drm_sched_backend_ops.timedout_job()'s documentation is outdated. It
mentions the deprecated function drm_sched_resubmit_jobs(). Furthermore,
it does not point out the important distinction between hardware and
firmware schedulers.
Since firmware schedulers typically only use one entity per scheduler,
timeout handling is significantly more simple because the entity the
faulted job came from can just be killed without affecting innocent
processes.
Update the documentation with that distinction and other details.
Reformat the docstring to work to a unified style with the other
handles.
Acked-by: Danilo Krummrich <dakr@kernel.org>
Signed-off-by: Philipp Stanner <phasta@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20250305130551.136682-5-phasta@kernel.org
drm_sched_backend_ops.run_job() returns a dma_fence for the scheduler.
That fence is signalled by the driver once the hardware completed the
associated job. The scheduler does not increment the reference count on
that fence, but implicitly expects to inherit this fence from run_job().
This is relatively subtle and prone to misunderstandings.
This implies that, to keep a reference for itself, a driver needs to
call dma_fence_get() in addition to dma_fence_init() in that callback.
It's further complicated by the fact that the scheduler even decrements
the refcount in drm_sched_run_job_work() since it created a new
reference in drm_sched_fence_scheduled(). It does, however, still use
its pointer to the fence after calling dma_fence_put() - which is safe
because of the aforementioned new reference, but actually still violates
the refcounting rules.
Move the call to dma_fence_put() to the position behind the last usage
of the fence.
Suggested-by: Danilo Krummrich <dakr@kernel.org>
Signed-off-by: Philipp Stanner <pstanner@redhat.com>
Reviewed-by: Danilo Krummrich <dakr@kernel.org>
Signed-off-by: Philipp Stanner <phasta@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20250305130551.136682-4-phasta@kernel.org
The documentation for drm_sched_backend_ops.run_job() mentions a certain
function called drm_sched_job_recovery(). This function does not exist.
What's actually meant is drm_sched_resubmit_jobs(), which is by now also
deprecated.
Furthermore, the scheduler expects to "inherit" a reference on the fence
from the run_job() callback. This, so far, is also not documented.
Remove the mention of the removed function.
Discourage the behavior of drm_sched_backend_ops.run_job() being called
multiple times for the same job.
Document the necessity of incrementing the refcount in run_job().
Acked-by: Danilo Krummrich <dakr@kernel.org>
Signed-off-by: Philipp Stanner <phasta@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20250305130551.136682-3-phasta@kernel.org
The fence_value_str and timeline_value_str callbacks were just an
unnecessary abstraction in the SW sync implementation.
The only caller of those callbacks already knew that the fence in
questions is a timeline_fence. So print the values directly instead
of using a redirection.
Additional to that remove the implementations from virtgpu and vgem.
As far as I can see those were never used in the first place.
Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Simona Vetter <simona.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20250211163109.12200-3-christian.koenig@amd.com
There isn't much worse than documentation giving an incorrect advise.
Grabbing a spinlock while interrupts are disabled usually means that you
must also disable interrupts for all other uses of this spinlock.
Otherwise really hard to debug issues can occur. So fix that invalid
documentation.
v2: use Dmitry's suggestion on the documentation
Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Simona Vetter <simona.vetter@ffwll.ch> (v1)
Link: https://patchwork.freedesktop.org/patch/msgid/20250211163109.12200-2-christian.koenig@amd.com
Add drm_gem_is_imported() that tests if a GEM object's buffer has
been imported. Update the GEM code accordingly.
GEM code usually tests for imports if import_attach has been set
in struct drm_gem_object. But attaching a dma-buf on import requires
a DMA-capable importer device, which is not the case for many serial
busses like USB or I2C. The new helper tests if a GEM object's dma-buf
has been created from the GEM object.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Anusha Srivatsa <asrivats@redhat.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250226172457.217725-2-tzimmermann@suse.de
The XE_PL_TT watermark was set to 50% of system memory.
The idea behind that was unclear since the net effect is that
TT memory will be evicted to TTM_PL_SYSTEM memory if that
watermark is exceeded, requiring PPGTT rebinds and dma
remapping. But there is no similar watermark for TTM_PL_1SYSTEM
memory.
The TTM functionality that tries to swap out system memory to
shmem objects if a 50% limit of total system memory is reached
is orthogonal to this, and with the shrinker added, it's no
longer in effect.
