Commit graph

3 commits

Author SHA1 Message Date
Darrick J. Wong 4b4f0876ab bcachefs: mean_and_variance: put struct mean_and_variance_weighted on a diet
The only caller of this code (time_stats) always knows the weights and
whether or not any information has been collected.  Pass this
information into the mean and variance code so that it doesn't have to
store that information.  This reduces the structure size from 24 to 16
bytes, which shrinks each time_stats counter to 192 bytes from 208.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-03-13 21:37:58 -04:00
Randy Dunlap 920388254f bcachefs: mean and variance: fix kernel-doc for function params
Add missing function parameter descriptions in mean_and_variance.c.
The also eliminates the "Excess function parameter" warnings.

Prevents these kernel-doc warnings:

mean_and_variance.c:67: warning: Function parameter or member 's' not described in 'mean_and_variance_get_mean'
mean_and_variance.c:78: warning: Function parameter or member 's1' not described in 'mean_and_variance_get_variance'
mean_and_variance.c:94: warning: Function parameter or member 's' not described in 'mean_and_variance_get_stddev'
mean_and_variance.c:108: warning: Function parameter or member 's' not described in 'mean_and_variance_weighted_update'
mean_and_variance.c:108: warning: Function parameter or member 'x' not described in 'mean_and_variance_weighted_update'
mean_and_variance.c:108: warning: Excess function parameter 's1' description in 'mean_and_variance_weighted_update'
mean_and_variance.c:108: warning: Excess function parameter 's2' description in 'mean_and_variance_weighted_update'
mean_and_variance.c:134: warning: Function parameter or member 's' not described in 'mean_and_variance_weighted_get_mean'
mean_and_variance.c:143: warning: Function parameter or member 's' not described in 'mean_and_variance_weighted_get_variance'
mean_and_variance.c:153: warning: Function parameter or member 's' not described in 'mean_and_variance_weighted_get_stddev'

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Brian Foster <bfoster@redhat.com>
Cc: linux-bcachefs@vger.kernel.org
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-01 11:47:42 -05:00
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