On Linus’ Return to Kernel Development

On October 23, 2018, Linus Torvalds came out of his self-imposed isolation, pulling a lot of patches from
the git trees of various developers. It was his first appearance on the Linux Kernel Mailing
List

since September 16, 2018, when he announced he would take a break from kernel development to address his
sometimes harsh behavior toward developers. On the 23rd, he announced his return, which I cover here
after summarizing some of his pull activities.

For most of his pulls, he just replied with an email that said, “pulled”. But in one of them, he noticed that
Ingo Molnar had some issues with his email, in particular that Ingo’s mail client
used the iso-8859-1
character set instead of the more usual UTF-8. Linus said, “using iso-8859-1 instead of utf-8 in this
day and age is just all kinds of odd. It looks like it was all fine, but if Mutt has an option to
just send as utf-8, I encourage everybody to just use that and try to just have utf-8 everywhere. We’ve
had too many silly issues when people mix locales etc and some point in the chain gets it wrong.”

On the 24th, Linus continued pulling from developer trees. One of these was a batch of networking
updates from David Miller, and it included contributions from a lot of different people. Linus noticed
that the Kconfig rules were running into unmet dependency warnings because the code expected to run on
the Qualcomm architecture, which Linus didn’t use. He suggested it was a simple matter of updating the
dependency list in the code. He also asked why the developers didn’t notice that problem when testing
their patches. Kalle Valo explained, “Mostly bad timing due to my vacation. I did do allmodconfig
build but not sure why I missed the warning, also the kbuild bot didn’t report anything. Jeff did
report it last week, but I was on vacation at the time and just came back yesterday and didn’t have
time to react to it yet.”

That seemed fine to Linus, who said he’d pull the fix when it became available. He remarked, “I just
don’t want my tree to have warnings that I see, and that may hide new warnings coming in when I do my
next pull request.”

On the 25th, Linus continued pulling from developer trees. In one instance, the issue of minimal tool
versions came up. Linus prefers to support as many regular users as possible, which means supporting
tool versions from the Linux distributions.

In response to a hard-to-read patch, Andi Kleen suggested changing the minimum
supported binutils
version from 2.20 to 2.21, which would support some useful assembler opcodes that would make the patch
easier to review. Andy Lutomirski, another of the patch reviewers, said this would be fine. And Linus
said:

Source: Linux Journal