Motivated by the pre-review process for i915 gem/gt features, but
probably useful in general for complex stuff.
v2: Add reminder to not forget userspace projects in the discussion
(Simon, Jason)
v3: Actually put this into a folder, so we have it all (.rst files and
headers for kerneldoc) contained somewhere separate (Jason)
Cc: Simon Ser <contact@emersion.fr>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Jason Ekstrand <jason@jlekstrand.net>
Cc: Dave Airlie <airlied@redhat.com>
Acked-by: Jason Ekstrand <jason@jlekstrand.net>
Acked-by: Simon Ser <contact@emersion.fr>
Acked-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Acked-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210325225859.1684116-1-daniel.vetter@ffwll.ch
We've discussed a bit how to get the gem/gt team better integrated
and collaborate more with the wider community and agreed to the
following:
- all gem/gt patches are reviewed on dri-devel for now. That's
overkill, but in the past there was definitely too little of that.
- i915-gem folks are encouraged to cross review core patches from
other teams
- big features (especially uapi changes) need to be discussed in an
rfc patch that documents the interface and big picture design,
before we get lost in the details of the code
- Also a rough TODO (can be refined as we go ofc) to get gem/gt back
on track, like we've e.g. done with DAL/DC to get that in shape.
v2:
- add dma_fence annotations (Dave)
- tasklet helpers (Jani on irc)
There was also a discussion about moving these into gitlab issues, or
gitlab issues as additional discussion place at least. For now it's
just the TODO file
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Jason Ekstrand <jason@jlekstrand.net>
Cc: Dave Airlie <airlied@redhat.com>
Acked-by: Dave Airlie <airlied@redhat.com>
Acked-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210324211041.1354941-1-daniel.vetter@ffwll.ch
Module parameter is added (request_timeout_ms) to allow configuring the
default request/fence expiry.
Default value is inherited from CONFIG_DRM_I915_REQUEST_TIMEOUT.
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20210324121335.2307063-8-tvrtko.ursulin@linux.intel.com
A new Kconfig option CONFIG_DRM_I915_REQUEST_TIMEOUT is added, defaulting
to 20s, and this timeout is applied to all users contexts using the
previously added watchdog facility.
Result of this is that any user submission will simply fail after this
timeout, either causing a reset (for non-preemptable), or incomplete
results.
This can have an effect that workloads which used to work fine will
suddenly start failing. Even workloads comprised of short batches but in
long dependency chains can be terminated.
And because of lack of agreement on usefulness and safety of fence error
propagation this partial execution can be invisible to userspace even if
it is "listening" to returned fence status.
Another interaction is with hangcheck where care needs to be taken timeout
is not set lower or close to three times the heartbeat interval. Otherwise
a hang in any application can cause complete termination of all
submissions from unrelated clients. Any users modifying the per engine
heartbeat intervals therefore need to be aware of this potential denial of
service to avoid inadvertently enabling it.
Given all this I am personally not convinced the scheme is a good idea.
Intuitively it feels object importers would be better positioned to
enforce the time they are willing to wait for something to complete.
v2:
* Improved commit message and Kconfig text.
* Pull in some helper code from patch which got dropped.
v3:
* Bump timeout to 20s to see if it helps Tigerlake.
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: Matthew Auld <matthew.auld@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20210324121335.2307063-7-tvrtko.ursulin@linux.intel.com
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
With the watchdog cancelling requests asynchronously to preempt-to-busy we
need to relax one assert making it apply only to requests not in error.
v2:
* Check against the correct request!
v3:
* Simplify the check to avoid the question of when to sample the fence
error vs sentinel bit.
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20210324121335.2307063-5-tvrtko.ursulin@linux.intel.com
Disallow sentinel requests follow previous sentinels to make request
cancellation work better when faced with a chain of requests which have
all been marked as in error.
Because in cases where we end up with a stream of cancelled requests we
want to turn off request coalescing so they each will get individually
skipped by the execlists_schedule_in (which is called per ELSP port, not
per request).
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
[danvet: Fix typo in the commit message that Matthew spotted.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20210324121335.2307063-4-tvrtko.ursulin@linux.intel.com
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
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
We get a lockdep splat when the reset mutex is held, because it can be
taken from fence_wait. This conflicts with the mmu notifier we have,
because we recurse between reset mutex and mmap lock -> mmu notifier.
Remove this recursion by calling revoke_mmaps before taking the lock.
