Add a tiny per-engine request mempool so that we should always have a request available for powermanagement allocations from tricky contexts. This reserve is expected to be only used for kernel contexts when barriers must be emitted [almost] without fail. The main consumer for this reserved request is expected to be engine-pm, for which we know that there will always be at least the previous pm request that we can reuse under mempressure (so there should always be a spare request for engine_park()). This is an alternative to using a comparatively bulky mempool, which requires custom handling for both our reserved allocation requirement and to protect our TYPESAFE_BY_RCU slab cache. The advantage of mempool would be that it would allow us to keep a larger per-engine request pool. However, converting over to mempool is straightforward should the need arise. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Janusz Krzysztofik <janusz.krzysztofik@linux.intel.com> Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Reviewed-and-tested-by: Janusz Krzysztofik <janusz.krzysztofik@linux.intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20200402184037.21630-1-chris@chris-wilson.co.uk |
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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.