -0700 Message-ID: <1396728482-25402-1-git-send-email-benjamin.widawsky@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mga02.intel.com (mga02.intel.com [134.134.136.20]) by gabe.freedesktop.org (Postfix) with ESMTP id 4F5A96E1BD for ; Sat, 5 Apr 2014 13:08:05 -0700 (PDT) List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" To: Intel GFX List-Id: intel-gfx@lists.freedesktop.org Our current code cannot handle a failure to evict well. You'll get at the very least the following splat, but usually a lot worse fallout after: [ 134.819441] ------------[ cut here ]------------ [ 134.819467] WARNING: CPU: 3 PID: 442 at drivers/gpu/drm/i915/i915_gem_evict.c:230 i915_gem_evict_vm+0x8a/0x1c0 [i915]() [ 134.819471] Modules linked in: i915 drm_kms_helper drm intel_gtt agpgart i2c_algo_bit ext4 crc16 mbcache jbd2 x86_pkg_temp_thermal coretemp kvm_intel kvm crc32c_intel ghash_clmulni_intel aesni_intel aes_x86_64 lrw iTCO_wdt gf128mul iTCO_vendor_support glue_helper ablk_helper cryptd microcode serio_raw i2c_i801 fan thermal battery e1000e acpi_cpufreq evdev ptp ac acpi_pad pps_core processor lpc_ich mfd_core snd_seq_dummy snd_seq_oss snd_seq_midi_event snd_seq snd_seq_device snd_timer snd soundcore sd_mod crc_t10dif crct10dif_common ahci libahci libata ehci_pci ehci_hcd usbcore scsi_mod usb_common [ 134.819565] CPU: 3 PID: 442 Comm: glxgears Not tainted 3.14.0-BEN+ #480 [ 134.819568] Hardware name: Intel Corporation Broadwell Client platform/WhiteTip Mountain 1, BIOS BDW-E1R1.86C.0063.R01.1402110503 02/11/2014 [ 134.819571] 0000000000000009 ffff88009b10fa80 ffffffff8159e6a5 0000000000000000 [ 134.819577] ffff88009b10fab8 ffffffff8104895d ffff880145c353c0 ffff880145f400f8 [ 134.819584] 0000000000000000 ffff8800a274d300 ffff88009b10fb78 ffff88009b10fac8 [ 134.819590] Call Trace: [ 134.819599] [] dump_stack+0x4e/0x7a [ 134.819607] [] warn_slowpath_common+0x7d/0xa0 [ 134.819635] [] warn_slowpath_null+0x1a/0x20 [ 134.819656] [] i915_gem_evict_vm+0x8a/0x1c0 [i915] [ 134.819677] [] ppgtt_release+0x17b/0x1e0 [i915] [ 134.819693] [] i915_gem_context_free+0x7d/0x180 [i915] [ 134.819707] [] context_idr_cleanup+0x3c/0x40 [i915] [ 134.819715] [] idr_for_each+0x104/0x1a0 [ 134.819730] [] ? i915_gem_context_free+0x180/0x180 [i915] [ 134.819735] [] ? mutex_lock_nested+0x28c/0x3d0 [ 134.819761] [] ? i915_driver_preclose+0x25/0x50 [i915] [ 134.819778] [] i915_gem_context_close+0x35/0xa0 [i915] [ 134.819802] [] i915_driver_preclose+0x30/0x50 [i915] [ 134.819816] [] drm_release+0x5d/0x5f0 [drm] [ 134.819822] [] __fput+0xea/0x240 [ 134.819827] [] ____fput+0xe/0x10 [ 134.819832] [] task_work_run+0xac/0xe0 [ 134.819837] [] do_exit+0x2cf/0xcf0 [ 134.819844] [] ? _raw_spin_unlock_irq+0x2c/0x60 [ 134.819849] [] do_group_exit+0x4c/0xc0 [ 134.819855] [] get_signal_to_deliver+0x2d1/0x920 [ 134.819861] [] do_signal+0x48/0x620 [ 134.819867] [] ? do_readv_writev+0x169/0x220 [ 134.819873] [] ? trace_hardirqs_on_caller+0xfd/0x1c0 [ 134.819879] [] ? __fget_light+0x13d/0x160 [ 134.819886] [] ? sysret_signal+0x5/0x47 [ 134.819892] [] do_notify_resume+0x65/0x80 [ 134.819897] [] int_signal+0x12/0x17 [ 134.819901] ---[ end trace dbf4da2122c3d683 ]--- At first I was going to call this a bandage to the problem. However, upon further thought, I rather like the idea of making evictions atomic, and less prone to failure anyway. The reason it can still somewhat be considered a band-aid however is GPU hangs. It would be nice if we had some way to interrupt the process when the GPU is hung. I'll leave it for a follow patch though. Cc: Chris Wilson Signed-off-by: Ben Widawsky --- drivers/gpu/drm/i915/i915_gem_evict.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/i915_gem_evict.c b/drivers/gpu/drm/i915/i915_gem_evict.c index 75fca63..91da738 100644 --- a/drivers/gpu/drm/i915/i915_gem_evict.c +++ b/drivers/gpu/drm/i915/i915_gem_evict.c @@ -225,10 +225,17 @@ int i915_gem_evict_vm(struct i915_address_space *vm, bool do_idle) i915_gem_retire_requests(vm->dev); } - list_for_each_entry_safe(vma, next, &vm->inactive_list, mm_list) + list_for_each_entry_safe(vma, next, &vm->inactive_list, mm_list) { + struct drm_i915_private *dev_priv = vm->dev->dev_private; + bool old_intr = dev_priv->mm.interruptible; + dev_priv->mm.interruptible = false; + if (vma->pin_count == 0) WARN_ON(i915_vma_unbind(vma)); + dev_priv->mm.interruptible = old_intr; + } + return 0; } -- 1.9.1