12ca695d2c
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
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 Restructured Text 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.