b887d61546
In the next patch, rings are the central timeline as requests may jump between engines. Therefore in the future as we retire in order along the engine timeline, we may retire out-of-order within a ring (as the ring now occurs along multiple engines), leading to much hilarity in miscomputing the position of ring->head. As an added bonus, retiring along the ring reduces the penalty of having one execlists client do cleanup for another (old legacy submission shares a ring between all clients). The downside is that slow and irregular (off the critical path) process of cleaning up stale requests after userspace becomes a modicum less efficient. In the long run, it will become apparent that the ordered ring->request_list matches the ring->timeline, a fun challenge for the future will be unifying the two lists to avoid duplication! v2: We need both engine-order and ring-order processing to maintain our knowledge of where individual rings have completed upto as well as knowing what was last executing on any engine. And finally by decoupling retiring the contexts on the engine and the timelines along the rings, we do have to keep a reference to the context on each request (previously it was guaranteed by the context being pinned). v3: Not just a reference to the context, but we need to keep it pinned as we manipulate the rings; i.e. we need a pin for both the manipulation of the engine state during its retirements, and a separate pin for the manipulation of the ring state. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20180430131503.5375-3-chris@chris-wilson.co.uk |
||
|---|---|---|
| Documentation | ||
| LICENSES | ||
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| drivers | ||
| firmware | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
README
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. 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.