3 posts tagged with "memory"

How to Clear Cache in Linux?​

1. Clear PageCache only.

$ sync; echo 1 > /proc/sys/vm/drop_caches

2. Clear dentries and inodes.

$ sync; echo 2 > /proc/sys/vm/drop_caches

3. Clear pagecache, dentries, and inodes.

$ sync; echo 3 > /proc/sys/vm/drop_caches 

• references:
  • Documentation for /proc/sys/vm/drop_caches

the key information to implement a memory pool​

• boundary:

How to solve the boundaries between different different chunks

• name:

How to get an allocated memory chunk

• reference count

whether the chunk is still used. I want to free the memory only if the process termination or free, with threads free, only do reference count minus 1.

• data structure:

which data structure will be efficient?

find memory leak of a running process​

$ cat /proc/$pid/smaps

1. find out the PID of the process

$ ps -aux

2. capture /proc/PID/smaps and save into some file like before_meminc.txt
3. wait till memory gets increased
4. try again step 2
5. find the difference between first smaps and 2nd smaps, e.g. with

$ diff -u before_meminc.txt after_meminc.txt

6. note down the address range where memory got increased

7. use pstack and watch command to get the right call stack

$ watch -n 1 'pstack $PID | tee -a $PID.stack'

C-c when we caputred right stack

8. check our stack file, find the functions between address range which we got from step 6.