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path: root/drivers/gpu/drm/i915/i915_request.c
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2021-04-26drm/i915: Take request reference before arming the watchdog timerTvrtko Ursulin1-1/+2
Reference needs to be taken before arming the timer. Luckily, given the default timer period of 20s, the potential to hit the race is extremely unlikely. Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Fixes: 9b4d0598ee94 ("drm/i915: Request watchdog infrastructure") Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20210326105759.2387104-1-tvrtko.ursulin@linux.intel.com (cherry picked from commit f7c379779161d364eb30338529490eac7dc377b7) Signed-off-by: Jani Nikula <jani.nikula@intel.com>
2021-04-08Merge tag 'drm-intel-gt-next-2021-04-06' of ↵Dave Airlie1-2/+7
git://anongit.freedesktop.org/drm/drm-intel into drm-next Driver Changes: - Prepare for local/device memory support on DG1 by starting to use it for kernel internal allocations: context, ring and engine scratch (Matt A, CQ, Abdiel, Imre) - Sandybridge fix to avoid hard hang on ring resume (Chris) - Limit imported dma-buf size to int32 (Matt A) - Double check heartbeat timeout before resetting (Chris) - Use new tasklet API for execution list (Emil) - Fix SPDX checkpats warnings (Chris) - Fixes for various checkpatch warnings (Chris) - Selftest improvements (Chris) - Move the defer_request waiter active assertion to correct spot (Chris) - Make local-memory probing a GT operation (Matt, Tvrtko) - Protect against request freeing during cancellation on wedging (Chris) - Retire unexpected starting state error dumping (Chris) - Distinction of memory regions in debugging (Zbigniew) - Always flush the submission queue on checking for idle (Chris) - Consolidate 2big error check to helper (Matt) - Decrease number of subplatform bits (Tvrtko) - Remove unused internal request priority levels (Chris) - Document the unused internal header bits in buddy allocator (Matt) - Cleanup the region class/instance encoding (Matt) Signed-off-by: Dave Airlie <airlied@redhat.com> From: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/YGxksaZGXHnFxlwg@jlahtine-mobl.ger.corp.intel.com
2021-03-26drm/i915: Request watchdog infrastructureTvrtko Ursulin1-0/+52
Prepares the plumbing for setting request/fence expiration time. All code is put in place but is never activated due yet missing ability to actually configure the timer. Outline of the basic operation: A timer is started when request is ready for execution. If the request completes (retires) before the timer fires, timer is cancelled and nothing further happens. If the timer fires request is added to a lockless list and worker queued. Purpose of this is twofold: a) It allows request cancellation from a more friendly context and b) coalesces multiple expirations into a single event of consuming the list. Worker locklessly consumes the list of expired requests and cancels them all using previous added i915_request_cancel(). Associated timeout value is stored in rq->context.watchdog.timeout_us. v2: * Log expiration. v3: * Include more information about user timeline in the log message. v4: * Remove obsolete comment and fix formatting. (Matt) Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Reviewed-by: Matthew Auld <matthew.auld@intel.com> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> Link: https://patchwork.freedesktop.org/patch/msgid/20210324121335.2307063-6-tvrtko.ursulin@linux.intel.com
2021-03-26drm/i915: Individual request cancellationChris Wilson1-3/+30
Currently, we cancel outstanding requests within a context when the context is closed. We may also want to cancel individual requests using the same graceful preemption mechanism. v2 (Tvrtko): * Cancel waiters carefully considering no timeline lock and RCU. * Fixed selftests. v3 (Tvrtko): * Remove error propagation to waiters for now. v4 (Tvrtko): * Rebase for extracted i915_request_active_engine. (Matt) Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Reviewed-by: Matthew Auld <matthew.auld@intel.com> [danvet: Resolve conflict because intel_engine_flush_scheduler is still called intel_engine_flush_submission] Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> Link: https://patchwork.freedesktop.org/patch/msgid/20210324121335.2307063-3-tvrtko.ursulin@linux.intel.com
2021-03-26drm/i915: Extract active lookup engine to a helperTvrtko Ursulin1-0/+44
Move active engine lookup to exported i915_request_active_engine. Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Reviewed-by: Matthew Auld <matthew.auld@intel.com> [danvet: Slight rebase, engine->sched.lock is still called engine->active.lock.] Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> Link: https://patchwork.freedesktop.org/patch/msgid/20210324121335.2307063-2-tvrtko.ursulin@linux.intel.com
2021-03-24drm/i915: Protect against request freeing during cancellation on wedgingChris Wilson1-2/+7
As soon as we mark a request as completed, it may be retired. So when cancelling a request and marking it complete, make sure we first keep a reference to the request. Signed-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/20210201085715.27435-4-chris@chris-wilson.co.uk Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2021-03-24drm/i915: Do not share hwsp across contexts any more, v8.Maarten Lankhorst1-4/+0
