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Revision f6a00aa1


Added by Dmitry Konishchev about 11 years ago

qemu_img: is_not_zero() optimization

I run qemu-img under profiler and realized, that most of CPU time is
consumed by is_not_zero() function. I had made a couple of optimizations
on it and got the following output for `time qemu-img convert -O qcow2
volume.qcow2 snapshot.qcow2`:

Original qemu-img:
real 0m56.159s
user 0m34.670s
sys 0m12.079s

Patched qemu-img:
real 0m34.805s
user 0m18.445s
sys 0m12.552s

Signed-off-by: Dmitry Konishchev <>
Signed-off-by: Kevin Wolf <>


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