Running tar with GenWQE hardware-acceleration

Red Hat Enterprise Linux 9.2 LPAR mode z/VM guest

You can make tar use genwqe_gzip in place of the common code gzip.

About this task

If called with the z option, the tar utility uses the first gzip tool in the search path, which is usually the common code version. By inserting the path to the GenWQE gzip tool at the beginning of the PATH variable, you can make the tar utility use hardware acceleration.

The path points to /usr/lib64/genwqe/gzip and /usr/lib64/genwqe/gunzip, which are symbolic links to genwqe_gzip and genwqe_gunzip.

The acceleration is most marked for a single large text file. The example that follows compresses a directory with the Linux® source code.

Procedure

Run the tar command as usual to use software compression. To obtain performance data, specify the tar command as an argument to the time command.
```
# time tar cfz linux-src.sw.tar.gz linux-src
real 0m22.329s
user 0m22.147s
sys 0m0.849s
```
Run the tar command with an adjusted PATH variable to use GenWQE hardware acceleration. Again, use the time command to obtain performance data.
```
# time PATH=/usr/lib64/genwqe:$PATH \
tar cfz linux-src.hw.tar.gz linux-src
real 0m1.323s
user 0m0.242s
sys 0m1.023s
```

Results

In the example, the accelerated operation is significantly faster. The hardware-compressed data is slightly larger than the software-compressed version of the same data