forked from Minki/linux
mainlining shenanigans
756c6f0f7e
When a directory is growing rapidly, new blocks tend to get added at the end of the directory. These end up at the end of the freespace index, and when the directory gets large finding these new freespaces gets expensive. The code does a linear search across the frespace index from the first block in the directory to the last, hence meaning the newly added space is the last index searched. Instead, do a reverse order index search, starting from the last block and index in the freespace index. This makes most lookups for free space on rapidly growing directories O(1) instead of O(N), but should not have any impact on random insert workloads because the average search length is the same regardless of which end of the array we start at. The result is a major improvement in large directory grow rates: create time(sec) / rate (files/s) File count vanilla Prev commit Patched 10k 0.41 / 24.3k 0.42 / 23.8k 0.41 / 24.3k 20k 0.74 / 27.0k 0.76 / 26.3k 0.75 / 26.7k 100k 3.81 / 26.4k 3.47 / 28.8k 3.27 / 30.6k 200k 8.58 / 23.3k 7.19 / 27.8k 6.71 / 29.8k 1M 85.69 / 11.7k 48.53 / 20.6k 37.67 / 26.5k 2M 280.31 / 7.1k 130.14 / 15.3k 79.55 / 25.2k 10M 3913.26 / 2.5k 552.89 / 18.1k Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> |
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| 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.