On 03/23/11 22:24, Thor Lancelot Simon wrote:
I have a new machine with 24 2Ghz Opteron cores. It has 32GB of RAM.Building with sources on a fast SSD ("preloaded" into the page cache before the build using tar> /dev/null) and obj, dest, and rel dirs on tmpfs, system builds are extraordinarily slow. The system takes about 20 minutes to build a netbsd-5 based source tree with -j24 -- about the same amount of time as an older 8-core Intel based system running netbsd-5 requires with -j8. All cores spend well over 50% time in 'sys', even when all or almost all are running cc1 processes. The kernel is amd64 -current GENERIC from about 1 week ago -- no DIAGNOSTIC, DEBUG, KMEMSTATS, LOCKDEBUG, etc. Does anyone have any idea what might be wrong here?
Implement CPU-topology detection for your CPU. This lets our scheduler work more efficiently. Christoph
