lkml.org 
[lkml]   [2021]   [Dec]   [15]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
SubjectRE: [PATCH 2/9] lib/bitmap: implement bitmap_{empty,full} with bitmap_weight_eq()
Date
From: Yury Norov
> Sent: 14 December 2021 19:43
...
>
> I think that for long bitmaps the most time consuming operation is moving
> data to L1, and for short bitmaps the difference between approaches is
> barely measurable.
>
> But hweght_long on each iteration can't be more effective than the current
> version. So, I'll drop this patch for v2 and keep things unchanged.

Actually do bitmap_full/empty() calls make any sense at all?
The result is stale since bitmaps are designed to do locked operations.
If you have a lock covering the bitmap then you should be using
something that uses non-locked accesses.
Rightly or wrongly that isn't the bitmap api.

David

-
Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)
\
 
 \ /
  Last update: 2021-12-15 09:41    [W:0.147 / U:0.044 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site