Instead of sharing pages with breadcrumbs, give each timeline a single page. This allows unrelated timelines not to share locks any more during command submission. As an additional benefit, seqno wraparound no longer requires i915_vma_pin, which means we no longer need to worry about a potential -EDEADLK at a point where we are ready to submit. Changes since v1: - Fix erroneous i915_vma_acquire that should be a i915_vma_release (ickle). - Extra check for completion in intel_read_hwsp(). Changes since v2: - Fix inconsistent indent in hwsp_alloc() (kbuild) - memset entire cacheline to 0. Changes since v3: - Do same in intel_timeline_reset_seqno(), and clflush for good measure. Changes since v4: - Use refcounting on timeline, instead of relying on i915_active. - Fix waiting on kernel requests. Changes since v5: - Bump amount of slots to maximum (256), for best wraparounds. - Add hwsp_offset to i915_request to fix potential wraparound hang. - Ensure timeline wrap test works with the changes. - Assign hwsp in intel_timeline_read_hwsp() within the rcu lock to fix a hang. Changes since v6: - Rename i915_request_active_offset to i915_request_active_seqno(), and elaborate the function. (tvrtko) Changes since v7: - Move hunk to where it belongs. (jekstrand) - Replace CACHELINE_BYTES with TIMELINE_SEQNO_BYTES. (jekstrand) Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Reviewed-by: Thomas Hellström <thomas.hellstrom@intel.com> #v1 Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> Link: https://patchwork.freedesktop.org/patch/msgid/20210323155059.628690-2-maarten.lankhorst@linux.intel.com
2021-01-15drm/i915: Reduce test_and_set_bit to set_bit in i915_request_submit()Chris Wilson1-7/+9
Avoid the full blown memory barrier of test_and_set_bit() by noting the completed request and removing it from the lists. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Reviewed-by: Andi Shyti <andi.shyti@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20210114135612.13210-5-chris@chris-wilson.co.uk
2021-01-15drm/i915: Drop i915_request.lock serialisation around await_startChris Wilson1-2/+8
Originally, we used the signal->lock as a means of following the previous link in its timeline and peeking at the previous fence. However, we have replaced the explicit serialisation with a series of very careful probes that anticipate the links being deleted and the fences recycled before we are able to acquire a strong reference to it. We do not need the signal->lock crutch anymore, nor want the contention. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Reviewed-by: Andi Shyti <andi.shyti@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20210114135612.13210-2-chris@chris-wilson.co.uk
2021-01-15drm/i915: Mark up protected uses of 'i915_request_completed'Chris Wilson1-10/+9
When we know that we are inside the timeline mutex, or inside the submission flow (under active.lock or the holder's rcu lock), we know that the rq->hwsp is stable and we can use the simpler direct version. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Reviewed-by: Andi Shyti <andi.shyti@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20210114135612.13210-1-chris@chris-wilson.co.uk
2021-01-15Merge tag 'drm-intel-gt-next-2021-01-14' of ↵Dave Airlie1-11/+128
git://anongit.freedesktop.org/drm/drm-intel into drm-next UAPI Changes: - Deprecate I915_PMU_LAST and optimize state tracking (Tvrtko) Avoid relying on last item ABI marker in i915_drm.h, add a comment to mark as deprecated. Cross-subsystem Changes: Core Changes: Driver Changes: - Restore clear residuals security mitigations for Ivybridge and Baytrail (Chris) - Close #1858: Allow sysadmin to choose applied GPU security mitigations through i915.mitigations=... similar to CPU (Chris) - Fix for #2024: GPU hangs on HSW GT1 (Chris) - Fix for #2707: Driver hang when editing UVs in Blender (Chris, Ville) - Fix for #2797: False positive GuC loading error message (Chris) - Fix for #2859: Missing GuC firmware for older Cometlakes (Chris) - Lessen probability of GPU hang due to DMAR faults [reason 7, next page table ptr is invalid] on Tigerlake (Chris) - Fix REVID macros for TGL to fetch correct stepping (Aditya) - Limit frequency drop to RPe on parking (Chris, Edward) - Limit W/A 1406941453 to TGL, RKL and DG1 (Swathi) - Make W/A 22010271021 permanent on DG1 (Lucas) - Implement W/A 16011163337 to prevent a HS/DS hang on DG1 (Swathi) - Only disable preemption on gen8 render engines (Chris) - Disable arbitration around Braswell's PDP updates (Chris) - Disable arbitration on no-preempt requests (Chris) - Check for arbitration after writing start seqno before busywaiting (Chris) - Retain default context state across shrinking (Venkata, CQ) - Fix mismatch between misplaced vma check and vma insert for 32-bit addressing userspaces (Chris, CQ) - Propagate error for vmap() failure instead kernel NULL deref (Chris) - Propagate error from cancelled submit due to context closure immediately (Chris) - Fix RCU race on HWSP tracking per request (Chris) - Clear CMD parser shadow and GPU reloc batches (Matt A) - Populate logical context during first pin (Maarten) - Optimistically prune dma-resv from the shrinker (Chris) - Fix for virtual engine ownership race (Chris) - Remove timeslice suppression to restore fairness for virtual engines (Chris) - Rearrange IVB/HSW workarounds properly between GT and engine (Chris) - Taint the reset mutex with the shrinker (Chris) - Replace direct submit with direct call to tasklet (Chris) - Multiple corrections to virtual engine dequeue and breadcrumbs code (Chris) - Avoid wakeref from potentially hard IRQ context in PMU (Tvrtko) - Use raw clock for RC6 time estimation in PMU (Tvrtko) - Differentiate OOM failures from invalid map types (Chris) - Fix Gen9 to have 64 MOCS entries similar to Gen11 (Chris) - Ignore repeated attempts to suspend request flow