（转载）利用 thermald和Intel P-state防止笔记本过热

How to enable intel_pstate in Ubuntu 14.04
This is for Ubuntu 14.04 only! Don't use it in older Ubuntu versions or you may encounter various issues (see below).
While it's not mandatory, thermald should work better if Intel P-state is enabled. Intel P-state is not enabled by default in Ubuntu 14.04, but you can enable it easily (from what I've read, it's enabled by default in Fedora, Arch Linux and OpenSUSE for instance).intel_pstate is a new power scaling driver used for modern Intel CPUs which is currently used for Sandy Bridge and Ivy Bridge CPUs. According to Arjan van de Ven from Intel (for more info, see the comments he posted HERE), ondemand shouldn't be used any more and instead, modern Intel processors should use Intel P-state.In Ubuntu, pstate is disabled by default because it didn't work properly a while back. It looks like the issues that resulted in intel_pstate being disabled by default in Ubuntu were fixed, but pstate is still not enabled by default in Ubuntu 14.04.Note that while I didn't encounter any issues on my laptop running Ubuntu 14.04 with intel_pstate enabled and from what I've read, it works for others as well, it might not work properly for you so use it at your own risk and only enable it if you know how to disable it in case something goes wrong!

1. To enable intel_pstate in Ubuntu 14.04 (only enable it if your laptop is using Sandy Bridge or Ivy Bridge CPUs), edit the /etc/default/grub configuration file with a text editor as root - I'll use Gedit below:
gksu gedit /etc/default/grub
And for "GRUB_CMDLINE_LINUX_DEFAULT=" (it's on line 11 on my system), add "intel_pstate=enable", like this:
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash intel_pstate=enable"
Make sure you've changed the /etc/default/grub file properly or else your system may fail to boot! Once you're done, save the file and update Grub:
sudo update-grub
2. Restart your system and to check if intel_pstate is enabled, run the following command:cat /sys/devices/system/cpu/cpu*/cpufreq/scaling_driver
The command above should return "intel_pstate".
Another way of checking if Intel P-State is enabled is by using the following command:
cpupower frequency-info
And the output should be something like this:
analyzing CPU 0: driver: intel_pstate
CPUs which run at the same hardware frequency: 0
CPUs which need to have their frequency coordinated by software: 0
maximum transition latency: 0.97 ms.
hardware limits: 800 MHz - 3.10 GHz
available cpufreq governors: performance, powersave
current policy: frequency should be within 800 MHz and 3.10 GHz.
The governor "performance" may decide which speed to use
within this range.
boost state support:
Supported: yes
Active: yes
25500 MHz max turbo 4 active cores
25500 MHz max turbo 3 active cores
25500 MHz max turbo 2 active cores
25500 MHz max turbo 1 active cores
If Intel Pstate is not enabled after following the steps above, it most probably means that your CPU doesn't support intel_pstate so you should disable it (simply remove "intel_pstate=enable" from /etc/default/grub and run "sudo update-grub").
3. With intel_pstate, there are only two cpufreq governors: performance and powersave (there's no "ondemand"). In my test, the "powersave" governor offered significantly better results so that's what I recommend. So try the powersave mode firstly and only if you're not satisfied with the results, switch to performance.
You can switch between the "performance" and "powersave" intel_pstate governors manually by using the following commands:
- use the "powersave" intel_pstate cpufreq governor:
sudo cpupower frequency-set -g powersave- use the "performance" cpufreq intel_pstate governor:
sudo cpupower frequency-set -g performance
You can see the currently active cpufreq governor by using the following command:
cat /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor
4. If you want to make the "powersave" governor default in Ubuntu (using the commands above commands, the settings are lost after a reboot), firstly install cpufrequtils:
sudo apt-get install cpufrequtils
And then edit the /etc/init.d/cpufrequtils file and change GOVERNOR to "powersave" (GOVERNOR="powersave"). You can do this automatically by using the following command:
sudo sed -i 's/^GOVERNOR=.*/GOVERNOR="powersave"/' /etc/init.d/cpufrequtils
To revert this change and set the governor back to default (which is "ondemand" and that's not available for Intel P-State, but I'm adding this info in case you don't want to use Intel P-State any more), use the command below:
sudo sed -i 's/^GOVERNOR=.*/GOVERNOR="ondemand"/' /etc/init.d/cpufrequtils
It's also worth mentioning that TLP supports Intel P-State.

