Thank you to raise this issue. We will fix it and add back the --hash original functionality.

Thanks

Steven

From: Lin, Derek (HPS SW) [mailto:derek.lin2@hpe.com]
Sent: Friday, September 20, 2019 2:54 PM
To: devel@edk2.groups.io
Cc: Feng, Bob C <bob.c.feng@intel.com>; Shi, Steven <steven.shi@intel.com>
Subject: BaseTools --hash malfunction after migrate from stable201905 to stable201908

Hi BaseTools experts,

We saw the clean build performance improvement after updating from edk2-stable201905 to edk2-stable201908, which is promising.

But we found the incremental build time increase 25%~35%, which is not good.

We’re building server platform. And we use --hash to speed up incremental build as described in https://github.com/BobCF/edk2/wiki/Incremental-Build

After upgrading to edk2-stable201908, none of AutoGen is skipped when I did an incremental build without any code change.

Dig into the issue, it is caused by commit https://github.com/tianocore/edk2/commit/0e7e7a264cd80ab71ea0f9e9da2d0617d4b539c4

From the code change logic, it seems like it require both --hash and --binary-source to perform cache based incremental build. However, when we only have --hash in build flag, it is not functional.

Here’s a build time log retrieved from -y report.log.

201905 incremental | 201908 incremental | 201905 clean | 201908 clean

Build Duration: 00:03:44 00:04:40 00:07:12 00:06:19

AutoGen Duration: 00:02:40 00:03:15 00:04:28 00:03:09

Make Duration: 00:00:36 00:00:39 00:01:21 00:01:34

GenFds Duration: 00:00:27 00:00:28 00:01:22 00:01:18

We could see the AutoGen Duration has almost no change between clean and incremental build in 201908.

Could we fix this?

Thanks,

Derek