across reset (Chris) - Remove livelock from "do_idle_maps" VT-d W/A (Chris) - Cancel the preemption timeout early in case engine reset fails (Chris) - Code flow optimization in the scheduling code (Chris) - Clear the execlists timers upon reset (Chris) - Drain the breadcrumbs just once (Chris, Matt A) - Track the overall GT awake/busy time (Chris) - Tweak submission tasklet flushing to avoid starvation (Chris) - Track timelines created using the HWSP to restore on resume (Chris) - Use cmpxchg64 for 32b compatilibity for active tracking (Chris) - Prefer recycling an idle GGTT fence to avoid GPU wait (Chris) - Restructure GT code organization for clearer split between GuC and execlists (Chris, Daniele, John, Matt A) - Remove GuC code that will remain unused by new interfaces (Matt B) - Restructure the CS timestamp clocks code to local to GT (Chris) - Fix error return paths in perf code (Zhang) - Replace idr_init() by idr_init_base() in perf (Deepak) - Fix shmem_pin_map error path (Colin) - Drop redundant free_work worker for GEM contexts (Chris, Mika) - Increase readability and understandability of intel_workarounds.c (Lucas) - Defer enabling the breadcrumb interrupt to after submission (Chris) - Deal with buddy alloc block sizes beyond 4G (Venkata, Chris) - Encode fence specific waitqueue behaviour into the wait.flags (Chris) - Don't cancel the breadcrumb interrupt shadow too early (Chris) - Cancel submitted requests upon context reset (Chris) - Use correct locks in GuC code (Tvrtko) - Prevent use of engine->wa_ctx after error (Chris, Matt R) - Fix build warning on 32-bit (Arnd) - Avoid memory leak if platform would have more than 16 W/A (Tvrtko) - Avoid unnecessary #if CONFIG_PM in PMU code (Chris, Tvrtko) - Improve debugging output (Chris, Tvrtko, Matt R) - Make file local variables static (Jani) - Avoid uint*_t types in i915 (Jani) - Selftest improvements (Chris, Matt A, Dan) - Documentation fixes (Chris, Jose) Signed-off-by: Dave Airlie <airlied@redhat.com> # Conflicts: # drivers/gpu/drm/i915/gt/intel_breadcrumbs.c # drivers/gpu/drm/i915/gt/intel_breadcrumbs_types.h # drivers/gpu/drm/i915/gt/intel_lrc.c # drivers/gpu/drm/i915/gvt/mmio_context.h # drivers/gpu/drm/i915/i915_drv.h From: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20210114152232.GA21588@jlahtine-mobl.ger.corp.intel.com
2021-01-09drm/i915: Refactor marking a request as EIOChris Wilson1-0/+11
When wedging the device, we cancel all outstanding requests and mark them as EIO. Rather than duplicate the small function to do so between each submission backend, export one. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Andi Shyti <andi.shyti@intel.com> Reviewed-by: Andi Shyti <andi.shyti@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20210109163455.28466-3-chris@chris-wilson.co.uk
2020-12-31drm/i915: Drop i915_request.lock requirement for intel_rps_boost()Chris Wilson1-3/+1
Since we use a flag within i915_request.flags to indicate when we have boosted the request (so that we only apply the boost) once, this can be used as the serialisation with i915_request_retire() to avoid having to explicitly take the i915_request.lock which is more heavily contended. Signed-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/20201231093149.19086-1-chris@chris-wilson.co.uk
2020-12-31drm/i915/gt: Pull context closure check from request submit to schedule-inChris Wilson1-4/+0
We only need to evaluate the current status of the context when it is scheduled in, we will force a reschedule when the context is closed propagating the change to inflight contexts. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Matthew Brost <matthew.brost@intel.com> Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20201231093946.11649-1-chris@chris-wilson.co.uk
2020-12-31drm/i915/gt: Cancel submitted requests upon context resetChris Wilson1-0/+2
Since we process schedule-in of a context after submitting the request, if we decide to reset the context at that time, we also have to cancel the requets we have marked for submission. Signed-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/20201230220028.17089-1-chris@chris-wilson.co.uk
2020-12-24drm/i915/gt: Replace direct submit with direct call to taskletChris Wilson1-2/+10
Rather than having special case code for opportunistically calling process_csb() and performing a direct submit while holding the engine spinlock for submitting the request, simply call the tasklet directly. This allows us to retain the direct submission path, including the CS draining to allow fast/immediate submissions, without requiring any duplicated code paths, and most importantly greatly simplifying the control flow by removing reentrancy. This will enable us to close a few races in the virtual engines in the next few patches. The trickiest part here is to ensure that paired operations (such as schedule_in/schedule_out) remain under consistent locking domains, e.g. when pulled outside of the engine->active.lock v2: Use bh kicking, see commit 3c53776e29f8 ("Mark HI and TASKLET softirq synchronous"). v3: Update engine-reset to be tasklet aware Signed-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/20201224135544.1713-1-chris@chris-wilson.co.uk
2020-12-20drm/i915/gt: Another tweak for flushing the taskletsChris Wilson1-1/+1
tasklet_kill() ensures that we _yield_ the processor until a remote tasklet is completed. However, this leads to a starvation condition as being at the bottom of the scheduler's runqueue means that anything else is able to run, including all hogs keeping the tasklet occupied. Signed-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/20201220134858.10510-1-chris@chris-wilson.co.uk
