On Sun, Jan 21, 2024 at 11:36:44PM +0800, Kuan-Wei Chiu wrote: > Hello, > > The existing implementations of heap/heapsort follow the conventional > textbook approach, where each heapify operation requires approximately > 2*log2(n) comparisons. In this series, I introduce a bottom-up variant > that reduces the number of comparisons during heapify operations to > approximately log2(n), while maintaining the same number of swap > operations. > > Thanks, > Kuan-Wei > > Kuan-Wei Chiu (5): > bcachefs: Optimize eytzinger0_sort() using bottom-up heapsort > bcachefs: Introduce parent function for sort_cmp_size() > bcachefs: Optimize sort_cmp_size() using bottom-up heapsort > bcachefs: Optimize number of comparisons in heap_sift_down > bcache: Optimize number of comparisons in heap_sift > > drivers/md/bcache/util.h | 23 +++++---- > fs/bcachefs/util.c | 109 ++++++++++++++++++++++++++------------- > fs/bcachefs/util.h | 23 +++++---- > 3 files changed, 98 insertions(+), 57 deletions(-) Good stuff While we're looking at this code, we should be doing some cleanup too - there's no reason for the heap code to be duplicated in bcache and bcachefs anymore, and it'd also be nice to get fs/bcachefs/eytzinger.h moved to include/linux and bcache converted to use it. I also would not be surprised if there's another heap implementation in include/linux; we'll want to check for that and if there is decide which is worth keeping. Would you or Coli be interested in taking that on as well?
