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Linux kernel stable tree
414c12385d
It is currently up to the caller to handle stale return values from get_state_synchronize_rcu(). If poll_state_synchronize_rcu() returned true once, a grace period has elapsed, regardless of the fact that counter wrap might cause some future poll_state_synchronize_rcu() invocation to return false. For example, the caller might store a separate flag that indicates whether some previous call to poll_state_synchronize_rcu() determined that the relevant grace period had already ended. This approach works, but it requires extra storage and is easy to get wrong. This commit therefore introduces a get_completed_synchronize_rcu() that returns a cookie that causes poll_state_synchronize_rcu() to always return true. This already-completed cookie can be stored in place of the cookie that previously caused poll_state_synchronize_rcu() to return true. It can also be used to flag a given structure as not having been exposed to readers, and thus not requiring a grace period to elapse. This commit is in preparation for polled expedited grace periods. Link: https://lore.kernel.org/all/20220121142454.1994916-1-bfoster@redhat.com/ Link: https://docs.google.com/document/d/1RNKWW9jQyfjxw2E8dsXVTdvZYh0HnYeSHDKog9jhdN8/edit?usp=sharing Cc: Brian Foster <bfoster@redhat.com> Cc: Dave Chinner <david@fromorbit.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Ian Kent <raven@themaw.net> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> |
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| 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 | ||
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| 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.