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.
Dave Chinner
authored
generic/530 on a machine with enough ram and a non-preemptible kernel can run the AGI processing phase of log recovery enitrely out of cache. This means it never blocks on locks, never waits for IO and runs entirely through the unlinked lists until it either completes or blocks and hangs because it has run out of log space. It runs out of log space because the background CIL push is scheduled but never runs. queue_work() queues the CIL work on the current CPU that is busy, and the workqueue code will not run it on any other CPU. Hence if the unlinked list processing never yields the CPU voluntarily, the push work is delayed indefinitely. This results in the CIL aggregating changes until all the log space is consumed. When the log recoveyr processing evenutally blocks, the CIL flushes but because the last iclog isn't submitted for IO because it isn't full, the CIL flush never completes and nothing ever moves the log head forwards, or indeed inserts anything i...