mainlining shenanigans
a6283010e2
[Why]: When we call hmm_range_fault to map memory after a migration, we don't expect memory to be migrated again as a result of hmm_range_fault. The driver ensures that all memory is in GPU-accessible locations so that no migration should be needed. However, there is one corner case where hmm_range_fault can unexpectedly cause a migration from DEVICE_PRIVATE back to system memory due to a write-fault when a system memory page in the same range was mapped read-only (e.g. COW). Ranges with individual pages in different locations are usually the result of failed page migrations (e.g. page lock contention). The unexpected migration back to system memory causes a deadlock from recursive locking in our driver. [How]: Creating a task reference new member under svm_range_list struct. Setting this with "current" reference, right before the hmm_range_fault is called. This member is checked against "current" reference at svm_migrate_to_ram callback function. If equal, the migration will be ignored. Signed-off-by: Alex Sierra <alex.sierra@amd.com> Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> |
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| arch | ||
| block | ||
| certs | ||
| crypto | ||
| Documentation | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| LICENSES | ||
| 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 | ||
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.