Hi all! Here are compress threads for qcow2, to increase performance of compressed writes.
I've created the following test: []# cat ../gen.sh #!/bin/bash echo 'create pattern-file t_pat' ./qemu-img create -f raw t_pat 1000m ./qemu-io -c 'write -P 0xab 0 1000m' t_pat echo 'create randod t_rand' dd if=/dev/urandom of=t_rand bs=1M count=1000 []# cat ../test.sh #!/bin/bash rm -f t_out echo 'test pattern-file compression' time ./qemu-img convert -W -f raw -O qcow2 -c t_pat t_out rm -f t_out echo 'test random-file compression' time ./qemu-img convert -W -f raw -O qcow2 -c t_rand t_out rm -f t_out and results before the series (and without -W flag): test pattern-file compression real 0m16.658s user 0m16.450s sys 0m0.628s test random-file compression real 0m24.194s user 0m24.361s sys 0m0.395s results with -W flag, after first patch: test pattern-file compression real 0m16.242s user 0m16.895s sys 0m0.080s test random-file compression real 0m23.450s user 0m23.767s sys 0m1.085s results with -W flag, after third patch: test pattern-file compression real 0m5.747s user 0m22.637s sys 0m0.393s test random-file compression real 0m8.402s user 0m33.315s sys 0m0.926s So, we see significant performance gain. But this of course don't work without -W flag. results without -W flag, after third patch: test pattern-file compression real 0m16.908s user 0m16.775s sys 0m0.589s test random-file compression real 0m24.913s user 0m24.586s sys 0m0.898s Note: my cpu is 4-cores 8-threads i7-4790 Vladimir Sementsov-Ogievskiy (3): qemu-img: allow compressed not-in-order writes qcow2: refactor data compression qcow2: add compress threads block/qcow2.h | 3 ++ block/qcow2.c | 134 ++++++++++++++++++++++++++++++++++++++++++++++------------ qemu-img.c | 5 --- 3 files changed, 110 insertions(+), 32 deletions(-) -- 2.11.1