Hi I can confirm this bug. It's keeping me busy for a while, so I investigated a lot of ubuntu kernels by recompiling them and try them out. It seems it came already from a revision from Ubuntu 3.2.0-21.34-generic (backported from kernel v3.2.13) to Ubuntu 3.2.0-22.35-generic (backported from kernel v3.2.14). So from 3.2.0-22.35 it was introduced. I checked with git and there are 306 files changed, 131914 insertions(+), 129758 deletions(-), so alot has to be traced. I see some changes in the following files, which could cause the high idle load (my wild guess): arch/x86/kernel/apic/io_apic.c | 40 +- arch/x86/kernel/entry_32.S | 17 +- arch/x86/kernel/tls.c | 4 +- arch/x86/kernel/tsc.c | 10 + arch/x86/kernel/vm86_32.c | 2 + arch/x86/net/bpf_jit_comp.c | 14 +- and kernel/futex.c | 19 +- kernel/irq/chip.c | 3 +- kernel/irq/manage.c | 2 +- kernel/module.c | 3 +- kernel/power/hibernate.c | 7 +- kernel/sched.c | 55 +- kernel/time/ntp.c | 2 +-
or mm/bootmem.c | 5 +- mm/memcontrol.c | 4 + mm/memory.c | 16 +- mm/mempolicy.c | 2 +- mm/mincore.c | 2 +- mm/pagewalk.c | 2 +- mm/slub.c | 3 +- mm/sparse.c | 30 +- mm/swapfile.c | 4 +- I will check the linux kernels if they have it as well -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/995284 Title: High idle load on 64bit Ubuntu 12.04 with 3.2.0-24-generic kernel To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/995284/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
