1a9fb16c60
When trying to merge an extent map that was just inserted or unpinned, we will try to merge it with any adjacent extent map that is suitable. However we will only check if our extent map is mergeable after searching for the previous and next extent maps in the rbtree, meaning that we are doing unnecessary calls to rb_prev() and rb_next() in case our extent map is not mergeable (it's compressed, in the list of modifed extents, being logged or pinned), wasting CPU time chasing rbtree pointers and pulling in unnecessary cache lines. So change the logic to check first if an extent map is mergeable before searching for the next and previous extent maps in the rbtree. Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.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 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.