Commit baf4afc583 ("drm/sched: Improve teardown documentation")
added a list of drm_sched_fini()'s problems. The list triggers htmldocs
warning (but renders correctly in htmldocs output):
Documentation/gpu/drm-mm:571: ./drivers/gpu/drm/scheduler/sched_main.c:1359: ERROR: Unexpected indentation.
Separate the list from the preceding paragraph by a blank line to fix
the warning. While at it, also end the aforementioned paragraph by a
colon.
Fixes: baf4afc583 ("drm/sched: Improve teardown documentation")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Closes: https://lore.kernel.org/r/20241108175655.6d3fcfb7@canb.auug.org.au/
Signed-off-by: Bagas Sanjaya <bagasdotme@gmail.com>
[phasta: Adjust commit message]
Signed-off-by: Philipp Stanner <phasta@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20241217034915.62594-1-bagasdotme@gmail.com
If jobs are still enqueued in struct drm_gpu_scheduler.pending_list
when drm_sched_fini() gets called, those jobs will be leaked since that
function stops both job-submission and (automatic) job-cleanup. It is,
thus, up to the driver to take care of preventing leaks.
The related function drm_sched_wqueue_stop() also prevents automatic job
cleanup.
Those pitfals are not reflected in the documentation, currently.
Explicitly inform about the leak problem in the docstring of
drm_sched_fini().
Additionally, detail the purpose of drm_sched_wqueue_{start,stop} and
hint at the consequences for automatic cleanup.
Signed-off-by: Philipp Stanner <pstanner@redhat.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20241105143137.71893-2-pstanner@redhat.com
drm_sched_start()'s and drm_sched_stop()'s names suggest that those
functions might be intended for actively starting and stopping the
scheduler on initialization and teardown.
They are, however, only used on timeout handling (reset recovery). The
docstrings should reflect that to prevent confusion.
Document those functions' purpose.
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Philipp Stanner <pstanner@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20241029133819.78696-2-pstanner@redhat.com
drm_gpu_scheduler.submit_wq is used to submit jobs, jobs are in the path
of dma-fences, and dma-fences are in the path of reclaim. Mark scheduler
work queue with WQ_MEM_RECLAIM to ensure forward progress during
reclaim; without WQ_MEM_RECLAIM, work queues cannot make forward
progress during reclaim.
v2:
- Fixes tags (Philipp)
- Reword commit message (Philipp)
Cc: Luben Tuikov <ltuikov89@gmail.com>
Cc: Danilo Krummrich <dakr@kernel.org>
Cc: Philipp Stanner <pstanner@redhat.com>
Cc: stable@vger.kernel.org
Fixes: 34f50cc644 ("drm/sched: Use drm sched lockdep map for submit_wq")
Fixes: a6149f0393 ("drm/sched: Convert drm scheduler to use a work queue rather than kthread")
Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Acked-by: Nirmoy Das <nirmoy.das@intel.com>
Reviewed-by: Philipp Stanner <pstanner@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20241023235917.1836428-1-matthew.brost@intel.com
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
drm_sched_job_init()'s name suggests that after the function succeeded,
parameter "job" will be fully initialized. This is not the case; some
members are only later set, notably drm_sched_job.sched by
drm_sched_job_arm().
Document that drm_sched_job_init() does not set all struct members.
Document the lifetime of drm_sched_job.sched.
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Signed-off-by: Philipp Stanner <pstanner@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20241023141530.113370-2-pstanner@redhat.com
drm_sched_job_init() has no control over how users allocate struct
drm_sched_job. Unfortunately, the function can also not set some struct
members such as job->sched.
This could theoretically lead to UB by users dereferencing the struct's
pointer members too early.
It is easier to debug such issues if these pointers are initialized to
NULL, so dereferencing them causes a NULL pointer exception.
Accordingly, drm_sched_entity_init() does precisely that and initializes
its struct with memset().
Initialize parameter "job" to 0 in drm_sched_job_init().
Signed-off-by: Philipp Stanner <pstanner@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20241021105028.19794-2-pstanner@redhat.com
Reviewed-by: Christian König <christian.koenig@amd.com>
Having removed one re-lock cycle on the entity->lock in a patch titled
"drm/sched: Optimise drm_sched_entity_push_job", with only a tiny bit
larger refactoring we can do the same optimisation on the rq->lock.