2020-12-16drm/i915/gt: Move gen8 CS emitters into gen8_engine_cs.hChris Wilson1-0/+1
Reduce the pollution of intel_engine.h by moving gen8_emit_pipe_control and friends to gen8_engine_cs.h Signed-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/20201216135452.6063-1-chris@chris-wilson.co.uk
2020-11-26drm/i915/gt: Decouple completed requests on unwindChris Wilson1-1/+2
Since the introduction of preempt-to-busy, requests can complete in the background, even while they are not on the engine->active.requests list. As such, the engine->active.request list itself is not in strict retirement order, and we have to scan the entire list while unwinding to not miss any. However, if the request is completed we currently leave it on the list [until retirement], but we could just as simply remove it and stop treating it as active. We would only have to then traverse it once while unwinding in quick succession. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20201126140407.31952-1-chris@chris-wilson.co.uk
2020-11-24irq_work: CleanupPeter Zijlstra1-2/+2
Get rid of the __call_single_node union and clean up the API a little to avoid external code relying on the structure layout as much. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
2020-11-19drm/i915/gt: Update request status flags for debug pretty-printerChris Wilson1-12/+73
We plan to expand upon the number of available statuses for when we pretty-print the requests along the timelines, and so need a new set of flags. We have settled upon: Unready [U] - initial status after being submitted, the request is not ready for execution as it is waiting for external fences Ready [R] - all fences the request was waiting on have been signaled, and the request is now ready for execution and will be in a backend queue - a ready request may still need to wait on semaphores [internal fences] Ready/virtual [V] - same as ready, but queued over multiple backends Executing [E] - the request has been transferred from the backend queue and submitted for execution on HW - a completed request may still be regarded as executing, its status may not be updated until it is retired and removed from the lists Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20201119165616.10834-3-chris@chris-wilson.co.uk
2020-11-19drm/i915: Lift i915_request_show()Chris Wilson1-0/+39
Extract i915_request_show for reuse in other request chain pretty printers. For a bonus point, quietly change the seqno format from %llx to %lld to match everywhere else. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20201119165616.10834-2-chris@chris-wilson.co.uk
2020-09-30drm/i915: Cancel outstanding work after disabling heartbeats on an engineChris Wilson1-0/+5
We only allow persistent requests to remain on the GPU past the closure of their containing context (and process) so long as they are continuously checked for hangs or allow other requests to preempt them, as we need to ensure forward progress of the system. If we allow persistent contexts to remain on the system after the the hangcheck mechanism is disabled, the system may grind to a halt. On disabling the mechanism, we sent a pulse along the engine to remove all executing contexts from the engine which would check for hung contexts -- but we did not prevent those contexts from being resubmitted if they survived the final hangcheck. Fixes: 9a40bddd47ca ("drm/i915/gt: Expose heartbeat interval via sysfs") Testcase: igt/gem_ctx_persistence/heartbeat-stop Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Cc: <stable@vger.kernel.org> # v5.7+ Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Acked-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20200928221510.26044-1-chris@chris-wilson.co.uk (cherry picked from commit 7a991cd3e3da9a56d5616b62d425db000a3242f2) Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
2020-09-30drm/i915: Redo "Remove i915_request.lock requirement for execution callbacks"Chris Wilson1-10/+2
The reordering and rebasing of commit 2e4c6c1a9db5 ("drm/i915: Remove i915_request.lock requirement for execution callbacks") caused it to revert an earlier correction. Let us restore commit 99f0a640d464 ("drm/i915: Remove requirement for holding i915_request.lock for breadcrumbs") Fixes: 2e4c6c1a9db5 ("drm/i915: Remove i915_request.lock requirement for execution callbacks") Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com> Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20200925101107.27869-1-chris@chris-wilson.co.uk (cherry picked from commit 35faeb7de9ef83da510a048f2016061f1e31d5fc) Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
2020-09-07drm/i915: Remove i915_request.lock requirement for execution callbacksChris Wilson1-47/+58
To implement preempt-to-busy (and so efficient timeslicing and best utilization of the hardware submission ports) we let the GPU run asynchronously in respect to the ELSP submission queue. This created challenges in keeping and accessing the driver state mirroring the asynchronous GPU execution. Previous fix 1d9221e9d395 ("drm/i915: Skip signaling a signaled request") however did not correctly serialize request retirement with the execution callbacks. We were using the i915_request.lock to serialise adding an execution callback with __i915_request_submit. However, if we use an atomic llist_add to serialise multiple waiters and then check to see if the request is already executing, we can remove the irq-spinlock and fix serialization between retirement and execution callbacks in one go. v2: Avoid using the irq_work when outside of the irq-spinlocks, where we can execute the callbacks immediately. v3: Pay close attention to the order of setting ACTIVE on retirement, we need to ensure the request is signaled and breadcrumbs detached before we finish removing the request from the engine. v4: Expanded commit message. Fixes: 1d9221e9d395 ("drm/i915: Skip signaling a signaled request") Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20200716142207.13003-2-chris@chris-wilson.co.uk Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com> [Joonas: Rebased and reordered into drm-intel-gt-next branch] [Joonas: Added expanded commit message from Tvrtko and Chris] Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
