Slashdot Mirror

← Back to Stories (view on slashdot.org)

Knuth Got It Wrong

Posted by kdawson on from the to-be-or-not-to-be-heap dept.

davecb writes "Think you've mastered the art of server performance? Think again. Poul-Henning Kamp, in an article at ACM Queue, finds an off-by-ten error in btrees, because they fail to take virtual memory into account. And he solves the problem in the open source 'Varnish' HTTP accelerator, for all of us to see and use."

2 of 298 comments (clear)

  1. Why trust the OS? by michaelmalak · · Score: 4, Interesting

    I'm not sure what the advantages are of dancing around with the OS's virtual memory system. If it were me, I would detect the amount of physical memory available, allocate 80% of it, lock it into physical memory and manage the paging myself. It would be portable, not subject to changes in the VM algorithm by the OS authors, and easier to directly monitor and improve performance. But that's just me.

  2. Alas, no more by l00sr · · Score: 4, Interesting

    Unfortunately, he no longer gives out reward checks for finding bugs in his texts. This seems to be mostly because proud bug-finders inevitably post images of the checks online, which of course, contain Knuth's bank account numbers. More discussion here.