Adrian Bunk <bunk at stusta.de> writes: > Subject : x86_64: NR_IRQ increase causes 11.5% slowdown > in lmbench's fork benchmark > References : http://lkml.org/lkml/2006/11/2/192 > Submitter : Tim Chen <tim.c.chen at linux.intel.com> > Caused-By : Eric W. Biederman <ebiederm at xmission.com> > commit 550f2299ac8ffaba943cf211380d3a8d3fa75301 > Status : unknown I'm not really certain who to cc on this one. It appears the problem sequence is: fork() sched_setaffinity() It got worse just because NR_IRQS doubled (and all of the associated arrays doubled in size). I haven't seen anyone reproduce this but Tim Chen, and Tim wasn't able to root cause the problem so I believe we are going to have this regression :( Eric
