- 28 Apr, 2020 2 commits
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Chris Wilson authored
Give a small bump for our tolerance on comparing the expected vs measured clock ticks/time from 10% to 12.5% to accommodate a bad result on Sandybridge that was off by 10.3%. Hopefully, that is the worst we will see. Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/1802Signed-off-by:
Chris Wilson <chris@chris-wilson.co.uk> Reviewed-by:
Mika Kuoppala <mika.kuoppala@linux.intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20200428114307.5153-1-chris@chris-wilson.co.uk
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Colin Ian King authored
There is a spelling mistaking in a pr_notice message. Fix it. Signed-off-by:
Colin Ian King <colin.king@canonical.com> Reviewed-by:
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- 27 Apr, 2020 6 commits
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Matt Roper authored
The IRQ postinstall handling had open-coded pipe fault mask selection that never got updated for gen11. Switch it to use gen8_de_pipe_fault_mask() to ensure we don't miss updates for new platforms. Cc: José Roberto de Souza <jose.souza@intel.com> Fixes: d506a65d ("drm/i915: Catch GTT fault errors for gen11+ planes") Signed-off-by:
Matt Roper <matthew.d.roper@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20200424231423.4065231-1-matthew.d.roper@intel.comReviewed-by:
Ville Syrjälä <ville.syrjala@linux.intel.com>
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Chris Wilson authored
The bspec lists both the clock frequency and the effective interval. The interval corresponds to observed behaviour, so adjust the frequency to match. v2: Mika rightfully asked if we could measure the clock frequency from a selftest. Signed-off-by:
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Chris Wilson authored
We see that if the HW doesn't actually sleep, the HW may eat the poison we set in its write-only HWSP during sanitize: intel_gt_resume.part.8: 0000:00:02.0 __gt_unpark: 0000:00:02.0 gt_sanitize: 0000:00:02.0 force:yes process_csb: 0000:00:02.0 vcs0: cs-irq head=5, tail=90 process_csb: 0000:00:02.0 vcs0: csb[0]: status=0x5a5a5a5a:0x5a5a5a5a assert_pending_valid: Nothing pending for promotion! The CS TAIL pointer should have been reset by reset_csb_pointers(), so in this case it is likely that we have read back from the CPU cache and so we must clflush our control over that page. In doing so, push the sanitisation to the start of the GT sequence so that our poisoning is assuredly before we start talking to the HW. References: https://gitlab.freedesktop.org/drm/intel/-/issues/1794Signed-off-by:
Tvrtko Ursulin <tvrtko.ursulin@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20200427084000.10999-1-chris@chris-wilson.co.uk
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Chris Wilson authored
The hwsp_cacheline pointer from i915_request is very, very flimsy. The i915_request.timeline (and the hwsp_cacheline) are lost upon retiring (after an RCU grace). Therefore we need to confirm that once we have the right pointer for the cacheline, it is not in the process of being retired and disposed of before we attempt to acquire a reference to the cacheline. <3>[ 547.208237] BUG: KASAN: use-after-free in active_debug_hint+0x6a/0x70 [i915] <3>[ 547.208366] Read of size 8 at addr ffff88822a0d2710 by task gem_exec_parall/2536 <4>[ 547.208547] CPU: 3 PID: 2536 Comm: gem_exec_parall Tainted: G U 5.7.0-rc2-ged7a286b5d02d-kasan_117+ #1 <4>[ 547.208556] Hardware name: Dell Inc. XPS 13 9350/, BIOS 1.4.12 11/30/2016 <4>[ 547.208564] Call Trace: <4>[ 547.208579] dump_stack+0x96/0xdb <4>[ 547.208707] ? active_debug_hint+0x6a/0x70 [i915] <4>[ 547.208719] print_address_description.constprop.6+0x16/0x310 <4>[ 547.208841] ? active_debug_hint+0x6a/0x70 [i915] <4>[ 547.208963] ? active_debug_hint+0x6a/0x70 [i915] <4>[ 547.208975] __kasan_report+0x137/0x190 <4>[ 547.209106] ? active_debug_hint+0x6a/0x70 [i915] <4>[ 547.209127] kasan_report+0x32/0x50 <4>[ 547.209257] ? i915_gemfs_fini+0x40/0x40 [i915] <4>[ 547.209376] active_debug_hint+0x6a/0x70 [i915] <4>[ 547.209389] debug_print_object+0xa7/0x220 <4>[ 547.209405] ? lockdep_hardirqs_on+0x348/0x5f0 <4>[ 547.209426] debug_object_assert_init+0x297/0x430 <4>[ 547.209449] ? debug_object_free+0x360/0x360 <4>[ 547.209472] ? lock_acquire+0x1ac/0x8a0 <4>[ 547.209592] ? intel_timeline_read_hwsp+0x4f/0x840 [i915] <4>[ 