Commit graph

5 commits

Author SHA1 Message Date
Helge Deller
eba38cc757 bcachefs: Fix build on parisc by avoiding __multi3()
The gcc compiler on paric does support the __int128 type, although the
architecture does not have native 128-bit support.

The effect is, that the bcachefs u128_square() function will pull in the
libgcc __multi3() helper, which breaks the kernel build when bcachefs is
built as module since this function isn't currently exported in
arch/parisc/kernel/parisc_ksyms.c.
The build failure can be seen in the latest debian kernel build at:
https://buildd.debian.org/status/fetch.php?pkg=linux&arch=hppa&ver=6.7.1-1%7Eexp1&stamp=1706132569&raw=0

We prefer to not export that symbol, so fall back to the optional 64-bit
implementation provided by bcachefs and thus avoid usage of __multi3().

Signed-off-by: Helge Deller <deller@gmx.de>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-28 21:29:23 -05:00
Kent Overstreet
44fd13a4c6 bcachefs: Fixes for rust bindgen
bindgen doesn't seem to like u128 or DECLARE_FLEX_ARRAY(), but we can
hack around them.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-01 11:47:42 -05:00
Kent Overstreet
db32bb9a5f mean and variance: Add a missing include
abs() is in math.h

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:10:02 -04:00
Kent Overstreet
65bc410907 mean and variance: More tests
Add some more tests that test conventional and weighted mean
simultaneously, and with a table of values that represents events that
we'll be using this to look for so we can verify-by-eyeball that the
output looks sane.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:10:02 -04:00
Daniel Hill
92095781e0 bcachefs: Mean and variance
This module provides a fast 64bit implementation of basic statistics
functions, including mean, variance and standard deviation in both
weighted and unweighted variants, the unweighted variant has a 32bit
limitation per sample to prevent overflow when squaring.

Signed-off-by: Daniel Hill <daniel@gluo.nz>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:09:43 -04:00