Messages in this thread | | | From | David Laight <> | Subject | RE: [PATCH 2/9] lib/bitmap: implement bitmap_{empty,full} with bitmap_weight_eq() | Date | Wed, 15 Dec 2021 08:40:10 +0000 |
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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
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