(Currently both drm_sched_rq_add_entity() and
drm_sched_rq_update_fifo_locked() take and release the same lock.)
To achieve this we make drm_sched_rq_update_fifo_locked() and
drm_sched_rq_add_entity() expect the rq->lock to be held.
We also align drm_sched_rq_update_fifo_locked(),
drm_sched_rq_add_entity() and
drm_sched_rq_remove_fifo_locked() function signatures, by adding rq as a
parameter to the latter.
v2:
* Fix after rebase of the series.
* Avoid naming inconsistency between drm_sched_rq_add/remove. (Christian)
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@igalia.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Luben Tuikov <ltuikov89@gmail.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Cc: Philipp Stanner <pstanner@redhat.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Philipp Stanner <pstanner@redhat.com>
Signed-off-by: Philipp Stanner <pstanner@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20241016122013.7857-6-tursulin@igalia.com
When writing to a drm_sched_entity's run-queue, writers are protected
through the lock drm_sched_entity.rq_lock. This naming, however,
frequently collides with the separate internal lock of struct
drm_sched_rq, resulting in uses like this:
spin_lock(&entity->rq_lock);
spin_lock(&entity->rq->lock);
Rename drm_sched_entity.rq_lock to improve readability. While at it,
re-order that struct's members to make it more obvious what the lock
protects.
v2:
* Rename some rq_lock straddlers in kerneldoc, improve commit text. (Philipp)
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@igalia.com>
Suggested-by: Christian König <christian.koenig@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Luben Tuikov <ltuikov89@gmail.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Cc: Philipp Stanner <pstanner@redhat.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
[pstanner: Fix typo in docstring]
Signed-off-by: Philipp Stanner <pstanner@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20241016122013.7857-5-tursulin@igalia.com
It does not seem there is a need to set the current entity in FIFO mode
since ot only serves as being a "cursor" in round-robin mode. Even if
scheduling mode is changed at runtime the change in behaviour is simply
to restart from the first entity, instead of continuing in RR mode from
where FIFO left it, and that sounds completely fine.
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@igalia.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Luben Tuikov <ltuikov89@gmail.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Cc: Philipp Stanner <pstanner@redhat.com>
Acked-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Philipp Stanner <pstanner@redhat.com>
Signed-off-by: Philipp Stanner <pstanner@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20241016122013.7857-3-tursulin@igalia.com
In FIFO mode (which is the default), both drm_sched_entity_push_job() and
drm_sched_rq_update_fifo(), where the latter calls the former, are
currently taking and releasing the same entity->rq_lock.
We can avoid that design inelegance, and also have a miniscule
efficiency improvement on the submit from idle path, by introducing a new
drm_sched_rq_update_fifo_locked() helper and pulling up the lock taking to
its callers.
v2:
* Remove drm_sched_rq_update_fifo() altogether. (Christian)
v3:
* Improved commit message. (Philipp)
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@igalia.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Luben Tuikov <ltuikov89@gmail.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Cc: Philipp Stanner <pstanner@redhat.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Philipp Stanner <pstanner@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20241016122013.7857-2-tursulin@igalia.com
drm-misc-next for v6.12:
UAPI Changes:
- Add panthor/DEV_QUERY_TIMESTAMP_INFO query.
Cross-subsystem Changes:
- Updated dt bindings.
- Add documentation explaining default errnos for fences.
- Mark dma-buf heaps creation functions as __init.
Core Changes:
- Split DSC helpers from DP helpers.
- Clang build fixes for drm/mm test.
- Remove simple pipeline support for gem-vram,
no longer any users left after converting bochs.
- Add erno to drm_sched_start to distinguish between GPU and queue
reset.
- Add drm_framebuffer testcases.
- Fix uninitialized spinlock acquisition with CONFIG_DRM_PANIC=n.
- Use read_trylock instead of read_lock in dma_fence_begin_signalling to
quiesce lockdep.