Replace the 50% TTM_PL_TT limit with a 100% limit, in effect
allowing all graphics memory to be bound to the device unless it
has been swapped out by the shrinker.
Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Link: https://lore.kernel.org/intel-xe/20250305092220.123405-8-thomas.hellstrom@linux.intel.com
Rather than relying on the TTM watermark accounting add a shrinker
for xe_bos in TT or system memory.
Leverage the newly added TTM per-page shrinking and shmem backup
support.
Although xe doesn't fully support WONTNEED (purgeable) bos yet,
introduce and add shrinker support for purgeable ttm_tts.
v2:
- Cleanups bugfixes and a KUNIT shrinker test.
- Add writeback support, and activate if kswapd.
v3:
- Move the try_shrink() helper to core TTM.
- Minor cleanups.
v4:
- Add runtime pm for the shrinker. Shrinking may require an active
device for CCS metadata copying.
v5:
- Separately purge ghost- and zombie objects in the shrinker.
- Fix a format specifier - type inconsistency. (Kernel test robot).
v7:
- s/long/s64/ (Christian König)
- s/sofar/progress/ (Matt Brost)
v8:
- Rebase on Xe KUNIT update.
- Add content verifying to the shrinker kunit test.
- Split out TTM changes to a separate patch.
- Get rid of multiple bool arguments for clarity (Matt Brost)
- Avoid an error pointer dereference (Matt Brost)
- Avoid an integer overflow (Matt Auld)
- Address misc review comments by Matt Brost.
v9:
- Fix a compliation error.
- Rebase.
v10:
- Update to new LRU walk interface.
- Rework ghost-, zombie and purged object shrinking.
- Rebase.
v11:
- Use additional TTM helpers.
- Honor __GFP_FS and __GFP_IO
- Rebase.
v13:
- Use ttm_tt_setup_backup().
v14:
- Don't set up backup on imported bos.
v15:
- Rebase on backup interface changes.
Cc: Christian König <christian.koenig@amd.com>
Cc: Somalapuram Amaranath <Amaranath.Somalapuram@amd.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Cc: <dri-devel@lists.freedesktop.org>
Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Acked-by: Christian König <christian.koenig@amd.com>
Link: https://lore.kernel.org/intel-xe/20250305092220.123405-7-thomas.hellstrom@linux.intel.com
Following the design direction communicated here:
https://lore.kernel.org/linux-mm/b7491378-defd-4f1c-31e2-29e4c77e2d67@amd.com/T/#ma918844aa8a6efe8768fdcda0c6590d5c93850c9
Export a LRU walker for driver shrinker use. The walker
initially supports only trylocking, since that's the
method used by shrinkes. The walker makes use of
scoped_guard() to allow exiting from the LRU walk loop
without performing any explicit unlocking or
cleanup.
v8:
- Split out from another patch.
- Use a struct for bool arguments to increase readability (Matt Brost).
- Unmap user-space cpu-mappings before shrinking pages.
- Explain non-fatal error codes (Matt Brost)
v10:
- Instead of using the existing helper, Wrap the interface inside out and
provide a loop to de-midlayer things the LRU iteration (Christian König).
- Removing the R-B by Matt Brost since the patch was significantly changed.
v11:
- Split the patch up to include just the LRU walk helper.
v12:
- Indent after scoped_guard() (Matt Brost)
v15:
- Adapt to new definition of scoped_guard()
Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Acked-by: Dave Airlie <airlied@redhat.com>
Acked-by: Christian König <christian.koenig@amd.com>
Link: https://lore.kernel.org/intel-xe/20250305092220.123405-5-thomas.hellstrom@linux.intel.com
Provide a helper to shrink ttm_tt page-vectors on a per-page
basis. A ttm_backup backend could then in theory get away with
allocating a single temporary page for each struct ttm_tt.
This is accomplished by splitting larger pages before trying to
back them up.
In the future we could allow ttm_backup to handle backing up
large pages as well, but currently there's no benefit in
doing that, since the shmem backup backend would have to
split those anyway to avoid allocating too much temporary
memory, and if the backend instead inserts pages into the
swap-cache, those are split on reclaim by the core.
