在Ubuntu 9.04上加速系统预加载
本教程介绍如何在Ubuntu 9.04上安装预载 。 预加载是一个自适应的readahead守护进程。 它监视用户运行的应用程序,并通过分析此数据来预测用户可能运行哪些应用程序,并将这些二进制文件及其依赖项提取到内存中以加快启动时间。
本文档不附带任何形式的保证! 我不会保证这将为您工作!
安装预载
要安装预载,请打开终端(应用程序>附件>终端
):
然后键入
sudo aptitude install preload
安装预载。
已经这样了 预载将在后台静默运行。 如果要更改预加载行为的方式,可以修改其配置文件/etc/preload.conf
。 这是具有默认配置的文件:
sudo gedit /etc/preload.conf
[model] # cycle: # # This is the quantum of time for preload. Preload performs # data gathering and predictions every cycle. Use an even # number. # # Note: Setting this parameter too low will may reduce the # system performance and stability. # # unit: seconds # default: 20 # cycle = 20 # usecorrelation: # # Whether correlation coefficient should be used in the prediction # algorithm. There are arguments both for and against using it. # Currently it's believed that using it results in more accurate # prediction. The option may be removed in the future. # # default: true usecorrelation = true # minsize: # # Minimum sum of the length of maps of the process for # preload to consider tracking the application. # # Note: Setting this parameter too high will make preload less # effective, while setting it too low will make it eat # quadratically more resources, as it tracks more processes. # # unit: bytes # default: 2000000 # minsize = 2000000 # # The following control how much memory preload is allowed to use # for preloading in each cycle. All values are percentages and are # clamped to -100 to 100. # # The total memory preload uses for prefetching is then computed using # the following formulae: # # max (0, TOTAL * memtotal + FREE * memfree) + CHACED * memcached # where TOTAL, FREE, and CACHED are the respective values read at # runtime from /proc/meminfo. # # memtotal: precentage of total memory # # unit: signed_integer_percent # default: -10 # memtotal = -10 # memfree: precentage of free memory # # unit: signed_integer_percent # default: 100 # memfree = 100 # memcached: precentage of cached memory # # unit: signed_integer_percent # default: 30 # memcached = 30 ########################################################################### [system] # doscan: # # Whether preload should monitor running processes and update its # model state. Normally you do want that, that's all preload is # about, but you may temporarily want to turn it off for various # reasons like testing and only make predictions. Note that if # scanning is off, predictions are made based on whatever processes # have been running when preload started and the list of running # processes is not updated at all. # # default: true doscan = true # dopredict: # # Whether preload should make prediction and prefetch anything off # the disk. Quite like doscan, you normally want that, that's the # other half of what preload is about, but you may temporarily want # to turn it off, to only train the model for example. Note that # this allows you to turn scan/predict or or off on the fly, by # modifying the config file and signalling the daemon. # # default: true dopredict = true # autosave: # # Preload will automatically save the state to disk every # autosave period. This is only relevant if doscan is set to true. # Note that some janitory work on the model, like removing entries # for files that no longer exist happen at state save time. So, # turning off autosave completely is not advised. # # unit: seconds # default: 3600 # autosave = 3600 # mapprefix: # # A list of path prefixes that controll which mapped file are to # be considered by preload and which not. The list items are # separated by semicolons. Matching will be stopped as soon as # the first item is matched. For each item, if item appears at # the beginning of the path of the file, then a match occurs, and # the file is accepted. If on the other hand, the item has a # exclamation mark as its first character, then the rest of the # item is considered, and if a match happens, the file is rejected. # For example a value of !/lib/modules;/ means that every file other # than those in /lib/modules should be accepted. In this case, the # trailing item can be removed, since if no match occurs, the file is # accepted. It's advised to make sure /dev is rejected, since # preload doesn't special-handle device files internally. # # default: (empty list, accept all) mapprefix = /usr;/lib;!/ # exeprefix: # # The syntax for this is exactly the same as for mapprefix. The only # difference is that this is used to accept or reject binary exectuable # files instead of maps. # # default: (empty list, accept all) exeprefix = !/usr/sbin;!/usr/local/sbin;/usr;!/ |
如果您更改配置,则需要重新启动预加载:
sudo /etc/init.d/preload restart
链接
- 预载: http : //sourceforge.net/projects/preload/
- Ubuntu: http : //www.ubuntu.com/