Driver Changes:
- Assorted small fixes and updates for tegra, host1x, imagination,
nouveau, panfrost, panthor, panel/ili9341, mali, exynos,
panel/samsung-s6e3fa7, ast, bridge/ti-sn65dsi86, panel/himax-hx83112a,
bridge/tc358767, bridge/imx8mp-hdmi-tx, panel/khadas-ts050,
panel/nt36523, panel/sony-acx565akm, kmb, accel/qaic, omap, v3d.
- Add bridge/TI TDP158.
- Assorted documentation updates.
- Convert bochs from simple drm to gem shmem, and check modes
against available memory.
- Many VC4 fixes, most related to scaling and YUV support.
- Convert some drivers to use SYSTEM_SLEEP_PM_OPS and RUNTIME_PM_OPS.
- Rockchip 4k@60 support.
Signed-off-by: Dave Airlie <airlied@redhat.com>
From: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/445713a6-2427-4c53-8ec2-3a894ec62405@linux.intel.com
Avoid leaking a lockdep map on each drm sched creation and destruction
by using a single lockdep map for all drm sched allocated submit_wq.
v2:
- Use alloc_ordered_workqueue_lockdep_map (Tejun)
Cc: Luben Tuikov <ltuikov89@gmail.com>
Cc: Christian König <christian.koenig@amd.com>
Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: Nirmoy Das <nirmoy.das@intel.com>
Acked-by: Danilo Krummrich <dakr@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20241002131639.3425022-2-matthew.brost@intel.com
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Function drm_sched_entity_push_job() doesn't have a return value,
remove the return value description for it.
Correct several other typo errors.
v2 (Philipp):
- more correction with related comments.
Signed-off-by: Shuicheng Lin <shuicheng.lin@intel.com>
Reviewed-by: Philipp Stanner <pstanner@redhat.com>
Signed-off-by: Simona Vetter <simona.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20240917144732.2758572-1-shuicheng.lin@intel.com
Fixes a race condition reported here: https://github.com/AsahiLinux/linux/issues/309#issuecomment-2238968609
The whole premise of lockless access to a single-producer-single-
consumer queue is that there is just a single producer and single
consumer. That means we can't call drm_sched_can_queue() (which is
about queueing more work to the hw, not to the spsc queue) from
anywhere other than the consumer (wq).
This call in the producer is just an optimization to avoid scheduling
the consuming worker if it cannot yet queue more work to the hw. It
is safe to drop this optimization to avoid the race condition.
Suggested-by: Asahi Lina <lina@asahilina.net>
Fixes: a78422e9df ("drm/sched: implement dynamic job-flow control")
Closes: https://github.com/AsahiLinux/linux/issues/309
Cc: stable@vger.kernel.org
Signed-off-by: Rob Clark <robdclark@chromium.org>
Reviewed-by: Danilo Krummrich <dakr@kernel.org>
Tested-by: Janne Grunau <j@jannau.net>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20240913202301.16772-1-robdclark@gmail.com
The current implementation of drm_sched_start uses a hardcoded
-ECANCELED to dispose of a job when the parent/hw fence is NULL.
This results in drm_sched_job_done being called with -ECANCELED for
each job with a NULL parent in the pending list, making it difficult
to distinguish between recovery methods, whether a queue reset or a
full GPU reset was used.
To improve this, we first try a soft recovery for timeout jobs and
use the error code -ENODATA. If soft recovery fails, we proceed with
a queue reset, where the error code remains -ENODATA for the job.
Finally, for a full GPU reset, we use error codes -ECANCELED or
-ETIME. This patch adds an error code parameter to drm_sched_start,
allowing us to differentiate between queue reset and GPU reset
failures. This enables user mode and test applications to validate
the expected correctness of the requested operation. After a
successful queue reset, the only way to continue normal operation is
to call drm_sched_job_done with the specific error code -ENODATA.
v1: Initial implementation by Jesse utilized amdgpu_device_lock_reset_domain
and amdgpu_device_unlock_reset_domain to allow user mode to track
the queue reset status and distinguish between queue reset and
GPU reset.
v2: Christian suggested using the error codes -ENODATA for queue reset
and -ECANCELED or -ETIME for GPU reset, returned to
amdgpu_cs_wait_ioctl.
v3: To meet the requirements, we introduce a new function
drm_sched_start_ex with an additional parameter to set
dma_fence_set_error, allowing us to handle the specific error
codes appropriately and dispose of bad jobs with the selected
error code depending on whether it was a queue reset or GPU reset.
v4: Alex suggested using a new name, drm_sched_start_with_recovery_error,
which more accurately describes the function's purpose.
