4297ff84dc
When diagnosing a slowdown of generic/224 I noticed we were not doing anything when calling into shrink_delalloc(). This is because all writes in 224 are O_DIRECT, not delalloc, and thus our delalloc_bytes counter is 0, which short circuits most of the work inside of shrink_delalloc(). However O_DIRECT writes still consume metadata resources and generate ordered extents, which we can still wait on. Fix this by tracking outstanding DIO write bytes, and use this as well as the delalloc bytes counter to decide if we need to lookup and wait on any ordered extents. If we have more DIO writes than delalloc bytes we'll go ahead and wait on any ordered extents regardless of our flush state as flushing delalloc is likely to not gain us anything. Signed-off-by: Josef Bacik <josef@toxicpanda.com> [ use dio instead of odirect in identifiers ] 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.