In chasing my VNC problem I came across this reference on the kernel Bugzilla about a general problem with segfaulting on SMP AMD64 systems. Some pretty ugly stuff (the comment list is huge!). Anyway, guys are chasing suspected bugs all over the place, with a couple of theories but not really any firm leads…
Then, Linus (Torvalds, for those readers who don’t know Linux and therefore don’t know who Linus is) posts a message something like “err, guys, I think it might be this, here’s a patch which is totally untested and might not even compile so someone should check it”. Fixes the problem — it’s a workaround to an actual problem in the AMD64 chips (the patch shuts off the TLB flush filter, a component of the chip that seems to behave a little oddly under heavy load and for which AMD have issued at least two errata).
Andi Kleen challenged Linus over his patch, implying that shutting off the TLB flush filter is too heavy-handed (my words, not Andi’s). Linus then responded by saying “considering the pain this has caused for us, if I get even a single report that it fixes the problem, I _am_ going to commit that fix without any further questions”.
That’s the Linus we know and love! He lurked away watching the discussion, dropped the fix on there when it became clear that there was little traction, and then dealt out some “Diplomacy: Torvalds-style”. I’m a fan!
Crossed Wires 