使用linux-fincore查看Linux系统缓存哪些文件
概述
- linux-fincore 包含linux-fincore，linux-fincore，linux-fincore 三个工具。其中linux-fincore可以用来查看cache中有哪些文件。
编译安装
- 该工具最初发布于googlecode，但googlecode现在已经关闭了。可以从github上找到其代码。
- 本人选用的是 https://github.com/waleedmazhar/linux-ftools 这个链接的版本， 执行 ./configure; make; make install 可以直接编译安装。
- 如果因选择版本以及编译环境差异，执行make时可能会报错： 例如
aclocal-1.10: command not found和automake-1.10: command not found
cd . && /bin/sh /home/linux-ftools-master/missing --run aclocal-1.10
/home/linux-ftools-master/missing: line 54: aclocal-1.10: command not found
WARNING: `aclocal-1.10' is missing on your system. You should only need it if
you modified `acinclude.m4' or `configure.ac'. You might want
to install the `Automake' and `Perl' packages. Grab them from
any GNU archive site.
cd . && /bin/sh /home/linux-ftools-master/missing --run automake-1.10 --gnu
/home/linux-ftools-master/missing: line 54: automake-1.10: command not found
WARNING: `automake-1.10' is missing on your system. You should only need it if
you modified `Makefile.am', `acinclude.m4' or `configure.ac'.
You might want to install the `Automake' and `Perl' packages.
Grab them from any GNU archive site.
cd . && /bin/sh /home/linux-ftools-master/missing --run autoconf
configure.ac:7: error: possibly undefined macro: AM_INIT_AUTOMAKE
If this token and others are legitimate, please use m4_pattern_allow.
See the Autoconf documentation.
make: *** [configure] Error 1对于类似错误，网上一般会说要安装automake对应版本之类的。但实际上，服务器上已经有更高版本的automake工具。这其实是因为Makefile.in中写死了使用低版本的automake工具导致的，可以通过以下步骤解决：
- 执行aclocal，产生aclocal.m4文件
- 执行autoconf，生成configure文件
- 执行automake命令，产生Makefile.in：
automake --add-missing - 执行configure命令，生成Makefile文件
- 重新执行
make和make install,一切顺利.
使用说明
- help信息如下：
[root]# /usr/local/bin/linux-fincore
fincore version 1.3.0
fincore [options] files...
-s --summarize When comparing multiple files, print a summary report
-p --pages Print pages that are cached
-o --only-cached Only print stats for files that are actually in cache.
-g --graph Print a visual graph of each file's cached page distribution.
-S --min-size Require that each files size be larger than N bytes.
-C --min-cached-size Require that each files cached size be larger than N bytes.
-P --min-perc-cached Require percentage of a file that must be cached.
-h --help Print this message.
-L --vertical Print the output of this script vertically.- 通常用法：执行
linux-fincore --pages=false --summarize --only-cached *即可，其中*代表查看任意文件的cache。也可以指定某个目录/*，表示该目录中的所有文件。或指定某个具体的文件。 - 实例：
[root]#./linux-fincore --pages=false --summarize --only-cached *
filename size total_pages min_cached page cached_pages cached_size cached_perc
-------- ---- ----------- --------------- ------------ ----------- -----------
aclocal.m4 34,611 9 0 9 36,864 100.00
Could not mmap file: autom4te.cache: No such device
config.log 19,768 5 0 5 20,480 100.00
config.status 29,788 8 0 8 32,768 100.00
configure 171,672 42 0 42 172,032 100.00
configure.ac 864 1 0 1 4,096 100.00
Could not mmap file: debian: No such device
depcomp 17,574 5 0 5 20,480 100.00
INSTALL 9,416 3 0 3 12,288 100.00
install-sh 13,184 4 0 4 16,384 100.00
linux-fadvise 22,466 6 0 6 24,576 100.00
linux-fadvise.c 4,875 2 0 2 8,192 100.00
linux-fadvise.o 26,544 7 0 7 28,672 100.00
linux-fallocate 19,150 5 0 5 20,480 100.00
linux-fallocate.c 3,252 1 0 1 4,096 100.00
linux-fallocate.o 17,952 5 0 5 20,480 100.00
linux-fincore 42,137 11 0 11 45,056 100.00
linux-fincore.c 14,967 4 0 4 16,384 100.00
linux-fincore.o 67,592 17 0 17 69,632 100.00
linux-ftools.h 83 1 0 1 4,096 100.00
Makefile 20,772 6 0 6 24,576 100.00
Makefile.am 209 1 0 1 4,096 100.00
Makefile.in 20,055 5 0 5 20,480 100.00
missing 11,135 3 0 3 12,288 100.00
NEWS 65 1 0 1 4,096 100.00
README 6,001 2 0 2 8,192 100.00
RELEASE 372 1 0 1 4,096 100.00
showrlimit.c 1,961 1 0 1 4,096 100.00
waste_memory.c 699 1 0 1 4,096 100.00
---
total cached size: 643,072遇到问题
- 实测发现，直接执行
linux-fincore --pages=false --summarize --only-cached *有时并不能完全显示所有的缓存。比如：
- 在测试中构造一个32GB大小的文本文件file1.csv，然后wc -l file1.csv，
- 执行完毕后通过free可以看到系统cache已经有30多GB了，但执行上述linux-fincore命令却找不到file1.csv的cache记录（没有仔细分析其源码，不太清楚是什么原因）
- 但是直接指定file1.csv文件名或其目录的话，是可以看到具体的缓存信息的：
[root]# ./linux-fincore --pages=false --summarize --only-cached /home/cache_test/file1.csv
filename size total_pages min_cached page cached_pages cached_size cached_perc
-------- ---- ----------- --------------- ------------ ----------- -----------
/home/cache_test/file1.csv 33,792,286,436 8,250,070 0 6,802,594 27,863,425,024 82.45
---
total cached size: 27,863,425,024参考资料：
- http://blog.51cto.com/shanker/1787378
- https://www.linuxidc.com/Linux/2015-09/122930.htm
- https://blog.csdn.net/rapheler/article/details/52528577
- http://blog.yufeng.info/archives/688
- http://www.ywnds.com/?p=9914
- https://github.com/tobert/pcstat
- https://code.google.com/archive/p/linux-ftools/