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A mirror of the official Linux kernel repository just in case
4203431319
Before this change, the btrfs_get_io_geometry() function was calling btrfs_get_chunk_map() to get the extent mapping, necessary for calculating the I/O geometry. It was using that extent mapping only internally and freeing the pointer after its execution. That resulted in calling btrfs_get_chunk_map() de facto twice by the __btrfs_map_block() function. It was calling btrfs_get_io_geometry() first and then calling btrfs_get_chunk_map() directly to get the extent mapping, used by the rest of the function. Change that to passing the extent mapping to the btrfs_get_io_geometry() function as an argument. This could improve performance in some cases. For very large filesystems, i.e. several thousands of allocated chunks, not only this avoids searching two times the rbtree, saving time, it may also help reducing contention on the lock that protects the tree - thinking of writeback starting for multiple inodes, other tasks allocating or removing chunks, and anything else that requires access to the rbtree. Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Michal Rostecki <mrostecki@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> [ add Filipe's analysis ] Signed-off-by: David Sterba <dsterba@suse.com> |
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| 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.