2020-09-07drm/i915: Be wary of data races when reading the active execlistsChris Wilson1-2/+23
To implement preempt-to-busy (and so efficient timeslicing and best utilization of the hardware submission ports) we let the GPU run asynchronously in respect to the ELSP submission queue. This created challenges in keeping and accessing the driver state mirroring the asynchronous GPU execution. The latest occurence of this was spotted by KCSAN: [ 1413.563200] BUG: KCSAN: data-race in __await_execution+0x217/0x370 [i915] [ 1413.563221] [ 1413.563236] race at unknown origin, with read to 0xffff88885bb6c478 of 8 bytes by task 9654 on cpu 1: [ 1413.563548] __await_execution+0x217/0x370 [i915] [ 1413.563891] i915_request_await_dma_fence+0x4eb/0x6a0 [i915] [ 1413.564235] i915_request_await_object+0x421/0x490 [i915] [ 1413.564577] i915_gem_do_execbuffer+0x29b7/0x3c40 [i915] [ 1413.564967] i915_gem_execbuffer2_ioctl+0x22f/0x5c0 [i915] [ 1413.564998] drm_ioctl_kernel+0x156/0x1b0 [ 1413.565022] drm_ioctl+0x2ff/0x480 [ 1413.565046] __x64_sys_ioctl+0x87/0xd0 [ 1413.565069] do_syscall_64+0x4d/0x80 [ 1413.565094] entry_SYSCALL_64_after_hwframe+0x44/0xa9 To complicate matters, we have to both avoid the read tearing of *active and avoid any write tearing as perform the pending[] -> inflight[] promotion of the execlists. This is because we cannot rely on the memcpy doing u64 aligned copies on all kernels/platforms and so we opt to open-code it with explicit WRITE_ONCE annotations to satisfy KCSAN. v2: When in doubt, write the same comment again. v3: Expanded commit message. Fixes: b55230e5e800 ("drm/i915: Check for awaits on still currently executing requests") Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20200716142207.13003-1-chris@chris-wilson.co.uk Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com> [Joonas: Rebased and reordered into drm-intel-gt-next branch] [Joonas: Added expanded commit message from Tvrtko and Chris] Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
2020-09-07drm/i915/gt: Hold context/request reference while breadcrumbs are activeChris Wilson1-5/+4
Currently we hold no actual reference to the request nor context while they are attached to a breadcrumb. To avoid freeing the request/context too early, we serialise with cancel-breadcrumbs by taking the irq spinlock in i915_request_retire(). The alternative is to take a reference for a new breadcrumb and release it upon signaling; removing the more frequently hit contention point in i915_request_retire(). Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20200801160225.6814-2-chris@chris-wilson.co.uk Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com> [Joonas: Rebased and reordered into drm-intel-gt-next branch] Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
2020-09-07drm/i915/gt: Distinguish the virtual breadcrumbs from the irq breadcrumbsChris Wilson1-0/+1
On the virtual engines, we only use the intel_breadcrumbs for tracking signaling of stale breadcrumbs from the irq_workers. They do not have any associated interrupt handling, active requests are passed to a physical engine and associated breadcrumb interrupt handler. This causes issues for us as we need to ensure that we do not actually try and enable interrupts and the powermanagement required for them on the virtual engine, as they will never be disabled. Instead, let's specify the physical engine used for interrupt handler on a particular breadcrumb. v2: Drop b->irq_armed = true mocking for no interrupt HW Fixes: 4fe6abb8f513 ("drm/i915/gt: Ignore irq enabling on the virtual engines") Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20200731154834.8378-4-chris@chris-wilson.co.uk Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com> Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
2020-09-07drm/i915/gt: Replace intel_engine_transfer_stale_breadcrumbsChris Wilson1-3/+2
After staring at the breadcrumb enabling/cancellation and coming to the conclusion that the cause of the mysterious stale breadcrumbs must the act of submitting a completed requests, we can then redirect those completed requests onto a dedicated signaled_list at the time of construction and so eliminate intel_engine_transfer_stale_breadcrumbs(). Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20200731154834.8378-2-chris@chris-wilson.co.uk Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com> Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
2020-09-07drm/i915: Remove requirement for holding i915_request.lock for breadcrumbsChris Wilson1-27/+39