Additionally, it was recommended to add documentation details
about the new method.
v5: Fixed declaration of new function drm_sched_start_with_recovery_error.(Alex)
v6 (chk): rebase on upstream changes, cleanup the commit message,
drop the new function again and update all callers,
apply the errno also to scheduler fences with hw fences
v7 (chk): rebased
Signed-off-by: Jesse Zhang <Jesse.Zhang@amd.com>
Signed-off-by: Vitaly Prosyak <vitaly.prosyak@amd.com>
Signed-off-by: Christian König <christian.koenig@amd.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240826122541.85663-1-christian.koenig@amd.com
This was basically just another one of amdgpus hacks. The parameter
allowed to restart the scheduler without turning fence signaling on
again.
That this is absolutely not a good idea should be obvious by now since
the fences will then just sit there and never signal.
While at it cleanup the code a bit.
Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240722083816.99685-1-christian.koenig@amd.com
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Merge v6.8-rc6 into drm-next
Thomas Zimmermann asked to backmerge -rc6 for drm-misc branches,
there's a few same-area-changed conflicts (xe and amdgpu mostly) that
are getting a bit too annoying.
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Rather then loop over entities until one with a ready job is found,
re-queue the run job worker when drm_sched_entity_pop_job() returns NULL.
Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Fixes: 66dbd9004a ("drm/sched: Drain all entities in DRM sched run job worker")
Reviewed-by: Luben Tuikov <ltuikov89@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240130030413.2031009-1-matthew.brost@intel.com
The kfree() function was called in one case by the
drm_sched_init() function during error handling
even if the passed data structure member contained a null pointer.
This issue was detected by using the Coccinelle software.
Thus adjust a jump target.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Link: https://patchwork.freedesktop.org/patch/msgid/85066512-983d-480c-a44d-32405ab1b80e@web.de
Reviewed-by: Luben Tuikov <ltuikov89@gmail.com>
Signed-off-by: Luben Tuikov <ltuikov89@gmail.com>
Reverse run-queue priority enumeration such that the higest priority is now 0,
and for each consecutive integer the prioirty diminishes.
Run-queues correspond to priorities. To an external observer a scheduler
created with a single run-queue, and another created with
DRM_SCHED_PRIORITY_COUNT number of run-queues, should always schedule
sched->sched_rq[0] with the same "priority", as that index run-queue exists in
both schedulers, i.e. a scheduler with one run-queue or many. This patch makes
it so.
In other words, the "priority" of sched->sched_rq[n], n >= 0, is the same for
any scheduler created with any allowable number of run-queues (priorities), 0
to DRM_SCHED_PRIORITY_COUNT.
Cc: Rob Clark <robdclark@gmail.com>
Cc: Abhinav Kumar <quic_abhinavk@quicinc.com>
Cc: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Cc: Danilo Krummrich <dakr@redhat.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: linux-arm-msm@vger.kernel.org
Cc: freedreno@lists.freedesktop.org
Cc: dri-devel@lists.freedesktop.org
Signed-off-by: Luben Tuikov <ltuikov89@gmail.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231124052752.6915-6-ltuikov89@gmail.com
Rename DRM_SCHED_PRIORITY_MIN to DRM_SCHED_PRIORITY_LOW.
This mirrors DRM_SCHED_PRIORITY_HIGH, for a list of DRM scheduler priorities
in ascending order,
DRM_SCHED_PRIORITY_LOW,
DRM_SCHED_PRIORITY_NORMAL,
DRM_SCHED_PRIORITY_HIGH,
DRM_SCHED_PRIORITY_KERNEL.
