mainlining shenanigans
fa121a26b2
I noticed while running my snapshot torture test that we were getting a lot of metadata chunks allocated with very little actually used. Digging into this we would commit the transaction, still not have enough space, and then force a chunk allocation. I noticed that we were barely flushing any delalloc at all, despite the fact that we had around 13gib of outstanding delalloc reservations. It turns out this is because of our btrfs_calc_reclaim_metadata_size() calculation. It _only_ takes into account the outstanding ticket sizes, which isn't the whole story. In this particular workload we're slowly filling up the disk, which means our overcommit space will suddenly become a lot less, and our outstanding reservations will be well more than what we can handle. However we are only flushing based on our ticket size, which is much less than we need to actually reclaim. So fix btrfs_calc_reclaim_metadata_size() to take into account the overage in the case that we've gotten less available space suddenly. This makes it so we attempt to reclaim a lot more delalloc space, which allows us to make our reservations and we no longer are allocating a bunch of needless metadata chunks. CC: stable@vger.kernel.org # 4.4+ Signed-off-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: David Sterba <dsterba@suse.com> |
||
|---|---|---|
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| Documentation | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| LICENSES | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
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.