Andrew Morton on patch hoarding
Tuesday, April 22nd, 2008“Patch hoarding” refers to not committing kernel changes to the kernel trunk which has been a constant issue in the Linux community. At the CELF Embedded Linux Conference last week, Andrew Morton explained the why companies and developers should commit their changes to the kernel:
“One of the areas that he is most concerned about is the practice of “patch hoarding”—holding on to kernel changes as patches without submitting them upstream to the kernel hackers. It is hopefully only due to a lack of resources, but he has heard that some are doing it to try and gain a competitive advantage. This is simply wrong, he said, companies have a ‘moral if not legal obligation‘ to submit those patches.
There are many good reasons for getting code merged upstream that Morton outlined. The code will be better because of the review done by the kernel hackers; once it is done, the maintenance cost falls to near zero as well. He also touted the competitive advantage, noting that getting your code merged means that you have won—competing proposals won’t get in. Being the first to merge a feature can make it easier on yourself and harder on your competition.
There are downsides to getting your code upstream as well. Most of those stem from not getting code out there early enough for review. The kernel developers can ask for significant changes to the code especially in the area of user space interfaces. If a company already has lots of code using the new feature and/or interface, it could be very disruptive; ‘sorry, there’s no real fix for that except getting your code out early enough‘.
Another downside that companies may run into is with competitors being brought into the process. Morton and other kernel hackers will try to find others who might have a stake in a new feature to get them involved so that everybody’s needs are taken into account. This can blunt the “win” of getting your feature merged. Some are also concerned that competitors will get access to the code once it has been submitted; ‘tough luck’ Morton said, ‘everything in the kernel is GPL’.”
Read the full story on LWN.net here.