the some code of pgcacher copy from pcstat and hcache.
pgcacher is used to get page cache statistics for files.
pgcacher <-json <-pps>|-terse|-default> <-nohdr> <-bname> file file file
-worker concurrency workers
-pid int show all open maps for the given pid
-top int show top x cached files in descending order
-json output will be JSON
-pps include the per-page information in the output (can be huge!)
-terse print terse machine-parseable output
-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 characterscompile source code
git clone https://github.com/rfyiamcool/pgcacher.git
cd pgcacher
make build
sudo cp pgcacher /usr/local/bin/ use binary directly
test pass on ubuntu, centos 7.x and centos 8.x.
wget xiaorui-cc.oss-cn-hangzhou.aliyuncs.com/files/pgcacher
chmod 777 pgcacher
\mv pgcacher /usr/local/bin
$ sudo pgcacher -pid=29260 -worker=5
+-------------------+----------------+-------------+----------------+-------------+---------+
| Name | Size │ Pages │ Cached Size │ Cached Pages│ Percent │
|-------------------+----------------+-------------+----------------+-------------+---------|
| /root/rui/file4g | 3.906G | 1024000 | 3.906G | 1024000 | 100.000 |
| /root/rui/file3g | 2.930G | 768000 | 2.930G | 768000 | 100.000 |
| /root/rui/file2g | 1.953G | 512000 | 1.953G | 512000 | 100.000 |
| /root/rui/file1g | 1000.000M | 256000 | 1000.000M | 256000 | 100.000 |
| /root/rui/open_re | 1.791M | 459 | 1.791M | 459 | 100.000 |
|-------------------+----------------+-------------+----------------+-------------+---------|
│ Sum │ 9.767G │ 2560459 │ 9.767G │ 2560459 │ 100.000 │
+-------------------+----------------+-------------+----------------+-------------+---------+
$ dd if=/dev/urandom of=file1g bs=1M count=1000
$ dd if=/dev/urandom of=file2g bs=1M count=2000
$ dd if=/dev/urandom of=file3g bs=1M count=3000
$ dd if=/dev/urandom of=file4g bs=1M count=4000
$ cat file1g file2g file3g file4g > /dev/null
$ sudo pgcacher file1g file2g file3g file4g
+--------+----------------+-------------+----------------+-------------+---------+
| Name | Size │ Pages │ Cached Size │ Cached Pages│ Percent │
|--------+----------------+-------------+----------------+-------------+---------|
| file4g | 3.906G | 1024000 | 3.906G | 1024000 | 100.000 |
| file3g | 2.930G | 768000 | 2.930G | 768000 | 100.000 |
| file2g | 1.953G | 512000 | 1.953G | 512000 | 100.000 |
| file1g | 1000.000M | 256000 | 1000.000M | 256000 | 100.000 |
|--------+----------------+-------------+----------------+-------------+---------|
│ Sum │ 9.766G │ 2560000 │ 9.766G │ 2560000 │ 100.000 │
+--------+----------------+-------------+----------------+-------------+---------+
$ sudo pgcacher /root/rui/*
+------------+----------------+-------------+----------------+-------------+---------+
| Name | Size │ Pages │ Cached Size │ Cached Pages│ Percent │
|------------+----------------+-------------+----------------+-------------+---------|
| file4g | 3.906G | 1024000 | 3.906G | 1024000 | 100.000 |
| file3g | 2.930G | 768000 | 2.930G | 768000 | 100.000 |
| file2g | 1.953G | 512000 | 1.953G | 512000 | 100.000 |
| testfile | 1000.000M | 256000 | 1000.000M | 256000 | 100.000 |
| file1g | 1000.000M | 256000 | 1000.000M | 256000 | 100.000 |
| pgcacher | 2.440M | 625 | 2.440M | 625 | 100.000 |
| open_re | 1.791M | 459 | 1.791M | 459 | 100.000 |
| cache.go | 19.576K | 5 | 19.576K | 5 | 100.000 |
| open_re.go | 644B | 1 | 644B | 1 | 100.000 |
| nohup.out | 957B | 1 | 957B | 1 | 100.000 |
|------------+----------------+-------------+----------------+-------------+---------|
│ Sum │ 10.746G │ 2817091 │ 10.746G │ 2817091 │ 100.000 │
+------------+----------------+-------------+----------------+-------------+---------+
@tobert for pcstat