547.209737] ? i915_active_acquire_if_busy+0x66/0x120 [i915] <4>[ 547.209861] i915_active_acquire_if_busy+0x66/0x120 [i915] <4>[ 547.209990] ? __live_alloc.isra.15+0xc0/0xc0 [i915] <4>[ 547.210005] ? rcu_read_lock_sched_held+0xd0/0xd0 <4>[ 547.210017] ? print_usage_bug+0x580/0x580 <4>[ 547.210153] intel_timeline_read_hwsp+0xbc/0x840 [i915] <4>[ 547.210284] __emit_semaphore_wait+0xd5/0x480 [i915] <4>[ 547.210415] ? i915_fence_get_timeline_name+0x110/0x110 [i915] <4>[ 547.210428] ? lockdep_hardirqs_on+0x348/0x5f0 <4>[ 547.210442] ? _raw_spin_unlock_irq+0x2a/0x40 <4>[ 547.210567] ? __await_execution.constprop.51+0x2e0/0x570 [i915] <4>[ 547.210706] i915_request_await_dma_fence+0x8f7/0xc70 [i915] Fixes: 85bedbf1 ("drm/i915/gt: Eliminate the trylock for reading a timeline's hwsp") Signed-off-by:
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Chris Wilson authored
We evaluate *active, which is a pointer into execlists->inflight[] during dequeue to decide how long a preempt-timeout we need to apply. However, as soon as we do the submit_ports, the HW may send its ACK interrupt causing us to promote execlists->pending[] tp execlists->inflight[], overwriting the value of *active. We know *active is only stable until we submit (as we only submit when there is no pending promotion). [ 16.102328] BUG: KCSAN: data-race in execlists_dequeue+0x1449/0x1600 [i915] [ 16.102356] [ 16.102375] race at unknown origin, with read to 0xffff8881e9500488 of 8 bytes by task 429 on cpu 1: [ 16.102780] execlists_dequeue+0x1449/0x1600 [i915] [ 16.103160] __execlists_submission_tasklet+0x48/0x60 [i915] [ 16.103540] execlists_submit_request+0x38e/0x3c0 [i915] [ 16.103940] submit_notify+0x8f/0xc0 [i915] [ 16.104308] __i915_sw_fence_complete+0x61/0x420 [i915] [ 16.104683] i915_sw_fence_complete+0x58/0x80 [i915] [ 16.105054] i915_sw_fence_commit+0x16/0x20 [i915] [ 16.105457] __i915_request_queue+0x60/0x70 [i915] [ 16.105843] i915_gem_do_execbuffer+0x2d6b/0x4230 [i915] [ 16.106227] i915_gem_execbuffer2_ioctl+0x2b0/0x580 [i915] [ 16.106257] drm_ioctl_kernel+0xe9/0x130 [ 16.106279] drm_ioctl+0x27d/0x45e [ 16.106311] ksys_ioctl+0x89/0xb0 [ 16.106336] __x64_sys_ioctl+0x42/0x60 [ 16.106370] do_syscall_64+0x6e/0x2c0 [ 16.106397] entry_SYSCALL_64_after_hwframe+0x44/0xa9 Signed-off-by:
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Nick Desaulniers authored
The top level Makefile disables this warning. When building an i386_defconfig with Clang, this warning is triggered a whole bunch via includes of headers from perf. Link: https://github.com/ClangBuiltLinux/continuous-integration/pull/182Signed-off-by:
Nick Desaulniers <ndesaulniers@google.com> Reviewed-by:
Nathan Chancellor <natechancellor@gmail.com> Signed-off-by:
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- 25 Apr, 2020 4 commits
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Mika Kuoppala authored
Use indirect ctx bb to load cmd buffer control value from context image to avoid corruption. v2: add to lrc layout (Chris) v3: end to a cacheline (Chris) v4: add to lrc fixed (Chris) v5: value in offset+1 Testcase: igt/i915_selftest/gt_lrc Signed-off-by:
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Mika Kuoppala authored
Indirect ctx batchbuffers are a hw feature of which batch can be run, by hardware, during context restoration stage. Driver can setup a batchbuffer and also an offset into the context image. When context image is marshalled from memory to registers, and when the offset from the start of context register state is equal of what driver pre-determined, batch will run. So one can manipulate context restoration process at cacheline granularity, given some limitations, as you need to have rudimentaries in place before you can run a batch. Add selftest which will write the ring start register to a canary spot. This will test that hardware will run a batchbuffer for the context in question. v2: request wait fix, naming (Chris) v3: test order (Chris) v4: rebase Signed-off-by:
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Mika Kuoppala authored
Restoration of a previous timestamp can collide with updating the timestamp, causing a value corruption. Combat this issue by using indirect ctx bb to modify the context image during restoring process. We can preload value into scratch register. From which we then do the actual write with LRR. LRR is faster and thus less error prone as probability of race drops. v2: tidying (Chris) v3: lrr for all engines v4: grp v5: reg bit v6: wa_bb_offset, virtual engines (Chris) References: HSDES#16010904313 Testcase: igt/i915_selftest/gt_lrc Suggested-by:
