37ec8eb851
With or without locking it doesn't make sense for two writers to be writing to the same IOVA range at the same time. Even with locking we still have a race condition, whoever gets the lock first, so we still can't be sure what the result will be. With locking the result will be more sane, it will be correct for the last writer, but still useless because we can't be sure which writer will get the lock last. It's a fundamentally broken design to have two writers writing to the same IOVA range at the same time. So we can remove the locking and work on the assumption that no two writers will be writing to the same IOVA range at the same time. The only exception is when we have to allocate a middle page in the page tables, the middle page can cover more than just the IOVA range a writer has been allocated. However this isn't an issue in the AMD driver because it can atomically allocate middle pages using "cmpxchg64()". Signed-off-by: Tom Murphy <murphyt7@tcd.ie> Signed-off-by: Joerg Roedel <jroedel@suse.de> |
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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.