Due to potential backup- and recover errors, allow partially swapped
out struct ttm_tt's, although mark them as swapped out stopping them
from being swapped out a second time. More details in the ttm_pool.c
DOC section.
v2:
- A couple of cleanups and error fixes in ttm_pool_back_up_tt.
- s/back_up/backup/
- Add a writeback parameter to the exported interface.
v8:
- Use a struct for flags for readability (Matt Brost)
- Address misc other review comments (Matt Brost)
v9:
- Update the kerneldoc for the ttm_tt::backup field.
v10:
- Rebase.
v13:
- Rebase on ttm_backup interface change. Update kerneldoc.
- Rebase and adjust ttm_tt_is_swapped().
v15:
- Rebase on ttm_backup return value change.
- Rebase on previous restructuring of ttm_pool_alloc()
- Rework the ttm_pool backup interface (Christian König)
- Remove cond_resched() (Christian König)
- Get rid of the need to allocate an intermediate page array
when restoring a multi-order page (Christian König)
- Update documentation.
Cc: Christian König <christian.koenig@amd.com>
Cc: Somalapuram Amaranath <Amaranath.Somalapuram@amd.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Cc: <dri-devel@lists.freedesktop.org>
Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Acked-by: Christian Koenig <christian.koenig@amd.com>
Link: https://lore.kernel.org/intel-xe/20250305092220.123405-3-thomas.hellstrom@linux.intel.com
Provide a standalone shmem backup implementation.
Given the ttm_backup interface, this could
later on be extended to providing other backup
implementation than shmem, with one use-case being
GPU swapout to a user-provided fd.
v5:
- Fix a UAF. (kernel test robot, Dan Carptenter)
v6:
- Rename ttm_backup_shmem_copy_page() function argument
(Matthew Brost)
- Add some missing documentation
v8:
- Use folio_file_page to get to the page we want to writeback
instead of using the first page of the folio.
v13:
- Remove the base class abstraction (Christian König)
- Include ttm_backup_bytes_avail().
v14:
- Fix kerneldoc for ttm_backup_bytes_avail() (0-day)
- Work around casting of __randomize_layout struct pointer (0-day)
v15:
- Return negative error code from ttm_backup_backup_page()
(Christian König)
- Doc fixes. (Christian König).
Cc: Christian König <christian.koenig@amd.com>
Cc: Somalapuram Amaranath <Amaranath.Somalapuram@amd.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Cc: <dri-devel@lists.freedesktop.org>
Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Link: https://lore.kernel.org/intel-xe/20250305092220.123405-2-thomas.hellstrom@linux.intel.com
Commit 434e5ca5b5 ("drm/panthor: Expose size of driver internal BO's over
fdinfo") locks the VMS xarray, to avoid UAF errors when the same VM is
being concurrently destroyed by another thread. However, that puts the
current thread in atomic context, which means taking the VMS' heap locks
will trigger a warning as the thread is no longer allowed to sleep.
Because in this case replacing the heap mutex with a spinlock isn't
feasible, the fdinfo handler no longer traverses the list of heaps for
every single VM associated with an open DRM file. Instead, when a new heap
chunk is allocated, its size is accumulated into a pool-wide tally, which
also makes the atomic context code path somewhat faster.
Signed-off-by: Adrián Larumbe <adrian.larumbe@collabora.com>
Fixes: 434e5ca5b5 ("drm/panthor: Expose size of driver internal BO's over fdinfo")
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Signed-off-by: Steven Price <steven.price@arm.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250303190923.1639985-2-adrian.larumbe@collabora.com
Commit 0590c94c35 ("drm/panthor: Fix race condition when gathering fdinfo
group samples") introduced an xarray lock to deal with potential
use-after-free errors when accessing groups fdinfo figures. However, this
toggles the kernel's atomic context status, so the next nested mutex lock
will raise a warning when the kernel is compiled with mutex debug options:
CONFIG_DEBUG_RT_MUTEXES=y
CONFIG_DEBUG_MUTEXES=y
Replace Panthor's group fdinfo data mutex with a guarded spinlock.
Signed-off-by: Adrián Larumbe <adrian.larumbe@collabora.com>
Fixes: 0590c94c35 ("drm/panthor: Fix race condition when gathering fdinfo group samples")
Reviewed-by: Liviu Dudau <liviu.dudau@arm.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Signed-off-by: Steven Price <steven.price@arm.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250303190923.1639985-1-adrian.larumbe@collabora.com
