%%%%%%%%%%%%%
WITHOUT PATCH
%%%%%%%%%%%%%

dd if=/dev/zero of=/root/benchmark bs=512 count=20000
20000+0 records in
20000+0 records out
10240000 bytes (10 MB) copied, 0.674347 s, 15.2 MB/s

dd if=/dev/zero of=/root/benchmark bs=1024 count=20000
20000+0 records in
20000+0 records out
20480000 bytes (20 MB) copied, 0.89386 s, 22.9 MB/s

dd if=/dev/zero of=/root/benchmark bs=2048 count=20000
20000+0 records in
20000+0 records out
40960000 bytes (41 MB) copied, 1.36237 s, 30.1 MB/s

dd if=/dev/zero of=/root/benchmark bs=4096 count=20000
20000+0 records in
20000+0 records out
81920000 bytes (82 MB) copied, 2.81037 s, 29.1 MB/s

===============20000 blocks written averaged 24.325 MB/s
========================================================

dd if=/dev/zero of=/root/benchmark bs=512 count=40000
40000+0 records in
40000+0 records out
20480000 bytes (20 MB) copied, 1.31354 s, 15.6 MB/s

dd if=/dev/zero of=/root/benchmark bs=1024 count=40000
40000+0 records in
40000+0 records out
40960000 bytes (41 MB) copied, 1.8173 s, 22.5 MB/s

dd if=/dev/zero of=/root/benchmark bs=2048 count=40000
40000+0 records in
40000+0 records out
81920000 bytes (82 MB) copied, 3.23683 s, 25.3 MB/s

dd if=/dev/zero of=/root/benchmark bs=4096 count=40000
40000+0 records in
40000+0 records out
163840000 bytes (164 MB) copied, 6.79296 s, 24.1 MB/s

================== 40000 blocks written averaged 21.875 MB/s
============================================================

dd if=/dev/zero of=/root/benchmark bs=512 count=80000
80000+0 records in
80000+0 records out
40960000 bytes (41 MB) copied, 2.70969 s, 15.1 MB/s

dd if=/dev/zero of=/root/benchmark bs=1024 count=80000
80000+0 records in
80000+0 records out
81920000 bytes (82 MB) copied, 4.25879 s, 19.2 MB/s

dd if=/dev/zero of=/root/benchmark bs=2048 count=80000
80000+0 records in
80000+0 records out
163840000 bytes (164 MB) copied, 7.28753 s, 22.5 MB/s

dd if=/dev/zero of=/root/benchmark bs=4096 count=80000
80000+0 records in
80000+0 records out
327680000 bytes (328 MB) copied, 13.5436 s, 24.2 MB/s

==================== 80000 blocks written averaged 22.75 MB/s
=============================================================

%%%%%%%%%%
WITH PATCH (!)
%%%%%%%%%%

dd if=/dev/zero of=/root/benchmark bs=512 count=20000
20000+0 records in
20000+0 records out
10240000 bytes (10 MB) copied, 0.354359 s, 28.9 MB/s

dd if=/dev/zero of=/root/benchmark bs=1024 count=20000
20000+0 records in
20000+0 records out
20480000 bytes (20 MB) copied, 0.474818 s, 43.1 MB/s

dd if=/dev/zero of=/root/benchmark bs=2048 count=20000
20000+0 records in
20000+0 records out
40960000 bytes (41 MB) copied, 0.790466 s, 51.8 MB/s

dd if=/dev/zero of=/root/benchmark bs=4096 count=20000
20000+0 records in
20000+0 records out
81920000 bytes (82 MB) copied, 1.51956 s, 53.9 MB/s

================= 40000 blocks written averaged 44.425 MB/s (+82.6%)
====================================================================

dd if=/dev/zero of=/root/benchmark bs=512 count=40000
40000+0 records in
40000+0 records out
20480000 bytes (20 MB) copied, 0.731345 s, 28.0 MB/s

dd if=/dev/zero of=/root/benchmark bs=1024 count=40000
40000+0 records in
40000+0 records out
40960000 bytes (41 MB) copied, 1.06329 s, 38.5 MB/s

dd if=/dev/zero of=/root/benchmark bs=2048 count=40000
40000+0 records in
40000+0 records out
81920000 bytes (82 MB) copied, 1.85218 s, 44.2 MB/s

dd if=/dev/zero of=/root/benchmark bs=4096 count=40000
40000+0 records in
40000+0 records out
163840000 bytes (164 MB) copied, 4.08386 s, 40.1 MB/s

================= 40000 blocks written averaged 37.7 MB/s (+72.3%)
==================================================================

dd if=/dev/zero of=/root/benchmark bs=512 count=80000
80000+0 records in
80000+0 records out
40960000 bytes (41 MB) copied, 1.59573 s, 25.7 MB/s

dd if=/dev/zero of=/root/benchmark bs=1024 count=80000
80000+0 records in
80000+0 records out
81920000 bytes (82 MB) copied, 2.51223 s, 32.6 MB/s

dd if=/dev/zero of=/root/benchmark bs=2048 count=80000
80000+0 records in
80000+0 records out
163840000 bytes (164 MB) copied, 4.59659 s, 35.6 MB/s

dd if=/dev/zero of=/root/benchmark bs=4096 count=80000
80000+0 records in
80000+0 records out
327680000 bytes (328 MB) copied, 10.3018 s, 31.8 MB/s
(31.425-22.75)/22.75

=================== 80000 blocks written averaged 31.425 MB/s (+38.1%)
=====================================================================