Cc: Rob Clark <robdclark@gmail.com>
Cc: Abhinav Kumar <quic_abhinavk@quicinc.com>
Cc: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Cc: Danilo Krummrich <dakr@redhat.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: linux-arm-msm@vger.kernel.org
Cc: freedreno@lists.freedesktop.org
Cc: dri-devel@lists.freedesktop.org
Signed-off-by: Luben Tuikov <ltuikov89@gmail.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231124052752.6915-5-ltuikov89@gmail.com
Currently, job flow control is implemented simply by limiting the number
of jobs in flight. Therefore, a scheduler is initialized with a credit
limit that corresponds to the number of jobs which can be sent to the
hardware.
This implies that for each job, drivers need to account for the maximum
job size possible in order to not overflow the ring buffer.
However, there are drivers, such as Nouveau, where the job size has a
rather large range. For such drivers it can easily happen that job
submissions not even filling the ring by 1% can block subsequent
submissions, which, in the worst case, can lead to the ring run dry.
In order to overcome this issue, allow for tracking the actual job size
instead of the number of jobs. Therefore, add a field to track a job's
credit count, which represents the number of credits a job contributes
to the scheduler's credit limit.
Signed-off-by: Danilo Krummrich <dakr@redhat.com>
Reviewed-by: Luben Tuikov <ltuikov89@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231110001638.71750-1-dakr@redhat.com
Don't "wake up" the GPU scheduler unless the entity is ready, as well as we
can queue to the scheduler, i.e. there is no point in waking up the scheduler
for the entity unless the entity is ready.
Signed-off-by: Luben Tuikov <ltuikov89@gmail.com>
Fixes: bc8d6a9df9 ("drm/sched: Don't disturb the entity when in RR-mode scheduling")
Reviewed-by: Danilo Krummrich <dakr@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231110000123.72565-2-ltuikov89@gmail.com
Don't call drm_sched_select_entity() in drm_sched_run_job_queue(). In fact,
rename __drm_sched_run_job_queue() to just drm_sched_run_job_queue(), and let
it do just that, schedule the work item for execution.
The problem is that drm_sched_run_job_queue() calls drm_sched_select_entity()
to determine if the scheduler has an entity ready in one of its run-queues,
and in the case of the Round-Robin (RR) scheduling, the function
drm_sched_rq_select_entity_rr() does just that, selects the _next_ entity
which is ready, sets up the run-queue and completion and returns that
entity. The FIFO scheduling algorithm is unaffected.
Now, since drm_sched_run_job_work() also calls drm_sched_select_entity(), then
in the case of RR scheduling, that would result in drm_sched_select_entity()
having been called twice, which may result in skipping a ready entity if more
than one entity is ready. This commit fixes this by eliminating the call to
drm_sched_select_entity() from drm_sched_run_job_queue(), and leaves it only
in drm_sched_run_job_work().
v2: Rebased on top of Tvrtko's renames series of patches. (Luben)
Add fixes-tag. (Tvrtko)
Signed-off-by: Luben Tuikov <ltuikov89@gmail.com>
Fixes: f7fe64ad0f ("drm/sched: Split free_job into own work item")
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: Danilo Krummrich <dakr@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231107041020.10035-2-ltuikov89@gmail.com
Because a) helper is exported to other parts of the scheduler and
b) there isn't a plain drm_sched_wakeup to begin with, I think we can
drop the suffix and by doing so separate the intimiate knowledge
between the scheduler components a bit better.
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Luben Tuikov <ltuikov89@gmail.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231102105538.391648-6-tvrtko.ursulin@linux.intel.com
Reviewed-by: Luben Tuikov <ltuikov89@gmail.com>
Signed-off-by: Luben Tuikov <ltuikov89@gmail.com>
"If ready" is not immediately clear what it means - is the scheduler
ready or something else? Drop the suffix, clarify kerneldoc, and employ
the same naming scheme as in drm_sched_run_free_queue:
- drm_sched_run_job_queue - enqueues if there is something to enqueue
*and* scheduler is ready (can queue)
- __drm_sched_run_job_queue - low-level helper to simply queue the job
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Luben Tuikov <ltuikov89@gmail.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231102105538.391648-5-tvrtko.ursulin@linux.intel.com
Reviewed-by: Luben Tuikov <ltuikov89@gmail.com>
Signed-off-by: Luben Tuikov <ltuikov89@gmail.com>
The current name makes it sound like helper will free a queue, while what
it does is it enqueues the free job worker.