Since the breadcrumb enabling/cancelling itself is serialised by the breadcrumbs.irq_lock, with a bit of care we can remove the outer serialisation with i915_request.lock for concurrent dma_fence_enable_signaling(). This has the important side-effect of eliminating the nested i915_request.lock within request submission. The challenge in serialisation is around the unsubmission where we take an active request that wants a breadcrumb on the signaling engine and put it to sleep. We do not want a concurrent dma_fence_enable_signaling() to attach a breadcrumb as we unsubmit, so we must mark the request as no longer active before serialising with the concurrent enable-signaling. On retire, we serialise with the concurrent enable-signaling, but instead of clearing ACTIVE, we mark it as SIGNALED. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20200731154834.8378-1-chris@chris-wilson.co.uk Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com> [Joonas: Rebased and reordered into drm-intel-gt-next branch] Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
2020-09-07drm/i915/gem: Remove disordered per-file request list for throttlingChris Wilson1-21/+0
I915_GEM_THROTTLE dates back to the time before contexts where there was just a single engine, and therefore a single timeline and request list globally. That request list was in execution/retirement order, and so walking it to find a particular aged request made sense and could be split per file. That is no more. We now have many timelines with a file, as many as the user wants to construct (essentially per-engine, per-context). Each of those run independently and so make the single list futile. Remove the disordered list, and iterate over all the timelines to find a request to wait on in each to satisfy the criteria that the CPU is no more than 20ms ahead of its oldest request. It should go without saying that the I915_GEM_THROTTLE ioctl is no longer used as the primary means of throttling, so it makes sense to push the complication into the ioctl where it only impacts upon its few irregular users, rather than the execbuf/retire where everybody has to pay the cost. Fortunately, the few users do not create vast amount of contexts, so the loops over contexts/engines should be concise. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com> Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20200728152010.30701-1-chris@chris-wilson.co.uk Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com> Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
2020-09-07drm/i915: Soften the tasklet flush frequency before waitsChris Wilson1-2/+18
We include a tasklet flush before waiting on a request as a precaution against the HW being lax in event signaling. We now have a precautionary flush in the engine's heartbeat and so do not need to be quite so zealous on every request wait. If we focus on the request, the only tasklet flush that matters is if there is a delay in submitting this request to HW, so if the request is not ready to be executed, no advantage in reducing this wait can be gained by running the tasklet. And there is little point in doing busy work for no result. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com> Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20200715115147.11866-10-chris@chris-wilson.co.uk Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com> Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
2020-09-07drm/i915: Reduce i915_request.lock contention for i915_request_waitChris Wilson1-10/+8
Currently, we use i915_request_completed() directly in i915_request_wait() and follow up with a manual invocation of dma_fence_signal(). This appears to cause a large number of contentions on i915_request.lock as when the process is woken up after the fence is signaled by an interrupt, we will then try and call dma_fence_signal() ourselves while the signaler is still holding the lock. dma_fence_is_signaled() has the benefit of checking the DMA_FENCE_FLAG_SIGNALED_BIT prior to calling dma_fence_signal() and so avoids most of that contention. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Matthew Auld <matthew.auld@intel.com> Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20200716100754.5670-1-chris@chris-wilson.co.uk Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com> Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
2020-08-17drm/i915: Remove gen check before calling intel_rps_boostChris Wilson1-5/+2
It's been a while since gen6_rps_boost() [that only worked on gen6+] was replaced by intel_rps_boost() that understood itself when rps was active. Since the intel_rps_boost() is gen-agnostic, just call it. Signed-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/20200728152219.1387-1-chris@chris-wilson.co.uk Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
2020-07-13drm/i915: Skip signaling a signaled requestChris Wilson1-10/+13
Preempt-to-busy introduces various fascinating complications in that the requests may complete as we are unsubmitting them from HW. As they may then signal after unsubmission, we may find ourselves having to cleanup the signaling request from within the signaling callback. This causes us to recurse onto the same i915_request.lock. However, if the request is already signaled (as it will be before we enter the signal callbacks), we know we can skip the signaling of that request during submission, neatly evading the spinlock recursion. unsubmit(ve.rq0) # timeslice expiration or other preemption -> virtual_submit_request(ve.rq0) dma_fence_signal(ve.rq0) # request completed before preemption ack -> submit_notify(ve.rq1) -> virtual_submit_request(ve.rq1) # sees that we have completed ve.rq0 -> __i915_request_submit(ve.rq0) [ 264.210142] BUG: spinlock recursion on CPU#2, sample_multi_tr/2093 [ 264.210150] lock: 0xffff9efd6ac55080, .magic: dead4ead, .owner: sample_multi_tr/2093, .owner_cpu: 2 [ 264.210155] CPU: 2 PID: 2093 Comm: sample_multi_tr Tainted: G U [ 264.210158] Hardware name: Intel Corporation CoffeeLake