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| author | Peter Lieven | 2013-03-26 10:58:34 +0100 |
|---|---|---|
| committer | Juan Quintela | 2013-03-26 13:32:32 +0100 |
| commit | 49f676a00ab540fac1d2008be26434cf85607722 (patch) | |
| tree | cce8a4ec1cca6877846d177c9efc17fc26aee98d /include | |
| parent | buffer_is_zero: use vector optimizations if possible (diff) | |
| download | qemu-49f676a00ab540fac1d2008be26434cf85607722.tar.gz qemu-49f676a00ab540fac1d2008be26434cf85607722.tar.xz qemu-49f676a00ab540fac1d2008be26434cf85607722.zip | |
bitops: unroll while loop in find_next_bit()
this patch adopts the loop unrolling idea of bitmap_is_zero() to
speed up the skipping of large areas with zeros in find_next_bit().
this routine is extensively used to find dirty pages in
live migration.
testing only the find_next_bit performance on a zeroed bitfield
the loop onrolling decreased executing time by approx. 50% on x86_64.
Signed-off-by: Peter Lieven <pl@kamp.de>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Diffstat (limited to 'include')
0 files changed, 0 insertions, 0 deletions