mainlining shenanigans
90d2efe7bd
Suppose we have a kernel built with both CONFIG_RCU_STRICT_GRACE_PERIOD=y and CONFIG_PREEMPT=y. Suppose further that an RCU reader from which RCU core needs a quiescent state ends in rcu_preempt_deferred_qs_irqrestore(). This function will then invoke rcu_report_qs_rdp() in order to immediately report that quiescent state. Unfortunately, it will not have cleared that reader's CPU's rcu_data structure's ->cpu_no_qs.b.norm field. As a result, rcu_report_qs_rdp() will take an early exit because it will believe that this CPU has not yet encountered a quiescent state, and there will be no reporting of the current quiescent state. This commit therefore causes rcu_preempt_deferred_qs_irqrestore() to clear the ->cpu_no_qs.b.norm field before invoking rcu_report_qs_rdp(). Kudos to Boqun Feng and Neeraj Upadhyay for helping with analysis of this issue! Signed-off-by: Paul E. McKenney <paulmck@kernel.org> |
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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.