mainlining shenanigans
6ef7d36212
When we submit a new pair of contexts to ELSP for execution, we start a timer by which point we expect the HW to have switched execution to the pending contexts. If the promotion to the new pair of contexts has not occurred, we declare the executing context to have hung and force the preemption to take place by resetting the engine and resubmitting the new contexts. This can lead to an unfair situation where almost all of the preemption timeout is consumed by the first context which just switches into the second context immediately prior to the timer firing and triggering the preemption reset (assuming that the timer interrupts before we process the CS events for the context switch). The second context hasn't yet had a chance to yield to the incoming ELSP (and send the ACk for the promotion) and so ends up being blamed for the reset. If we see that a context switch has occurred since setting the preemption timeout, but have not yet received the ACK for the ELSP promotion, rearm the preemption timer and check again. This is especially significant if the first context was not schedulable and so we used the shortest timer possible, greatly increasing the chance of accidentally blaming the second innocent context. Fixes: |
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| arch | ||
| block | ||
| certs | ||
| crypto | ||
| Documentation | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| io_uring | ||
| 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.