So he is right, and Linux did have a problem on this
workload. Basically it was a combination of a glibc
inefficiency and the fact that nobody seems to have
reported such a workload before. The fix was basically
a small change to the way malloc/free works, and a
little patch to the kernel to optimise the new path
used by glibc.
That post found the fixes to have eliminated the big
dropoff. Note it still doesn't scale past 8-way, but
this is likely to be a MySQL issue -- BSD doesn't do
any better.
what epoch are you posting from?
Posted Jun 14, 2007 7:36 UTC (Thu) by drag (subscriber, #31333)
[Link]
Those things seem to have triggered some sort of bug.
Rest assured people do have real-world Linux boxes that have over 512 cpus in a single system image. SGI has boxes, at least, have Linux boxes with 4096 cpus in a single system image.
As far as clustering goes.. there are Linux systems with tens of thousands of cpus going.
Linux kernel itself does scale past 8 cpus. Of course nothing is perfect.