page cache

2010/1/3/下午16:15 

看了会电影，扯了会淡，看了会雪，听了会歌，精神不错~

ulk chapters:

 12 vfs,--> free

14 block-dev layer  --> study when work with MMC

15 page-cache -->now

16: access a file -->?

17: reclaim memory-->?

18: ext2/3 -->DONE

Flash knowledge, study when work with MMC....

ulk 15 page cache

1.regular file and block device file ,different address-space logic top.

for block-dev,there's a "Master-I-Node" concept.

inode_has_buffers(),check whether mapping->private list empty.

2.上面的buffer-head也是一种资源，故在存放它们的地方，在private list上。

读superblock/inodeblock这样的单个block的时候，读出的数据存放在block-dev的radix-tree里

chapter 15 ,page cache 顺利读完。。。明白了buffer-Head是怎么回事了，，，之前有点迷茫，虽然看过很多遍，现在看过底层的，返回来再看，又不一样的理解深度了，呵呵...

正在读accessing a file part,,too much

2009/1/4 凌晨0:25

看完电影  花木兰