e0fb0dccfd
A recent bug report uncovered a scenario where a filesystem never runs with freespace_initialized, and therefore the user observes significantly degraded write performance by virtue of running the early bucket allocator. The associated bug aside, the primary cause of the performance drop in this particular instance is that the early bucket allocator does not update the allocation cursor. This means that every allocation walks the alloc btree from the first bucket of the associated device looking for a bucket marked as free space. Update the early allocator code to set the alloc cursor to the last processed position in the tree, similar to how the freelist allocator behaves. With the alloc_cursor being updated, the retry logic also needs to be updated to restart from the beginning of the device when a free bucket is not available between the cursor and the end of the device. Track the restart position in a first_bucket variable to make the code a bit more easily readable and consistent with the freelist allocator. Signed-off-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
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.