Client Platform/CoffeeLake S UDIMM RVP, BIOS CNLSFWR1.R00.X212.B01.1909060036 09/06/2019 [ 264.210160] Call Trace: [ 264.210167] dump_stack+0x98/0xda [ 264.210174] spin_dump.cold+0x24/0x3c [ 264.210178] do_raw_spin_lock+0x9a/0xd0 [ 264.210184] _raw_spin_lock_nested+0x6a/0x70 [ 264.210314] __i915_request_submit+0x10a/0x3c0 [i915] [ 264.210415] virtual_submit_request+0x9b/0x380 [i915] [ 264.210516] submit_notify+0xaf/0x14c [i915] [ 264.210602] __i915_sw_fence_complete+0x8a/0x230 [i915] [ 264.210692] i915_sw_fence_complete+0x2d/0x40 [i915] [ 264.210762] __dma_i915_sw_fence_wake+0x19/0x30 [i915] [ 264.210767] dma_fence_signal_locked+0xb1/0x1c0 [ 264.210772] dma_fence_signal+0x29/0x50 [ 264.210871] i915_request_wait+0x5cb/0x830 [i915] [ 264.210876] ? dma_resv_get_fences_rcu+0x294/0x5d0 [ 264.210974] i915_gem_object_wait_fence+0x2f/0x40 [i915] [ 264.211084] i915_gem_object_wait+0xce/0x400 [i915] [ 264.211178] i915_gem_wait_ioctl+0xff/0x290 [i915] Fixes: 22b7a426bbe1 ("drm/i915/execlists: Preempt-to-busy") References: 6d06779e8672 ("drm/i915: Load balancing across a virtual engine") Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Cc: "Nayana, Venkata Ramana" <venkata.ramana.nayana@intel.com> Cc: <stable@vger.kernel.org> # v5.4+ Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20200713141636.29326-1-chris@chris-wilson.co.uk
2020-06-03drm/i915: Drop i915_request.i915 backpointerChris Wilson1-6/+6
We infrequently use the direct i915 backpointer from the i915_request, so do we really need to waste the space in the struct for it? 8 bytes from the most frequently allocated struct vs an 3 bytes and pointer chasing in using rq->engine->i915? Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Reviewed-by: Akeem G Abodunrin <akeem.g.abodunrin@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20200602220953.21178-1-chris@chris-wilson.co.uk
2020-05-29drm/i915: Check for awaits on still currently executing requestsChris Wilson1-1/+48
With the advent of preempt-to-busy, a request may still be on the GPU as we unwind. And in the case of a unpreemptible [due to HW] request, that request will remain indefinitely on the GPU even though we have returned it back to our submission queue, and cleared the active bit. We only run the execution callbacks on transferring the request from our submission queue to the execution queue, but if this is a bonded request that the HW is waiting for, we will not submit it (as we wait for a fresh execution) even though it is still being executed. As we know that there are always preemption points between requests, we know that only the currently executing request may be still active even though we have cleared the flag. However, we do not precisely know which request is in ELSP[0] due to a delay in processing events, and furthermore we only store the last request in a context in our state tracker. Fixes: 22b7a426bbe1 ("drm/i915/execlists: Preempt-to-busy") Testcase: igt/gem_exec_balancer/bonded-dual Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20200529143926.3245-1-chris@chris-wilson.co.uk
2020-05-29drm/i915: Add a few asserts around handling of i915_request_is_active()Chris Wilson1-2/+3
Let's assert that we only call the execute callbacks on making the request active, and that we do not execute the request without calling the callbacks. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20200529085809.23691-1-chris@chris-wilson.co.uk
2020-05-27drm/i915/gt: Do not schedule normal requests immediately along virtualChris Wilson1-4/+21
When we push a virtual request onto the HW, we update the rq->engine to point to the physical engine. A request that is then submitted by the user that waits upon the virtual engine, but along the physical engine in use, will then see that it is due to be submitted to the same engine and take a shortcut (and be queued without waiting for the completion fence). However, the virtual request may be preempted (either by higher priority users, or by timeslicing) and removed from the physical engine to be migrated over to one of its siblings. The dependent normal request however is oblivious to the removal of the virtual request and remains queued to execute on HW, believing that once it reaches the head of its queue all of its predecessors will have completed executing! v2: Beware restriction of signal->execution_mask prior to submission. Fixes: 6d06779e8672 ("drm/i915: Load balancing across a virtual engine") Testcase: igt/gem_exec_balancer/sliced Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Cc: <stable@vger.kernel.org> # v5.3+ Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20200526090753.11329-2-chris@chris-wilson.co.uk
2020-05-27drm/i915: Reorder await_execution before await_requestChris Wilson1-132/+132
Reorder the code so that we can reuse the await_execution from a special case in await_request in the next patch. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20200526090753.11329-1-chris@chris-wilson.co.uk
2020-05-26drm/i915: Improve execute_cb struct packingChris Wilson1-9/+14
Reduce the irq_work llist for attaching the callbacks to the signal for both smaller structs (two fewer pointers!) and simpler [debug] code: Function old new delta irq_execute_cb 35 34 -1 __igt_breadcrumbs_smoketest 1684 1682 -2 i915_request_retire 2003 1996 -7 __i915_request_create 1047 1040 -7 __notify_execute_cb 135 126 -9 __i915_request_ctor 188 178 -10 __await_execution.part.constprop 451 440 -11 igt_wait_request 924 714 -210 One minor artifact is that the order of cb exection is reversed. No current use cases are affected by that change. Signed-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/20200526112051.10229-1-chris@chris-wilson.co.uk
