32d7727080
In page_counter_set_max, we want to make sure the new limit is not below the concurrently-changing counter value. We read the counter and check that the limit is not below the counter before the swap. After the swap, we read the counter again and retry in case the counter is incremented as this may violate the requirement. Even though the page_counter_try_charge can see the old limit, it is guaranteed that the counter is not above the old limit after the increment. So in case the new limit is not below the old limit, the counter is guaranteed to be not above the new limit too. We can skip the retry in this case to optimize a little bit. Link: https://lkml.kernel.org/r/20220821154055.109635-1-minhquangbui99@gmail.com Signed-off-by: Bui Quang Minh <minhquangbui99@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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.