mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
synced 2026-05-04 12:16:51 -04:00
32db469edf
The number of buckets is calculated by performing a binary AND against
the mask of the hash table, which is one less than its size (which is a
power of two). This leads to all top bits being discarded, requiring
for short or similar inputs a hash function with a good avalanche
effect.
Use djb2a:
# current
common prefixes: 7 entries and 5/8 buckets used, longest chain
length 2, sum of chain length^2 11
classes: 134 entries and 100/256 buckets used, longest chain
length 5, sum of chain length^2 234
roles: 15 entries and 6/16 buckets used, longest chain length 5,
sum of chain length^2 57
types: 4448 entries and 3016/8192 buckets used, longest chain
length 41, sum of chain length^2 14922
users: 7 entries and 3/8 buckets used, longest chain length 3,
sum of chain length^2 17
bools: 306 entries and 221/512 buckets used, longest chain
length 4, sum of chain length^2 524
levels: 1 entries and 1/1 buckets used, longest chain length 1,
sum of chain length^2 1
categories: 1024 entries and 400/1024 buckets used, longest chain
length 4, sum of chain length^2 2740
# patch
common prefixes: 7 entries and 5/8 buckets used, longest chain
length 2, sum of chain length^2 11
classes: 134 entries and 101/256 buckets used, longest chain
length 3, sum of chain length^2 210
roles: 15 entries and 9/16 buckets used, longest chain length 3,
sum of chain length^2 31
types: 4448 entries and 3459/8192 buckets used, longest chain
length 5, sum of chain length^2 6778
users: 7 entries and 5/8 buckets used, longest chain length 3,
sum of chain length^2 13
bools: 306 entries and 236/512 buckets used, longest chain
length 5, sum of chain length^2 470
levels: 1 entries and 1/1 buckets used, longest chain length 1,
sum of chain length^2 1
categories: 1024 entries and 518/1024 buckets used, longest chain
length 7, sum of chain length^2 2992
Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
[PM: line length fixes in the commit message]
Signed-off-by: Paul Moore <paul@paul-moore.com>
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.