2020-05-21drm/i915: Avoid using rq->engine after free during i915_fence_releaseChris Wilson1-2/+33
In order to be valid to dereference during the i915_fence_release, after retiring the fence and releasing its refererences, we assume that rq->engine can only be a real engine (that stay intact until the device is shutdown after all fences have been flushed). However, due to a quirk of preempt-to-busy, we may retire a request that still belongs to a virtual engine and so eventually free it with rq->engine being invalid. To avoid dereferencing that invalid engine, we look at the execution_mask which if it indicates it may be executed on more than one engine, we know it originated on a virtual engine and may still be on one. Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/1906 Fixes: 43acd6516ca9 ("drm/i915: Keep a per-engine request pool") Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20200521140617.30015-2-chris@chris-wilson.co.uk
2020-05-14drm/i915: Drop no-semaphore boostingChris Wilson1-36/+4
Now that we have fast timeslicing on semaphores, we no longer need to prioritise none-semaphore work as we will yield any work blocked on a semaphore to the next in the queue. Previously with no timeslicing, blocking on the semaphore caused extremely bad scheduling with multiple clients utilising multiple rings. Now, there is no impact and we can remove the complication. Signed-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/20200513173504.28322-1-chris@chris-wilson.co.uk
2020-05-13drm/i915: Mark the addition of the initial-breadcrumb in the requestChris Wilson1-1/+6
The initial-breadcrumb is used to mark the end of the awaiting and the beginning of the user payload. We verify that we do not start the user payload before all signaler are completed, checking our semaphore setup by looking for the initial breadcrumb being written too early. We also want to ensure that we do not add semaphore waits after we have already closed the semaphore section, an issue for later deferred waits. Signed-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/20200513165937.9508-2-chris@chris-wilson.co.uk
2020-05-09drm/i915: Replace the hardcoded I915_FENCE_TIMEOUTChris Wilson1-1/+2
Expose the hardcoded timeout for unsignaled foreign fences as a Kconfig option, primarily to allow brave systems to disable the timeout and solely rely on correct signaling. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Acked-by: Michael J. Ruhl <michael.j.ruhl@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20200509105021.12542-1-chris@chris-wilson.co.uk
2020-05-08drm/i915: Prevent using semaphores to chain up to external fencesChris Wilson1-0/+26
The downside of using semaphores is that we lose metadata passing along the signaling chain. This is particularly nasty when we need to pass along a fatal error such as EFAULT or EDEADLK. For fatal errors we want to scrub the request before it is executed, which means that we cannot preload the request onto HW and have it wait upon a semaphore. Signed-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/20200508092933.738-3-chris@chris-wilson.co.uk
2020-05-08drm/i915: Peel dma-fence-chains for awaitLionel Landwerlin1-1/+28
To allow faster engine to engine synchronization, peel the layer of dma-fence-chain to expose potential i915 fences so that the i915_request code can emit HW semaphore wait/signal operations in the ring which is faster than waking up the host to submit unblocked workloads after interrupt notification. This is similar to the peeling we do for e.g. dma_fence_array. Signed-off-by: Lionel Landwerlin <lionel.g.landwerlin@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/20200508185448.29709-1-chris@chris-wilson.co.uk
2020-05-08drm/i915: Pull waiting on an external dma-fence into its routineChris Wilson1-6/+10
As a means for a small code consolidation, but primarily to start thinking more carefully about internal-vs-external linkage, pull the pair of i915_sw_fence_await_dma_fence() calls into a common routine. Signed-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/20200508092933.738-2-chris@chris-wilson.co.uk
2020-05-08drm/i915: Ignore submit-fences on the same timelineChris Wilson1-0/+3
While we ordinarily do not skip submit-fences due to the accompanying hook that we want to callback on execution, a submit-fence on the same timeline is meaningless. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20200508092933.738-1-chris@chris-wilson.co.uk
2020-05-07drm/i915: Remove wait priority boostingChris Wilson1-3/+0
Upon waiting a request (when asked), we gave that request a small priority boost, not enough for it to cause preemption, but enough for it to be scheduled next before all equals. We also used that bit to give new clients a small priority boost, similar to FQ_CODEL, such that we favoured short interactive tasks ahead of long running streams. However, this is causing lots of complications with timeslicing where we both want to honour the boost and yet ignore it. Those complications cause unexpected user behaviour (tasks not being timesliced and run concurrently as epxected), and the easiest way to resolve that is to remove the boost. Hopefully, we can find a compromise again if we need to, but in theory timeslicing itself and future more advanced schedulers should give us the interactivity boost we seek. Testcase: igt/gem_exec_schedule/lateslice Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20200507152338.7452-3-chris@chris-wilson.co.uk
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