看不懂

大哥，能翻译一下中文么…

好吧，我说个大概（抛砖引玉@peterliu1218 ）。
thermald是Intel开源技术中心开发的一款用于监视和控制cpu温度并防止其过热的工具，但它不会对系统性能产生重大的影响。值得一提的是仅在温度达到某个阈值的时候thermald才会应用各种降温方式，所以如果你的电脑通常情况下温度不够高的话，使用它将不会感到有什么不同。这位作者说他在其官方页面中找不到thermald支持哪些类型的处理器的信息，但根据Debian wiki，其只支持 Intel Sandy Bridge 和更新的CPUs，另外有一个bug指出其对Haswell支持的不够好。
默认情况下，thermald安装好后，是不需要怎么配置的，但如果有需要（见原文）可以编辑/etc/thermald/thermal-conf.xml 文件，更多信息请参考thermal-conf.xml的man page ("man thermal-conf.xml")。
如何在ubuntu14.04中开启intel_pstate
注意这仅仅适用于ubuntu14.04，不要在老版本的ubuntu中尝试，否则你可能会遭遇各种问题（见下面）。
在Intel P-stat开启的情况下，thermald会工作的更好。Intel P-stat在ubuntu14.04默认没有开启，但你能很容易地开启它(就作者所知道的在Fedora, Arch Linux 以及OpenSUSE中是默认开启的)。
1.为了在ubuntu14.04开启Intel P-stat（仅当你的笔记本使用 Sandy Bridge或者 Ivy Bridge CPUs），以root身份用文本编辑器编辑 /etc/default/grub，在下面作者采用Gedit。
gksu gedit /etc/default/grub
找到"GRUB_CMDLINE_LINUX_DEFAULT=" 这一行，改为
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash intel_pstate=enable"
确保你的操作正确否则可能导致你启动失败，然后保存并且运行
sudo update-grub
2.重启你的笔记本，通过下面的命令检查intel_pstate是否开启
cat /sys/devices/system/cpu/cpu*/cpufreq/scaling_driver
此命令将会返回"intel_pstate". 。
另外一种检查方式是使用下面的命令
cpupower frequency-info
其输出将会是类似下面这样的信息：
analyzing CPU 0:
driver: intel_pstate
CPUs which run at the same hardware frequency: 0
CPUs which need to have their frequency coordinated by software: 0
maximum transition latency: 0.97 ms.
hardware limits: 800 MHz - 3.10 GHz
available cpufreq governors: performance, powersave
current policy: frequency should be within 800 MHz and 3.10 GHz.
The governor "performance" may decide which speed to use
within this range.
boost state support:
Supported: yes
Active: yes
25500 MHz max turbo 4 active cores
25500 MHz max turbo 3 active cores
25500 MHz max turbo 2 active cores
25500 MHz max turbo 1 active cores
如果采用上面的步骤发现没有开启intel_pstate ，这可能意味着你的CPU不支持intel_pstate ，所以这时你需要禁用掉它（只需简单地从 /etc/default/grub中 移除"intel_pstate=enable" ，保存然后sudo update-grub就行了）。
3.intel_pstate只有两个 cpufreq governors: performance 和 powersave (没有 "ondemand")。你可以通过下面的命令手动在两者之间切换：
- 使用 "powersave" intel_pstate cpufreq governor:
sudo cpupower frequency-set -g powersave
- 使用 "performance" cpufreq intel_pstate governor:
sudo cpupower frequency-set -g performance
你能通过下面的命令看到当前激活的 cpufreq governor
cat /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor
4.如果你想让 "powersave" governor在ubuntu中成为默认(使用之前的命令将会在重启后失效),。首先安装 cpufrequtils:
sudo apt-get install cpufrequtils
然后编辑/etc/init.d/cpufrequtils 文件 并且将 GOVERNOR值 设置为"powersave" (即GOVERNOR="powersave"). 你也可以使用下面的命令：:
sudo sed -i 's/^GOVERNOR=.*/GOVERNOR="powersave"/' /etc/init.d/cpufrequtils
为了恢复这一设置并将governor值设为默认 (默认为 "ondemand" 并且它不可用于Intel P-State, 作者加入这条是考虑到你可能不再想使用 Intel P-State )。使用下面的命令：
sudo sed -i 's/^GOVERNOR=.*/GOVERNOR="ondemand"/' /etc/init.d/cpufrequtils
值得一提的是 TLP 支持 Intel P-State。
安装thermald
使用下面的命令：
sudo apt-get install thermald