Rename it to drm_sched_run_free_queue to align with existing
drm_sched_run_job_queue.
Despite that creating an illusion there are two queues, while in reality
there is only one, at least it creates a consistent naming for the two
enqueuing helpers.
At the same time simplify the "if done" helper by dropping the suffix and
adding a double underscore prefix to the one which just enqueues.
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Luben Tuikov <ltuikov89@gmail.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231102105538.391648-4-tvrtko.ursulin@linux.intel.com
Reviewed-by: Luben Tuikov <ltuikov89@gmail.com>
Signed-off-by: Luben Tuikov <ltuikov89@gmail.com>
Whether or not there are more jobs to clean up does not depend on the
existance of the current job, given both drm_sched_get_finished_job and
drm_sched_free_job_queue_if_done take and drop the job list lock.
Therefore it is confusing to make it read like there is a dependency.
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Luben Tuikov <ltuikov89@gmail.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231102105538.391648-3-tvrtko.ursulin@linux.intel.com
Reviewed-by: Luben Tuikov <ltuikov89@gmail.com>
Signed-off-by: Luben Tuikov <ltuikov89@gmail.com>
"Get cleanup job" makes it sound like helper is returning a job which will
execute some cleanup, or something, while the kerneldoc itself accurately
says "fetch the next _finished_ job". So lets rename the helper to be self
documenting.
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Luben Tuikov <ltuikov89@gmail.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231102105538.391648-2-tvrtko.ursulin@linux.intel.com
Reviewed-by: Luben Tuikov <ltuikov89@gmail.com>
Signed-off-by: Luben Tuikov <ltuikov89@gmail.com>
Rather than call free_job and run_job in same work item have a dedicated
work item for each. This aligns with the design and intended use of work
queues.
v2:
- Test for DMA_FENCE_FLAG_TIMESTAMP_BIT before setting
timestamp in free_job() work item (Danilo)
v3:
- Drop forward dec of drm_sched_select_entity (Boris)
- Return in drm_sched_run_job_work if entity NULL (Boris)
v4:
- Replace dequeue with peek and invert logic (Luben)
- Wrap to 100 lines (Luben)
- Update comments for *_queue / *_queue_if_ready functions (Luben)
v5:
- Drop peek argument, blindly reinit idle (Luben)
- s/drm_sched_free_job_queue_if_ready/drm_sched_free_job_queue_if_done (Luben)
- Update work_run_job & work_free_job kernel doc (Luben)
v6:
- Do not move drm_sched_select_entity in file (Luben)
Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Link: https://lore.kernel.org/r/20231031032439.1558703-4-matthew.brost@intel.com
Reviewed-by: Luben Tuikov <ltuikov89@gmail.com>
Signed-off-by: Luben Tuikov <ltuikov89@gmail.com>
In Xe, the new Intel GPU driver, a choice has made to have a 1 to 1
mapping between a drm_gpu_scheduler and drm_sched_entity. At first this
seems a bit odd but let us explain the reasoning below.
1. In Xe the submission order from multiple drm_sched_entity is not
guaranteed to be the same completion even if targeting the same hardware
engine. This is because in Xe we have a firmware scheduler, the GuC,
which allowed to reorder, timeslice, and preempt submissions. If a using
shared drm_gpu_scheduler across multiple drm_sched_entity, the TDR falls
apart as the TDR expects submission order == completion order. Using a
dedicated drm_gpu_scheduler per drm_sched_entity solve this problem.
2. In Xe submissions are done via programming a ring buffer (circular
buffer), a drm_gpu_scheduler provides a limit on number of jobs, if the
limit of number jobs is set to RING_SIZE / MAX_SIZE_PER_JOB we get flow
control on the ring for free.