Joseph Koston <joseph.koston@intel.com> Cc: Chris Wilson <chris@chris-wilson.co.uk> Signed-off-by:
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Mika Kuoppala authored
General purpose registers are per engine and in a fixed location. Add to live_lrc_fixed. Signed-off-by:
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- 24 Apr, 2020 15 commits
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Chris Wilson authored
We only hold the active spinlock while dumping the error state, and this does not prevent another thread from retiring the request -- as it is quite possible that despite us capturing the current state, the GPU has completed the request. As such, it is dangerous to dereference state below the request as it may already be freed, and the simplest way to avoid the danger is not include it in the error state. Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/1788Signed-off-by:
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Chris Wilson authored
For many configuration details within RC6 and RPS we are programming intervals for the internal clocks. From gen11, these clocks are configuration via the RPM_CONFIG and so for convenience, we would like to convert to/from more natural units (ns). Signed-off-by:
Andi Shyti <andi.shyti@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20200424162805.25920-2-chris@chris-wilson.co.uk
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Chris Wilson authored
Add tracek to the RPS events (interrupts, worker, enabling, threshold selection, frequency setting), so that if we have to debug reticent HW we have some traces to start from. Signed-off-by:
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Chris Wilson authored
The RPS DOWN_TIMEOUT interrupt is signaled after a period of rc6, and upon receipt of that interrupt we reprogram the GPU clocks down to the next idle notch [to help convserve power during rc6]. However, on execlists, we benefit from soft-rc6 immediately parking the GPU and setting idle frequencies upon idling [within a jiffie], and here the interrupt prevents us from restarting from our last frequency. In the process, we can simply opt for a static pm_events mask and rely on the enable/disable interrupts to flush the worker on parking. This will reduce the amount of oscillation observed during steady workloads with microsleeps, as each time the rc6 timeout occurs we immediately follow with a waitboost for a dropped frame. Signed-off-by:
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Ville Syrjälä authored
Split some overly long lines. Signed-off-by:
José Roberto de Souza <jose.souza@intel.com>
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Ville Syrjälä authored
Relocate a bunch of DDI specific code from intel_dp.c to intel_ddi.c by introducing a .set_idle_link_train() vfunc. Signed-off-by:
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Ville Syrjälä authored
Sort out some of the mess between intel_ddi.c intel_dp.c by introducing a .set_signal_levels() vfunc. Signed-off-by:
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Ville Syrjälä authored
Sort out some of the mess between intel_ddi.c intel_dp.c by introducing a .set_link_train() vfunc. Signed-off-by:
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Ville Syrjälä authored
Change intel_{gmch,pch}_panel_fitting() to return a normal error vs. success int. We'll need this later to validate that the margin properties aren't misconfigured. Signed-off-by:Manasi Navare <manasi.d.navare@intel.com>
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Ville Syrjälä authored
Pass the entire connector state to intel_{gmch,pch}_panel_fitting(). For now we just need to get at .scaling_mode but in the future we'll want access to the margin properties as well. v2: Deal with intel_dp_ycbcr420_config() Signed-off-by: -
Ville Syrjälä authored
Follow the new naming convention and call the crtc state "crtc_state", and while at it drop the redundant crtc argument. Signed-off-by:
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Ville Syrjälä authored
Make things a bit more abstract by replacing the pch_pfit.pos/size raw register values with a drm_rect. Makes it slighly more convenient to eg. compute the scaling factors. v2: Use drm_rect_init() Signed-off-by:
