The pcstat tool can get page cache statistics for one file by the file's name, or all cached files for a process by the process's pid.
However, I often meet with a question: I know os cached memories by cat /proc/meminfo or free, but I can't find out those BIG files which is being cached. Of course I can use the ps aux command to get those processes who used a lot of memory and get the details by the pcstat --pid [pid], but pcstat does not sort the result, and it is not convenient.
So I add a feature to pcstat: you can use the option --top [X] to show the top X biggest cached files globally. After that, you can use lsof to find out the bad guy.
I also build a bin file. You can download it from here, have a try! I have tested it on centos7.2 and ubuntu 16.04.
hcache has the same options that is used by pcstat, and a new option --top [X]. Attention, you CANNOT use both -pid and -top.
hcache <-json <-pps>|-terse|-default> <-nohdr> <-bname> file file file
-json output will be JSON
-pps include the per-page information in the output (can be huge!)
-terse print terse machine-parseable output
-default print ascii tables
-histo print a histogram using unicode block characters
-nohdr don't print the column header in terse or default format
-bname use basename(file) in the output (use for long paths)
-plain return data with no box characters
-unicode return data with unicode box characters
-pid int show all open maps for the given pid
-top int show top x cached files
$ sudo hcache --top 10
[sudo] password for silenceshell:
+----------------------------------------------------------------------------------+----------------+------------+-----------+---------+
| Name | Size (bytes) | Pages | Cached | Percent |
|----------------------------------------------------------------------------------+----------------+------------+-----------+---------|
| /opt/google/chrome/chrome | 114911208 | 28055 | 25457 | 090.740 |
| /usr/share/code/code | 67688720 | 16526 | 12274 | 074.271 |
| /home/silenceshell/Software/pycharm-community-2016.2/lib/pycharm.jar | 95177431 | 23237 | 11325 | 048.737 |
| /opt/atom/atom | 62641344 | 15294 | 10578 | 069.164 |
| /usr/bin/dockerd | 39121168 | 9552 | 7103 | 074.361 |
| /home/silenceshell/Software/pycharm-community-2016.2/jre/jre/lib/amd64/libjfxwebkit.so | 57455824 | 14028 | 6625 | 047.227 |
| /usr/lib/x86_64-linux-gnu/libQtWebKit.so.4.10.2 | 36462184 | 8902 | 6316 | 070.950 |
| /usr/lib/beyondcompare/BCompare | 30640160 | 7481 | 5505 | 073.586 |
| /usr/bin/SecureCRT | 29524560 | 7209 | 4806 | 066.667 |
| /usr/share/code/libnode.so | 21135976 | 5161 | 4588 | 088.898 |
+----------------------------------------------------------------------------------+----------------+------------+-----------+---------+
$
$ sudo ./hcache --top 3 --bname
+-------------+----------------+------------+-----------+---------+
| Name | Size (bytes) | Pages | Cached | Percent |
|-------------+----------------+------------+-----------+---------|
| chrome | 114911208 | 28055 | 25476 | 090.807 |
| pycharm.jar | 95177431 | 23237 | 11479 | 049.400 |
| atom | 62641344 | 15294 | 10578 | 069.164 |
+-------------+----------------+------------+-----------+---------+
$
$ lsof /usr/lib/x86_64-linux-gnu/libQtWebKit.so.4.10.2
COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME
quiterss 20630 silenceshell mem REG 8,5 36462184 3936610 /usr/lib/x86_64-linux-gnu/libQtWebKit.so.4.10.2
hcache needs go version > 1.12 for go mod
git clone https://github.com/silenceshell/hcache.git
cd hcache
make build
sudo cp hcache /usr/local/bin/
Go 1.4 or higher and golang.org/x/sys/unix.
From the mincore(2) man page:
- Available since Linux 2.3.99pre1 and glibc 2.2.
- mincore() is not specified in POSIX.1-2001, and it is not available on all UNIX implementations.
- Before kernel 2.6.21, mincore() did not return correct information some mappings.
silenceshell
Apache 2.0
@tobert for pcstat and @mitchellh for go-ps