1. 06 12月, 2011 15 次提交
  2. 05 12月, 2011 20 次提交
  3. 04 12月, 2011 1 次提交
    • K
      xen/pm_idle: Make pm_idle be default_idle under Xen. · e5fd47bf
      Konrad Rzeszutek Wilk 提交于
      The idea behind commit d91ee586 ("cpuidle: replace xen access to x86
      pm_idle and default_idle") was to have one call - disable_cpuidle()
      which would make pm_idle not be molested by other code.  It disallows
      cpuidle_idle_call to be set to pm_idle (which is excellent).
      
      But in the select_idle_routine() and idle_setup(), the pm_idle can still
      be set to either: amd_e400_idle, mwait_idle or default_idle.  This
      depends on some CPU flags (MWAIT) and in AMD case on the type of CPU.
      
      In case of mwait_idle we can hit some instances where the hypervisor
      (Amazon EC2 specifically) sets the MWAIT and we get:
      
        Brought up 2 CPUs
        invalid opcode: 0000 [#1] SMP
      
        Pid: 0, comm: swapper Not tainted 3.1.0-0.rc6.git0.3.fc16.x86_64 #1
        RIP: e030:[<ffffffff81015d1d>]  [<ffffffff81015d1d>] mwait_idle+0x6f/0xb4
        ...
        Call Trace:
         [<ffffffff8100e2ed>] cpu_idle+0xae/0xe8
         [<ffffffff8149ee78>] cpu_bringup_and_idle+0xe/0x10
        RIP  [<ffffffff81015d1d>] mwait_idle+0x6f/0xb4
         RSP <ffff8801d28ddf10>
      
      In the case of amd_e400_idle we don't get so spectacular crashes, but we
      do end up making an MSR which is trapped in the hypervisor, and then
      follow it up with a yield hypercall.  Meaning we end up going to
      hypervisor twice instead of just once.
      
      The previous behavior before v3.0 was that pm_idle was set to
      default_idle regardless of select_idle_routine/idle_setup.
      
      We want to do that, but only for one specific case: Xen.  This patch
      does that.
      
      Fixes RH BZ #739499 and Ubuntu #881076
      Reported-by: NStefan Bader <stefan.bader@canonical.com>
      Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      e5fd47bf
  4. 03 12月, 2011 4 次提交