title: How to set intel_idle.max_cstate=0 to disable c-states?
body: <p>I would like to disable c-states on my computer.</p>
  
  <p>I disabled c-state on BIOS but I don't obtain any result. However, I found an explanation :
  "Most newer Linux distributions, on systems with Intel processors, use the “intel_idle” driver (probably compiled into your kernel and not a separate module) to use C-states. This driver uses knowledge of the various CPUs to control C-states without input from system firmware (BIOS). This driver will mostly ignore any other BIOS setting and kernel parameters"</p>
  
  <p>I found two solutions to solve this problem but I don't know how to apply:</p>
  
  <p>1)  " so if you want control over C-states, you should use kernel parameter “intel_idle.max_cstate=0” to disable this driver."</p>
  
  <p>I don't know neither how I can check the value (of intel_idle.max_cstate ) and neither how I can change its value.</p>
  
  <p>2)  "To dynamically control C-states, open the file /dev/cpu_dma_latency and write the maximum allowable latency to it. This will prevent C-states with transition latencies higher than the specified value from being used, as long as the file /dev/cpu_dma_latency is kept open. Writing a maximum allowable latency of 0 will keep the processors in C0"</p>
  
  <p>I can't read the file cpu_dma_latency.</p>
  
  <p>Thanks for your help.</p>
  
  <p>Computer:
  Intel Xeon CPU E5-2620
  Gnome 2.28.2
  Linux 2.6.32-358</p>