The reset code still needs fixing, as taking mmap locks during reset
is not allowed.
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
[danvet: Add FIXME.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20210323155059.628690-64-maarten.lankhorst@linux.intel.com
Instead of force unbinding and rebinding every time, we try to check
if our notifier seqcount is still correct when pages are bound. This
way we only rebind userptr when we need to, and prevent stalls.
Changes since v1:
- Missing mutex_unlock, reported by kbuild.
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom@intel.com>
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20210323155059.628690-63-maarten.lankhorst@linux.intel.com
We need to lock the global gtt dma_resv, use i915_vm_lock_objects
to handle this correctly. Add ww handling for this where required.
Add the object lock around unpin/put pages, and use the unlocked
versions of pin_pages and pin_map where required.
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20210323155059.628690-61-maarten.lankhorst@linux.intel.com
igt_emit_store_dw needs to use the unlocked version, as it's not
holding a lock. This fixes igt_gpu_fill_dw() which is used by
some other selftests.
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20210323155059.628690-51-maarten.lankhorst@linux.intel.com
We may create page table objects on the fly, but we may need to
wait with the ww lock held. Instead of waiting on a freed obj
lock, ensure we have the same lock for each object to keep
-EDEADLK working. This ensures that i915_vma_pin_ww can lock
the page tables when required.
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20210323155059.628690-41-maarten.lankhorst@linux.intel.com
Because of the long lifetime of the mapping, we cannot wrap this in a
simple limited ww lock. Just use the unlocked version of pin_map,
because we'll likely release the mapping a lot later, in a different
thread.
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20210323155059.628690-39-maarten.lankhorst@linux.intel.com
vmap is using pin_pages, but needs to use ww locking,
add pin_pages_unlocked to correctly lock the mapping.
Also add ww locking to begin/end cpu access.
Changes since v1:
- Fix i915_gem_map_dma_buf by using pin_pages_unlocked().
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20210323155059.628690-38-maarten.lankhorst@linux.intel.com
In the ucode functions, the calls are done before userspace runs,
when debugging using debugfs, or when creating semi-permanent mappings;
we can safely use the unlocked versions that does the ww dance for us.
Because there is no pin_pages_unlocked yet, add it as convenience function.
This removes possible lockdep splats about missing resv lock for ucode.
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20210323155059.628690-37-maarten.lankhorst@linux.intel.com
By default, we assume that it's called inside igt_create_request
to keep existing selftests working, but allow for manual pinning
when passing a ww context.
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20210323155059.628690-34-maarten.lankhorst@linux.intel.com
Stolen objects need to lock, and we may call put_pages when
refcount drops to 0, ensure all calls are handled correctly.
Changes since v1:
- Rebase on top of upstream changes.
Idea-from: Thomas Hellström <thomas.hellstrom@intel.com>
Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20210323155059.628690-33-maarten.lankhorst@linux.intel.com
We need to take the obj lock to pin pages, so wait until the callers
have done so, before making the object unshrinkable.
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20210323155059.628690-30-maarten.lankhorst@linux.intel.com
Take the ww lock around engine_unpark. Because of the
many many places where rpm is used, I chose the safest option
and used a trylock to opportunistically take this lock for
__engine_unpark.
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20210323155059.628690-28-maarten.lankhorst@linux.intel.com
Make creation separate from pinning, in order to take the lock only
once, and pin the mapping with the lock held.
Changes since v1:
- Rebase on top of upstream changes.
Changes since v2:
- Fully clear wa_ctx on error.
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20210323155059.628690-27-maarten.lankhorst@linux.intel.com
We previously complained when ww == NULL.
This function is now only used in selftests to pin an object,
and ww locking is now fixed.
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
[danvet: Resolve conflict because we don't have a set-domain refactor,
see
https://lore.kernel.org/intel-gfx/20210203090205.25818-8-chris@chris-wilson.co.uk/
The really worrying thing here is that the above patch had a change in
arguments for i915_gem_object_set_to_gtt_domain(), without any
explanation. I decided to just faithfully apply Maarten's change but
not the argument change which was in Maarten's context diff.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20210323155059.628690-26-maarten.lankhorst@linux.intel.com
This should be done as part of the ww loop, in order to remove a
i915_vma_pin that needs ww held.
Now only i915_ggtt_pin() callers remaining.
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20210323155059.628690-25-maarten.lankhorst@linux.intel.com
