It has been almost three years since the
of the linux-next tree; during that
time, it has become an indispensable part of the kernel development
process. By the time code is merged into the mainline during the merge
window, it has already seen a fair amount of integration and compilation
testing in linux-next - and even some actual run testing. That has helped
to make the merge window run more smoothly. So it's not surprising that
developers are getting increasingly grumpy when code is seen to be
circumventing linux-next and creating problems in the mainline.
We've had a couple of examples of that grumpiness in the 2.6.38 cycle.
When Al Viro posted his first VFS pull request, linux-next maintainer Stephen
Rothwell complained that this was his first
sighting of that code, despite the fact that it had apparently been around
for a few months. Al is known for pulling together mainline submissions at
the last minute, so this sort of thing is not entirely surprising; it
remains to be seen whether he can be pushed into changing his ways.
The other complaint came after the merging of the transparent huge pages
patch set, which went in by way of Andrew Morton's -mm tree. Tony Luck,
having discovered that the ia64 architecture no longer built in the
Didn't Andrew make some rash promise at kernel summit about
stopping eating if "-mm" wasn't included in linux-next by the end
of November? Must be getting pretty hungry by now.
Andrew responded that "It's taking a
while - Stephen and I are discussing a plan." Integrating -mm was
always going to be a bit of a challenge; linux-next is supposed to contain
code which is ready for merging into the mainline, while -mm can carry
under-development code for years. Until that gets worked out, though,
memory management developers are going to be in a bit of a difficult
position; there is no maintainer tree they can get into which feeds into
linux-next. Those developers will need to either get their own trees into
linux-next (an easy thing to do) or take the complaints when code which
lived in -mm is seen by testers for the first time when it hits the
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