Regressions and progress
Posted Oct 9, 2007 21:57 UTC (Tue) by Blaisorblade
In reply to: Regressions and progress
Parent article: Still waiting for swap prefetch
This Linus quote is also from a couple of years ago, about drivers (when somebody fixed ACPI and broke suspend for most stuff). And he's a maintainer, and he must have this opinion (or the community should replace him).
What matters is "how deep do you need to stack DM" (is it a real problem) and "4k is a default (other choices are kept, so *you* will make the 8k choice, which is mostly worse)".
That is a known problem since years, and Device Mapper can be changed to be non-recursive; see the LWN articles about changes in link-resolution from recursive to iterative to understand what I mean - that's the same stuff. Technically, this is a tail-call optimization to reduce stack depth.
After reading the discussion over Con's community management, and thinking to Reiser4, I think that Linux is not about politics, but about communities, or rather Social Networks of developers and their influence on community filtering they do (that's a lot of academic buzzwords).
That said, it's known that many problem (including VM and I think scheduling) are computationally hard, so whichever solution you choose it has weak points (it's a theorem in some cases - you can prove that for each compressor there is a file the compressor expands). The point is how hard is the regression.
Distributions had to be fixed not to renice X to -10 (as usual for 2.4) when 2.6 came out. A stable kernel cannot require such a big change. I can fix my X startup script (well, working my way through X startup is not fun, even for an experienced Linux developer like me), but the Ubuntu average user cannot (I know tens of such users, switching from Windows because Vista sucks and Linux had Beryl - they are good Physics students).
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