A problem with this design is currently a drm_gpu_scheduler uses a
kthread for submission / job cleanup. This doesn't scale if a large
number of drm_gpu_scheduler are used. To work around the scaling issue,
use a worker rather than kthread for submission / job cleanup.
v2:
- (Rob Clark) Fix msm build
- Pass in run work queue
v3:
- (Boris) don't have loop in worker
v4:
- (Tvrtko) break out submit ready, stop, start helpers into own patch
v5:
- (Boris) default to ordered work queue
v6:
- (Luben / checkpatch) fix alignment in msm_ringbuffer.c
- (Luben) s/drm_sched_submit_queue/drm_sched_wqueue_enqueue
- (Luben) Update comment for drm_sched_wqueue_enqueue
- (Luben) Positive check for submit_wq in drm_sched_init
- (Luben) s/alloc_submit_wq/own_submit_wq
v7:
- (Luben) s/drm_sched_wqueue_enqueue/drm_sched_run_job_queue
v8:
- (Luben) Adjust var names / comments
Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: Luben Tuikov <luben.tuikov@amd.com>
Link: https://lore.kernel.org/r/20231031032439.1558703-3-matthew.brost@intel.com
Signed-off-by: Luben Tuikov <ltuikov89@gmail.com>
Add scheduler wqueue ready, stop, and start helpers to hide the
implementation details of the scheduler from the drivers.
v2:
- s/sched_wqueue/sched_wqueue (Luben)
- Remove the extra white line after the return-statement (Luben)
- update drm_sched_wqueue_ready comment (Luben)
Cc: Luben Tuikov <luben.tuikov@amd.com>
Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: Luben Tuikov <luben.tuikov@amd.com>
Link: https://lore.kernel.org/r/20231031032439.1558703-2-matthew.brost@intel.com
Signed-off-by: Luben Tuikov <ltuikov89@gmail.com>
When a fence signals there is a very small race window where the timestamp
isn't updated yet. sync_file solves this by busy waiting for the
timestamp to appear, but on other ocassions didn't handled this
correctly.
Provide a dma_fence_timestamp() helper function for this and use it in
all appropriate cases.
Another alternative would be to grab the spinlock when that happens.
v2 by teddy: add a wait parameter to wait for the timestamp to show up, in case
the accurate timestamp is needed and/or the timestamp is not based on
ktime (e.g. hw timestamp)
v3 chk: drop the parameter again for unified handling
Signed-off-by: Yunxiang Li <Yunxiang.Li@amd.com>
Signed-off-by: Christian König <christian.koenig@amd.com>
Fixes: 1774baa64f ("drm/scheduler: Change scheduled fence track v2")
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
CC: stable@vger.kernel.org
Link: https://patchwork.freedesktop.org/patch/msgid/20230929104725.2358-1-christian.koenig@amd.com
The GPU scheduler has now a variable number of run-queues, which are set up at
drm_sched_init() time. This way, each driver announces how many run-queues it
requires (supports) per each GPU scheduler it creates. Note, that run-queues
correspond to scheduler "priorities", thus if the number of run-queues is set
to 1 at drm_sched_init(), then that scheduler supports a single run-queue,
i.e. single "priority". If a driver further sets a single entity per
run-queue, then this creates a 1-to-1 correspondence between a scheduler and
a scheduled entity.
Cc: Lucas Stach <l.stach@pengutronix.de>
Cc: Russell King <linux+etnaviv@armlinux.org.uk>
Cc: Qiang Yu <yuq825@gmail.com>
Cc: Rob Clark <robdclark@gmail.com>
Cc: Abhinav Kumar <quic_abhinavk@quicinc.com>
Cc: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Cc: Danilo Krummrich <dakr@redhat.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Cc: Boris Brezillon <boris.brezillon@collabora.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: Emma Anholt <emma@anholt.net>
Cc: etnaviv@lists.freedesktop.org
Cc: lima@lists.freedesktop.org
Cc: linux-arm-msm@vger.kernel.org
Cc: freedreno@lists.freedesktop.org
Cc: nouveau@lists.freedesktop.org
Cc: dri-devel@lists.freedesktop.org
Signed-off-by: Luben Tuikov <luben.tuikov@amd.com>
Acked-by: Christian König <christian.koenig@amd.com>
Link: https://lore.kernel.org/r/20231023032251.164775-1-luben.tuikov@amd.com
Drivers that can delegate waits to the firmware/GPU pass the scheduled
fence to drm_sched_job_add_dependency(), and issue wait commands to
the firmware/GPU at job submission time. For this to be possible, they
need all their 'native' dependencies to have a valid parent since this
is where the actual HW fence information are encoded.
