3f6a6f343c
Currently, we use i915_request_completed() directly in i915_request_wait() and follow up with a manual invocation of dma_fence_signal(). This appears to cause a large number of contentions on i915_request.lock as when the process is woken up after the fence is signaled by an interrupt, we will then try and call dma_fence_signal() ourselves while the signaler is still holding the lock. dma_fence_is_signaled() has the benefit of checking the DMA_FENCE_FLAG_SIGNALED_BIT prior to calling dma_fence_signal() and so avoids most of that contention. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Matthew Auld <matthew.auld@intel.com> Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20200716100754.5670-1-chris@chris-wilson.co.uk Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com> Signed-off-by: Joonas Lahtinen <joonas.lahtinen@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.