On Thu, 2020-05-28 at 11:51 -0700, Linus Torvalds wrote: > On Wed, May 27, 2020 at 10:40 PM Christoph Hellwig <hch@xxxxxx> wrote: > > this series fixes a few issues and cleans up the helpers that read from > > or write to kernel space buffers, and ensures that we don't change the > > address limit if we are using the ->read_iter and ->write_iter methods > > that don't need the changed address limit. > > Apart from the "please don't mix irrelevant whitespace changes with > other changes" comment, this looks fine to me. > > And a rant related to that change: I'm really inclined to remove the > checkpatch check for 80 columns entirely, but it shouldn't have been > triggering for old lines even now. > > Or maybe make it check for something more reasonable, like 100 characters. > > I find it ironic and annoying how "checkpatch" warns about that silly > legacy limit, when checkpatch itself then on the very next few lines > has a line that is 124 columns wide Yeah. perl ain't c. And this discussion has been had many times. Here's one from 2009 https://lkml.org/lkml/2009/12/15/490 Another from 2012 https://lkml.org/lkml/2012/2/5/141 Line lengths checks are normally pretty silly. Hard limits at 80 really don't work well, especially with some of the 25+ character length identifiers used today. I think a line length warning at 132 is generally reasonable but it could depend on complexity and identifier lengths. > And yes, that 124 character line has a good reason for it. But that's > kind of the point. There are lots of perfectly fine reasons for longer > lines. > > I'd much rather check for "no deep indentation" or "no unnecessarily > complex conditionals" or other issues that are more likely to be > _real_ problems. That deep indentation test already exists at 6 tabs. Maybe it should be 5 instead. Or maybe even 4, but that's a pretty easy to need and common use case. Tab depth use in the kernel is more or less $ git grep -Poh '^\t+(if|do|while|for|switch)\b' | \ sed -r 's/\w+//g' | \ awk '{print length($0);}' | \ sort | uniq -c | sort -rn 903993 1 339059 2 89334 3 18216 4 3282 5 605 6 148 7 36 8 4 9 1 10 > But do we really have 80x25 terminals any more that > we'd care about? trivial btw: VT100s were 80x24 or 132x24, PCs were 80x25