In drm_sched_main(), we currently call drm_sched_fence_set_parent()
after drm_sched_fence_scheduled(), leaving a short period of time
during which the job depending on this fence can be submitted.
Since setting parent and signaling the fence are two things that are
kinda related (you can't have a parent if the job hasn't been scheduled),
it probably makes sense to pass the parent fence to
drm_sched_fence_scheduled() and let it call drm_sched_fence_set_parent()
before it signals the scheduled fence.
Here is a detailed description of the race we are fixing here:
Thread A Thread B
- calls drm_sched_fence_scheduled()
- signals s_fence->scheduled which
wakes up thread B
- entity dep signaled, checking
the next dep
- no more deps waiting
- entity is picked for job
submission by drm_gpu_scheduler
- run_job() is called
- run_job() tries to
collect native fence info from
s_fence->parent, but it's
NULL =>
BOOM, we can't do our native
wait
- calls drm_sched_fence_set_parent()
v2:
* Fix commit message
v3:
* Add a detailed description of the race to the commit message
* Add Luben's R-b
Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
Cc: Frank Binns <frank.binns@imgtec.com>
Cc: Sarah Walker <sarah.walker@imgtec.com>
Cc: Donald Robson <donald.robson@imgtec.com>
Cc: Luben Tuikov <luben.tuikov@amd.com>
Cc: David Airlie <airlied@gmail.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: "Christian König" <christian.koenig@amd.com>
Reviewed-by: Luben Tuikov <luben.tuikov@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230623075204.382350-1-boris.brezillon@collabora.com
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Backmerge tag 'v6.4-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux into drm-next
Linux 6.4-rc7
Need this to pull in the msm work.
Signed-off-by: Dave Airlie <airlied@redhat.com>
Rename drm_sched_wakeup() to drm_sched_wakeup_if_canqueue() since the former
is misleading, as it wakes up the GPU scheduler _only if_ more jobs can be
queued to the underlying hardware.
This distinction is important to make, since the wake conditional in the GPU
scheduler thread wakes up when other conditions are also true, e.g. when there
are jobs to be cleaned. For instance, a user might want to wake up the
scheduler only because there are more jobs to clean, but whether we can queue
more jobs is irrelevant.
v2: Separate "canqueue" to "can_queue". (Alex D.)
Cc: Christian König <christian.koenig@amd.com>
Cc: Alex Deucher <Alexander.Deucher@amd.com>
Signed-off-by: Luben Tuikov <luben.tuikov@amd.com>
Link: https://lore.kernel.org/r/20230517233550.377847-2-luben.tuikov@amd.com
Reviewed-by: Alex Deucher <Alexander.Deucher@amd.com>
Rename drm_sched_ready() to drm_sched_can_queue(). "ready" can mean many
things and is thus meaningless in this context. Instead, rename to a name
which precisely conveys what is being checked.
Cc: Christian König <christian.koenig@amd.com>
Cc: Alex Deucher <Alexander.Deucher@amd.com>
Signed-off-by: Luben Tuikov <luben.tuikov@amd.com>
Reviewed-by: Alex Deucher <Alexander.Deucher@amd.com>
Link: https://lore.kernel.org/r/20230517233550.377847-1-luben.tuikov@amd.com
The rq pointer points inside the drm_gpu_scheduler structure. Thus
it can't be NULL.
Found by Linux Verification Center (linuxtesting.org) with SVACE.
Fixes: c61cdbdbff ("drm/scheduler: Fix hang when sched_entity released")
Signed-off-by: Vladislav Efanov <VEfanov@ispras.ru>
Link: https://lore.kernel.org/r/20230517125247.434103-1-VEfanov@ispras.ru
Reviewed-by: Luben Tuikov <luben.tuikov@amd.com>
Signed-off-by: Luben Tuikov <luben.tuikov@amd.com>