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Ville Syrjälä authored
Most of the pfit functions are of the form: func() { if (pfit_enabled) { ... } } Flip the pfit_enabled check around to flatten the functions. And while we're touching all this let's do the usual s/pipe_config/crtc_state/ replacement. Reviewed-by: -
Ville Syrjälä authored
Fix skl_update_scaler_crtc() to deal with different scaling modes correctly. The current implementation assumes DRM_MODE_SCALE_FULLSCREEN. Fortunately we don't expose any border properties currently so the code does actually end up doing the right thing (assigning a scaler for pfit). The code does need to be fixed before any borders are exposed. Also we have redundant calls to skl_update_scaler_crtc() in dp/hdmi .compute_config() which can be nuked. They were anyway called before we had even computed the pfit state so were basically nonsense. The real call we need to keep is in intel_crtc_atomic_check(). v2: Deal witrh skl_update_scaler_crtc() in intel_dp_ycbcr420_config() Reviewed-by:
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Chris Wilson authored
The history of i915_vma_close() is confusing, as is its use. As the lifetime of the i915_vma is currently bounded by the object it is attached to, we needed a means of identify when a vma was no longer in use by userspace (via the user's fd). This is further complicated by that only ppgtt vma should be closed at the user's behest, as the ggtt were always shared. Now that we attach the vma to a lut on the user's context, the open count does indicate how many unique and open context/vm are referencing this vma from the user. As such, we can and should just use the open_count to track when the vma is still in use by userspace. It's a poor man's replacement for reference counting. Closes: https://gitlab.freedesktop.org/drm/intel/issues/1193Signed-off-by:
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- 23 Apr, 2020 6 commits
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Mika Kuoppala authored
More often than not, we need a byte offset into lrc register state from the start of the hw state. Make it so. Signed-off-by:
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Mika Kuoppala authored
Add per ctx bb and indirect ctx bb register locations to live_lrc_fixed for verification. Signed-off-by:
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Chris Wilson authored
Under ideal circumstances, the driver should be able to keep the GPU fully saturated with work. Measure how close to ideal we get under the harshest of conditions with no user payload. v2: Also measure throughput using only one thread. Signed-off-by:
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Chris Wilson authored
intel_gt_wait_for_idle() tries to wait until all the outstanding requests are retired and the GPU is idle. As a side effect of retiring requests, we may submit more work to flush any pm barriers, and so the wait-for-idle tries to flush the background pm work and catch the new requests. However, if the work completed in the background before we were able to flush, it would queue the extra barrier request without us noticing -- and so we would return from wait-for-idle with one request remaining. (This breaks e.g. record_default_state where we need to wait until that barrier is retired, and it may slow suspend down by causing us to wait on the background retirement worker as opposed to immediately retiring the barrier.) However, since we track if there has been a submission since the engine pm barrier, we can very quickly detect if the idle barrier is still outstanding. Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/1763Signed-off-by:
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Chris Wilson authored
