Just forwarding to the list ---------- Forwarded message ---------- From: Joel Fernandes <agnel.joel@xxxxxxxxx> Date: Tue, May 4, 2010 at 12:40 PM Subject: Re: System memory increased while process is running is not released back upon process exit To: ravikumar <ravikumar.vallabhu@xxxxxxxxx> Hi Ravikumar, >> >> I've some application which will do much I/O disk. While this application >> is running the memory usage of system is continuously increasing. >> After stopping my process , no memory usage increased. But >> leaked/increased memory was not released back upon my application exit.This >> proves that there is no potential memory leaks in my process. Also >> /proc/<PID>/status file contents are not changing from start to end. >> >> Where is leaked memory was gone even though my application terminates ? >> >> I assumed that memory reserved for kernel buffer cache is not releasing >> back. Correct me if assumption is wrong. Your assumptions is correct. >> I stuck up at this stage to analyze the issue. >> Is really Linux Kernel is taken the physical memory for buffering and not >> releasing in back ? >> If yes , how long it will hold ? It will hold it as long as it can, its only we're low on memory that memory is freed, There is a way to release this memory (but note that dirty pages cannot be freed before they are written back to their backing devices) from Documentation/sysctl/vm.txt ============================================================== drop_caches Writing to this will cause the kernel to drop clean caches, dentries and inodes from memory, causing that memory to become free. To free pagecache: echo 1 > /proc/sys/vm/drop_caches To free dentries and inodes: echo 2 > /proc/sys/vm/drop_caches To free pagecache, dentries and inodes: echo 3 > /proc/sys/vm/drop_caches As this is a non-destructive operation and dirty objects are not freeable, the user should run `sync' first. ============================================================== HTH -Joel -- To unsubscribe from this list: send an email with "unsubscribe kernelnewbies" to ecartis@xxxxxxxxxxxx Please read the FAQ at http://kernelnewbies.org/FAQ
