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Linux kernel source tree
00c0cf8444
As we can a have non-contiguous range in the eb->folios, any item can be
straddling two folios and we need to check if it can be read in one go
or in two parts. For that there's a check which is not implemented in
the simplest way:
offset in folio + size <= folio size
With a simple expression transformation:
oil + size <= unit_size
size <= unit_size - oil
sizeof() <= part
this can be simplified and reusing existing run-time or compile-time
constants.
Add likely() annotation for this expression as this is the fast path and
compiler sometimes reorders that after the followup block with the
memcpy (observed in practice with other simplifications).
Overall effect on stack consumption:
btrfs_get_8 -8 (80 -> 72)
btrfs_set_8 -8 (88 -> 80)
And .ko size (due to optimizations making use of the direct constants):
text data bss dec hex filename
1456601 115665 16088 1588354 183c82 pre/btrfs.ko
1456093 115665 16088 1587846 183a86 post/btrfs.ko
DELTA: -508
Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: David Sterba <dsterba@suse.com>
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| arch | ||
| block | ||
| certs | ||
| crypto | ||
| Documentation | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| io_uring | ||
| ipc | ||
| kernel | ||
| lib | ||
| LICENSES | ||
| mm | ||
| net | ||
| rust | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .clippy.toml | ||
| .cocciconfig | ||
| .editorconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| .pylintrc | ||
| .rustfmt.toml | ||
| 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 reStructuredText 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.