b8e753128e
Currently, the coredump_task_exit() function sets the task state to TASK_UNINTERRUPTIBLE|TASK_FREEZABLE, which usually works well. But a combination of large memory and slow (and/or highly contended) mass storage can cause application core dumps to take more than two minutes, which can cause check_hung_task(), which is invoked by check_hung_uninterruptible_tasks(), to produce task-blocked splats. There does not seem to be any reasonable benefit to getting these splats. Furthermore, as Oleg Nesterov points out, TASK_UNINTERRUPTIBLE could be misleading because the task sleeping in coredump_task_exit() really is killable, albeit indirectly. See the check of signal->core_state in prepare_signal() and the check of fatal_signal_pending() in dump_interrupted(), which bypass the normal unkillability of TASK_UNINTERRUPTIBLE, resulting in coredump_finish() invoking wake_up_process() on any threads sleeping in coredump_task_exit(). Therefore, change that TASK_UNINTERRUPTIBLE to TASK_IDLE. Reported-by: Anhad Jai Singh <ffledgling@meta.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Acked-by: Oleg Nesterov <oleg@redhat.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Christian Brauner <brauner@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org> Cc: Chris Mason <clm@fb.com> Cc: Rik van Riel <riel@surriel.com>
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 reStructuredText 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.