人工帮顶！(ฅ>ω<*ฅ)咦~我的小尾巴呢？(๑• . •๑)ε-(´∀‘; )ヾ(Ő∀Ő๑)ﾉ╰(*´）`*)╯请叫我=☞表情帝 欧也！

kewangwuxian12说得很清楚，都说完了，我补充整理一下就好了。
其实Linux内核对CPU的工作频率管理，已经跟不上现代的CPU的需求，无法在效能与省电取得平衡，所以intel自己写了一段内核代码，Intel_pstate。（现在默认的管理方式，你可以看一下：http://tieba.baidu.com/p/2964008035）
在ubuntu14.04的内核3.13中，已经放入这段代码，但没有默认启用（我猜是因为还有很多使用者，还在使用SandyBridge之前的CPU）。假如你是SandyBridge或IvyBridge架构的CPU，可以启动Intel_pstate，来取代现在默认的cpufreq，以获得较好的效能与省电平衡。
启用的方式很简单，就是在/etc/default/grub这个档案中，把
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"
变成
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash intel_pstate=enable"
然后，sudo update-grub 即可。简单说，假如你想回复原状，拿掉intel_pstate=enable，再update-grub即可。（默认cpufreq的ondemand ）
与现在的cpufreq的四种方式相较，intel_pstate只有两种，powersave与performance
切换这两者可以用
sudo cpupower frequency-set -g powersave
sudo cpupower frequency-set -g performance
指令切换（你要先安装 sudo apt-get install linux-tools-common）
另外，thermald是防止CPU过热的工具，但同样只支持SandyBridge或IvyBridge架构的CPU。这个工具是在背景执行的服务，你也不需要刻意去设置什麼。安装：
sudo apt-get install thermald 即可。
注：我这几天有在试，intel_pstate效能与原来一样，但电池可以用比较久，原来3，现在可以到3.5。值得一试。

tone@ubuntu:~$ cpupower frequency-info
WARNING: cpupower not found for kernel 3.13.0-24
You may need to install the following packages for this specific kernel:
linux-tools-3.13.0-24-generic
linux-cloud-tools-3.13.0-24-generic
You may also want to install one of the following packages to keep up to date:
linux-tools-generic
linux-cloud-tools-generic

申请加精@林自明

试了5天，我将继续使用p-state的模式，但会拿掉thermald ....
p-state在效能与省电上，的确比之前cpufreq的模式表现得更好。
但是thermald....
电脑的确比较不热，但风扇很早就开始转了，偏偏我的风扇比较大声，听得有点受不了...
我还是推荐风扇小声的电脑，或是不会受到风扇声音影响的人，装上thermald

楼主 ～(*^.^*)亲亲~么么哒！(＊￣）￣＊)我是表情小王子，(๑• . •๑)(๑´ㅂ`๑)

太高端了