During the virtual engine's submission tasklet, we take the request and insert into the submission queue on each of our siblings. This seems quite simply, and so no problems with ordering. However, the sibling execlists' submission tasklets may run concurrently with the virtual engine's tasklet, submitting the request to HW before the virtual finishes its task of telling all the siblings. If this happens, the sibling tasklet may *reorder* the ve->sibling[] array that the virtual engine tasklet is processing. This can *only* reorder within the elements already processed by the virtual engine, nevertheless the race is detected by KCSAN: [ 185.580014] BUG: KCSAN: data-race in execlists_dequeue [i915] / virtual_submission_tasklet [i915] [ 185.580054] [ 185.580076] write to 0xffff8881f1919860 of 8 bytes by interrupt on cpu 2: [ 185.580553] execlists_dequeue+0x6ad/0x1600 [i915] [ 185.581044] __execlists_submission_tasklet+0x48/0x60 [i915] [ 185.581517] execlists_submission_tasklet+0xd3/0x170 [i915] [ 185.581554] tasklet_action_common.isra.0+0x42/0x90 [ 185.581585] __do_softirq+0xc8/0x206 [ 185.581613] run_ksoftirqd+0x15/0x20 [ 185.581641] smpboot_thread_fn+0x15a/0x270 [ 185.581669] kthread+0x19a/0x1e0 [ 185.581695] ret_from_fork+0x1f/0x30 [ 185.581717] [ 185.581736] read to 0xffff8881f1919860 of 8 bytes by interrupt on cpu 0: [ 185.582231] virtual_submission_tasklet+0x10e/0x5c0 [i915] [ 185.582265] tasklet_action_common.isra.0+0x42/0x90 [ 185.582291] __do_softirq+0xc8/0x206 [ 185.582315] run_ksoftirqd+0x15/0x20 [ 185.582340] smpboot_thread_fn+0x15a/0x270 [ 185.582368] kthread+0x19a/0x1e0 [ 185.582395] ret_from_fork+0x1f/0x30 [ 185.582417] We can prevent this race by checking for the ve->request after looking up the sibling array. Signed-off-by:
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Imre Deak authored
Fix the check for when an AUX power well enabling timeout is expected on a legacy TypeC port. Fixes: 89e01caa ("drm/i915: Use single set of AUX powerwell ops for gen11+") Cc: Matt Roper <matthew.d.roper@intel.com> Cc: José Roberto de Souza <jose.souza@intel.com> Signed-off-by:
Imre Deak <imre.deak@intel.com> Reviewed-by:
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- 22 Apr, 2020 4 commits
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Chris Wilson authored
When we migrated to execlists, one of the conditions we wanted to test for was whether the breadcrumb seqno was being written before the breadcumb interrupt was delivered. This was following on from issues observed on previous generations which were not so strongly ordered. With the removal of the missed interrupt detection, we have not reliable means of detecting the out-of-order seqno/interrupt but instead tried to assert that the relationship between the CS event interrupt and the breadwrite should be strongly ordered. However, Icelake proves it is possible for the HW implementation to forget about minor little details such as write ordering and so the order between *processing* the CS event and the breadcrumb is unreliable. Remove the unreliable assertion, but leave a debug telltale in case we have reason to suspect. Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/1658Signed-off-by:
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Chris Wilson authored
While the ggtt vma are protected by their object lifetime, the list continues until it hits a non-ggtt vma, and that vma is not protected and may be freed as we inspect it. Hence, we require the obj->vma.lock to protect the list as we iterate. An example of forgetting to hold the obj->vma.lock is [1642834.464973] general protection fault, probably for non-canonical address 0xdead000000000122: 0000 [#1] SMP PTI [1642834.464977] CPU: 3 PID: 1954 Comm: Xorg Not tainted 5.6.0-300.fc32.x86_64 #1 [1642834.464979] Hardware name: LENOVO 20ARS25701/20ARS25701, BIOS GJET94WW (2.44 ) 09/14/2017 [1642834.465021] RIP: 0010:i915_gem_object_set_tiling+0x2c0/0x3e0 [i915] [1642834.465024] Code: 8b 84 24 18 01 00 00 f6 c4 80 74 59 49 8b 94 24 a0 00 00 00 49 8b 84 24 e0 00 00 00 49 8b 74 24 10 48 8b 92 30 01 00 00 89 c7 <80> ba 0a 06 00 00 03 0f 87 86 00 00 00 ba 00 00 08 00 b9 00 00 10 [1642834.465025] RSP: 0018:ffffa98780c77d60 EFLAGS: 00010282 [1642834.465028] RAX: ffff8d232bfb2578 RBX: 0000000000000002 RCX: ffff8d25873a0000 [1642834.465029] RDX: dead000000000122 RSI: fffff0af8ac6e408 RDI: 000000002bfb2578 [1642834.465030] RBP: ffff8d25873a0000 R08: ffff8d252bfb5638 R09: 0000000000000000 [1642834.465031] R10: 0000000000000000 R11: ffff8d252bfb5640 R12: ffffa987801cb8f8 [1642834.465032] R13: 0000000000001000 R14: ffff8d233e972e50 R15: ffff8d233e972d00 [1642834.465034] FS: 00007f6a3d327f00(0000) GS:ffff8d25926c0000(0000) knlGS:0000000000000000 [1642834.465036] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [1642834.465037] CR2: 00007f6a2064d000 CR3: 00000002fb57c001 CR4: 00000000001606e0 [1642834.465038] Call Trace: [1642834.465083] i915_gem_set_tiling_ioctl+0x122/0x230 [i915] [1642834.465121] ? i915_gem_object_set_tiling+0x3e0/0x3e0 [i915] [1642834.465151] drm_ioctl_kernel+0x86/0xd0 [drm] [1642834.465156] ? avc_has_perm+0x3b/0x160 [1642834.465178] drm_ioctl+0x206/0x390 [drm] [1642834.465216] ? i915_gem_object_set_tiling+0x3e0/0x3e0 [i915] [1642834.465221] ? selinux_file_ioctl+0x122/0x1c0 [1642834.465226] ? __do_munmap+0x24b/0x4d0 [1642834.465231] ksys_ioctl+0x82/0xc0 [1642834.465235] __x64_sys_ioctl+0x16/0x20 [1642834.465238] do_syscall_64+0x5b/0xf0 [1642834.465243] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [1642834.465245] RIP: 0033:0x7f6a3d7b047b [1642834.465247] Code: 0f 1e fa 48 8b 05 1d aa 0c 00 64 c7 00 26 00 00 00 48 c7 c0 ff ff ff ff c3 66 0f 1f 44 00 00 f3 0f 1e fa b8 10 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d ed a9 0c 00 f7 d8 64 89 01 48 [1642834.465249] RSP: 002b:00007ffe71adba28 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 [1642834.465251] RAX: ffffffffffffffda RBX: 000055f99048fa40 RCX: 00007f6a3d7b047b [1642834.465253] RDX: 00007ffe71adba30 RSI: 00000000c0106461 RDI: 000000000000000e [1642834.465254] RBP: 0000000000000002 R08: 000055f98f3f1798 R09: 0000000000000002 [1642834.465255] R10: 0000000000001000 R11: 0000000000000246 R12: 0000000000000080 [1642834.465257] R13: 000055f98f3f1690 R14: 00000000c0106461 R15: 00007ffe71adba30 Now to take the spinlock during the list iteration, we need to break it down into two phases. In the first phase under the lock, we cannot sleep and so must defer the actual work to a second list, protected by the ggtt->mutex. We also need to hold the spinlock during creation of a new vma to serialise with updates of the tiling on the object. Reported-by:
Dave Airlie <airlied@redhat.com> Fixes: 2850748e ("drm/i915: Pull i915_vma_pin under the vm->mutex") Signed-off-by:
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Chris Wilson authored
Since batch buffers dominant execution time, most preemption requests should naturally occur during execution of a batch buffer. We wish to verify that should a preemption occur within a batch buffer, when we come to restart that batch buffer, it occurs at the interrupted instruction and most importantly does not rollback to an earlier point. v2: Do not clear the GPR at the start of the batch, but rely on them being clear for new contexts. Suggested-by:
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Chris Wilson authored
For verifying reciving the EI interrupts, we need to hold the GPU in very precise conditions (in terms of C0 cycles during the EI). If we preempt the busy load to handle the heartbeat, this may perturb the busy load causing us to miss the interrupt. The other tests, while not as time sensitive, may also be slightly perturbed, so apply the heartbeat protection across all the measurements. Signed-off-by:
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- 21 Apr, 2020 3 commits
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Chris Wilson authored
Having noticed that MI_BB_START is incurring a memory stall (see the correlation with uncore frequency), we have to unroll the loop in order to diminish the impact of the MI_BB_START on the instruction throughput. Signed-off-by:
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Chris Wilson authored
Since we may lose the content of any buffer when we relinquish control of the system (e.g. suspend/resume), we have to be careful not to rely on regaining control. A good method to detect when we might be using garbage is by always injecting that garbage prior to first use on load/resume/etc. v2: Drop sanitize callback on cleanup v3: Move seqno reset to timeline enter, so we reset all timelines. However, this is done on every activation during runtime and not reset. The similar level of paranoia we apply to correcting context state after a period of inactivity. Suggested-by:
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Chris Wilson authored
Let's isolate the impact of cpu frequency selection on determing the GPU throughput in response to selection of RPS frequencies. For real systems, we do have to be concerned with the impact of integrating c-states, p-states and rp-states, but for the sake of proving whether or not RPS works, one baby step at a time. For the record, as one would hope, it does not seem to impact on the measured performance, but we do it anyway to reduce the number of variables. Later, we can extend the testing to encourage the the cpu/pkg to try and sleep while the GPU is busy. Signed-off-by:
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