ad3ea16746
commit b8cd0ee8cda68a888a317991c1e918a8cba1a568 upstream. Event merges are expensive when event queue size is large, so limit the linear search to 128 merge tests. [Stable backport notes] The following statement from upstream commit is irrelevant for backport: - -In combination with 128 size hash table, there is a potential to merge -with up to 16K events in the hashed queue. - [Stable backport notes] The problem is as old as fanotify and described in the linked cover letter "Performance improvement for fanotify merge". This backported patch fixes the performance issue at the cost of merging fewer potential events. Fixing the performance issue is more important than preserving the "event merge" behavior, which was not predictable in any way that applications could rely on. Link: https://lore.kernel.org/r/20210304104826.3993892-6-amir73il@gmail.com Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz> Cc: <stable@vger.kernel.org> Link: https://lore.kernel.org/linux-fsdevel/20210202162010.305971-1-amir73il@gmail.com/ Link: https://lore.kernel.org/linux-fsdevel/20210915163334.GD6166@quack2.suse.cz/ Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.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.