mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
synced 2026-05-14 06:30:20 -04:00
0b1217bfdf
When the DRM scheduler times out, it's possible that the GPU isn't hung;
instead, a job just took unusually long (longer than the timeout) but is
still running, and there is, thus, no reason to reset the hardware. This
can occur in two scenarios:
1. The job is taking longer than the timeout, but the driver determined
through a GPU-specific mechanism that the hardware is still making
progress. Hence, the driver would like the scheduler to skip the
timeout and treat the job as still pending from then onward. This
happens in v3d, Etnaviv, and Xe.
2. Timeout has fired before the free-job worker. Consequently, the
scheduler calls `sched->ops->timedout_job()` for a job that isn't
timed out.
These two scenarios are problematic because the job was removed from the
`sched->pending_list` before calling `sched->ops->timedout_job()`, which
means that when the job finishes, it won't be freed by the scheduler
though `sched->ops->free_job()` - leading to a memory leak.
To solve these problems, create a new `drm_gpu_sched_stat`, called
DRM_GPU_SCHED_STAT_NO_HANG, which allows a driver to skip the reset. The
new status will indicate that the job must be reinserted into
`sched->pending_list`, and the hardware / driver will still complete that
job.
Reviewed-by: Philipp Stanner <phasta@kernel.org>
Link: https://lore.kernel.org/r/20250714-sched-skip-reset-v6-2-5c5ba4f55039@igalia.com
Signed-off-by: Maíra Canal <mcanal@igalia.com>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.