56f581bad4
One more complication of preempt-to-busy with respect to the virtual engine is that we may have retired the last request along the virtual engine at the same time as preparing to submit the completed request to a new engine. That submit will be shortcircuited, but not before we have updated the context with the new register offsets and marked the virtual engine as bound to the new engine (by calling swap on ve->siblings[]). As we may have just retired the completed request, we may also be in the middle of calling virtual_context_exit() to turn off the power management associated with the virtual engine, and that in turn walks the ve->siblings[]. If we happen to call swap() on the array as we walk, we will call intel_engine_pm_put() twice on the same engine. In this patch, we prevent this by only updating the bound engine after a successful submission which weeds out the already completed requests. Alternatively, we could walk a non-volatile array for the pm, such as using the engine->mask. The small advantage to performing the update after the submit is that we then only have to do a swap for active requests. Fixes: |
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| Documentation | ||
| LICENSES | ||
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
README
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.