1b7306f5dd
The script 'bench_write_req.py' allows comparing performances of write request for two qemu-img binary files. An example with (qemu-img binary 1) and without (qemu-img binary 2) the applied patch "qcow2: skip writing zero buffers to empty COW areas" (git commit ID: c8bb23cbdbe32f5) has the following results: SSD: ---------------- ------------------- ------------------- <qemu-img binary 1> <qemu-img binary 2> <cluster front> 0.10 +- 0.00 8.16 +- 0.65 <cluster middle> 0.10 +- 0.00 7.37 +- 1.10 <cross cluster> 7.40 +- 1.08 21.97 +- 4.19 <cluster 64K> 2.14 +- 0.94 8.48 +- 1.66 ---------------- ------------------- ------------------- HDD: ---------------- ------------------- ------------------- <qemu-img binary 1> <qemu-img binary 2> <cluster front> 2.30 +- 0.01 6.19 +- 0.06 <cluster middle> 2.20 +- 0.09 6.20 +- 0.06 <cross cluster> 8.32 +- 0.16 8.26 +- 0.14 <cluster 64K> 8.20 +- 0.05 6.26 +- 0.10 ---------------- ------------------- ------------------- Suggested-by: Denis V. Lunev <den@openvz.org> Suggested-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <1594741846-475697-1-git-send-email-andrey.shinkevich@virtuozzo.com> Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>